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arrow_row/
lib.rs

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17
18//! A comparable row-oriented representation of a collection of [`Array`].
19//!
20//! [`Row`]s are [normalized for sorting], and can therefore be very efficiently [compared],
21//! using [`memcmp`] under the hood, or used in [non-comparison sorts] such as [radix sort].
22//! This makes the row format ideal for implementing efficient multi-column sorting,
23//! grouping, aggregation, windowing and more, as described in more detail
24//! [in this blog post](https://arrow.apache.org/blog/2022/11/07/multi-column-sorts-in-arrow-rust-part-1/).
25//!
26//! For example, given three input [`Array`], [`RowConverter`] creates byte
27//! sequences that [compare] the same as when using [`lexsort`].
28//!
29//! ```text
30//!    ┌─────┐   ┌─────┐   ┌─────┐
31//!    │     │   │     │   │     │
32//!    ├─────┤ ┌ ┼─────┼ ─ ┼─────┼ ┐              ┏━━━━━━━━━━━━━┓
33//!    │     │   │     │   │     │  ─────────────▶┃             ┃
34//!    ├─────┤ └ ┼─────┼ ─ ┼─────┼ ┘              ┗━━━━━━━━━━━━━┛
35//!    │     │   │     │   │     │
36//!    └─────┘   └─────┘   └─────┘
37//!                ...
38//!    ┌─────┐ ┌ ┬─────┬ ─ ┬─────┬ ┐              ┏━━━━━━━━┓
39//!    │     │   │     │   │     │  ─────────────▶┃        ┃
40//!    └─────┘ └ ┴─────┴ ─ ┴─────┴ ┘              ┗━━━━━━━━┛
41//!     UInt64      Utf8     F64
42//!
43//!           Input Arrays                          Row Format
44//!     (Columns)
45//! ```
46//!
47//! _[`Rows`] must be generated by the same [`RowConverter`] for the comparison
48//! to be meaningful._
49//!
50//! # Basic Example
51//! ```
52//! # use std::sync::Arc;
53//! # use arrow_row::{RowConverter, SortField};
54//! # use arrow_array::{ArrayRef, Int32Array, StringArray};
55//! # use arrow_array::cast::{AsArray, as_string_array};
56//! # use arrow_array::types::Int32Type;
57//! # use arrow_schema::DataType;
58//!
59//! let a1 = Arc::new(Int32Array::from_iter_values([-1, -1, 0, 3, 3])) as ArrayRef;
60//! let a2 = Arc::new(StringArray::from_iter_values(["a", "b", "c", "d", "d"])) as ArrayRef;
61//! let arrays = vec![a1, a2];
62//!
63//! // Convert arrays to rows
64//! let converter = RowConverter::new(vec![
65//!     SortField::new(DataType::Int32),
66//!     SortField::new(DataType::Utf8),
67//! ]).unwrap();
68//! let rows = converter.convert_columns(&arrays).unwrap();
69//!
70//! // Compare rows
71//! for i in 0..4 {
72//!     assert!(rows.row(i) <= rows.row(i + 1));
73//! }
74//! assert_eq!(rows.row(3), rows.row(4));
75//!
76//! // Convert rows back to arrays
77//! let converted = converter.convert_rows(&rows).unwrap();
78//! assert_eq!(arrays, converted);
79//!
80//! // Compare rows from different arrays
81//! let a1 = Arc::new(Int32Array::from_iter_values([3, 4])) as ArrayRef;
82//! let a2 = Arc::new(StringArray::from_iter_values(["e", "f"])) as ArrayRef;
83//! let arrays = vec![a1, a2];
84//! let rows2 = converter.convert_columns(&arrays).unwrap();
85//!
86//! assert!(rows.row(4) < rows2.row(0));
87//! assert!(rows.row(4) < rows2.row(1));
88//!
89//! // Convert selection of rows back to arrays
90//! let selection = [rows.row(0), rows2.row(1), rows.row(2), rows2.row(0)];
91//! let converted = converter.convert_rows(selection).unwrap();
92//! let c1 = converted[0].as_primitive::<Int32Type>();
93//! assert_eq!(c1.values(), &[-1, 4, 0, 3]);
94//!
95//! let c2 = converted[1].as_string::<i32>();
96//! let c2_values: Vec<_> = c2.iter().flatten().collect();
97//! assert_eq!(&c2_values, &["a", "f", "c", "e"]);
98//! ```
99//!
100//! # Lexicographic Sorts (lexsort)
101//!
102//! The row format can also be used to implement a fast multi-column / lexicographic sort
103//!
104//! ```
105//! # use arrow_row::{RowConverter, SortField};
106//! # use arrow_array::{ArrayRef, UInt32Array};
107//! fn lexsort_to_indices(arrays: &[ArrayRef]) -> UInt32Array {
108//!     let fields = arrays
109//!         .iter()
110//!         .map(|a| SortField::new(a.data_type().clone()))
111//!         .collect();
112//!     let converter = RowConverter::new(fields).unwrap();
113//!     let rows = converter.convert_columns(arrays).unwrap();
114//!     let mut sort: Vec<_> = rows.iter().enumerate().collect();
115//!     sort.sort_unstable_by(|(_, a), (_, b)| a.cmp(b));
116//!     UInt32Array::from_iter_values(sort.iter().map(|(i, _)| *i as u32))
117//! }
118//! ```
119//!
120//! # Flattening Dictionaries
121//!
122//! For performance reasons, dictionary arrays are flattened ("hydrated") to their
123//! underlying values during row conversion. See [the issue] for more details.
124//!
125//! This means that the arrays that come out of [`RowConverter::convert_rows`]
126//! may not have the same data types as the input arrays. For example, encoding
127//! a `Dictionary<Int8, Utf8>` and then will come out as a `Utf8` array.
128//!
129//! ```
130//! # use arrow_array::{Array, ArrayRef, DictionaryArray};
131//! # use arrow_array::types::Int8Type;
132//! # use arrow_row::{RowConverter, SortField};
133//! # use arrow_schema::DataType;
134//! # use std::sync::Arc;
135//! // Input is a Dictionary array
136//! let dict: DictionaryArray::<Int8Type> = ["a", "b", "c", "a", "b"].into_iter().collect();
137//! let sort_fields = vec![SortField::new(dict.data_type().clone())];
138//! let arrays = vec![Arc::new(dict) as ArrayRef];
139//! let converter = RowConverter::new(sort_fields).unwrap();
140//! // Convert to rows
141//! let rows = converter.convert_columns(&arrays).unwrap();
142//! let converted = converter.convert_rows(&rows).unwrap();
143//! // result was a Utf8 array, not a Dictionary array
144//! assert_eq!(converted[0].data_type(), &DataType::Utf8);
145//! ```
146//!
147//! [non-comparison sorts]: https://en.wikipedia.org/wiki/Sorting_algorithm#Non-comparison_sorts
148//! [radix sort]: https://en.wikipedia.org/wiki/Radix_sort
149//! [normalized for sorting]: http://wwwlgis.informatik.uni-kl.de/archiv/wwwdvs.informatik.uni-kl.de/courses/DBSREAL/SS2005/Vorlesungsunterlagen/Implementing_Sorting.pdf
150//! [`memcmp`]: https://www.man7.org/linux/man-pages/man3/memcmp.3.html
151//! [`lexsort`]: https://docs.rs/arrow-ord/latest/arrow_ord/sort/fn.lexsort.html
152//! [compared]: PartialOrd
153//! [compare]: PartialOrd
154//! [the issue]: https://github.com/apache/arrow-rs/issues/4811
155
156#![doc(
157    html_logo_url = "https://arrow.apache.org/img/arrow-logo_chevrons_black-txt_white-bg.svg",
158    html_favicon_url = "https://arrow.apache.org/img/arrow-logo_chevrons_black-txt_transparent-bg.svg"
159)]
160#![cfg_attr(docsrs, feature(doc_cfg))]
161#![warn(missing_docs)]
162use std::cmp::Ordering;
163use std::hash::{Hash, Hasher};
164use std::iter::Map;
165use std::slice::Windows;
166use std::sync::Arc;
167
168use arrow_array::cast::*;
169use arrow_array::types::{ArrowDictionaryKeyType, ByteArrayType, ByteViewType};
170use arrow_array::*;
171use arrow_buffer::{ArrowNativeType, Buffer, OffsetBuffer, ScalarBuffer};
172use arrow_schema::*;
173use variable::{decode_binary_view, decode_string_view};
174
175use crate::fixed::{decode_bool, decode_fixed_size_binary, decode_primitive};
176use crate::list::{compute_lengths_fixed_size_list, encode_fixed_size_list};
177use crate::variable::{decode_binary, decode_string};
178use arrow_array::types::{Int16Type, Int32Type, Int64Type};
179
180mod fixed;
181mod list;
182mod run;
183mod variable;
184
185/// Converts [`ArrayRef`] columns into a [row-oriented](self) format.
186///
187/// *Note: The encoding of the row format may change from release to release.*
188///
189/// ## Overview
190///
191/// The row format is a variable length byte sequence created by
192/// concatenating the encoded form of each column. The encoding for
193/// each column depends on its datatype (and sort options).
194///
195/// The encoding is carefully designed in such a way that escaping is
196/// unnecessary: it is never ambiguous as to whether a byte is part of
197/// a sentinel (e.g. null) or a value.
198///
199/// ## Unsigned Integer Encoding
200///
201/// A null integer is encoded as a `0_u8`, followed by a zero-ed number of bytes corresponding
202/// to the integer's length.
203///
204/// A valid integer is encoded as `1_u8`, followed by the big-endian representation of the
205/// integer.
206///
207/// ```text
208///               ┌──┬──┬──┬──┐      ┌──┬──┬──┬──┬──┐
209///    3          │03│00│00│00│      │01│00│00│00│03│
210///               └──┴──┴──┴──┘      └──┴──┴──┴──┴──┘
211///               ┌──┬──┬──┬──┐      ┌──┬──┬──┬──┬──┐
212///   258         │02│01│00│00│      │01│00│00│01│02│
213///               └──┴──┴──┴──┘      └──┴──┴──┴──┴──┘
214///               ┌──┬──┬──┬──┐      ┌──┬──┬──┬──┬──┐
215///  23423        │7F│5B│00│00│      │01│00│00│5B│7F│
216///               └──┴──┴──┴──┘      └──┴──┴──┴──┴──┘
217///               ┌──┬──┬──┬──┐      ┌──┬──┬──┬──┬──┐
218///  NULL         │??│??│??│??│      │00│00│00│00│00│
219///               └──┴──┴──┴──┘      └──┴──┴──┴──┴──┘
220///
221///              32-bit (4 bytes)        Row Format
222///  Value        Little Endian
223/// ```
224///
225/// ## Signed Integer Encoding
226///
227/// Signed integers have their most significant sign bit flipped, and are then encoded in the
228/// same manner as an unsigned integer.
229///
230/// ```text
231///        ┌──┬──┬──┬──┐       ┌──┬──┬──┬──┐       ┌──┬──┬──┬──┬──┐
232///     5  │05│00│00│00│       │05│00│00│80│       │01│80│00│00│05│
233///        └──┴──┴──┴──┘       └──┴──┴──┴──┘       └──┴──┴──┴──┴──┘
234///        ┌──┬──┬──┬──┐       ┌──┬──┬──┬──┐       ┌──┬──┬──┬──┬──┐
235///    -5  │FB│FF│FF│FF│       │FB│FF│FF│7F│       │01│7F│FF│FF│FB│
236///        └──┴──┴──┴──┘       └──┴──┴──┴──┘       └──┴──┴──┴──┴──┘
237///
238///  Value  32-bit (4 bytes)    High bit flipped      Row Format
239///          Little Endian
240/// ```
241///
242/// ## Float Encoding
243///
244/// Floats are converted from IEEE 754 representation to a signed integer representation
245/// by flipping all bar the sign bit if they are negative.
246///
247/// They are then encoded in the same manner as a signed integer.
248///
249/// ## Fixed Length Bytes Encoding
250///
251/// Fixed length bytes are encoded in the same fashion as primitive types above.
252///
253/// For a fixed length array of length `n`:
254///
255/// A null is encoded as `0_u8` null sentinel followed by `n` `0_u8` bytes
256///
257/// A valid value is encoded as `1_u8` followed by the value bytes
258///
259/// ## Variable Length Bytes (including Strings) Encoding
260///
261/// A null is encoded as a `0_u8`.
262///
263/// An empty byte array is encoded as `1_u8`.
264///
265/// A non-null, non-empty byte array is encoded as `2_u8` followed by the byte array
266/// encoded using a block based scheme described below.
267///
268/// The byte array is broken up into fixed-width blocks, each block is written in turn
269/// to the output, followed by `0xFF_u8`. The final block is padded to 32-bytes
270/// with `0_u8` and written to the output, followed by the un-padded length in bytes
271/// of this final block as a `u8`. The first 4 blocks have a length of 8, with subsequent
272/// blocks using a length of 32, this is to reduce space amplification for small strings.
273///
274/// Note the following example encodings use a block size of 4 bytes for brevity:
275///
276/// ```text
277///                       ┌───┬───┬───┬───┬───┬───┐
278///  "MEEP"               │02 │'M'│'E'│'E'│'P'│04 │
279///                       └───┴───┴───┴───┴───┴───┘
280///
281///                       ┌───┐
282///  ""                   │01 |
283///                       └───┘
284///
285///  NULL                 ┌───┐
286///                       │00 │
287///                       └───┘
288///
289/// "Defenestration"      ┌───┬───┬───┬───┬───┬───┐
290///                       │02 │'D'│'e'│'f'│'e'│FF │
291///                       └───┼───┼───┼───┼───┼───┤
292///                           │'n'│'e'│'s'│'t'│FF │
293///                           ├───┼───┼───┼───┼───┤
294///                           │'r'│'a'│'t'│'r'│FF │
295///                           ├───┼───┼───┼───┼───┤
296///                           │'a'│'t'│'i'│'o'│FF │
297///                           ├───┼───┼───┼───┼───┤
298///                           │'n'│00 │00 │00 │01 │
299///                           └───┴───┴───┴───┴───┘
300/// ```
301///
302/// This approach is loosely inspired by [COBS] encoding, and chosen over more traditional
303/// [byte stuffing] as it is more amenable to vectorisation, in particular AVX-256.
304///
305/// ## Dictionary Encoding
306///
307/// Dictionary encoded arrays are hydrated to their underlying values
308///
309/// ## REE Encoding
310///
311/// REE (Run End Encoding) arrays, A form of Run Length Encoding, are hydrated to their underlying values.
312///
313/// ## Struct Encoding
314///
315/// A null is encoded as a `0_u8`.
316///
317/// A valid value is encoded as `1_u8` followed by the row encoding of each child.
318///
319/// This encoding effectively flattens the schema in a depth-first fashion.
320///
321/// For example
322///
323/// ```text
324/// ┌───────┬────────────────────────┬───────┐
325/// │ Int32 │ Struct[Int32, Float32] │ Int32 │
326/// └───────┴────────────────────────┴───────┘
327/// ```
328///
329/// Is encoded as
330///
331/// ```text
332/// ┌───────┬───────────────┬───────┬─────────┬───────┐
333/// │ Int32 │ Null Sentinel │ Int32 │ Float32 │ Int32 │
334/// └───────┴───────────────┴───────┴─────────┴───────┘
335/// ```
336///
337/// ## List and Map Encoding
338///
339/// Lists are encoded by first encoding all child elements to the row format.
340///
341/// The Map encoding is the same with the only difference being that the child elements are key-value pairs.
342///
343/// A list/map value is then encoded as the concatenation of each of the child elements,
344/// separately encoded using the variable length encoding described above, followed
345/// by the variable length encoding of an empty byte array.
346///
347/// For example given:
348///
349/// ```text
350/// [1_u8, 2_u8, 3_u8]
351/// [1_u8, null]
352/// []
353/// null
354/// ```
355///
356/// The elements would be converted to:
357///
358/// ```text
359///     ┌──┬──┐     ┌──┬──┐     ┌──┬──┐     ┌──┬──┐        ┌──┬──┐
360///  1  │01│01│  2  │01│02│  3  │01│03│  1  │01│01│  null  │00│00│
361///     └──┴──┘     └──┴──┘     └──┴──┘     └──┴──┘        └──┴──┘
362///```
363///
364/// Which would be encoded as
365///
366/// ```text
367///                         ┌──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┐
368///  [1_u8, 2_u8, 3_u8]     │02│01│01│00│00│02│02│01│02│00│00│02│02│01│03│00│00│02│01│
369///                         └──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┘
370///                          └──── 1_u8 ────┘   └──── 2_u8 ────┘  └──── 3_u8 ────┘
371///
372///                         ┌──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┐
373///  [1_u8, null]           │02│01│01│00│00│02│02│00│00│00│00│02│01│
374///                         └──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┘
375///                          └──── 1_u8 ────┘   └──── null ────┘
376///
377///```
378///
379/// With `[]` represented by an empty byte array, and `null` a null byte array.
380///
381/// ### Map Equality
382///
383/// **Note:** Maps with different order of keys are not equal in row format
384/// i.e. row_format({"hello": 1, "world": 2}) != row_format({"world": 2, "hello": 1})
385///
386/// ```
387/// # use std::sync::Arc;
388/// # use arrow_row::{RowConverter, SortField};
389/// # use arrow_array::{Array, Int32Array, StringArray, MapArray};
390///
391/// // [{ "hello": 1, "world": 2 }, { "hey": 3, "you": 4 }]
392/// let map_1 = MapArray::from_vec_of_maps::<StringArray, Int32Array, _, _>(vec![
393///   Some(vec![("hello", Some(1)), ("world", Some(2))]),
394///   Some(vec![("hey", Some(3)), ("you", Some(4))]),
395/// ], false);
396/// // [{ "world": 2, "hello": 1 }, { "hey": 3, "you": 4 }]
397/// let map_2 = MapArray::from_vec_of_maps::<StringArray, Int32Array, _, _>(vec![
398///   Some(vec![("world", Some(2)), ("hello", Some(1))]),
399///   Some(vec![("hey", Some(3)), ("you", Some(4))]),
400/// ], false);
401///
402/// let converter = RowConverter::new(vec![SortField::new(map_1.data_type().clone())]).unwrap();
403///
404/// let map_1_rows = converter.convert_columns(&[Arc::new(map_1)]).unwrap();
405/// let map_2_rows = converter.convert_columns(&[Arc::new(map_2)]).unwrap();
406///
407/// // Attention! these maps are NOT equal since the order of the keys are different
408/// assert_ne!(map_1_rows.row(0), map_2_rows.row(0));
409///
410/// // These maps ARE equal since the order and the content of the keys and values are the same
411/// assert_eq!(map_1_rows.row(1), map_2_rows.row(1));
412/// ```
413///
414/// If you DO want to treat maps with different order of keys as the same in row format you should canonicalize them first.
415///
416/// ## Fixed Size List Encoding
417///
418/// Fixed Size Lists are encoded by first encoding all child elements to the row format.
419///
420/// A non-null list value is then encoded as 0x01 followed by the concatenation of each
421/// of the child elements. A null list value is encoded as a null marker.
422///
423/// For example given:
424///
425/// ```text
426/// [1_u8, 2_u8]
427/// [3_u8, null]
428/// null
429/// ```
430///
431/// The elements would be converted to:
432///
433/// ```text
434///     ┌──┬──┐     ┌──┬──┐     ┌──┬──┐        ┌──┬──┐
435///  1  │01│01│  2  │01│02│  3  │01│03│  null  │00│00│
436///     └──┴──┘     └──┴──┘     └──┴──┘        └──┴──┘
437///```
438///
439/// Which would be encoded as
440///
441/// ```text
442///                 ┌──┬──┬──┬──┬──┐
443///  [1_u8, 2_u8]   │01│01│01│01│02│
444///                 └──┴──┴──┴──┴──┘
445///                     └ 1 ┘ └ 2 ┘
446///                 ┌──┬──┬──┬──┬──┐
447///  [3_u8, null]   │01│01│03│00│00│
448///                 └──┴──┴──┴──┴──┘
449///                     └ 1 ┘ └null┘
450///                 ┌──┐
451///  null           │00│
452///                 └──┘
453///
454///```
455///
456/// ## ListView Encoding
457///
458/// ListView arrays differ from List arrays in their representation: instead of using
459/// consecutive offset pairs to define each list, ListView uses explicit offset and size
460/// pairs for each element. This allows ListView elements to reference arbitrary (potentially
461/// overlapping) regions of the child array.
462///
463/// Despite this structural difference, ListView uses the **same row encoding as List**.
464/// Each list value is encoded as the concatenation of its child elements (each separately
465/// variable-length encoded), followed by a variable-length encoded empty byte array terminator.
466///
467/// **Important**: When a ListView is decoded back from row format, it is still a
468/// ListView, but any child element sharing that may have existed in the original
469/// (where multiple list entries could reference overlapping regions of the child
470/// array) is **not preserved** - each list's children are decoded independently
471/// with sequential offsets.
472///
473/// For example, given a ListView with offset/size pairs:
474///
475/// ```text
476/// offsets: [0, 1, 0]
477/// sizes:   [2, 2, 0]
478/// values:  [1_u8, 2_u8, 3_u8]
479///
480/// Resulting lists:
481/// [1_u8, 2_u8]  (offset=0, size=2 -> values[0..2])
482/// [2_u8, 3_u8]  (offset=1, size=2 -> values[1..3])
483/// []            (offset=0, size=0 -> empty)
484/// ```
485///
486/// The elements would be encoded identically to List encoding:
487///
488/// ```text
489///                         ┌──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┐
490///  [1_u8, 2_u8]           │02│01│01│00│00│02│02│01│02│00│00│02│01│
491///                         └──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┘
492///                          └──── 1_u8 ────┘   └──── 2_u8 ────┘
493///
494///                         ┌──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┐
495///  [2_u8, 3_u8]           │02│01│02│00│00│02│02│01│03│00│00│02│01│
496///                         └──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┘
497///                          └──── 2_u8 ────┘   └──── 3_u8 ────┘
498///
499///```
500///
501/// Note that element `2_u8` appears in both encoded rows, even though it was shared
502/// in the original ListView, and `[]` is represented by an empty byte array.
503///
504/// ## Union Encoding
505///
506/// A union value is encoded as a single type-id byte followed by the row encoding of the selected child value.
507/// The type-id byte is always present; union arrays have no top-level null marker, so nulls are represented by the child encoding.
508///
509/// For example, given a union of Int32 (type_id = 0) and Utf8 (type_id = 1):
510///
511/// ```text
512///                           ┌──┬──────────────┐
513///  3                        │00│01│80│00│00│03│
514///                           └──┴──────────────┘
515///                            │  └─ signed integer encoding (non-null)
516///                            └──── type_id
517///
518///                           ┌──┬────────────────────────────────┐
519/// "abc"                     │01│02│'a'│'b'│'c'│00│00│00│00│00│03│
520///                           └──┴────────────────────────────────┘
521///                            │  └─ string encoding (non-null)
522///                            └──── type_id
523///
524///                           ┌──┬──────────────┐
525/// null Int32                │00│00│00│00│00│00│
526///                           └──┴──────────────┘
527///                            │  └─ signed integer encoding (null)
528///                            └──── type_id
529///
530///                           ┌──┬──┐
531/// null Utf8                 │01│00│
532///                           └──┴──┘
533///                            │  └─ string encoding (null)
534///                            └──── type_id
535/// ```
536///
537/// See [`UnionArray`] for more details on union types.
538///
539/// # Ordering
540///
541/// ## Float Ordering
542///
543/// Floats are totally ordered in accordance to the `totalOrder` predicate as defined
544/// in the IEEE 754 (2008 revision) floating point standard.
545///
546/// The ordering established by this does not always agree with the
547/// [`PartialOrd`] and [`PartialEq`] implementations of `f32`. For example,
548/// they consider negative and positive zero equal, while this does not
549///
550/// ## Null Ordering
551///
552/// The encoding described above will order nulls first, this can be inverted by representing
553/// nulls as `0xFF_u8` instead of `0_u8`
554///
555/// ## Union Ordering
556///
557/// Values of the same type are ordered according to the ordering of that type.
558/// Values of different types are ordered by their type id.
559/// The type_id is negated when descending order is specified.
560///
561/// ## Reverse Column Ordering
562///
563/// The order of a given column can be reversed by negating the encoded bytes of non-null values
564///
565/// [COBS]: https://en.wikipedia.org/wiki/Consistent_Overhead_Byte_Stuffing
566/// [byte stuffing]: https://en.wikipedia.org/wiki/High-Level_Data_Link_Control#Asynchronous_framing
567#[derive(Debug)]
568pub struct RowConverter {
569    fields: Arc<[SortField]>,
570    /// State for codecs
571    codecs: Vec<Codec>,
572}
573
574#[derive(Debug)]
575enum Codec {
576    /// No additional codec state is necessary
577    Stateless,
578    /// A row converter for the dictionary values
579    /// and the encoding of a row containing only nulls
580    Dictionary(RowConverter, OwnedRow),
581    /// A row converter for the child fields
582    /// and the encoding of a row containing only nulls
583    Struct(RowConverter, OwnedRow),
584    /// A row converter for the child field
585    List(RowConverter),
586    /// A row converter for the entries in map (keys and values and not the struct)
587    Map(RowConverter),
588    /// A row converter for the values array of a run-end encoded array
589    RunEndEncoded(RowConverter),
590    /// Row converters for each union field (indexed by field position)
591    /// the type_ids for each field position, and the encoding of null rows for each field
592    Union(Vec<RowConverter>, Vec<i8>, Vec<OwnedRow>),
593}
594
595/// Computes the minimum offset and maximum end (offset + size) for a ListView array.
596/// Returns (min_offset, max_end) which can be used to slice the values array.
597fn compute_list_view_bounds<O: OffsetSizeTrait>(array: &GenericListViewArray<O>) -> (usize, usize) {
598    if array.is_empty() {
599        return (0, 0);
600    }
601
602    let offsets = array.value_offsets();
603    let sizes = array.value_sizes();
604    let values_len = array.values().len();
605
606    let mut min_offset = usize::MAX;
607    let mut max_end = 0usize;
608
609    for i in 0..array.len() {
610        let offset = offsets[i].as_usize();
611        let size = sizes[i].as_usize();
612        let end = offset + size;
613
614        if size > 0 {
615            min_offset = min_offset.min(offset);
616            max_end = max_end.max(end);
617        }
618
619        // Early exit if we've found the full range of the values array. This is possible with
620        // ListViews since offsets and sizes are arbitrary and the full range can be covered early
621        // in the iteration contrary to regular Lists.
622        if min_offset == 0 && max_end == values_len {
623            break;
624        }
625    }
626
627    if min_offset == usize::MAX {
628        // All lists are empty
629        (0, 0)
630    } else {
631        (min_offset, max_end)
632    }
633}
634
635impl Codec {
636    fn new(sort_field: &SortField) -> Result<Self, ArrowError> {
637        match &sort_field.data_type {
638            DataType::Dictionary(_, values) => {
639                let sort_field =
640                    SortField::new_with_options(values.as_ref().clone(), sort_field.options);
641
642                let converter = RowConverter::new(vec![sort_field])?;
643                let null_array = new_null_array(values.as_ref(), 1);
644                let nulls = converter.convert_columns(&[null_array])?;
645
646                let owned = OwnedRow {
647                    data: nulls.buffer.into(),
648                    config: nulls.config,
649                };
650                Ok(Self::Dictionary(converter, owned))
651            }
652            DataType::RunEndEncoded(_, values) => {
653                // Similar to List implementation
654                let options = SortOptions {
655                    descending: false,
656                    nulls_first: sort_field.options.nulls_first != sort_field.options.descending,
657                };
658
659                let field = SortField::new_with_options(values.data_type().clone(), options);
660                let converter = RowConverter::new(vec![field])?;
661                Ok(Self::RunEndEncoded(converter))
662            }
663            d if !d.is_nested() => Ok(Self::Stateless),
664            DataType::List(f)
665            | DataType::LargeList(f)
666            | DataType::ListView(f)
667            | DataType::LargeListView(f) => {
668                // The encoded contents will be inverted if descending is set to true
669                // As such we set `descending` to false and negate nulls first if it
670                // it set to true
671                let options = SortOptions {
672                    descending: false,
673                    nulls_first: sort_field.options.nulls_first != sort_field.options.descending,
674                };
675
676                let field = SortField::new_with_options(f.data_type().clone(), options);
677                let converter = RowConverter::new(vec![field])?;
678                Ok(Self::List(converter))
679            }
680            DataType::Map(f, _) => {
681                // The encoded contents will be inverted if `descending` is set to true
682                // As such we set `descending` to false and negate nulls first if it
683                // `descending` set to true.
684                let options = SortOptions {
685                    descending: false,
686                    nulls_first: sort_field.options.nulls_first != sort_field.options.descending,
687                };
688
689                let DataType::Struct(fields) = f.data_type() else {
690                    return Err(ArrowError::InvalidArgumentError(format!(
691                        "expected struct field in map, got {:?}",
692                        f.data_type()
693                    )));
694                };
695
696                // For Map type we unwrap the intermediate struct type to avoid going through Struct codec to improve performance
697                let fields = fields
698                    .iter()
699                    .map(|struct_field| {
700                        SortField::new_with_options(struct_field.data_type().clone(), options)
701                    })
702                    .collect::<Vec<_>>();
703                assert_eq!(fields.len(), 2);
704                let converter = RowConverter::new(fields)?;
705                Ok(Self::Map(converter))
706            }
707            DataType::FixedSizeList(f, _) => {
708                let field = SortField::new_with_options(f.data_type().clone(), sort_field.options);
709                let converter = RowConverter::new(vec![field])?;
710                Ok(Self::List(converter))
711            }
712            DataType::Struct(f) => {
713                let sort_fields = f
714                    .iter()
715                    .map(|x| SortField::new_with_options(x.data_type().clone(), sort_field.options))
716                    .collect();
717
718                let converter = RowConverter::new(sort_fields)?;
719                let nulls: Vec<_> = f.iter().map(|x| new_null_array(x.data_type(), 1)).collect();
720
721                let nulls = converter.convert_columns(&nulls)?;
722                let owned = OwnedRow {
723                    data: nulls.buffer.into(),
724                    config: nulls.config,
725                };
726
727                Ok(Self::Struct(converter, owned))
728            }
729            DataType::Union(fields, _mode) => {
730                // similar to dictionaries and lists, we set descending to false and negate nulls_first
731                // since the encoded contents will be inverted if descending is set
732                let options = SortOptions {
733                    descending: false,
734                    nulls_first: sort_field.options.nulls_first != sort_field.options.descending,
735                };
736
737                let mut converters = Vec::with_capacity(fields.len());
738                let mut type_ids = Vec::with_capacity(fields.len());
739                let mut null_rows = Vec::with_capacity(fields.len());
740
741                for (type_id, field) in fields.iter() {
742                    let sort_field =
743                        SortField::new_with_options(field.data_type().clone(), options);
744                    let converter = RowConverter::new(vec![sort_field])?;
745
746                    let null_array = new_null_array(field.data_type(), 1);
747                    let nulls = converter.convert_columns(&[null_array])?;
748                    let owned = OwnedRow {
749                        data: nulls.buffer.into(),
750                        config: nulls.config,
751                    };
752
753                    converters.push(converter);
754                    type_ids.push(type_id);
755                    null_rows.push(owned);
756                }
757
758                Ok(Self::Union(converters, type_ids, null_rows))
759            }
760            _ => Err(ArrowError::NotYetImplemented(format!(
761                "not yet implemented: {:?}",
762                sort_field.data_type
763            ))),
764        }
765    }
766
767    fn encoder(&self, array: &dyn Array) -> Result<Encoder<'_>, ArrowError> {
768        match self {
769            Codec::Stateless => Ok(Encoder::Stateless),
770            Codec::Dictionary(converter, nulls) => {
771                let values = array.as_any_dictionary().values().clone();
772                let rows = converter.convert_columns(&[values])?;
773                Ok(Encoder::Dictionary(rows, nulls.row()))
774            }
775            Codec::Struct(converter, null) => {
776                let v = as_struct_array(array);
777                let rows = converter.convert_columns(v.columns())?;
778                Ok(Encoder::Struct(rows, null.row()))
779            }
780            Codec::List(converter) => {
781                let values = match array.data_type() {
782                    DataType::List(_) => {
783                        let list_array = as_list_array(array);
784                        let first_offset = list_array.offsets()[0] as usize;
785                        let last_offset =
786                            list_array.offsets()[list_array.offsets().len() - 1] as usize;
787
788                        // values can include more data than referenced in the ListArray, only encode
789                        // the referenced values.
790                        list_array
791                            .values()
792                            .slice(first_offset, last_offset - first_offset)
793                    }
794                    DataType::LargeList(_) => {
795                        let list_array = as_large_list_array(array);
796
797                        let first_offset = list_array.offsets()[0] as usize;
798                        let last_offset =
799                            list_array.offsets()[list_array.offsets().len() - 1] as usize;
800
801                        // values can include more data than referenced in the LargeListArray, only encode
802                        // the referenced values.
803                        list_array
804                            .values()
805                            .slice(first_offset, last_offset - first_offset)
806                    }
807                    DataType::ListView(_) => {
808                        let list_view_array = array.as_list_view::<i32>();
809                        let (min_offset, max_end) = compute_list_view_bounds(list_view_array);
810                        list_view_array
811                            .values()
812                            .slice(min_offset, max_end - min_offset)
813                    }
814                    DataType::LargeListView(_) => {
815                        let list_view_array = array.as_list_view::<i64>();
816                        let (min_offset, max_end) = compute_list_view_bounds(list_view_array);
817                        list_view_array
818                            .values()
819                            .slice(min_offset, max_end - min_offset)
820                    }
821                    DataType::FixedSizeList(_, _) => {
822                        as_fixed_size_list_array(array).values().clone()
823                    }
824                    _ => unreachable!(),
825                };
826                let rows = converter.convert_columns(&[values])?;
827                Ok(Encoder::List(rows))
828            }
829            Codec::Map(converter) => {
830                let map_array = as_map_array(array);
831
832                let first_offset = map_array.offsets()[0] as usize;
833                let last_offset = map_array.offsets()[map_array.offsets().len() - 1] as usize;
834
835                // entries can include more data than referenced in the MapArray, only encode
836                // the referenced entries.
837                let sliced_entries = map_array
838                    .entries()
839                    .slice(first_offset, last_offset - first_offset);
840
841                // the converter for the map is the keys and values and not the wrapping struct
842                let rows = converter.convert_columns(sliced_entries.columns())?;
843                Ok(Encoder::Map(rows))
844            }
845            Codec::RunEndEncoded(converter) => {
846                let values = match array.data_type() {
847                    DataType::RunEndEncoded(r, _) => match r.data_type() {
848                        DataType::Int16 => array.as_run::<Int16Type>().values_slice(),
849                        DataType::Int32 => array.as_run::<Int32Type>().values_slice(),
850                        DataType::Int64 => array.as_run::<Int64Type>().values_slice(),
851                        _ => unreachable!("Unsupported run end index type: {r:?}"),
852                    },
853                    _ => unreachable!(),
854                };
855                let rows = converter.convert_columns(std::slice::from_ref(&values))?;
856                Ok(Encoder::RunEndEncoded(rows))
857            }
858            Codec::Union(converters, field_to_type_ids, _) => {
859                let union_array = array
860                    .as_any()
861                    .downcast_ref::<UnionArray>()
862                    .expect("expected Union array");
863
864                let type_ids = union_array.type_ids().clone();
865                let offsets = union_array.offsets().cloned();
866
867                let mut child_rows = Vec::with_capacity(converters.len());
868                for (field_idx, converter) in converters.iter().enumerate() {
869                    let type_id = field_to_type_ids[field_idx];
870                    let child_array = union_array.child(type_id);
871                    let rows = converter.convert_columns(std::slice::from_ref(child_array))?;
872                    child_rows.push(rows);
873                }
874
875                Ok(Encoder::Union {
876                    child_rows,
877                    field_to_type_ids: field_to_type_ids.clone(),
878                    type_ids,
879                    offsets,
880                })
881            }
882        }
883    }
884
885    fn size(&self) -> usize {
886        match self {
887            Codec::Stateless => 0,
888            Codec::Dictionary(converter, nulls) => converter.size() + nulls.data.len(),
889            Codec::Struct(converter, nulls) => converter.size() + nulls.data.len(),
890            Codec::List(converter) => converter.size(),
891            Codec::Map(converter) => converter.size(),
892            Codec::RunEndEncoded(converter) => converter.size(),
893            Codec::Union(converters, _, null_rows) => {
894                converters.iter().map(|c| c.size()).sum::<usize>()
895                    + null_rows.iter().map(|n| n.data.len()).sum::<usize>()
896            }
897        }
898    }
899}
900
901#[derive(Debug)]
902enum Encoder<'a> {
903    /// No additional encoder state is necessary
904    Stateless,
905    /// The encoding of the child array and the encoding of a null row
906    Dictionary(Rows, Row<'a>),
907    /// The row encoding of the child arrays and the encoding of a null row
908    ///
909    /// It is necessary to encode to a temporary [`Rows`] to avoid serializing
910    /// values that are masked by a null in the parent StructArray, otherwise
911    /// this would establish an ordering between semantically null values
912    Struct(Rows, Row<'a>),
913    /// The row encoding of the child array
914    List(Rows),
915    /// The row encoding of the map entries
916    Map(Rows),
917    /// The row encoding of the values array
918    RunEndEncoded(Rows),
919    /// The row encoding of each union field's child array, type_ids buffer, offsets buffer (for Dense), and mode
920    Union {
921        child_rows: Vec<Rows>,
922        field_to_type_ids: Vec<i8>,
923        type_ids: ScalarBuffer<i8>,
924        offsets: Option<ScalarBuffer<i32>>,
925    },
926}
927
928/// Configure the data type and sort order for a given column
929#[derive(Debug, Clone, PartialEq, Eq)]
930pub struct SortField {
931    /// Sort options
932    options: SortOptions,
933    /// Data type
934    data_type: DataType,
935}
936
937impl SortField {
938    /// Create a new column with the given data type
939    pub fn new(data_type: DataType) -> Self {
940        Self::new_with_options(data_type, Default::default())
941    }
942
943    /// Create a new column with the given data type and [`SortOptions`]
944    pub fn new_with_options(data_type: DataType, options: SortOptions) -> Self {
945        Self { options, data_type }
946    }
947
948    /// Return size of this instance in bytes.
949    ///
950    /// Includes the size of `Self`.
951    pub fn size(&self) -> usize {
952        self.data_type.size() + std::mem::size_of::<Self>() - std::mem::size_of::<DataType>()
953    }
954}
955
956impl RowConverter {
957    /// Create a new [`RowConverter`] with the provided schema
958    pub fn new(fields: Vec<SortField>) -> Result<Self, ArrowError> {
959        if !Self::supports_fields(&fields) {
960            return Err(ArrowError::NotYetImplemented(format!(
961                "Row format support not yet implemented for: {fields:?}"
962            )));
963        }
964
965        let codecs = fields.iter().map(Codec::new).collect::<Result<_, _>>()?;
966        Ok(Self {
967            fields: fields.into(),
968            codecs,
969        })
970    }
971
972    /// Check if the given fields are supported by the row format.
973    pub fn supports_fields(fields: &[SortField]) -> bool {
974        fields.iter().all(|x| Self::supports_datatype(&x.data_type))
975    }
976
977    fn supports_datatype(d: &DataType) -> bool {
978        match d {
979            _ if !d.is_nested() => true,
980            DataType::List(f)
981            | DataType::LargeList(f)
982            | DataType::ListView(f)
983            | DataType::LargeListView(f)
984            | DataType::FixedSizeList(f, _)
985            | DataType::Map(f, _) => Self::supports_datatype(f.data_type()),
986            DataType::Struct(f) => f.iter().all(|x| Self::supports_datatype(x.data_type())),
987            DataType::RunEndEncoded(_, values) => Self::supports_datatype(values.data_type()),
988            DataType::Union(fs, _mode) => fs
989                .iter()
990                .all(|(_, f)| Self::supports_datatype(f.data_type())),
991            _ => false,
992        }
993    }
994
995    /// Convert [`ArrayRef`] columns into [`Rows`]
996    ///
997    /// See [`Row`] for information on when [`Row`] can be compared
998    ///
999    /// See [`Self::convert_rows`] for converting [`Rows`] back into [`ArrayRef`]
1000    ///
1001    /// # Panics
1002    ///
1003    /// Panics if the schema of `columns` does not match that provided to [`RowConverter::new`]
1004    pub fn convert_columns(&self, columns: &[ArrayRef]) -> Result<Rows, ArrowError> {
1005        let num_rows = columns.first().map(|x| x.len()).unwrap_or(0);
1006        let mut rows = self.empty_rows(num_rows, 0);
1007        self.append(&mut rows, columns)?;
1008        Ok(rows)
1009    }
1010
1011    /// Convert [`ArrayRef`] columns appending to an existing [`Rows`]
1012    ///
1013    /// See [`Row`] for information on when [`Row`] can be compared
1014    ///
1015    /// # Panics
1016    ///
1017    /// Panics if
1018    /// * The schema of `columns` does not match that provided to [`RowConverter::new`]
1019    /// * The provided [`Rows`] were not created by this [`RowConverter`]
1020    ///
1021    /// ```
1022    /// # use std::sync::Arc;
1023    /// # use std::collections::HashSet;
1024    /// # use arrow_array::cast::AsArray;
1025    /// # use arrow_array::StringArray;
1026    /// # use arrow_row::{Row, RowConverter, SortField};
1027    /// # use arrow_schema::DataType;
1028    /// #
1029    /// let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
1030    /// let a1 = StringArray::from(vec!["hello", "world"]);
1031    /// let a2 = StringArray::from(vec!["a", "a", "hello"]);
1032    ///
1033    /// let mut rows = converter.empty_rows(5, 128);
1034    /// converter.append(&mut rows, &[Arc::new(a1)]).unwrap();
1035    /// converter.append(&mut rows, &[Arc::new(a2)]).unwrap();
1036    ///
1037    /// let back = converter.convert_rows(&rows).unwrap();
1038    /// let values: Vec<_> = back[0].as_string::<i32>().iter().map(Option::unwrap).collect();
1039    /// assert_eq!(&values, &["hello", "world", "a", "a", "hello"]);
1040    /// ```
1041    pub fn append(&self, rows: &mut Rows, columns: &[ArrayRef]) -> Result<(), ArrowError> {
1042        assert!(
1043            Arc::ptr_eq(&rows.config.fields, &self.fields),
1044            "rows were not produced by this RowConverter"
1045        );
1046
1047        if columns.len() != self.fields.len() {
1048            return Err(ArrowError::InvalidArgumentError(format!(
1049                "Incorrect number of arrays provided to RowConverter, expected {} got {}",
1050                self.fields.len(),
1051                columns.len()
1052            )));
1053        }
1054        for column in columns.iter().skip(1) {
1055            if column.len() != columns[0].len() {
1056                return Err(ArrowError::InvalidArgumentError(format!(
1057                    "RowConverter columns must all have the same length, expected {} got {}",
1058                    columns[0].len(),
1059                    column.len()
1060                )));
1061            }
1062        }
1063
1064        let encoders = columns
1065            .iter()
1066            .zip(&self.codecs)
1067            .zip(self.fields.iter())
1068            .map(|((column, codec), field)| {
1069                if !column.data_type().equals_datatype(&field.data_type) {
1070                    return Err(ArrowError::InvalidArgumentError(format!(
1071                        "RowConverter column schema mismatch, expected {} got {}",
1072                        field.data_type,
1073                        column.data_type()
1074                    )));
1075                }
1076                codec.encoder(column.as_ref())
1077            })
1078            .collect::<Result<Vec<_>, _>>()?;
1079
1080        let write_offset = rows.num_rows();
1081        let lengths = row_lengths(columns, &encoders);
1082        let total = lengths.extend_offsets(rows.offsets[write_offset], &mut rows.offsets);
1083        rows.buffer.resize(total, 0);
1084
1085        for ((column, field), encoder) in columns.iter().zip(self.fields.iter()).zip(encoders) {
1086            // We encode a column at a time to minimise dispatch overheads
1087            encode_column(
1088                &mut rows.buffer,
1089                &mut rows.offsets[write_offset..],
1090                column.as_ref(),
1091                field.options,
1092                &encoder,
1093            )
1094        }
1095
1096        if cfg!(debug_assertions) {
1097            assert_eq!(*rows.offsets.last().unwrap(), rows.buffer.len());
1098            rows.offsets
1099                .windows(2)
1100                .for_each(|w| assert!(w[0] <= w[1], "offsets should be monotonic"));
1101        }
1102
1103        Ok(())
1104    }
1105
1106    /// Convert [`Rows`] columns into [`ArrayRef`]
1107    ///
1108    /// See [`Self::convert_columns`] for converting [`ArrayRef`] into [`Rows`]
1109    ///
1110    /// # Panics
1111    ///
1112    /// Panics if the rows were not produced by this [`RowConverter`]
1113    pub fn convert_rows<'a, I>(&self, rows: I) -> Result<Vec<ArrayRef>, ArrowError>
1114    where
1115        I: IntoIterator<Item = Row<'a>>,
1116    {
1117        let mut validate_utf8 = false;
1118        let mut rows: Vec<_> = rows
1119            .into_iter()
1120            .map(|row| {
1121                assert!(
1122                    Arc::ptr_eq(&row.config.fields, &self.fields),
1123                    "rows were not produced by this RowConverter"
1124                );
1125                validate_utf8 |= row.config.validate_utf8;
1126                row.data
1127            })
1128            .collect();
1129
1130        // SAFETY
1131        // We have validated that the rows came from this [`RowConverter`]
1132        // and therefore must be valid
1133        let result = unsafe { self.convert_raw(&mut rows, validate_utf8) }?;
1134
1135        if cfg!(debug_assertions) {
1136            for (i, row) in rows.iter().enumerate() {
1137                if !row.is_empty() {
1138                    return Err(ArrowError::InvalidArgumentError(format!(
1139                        "Codecs {codecs:?} did not consume all bytes for row {i}, remaining bytes: {row:?}",
1140                        codecs = self.codecs
1141                    )));
1142                }
1143            }
1144        }
1145
1146        Ok(result)
1147    }
1148
1149    /// Returns an empty [`Rows`] with capacity for `row_capacity` rows with
1150    /// a total length of `data_capacity`
1151    ///
1152    /// This can be used to buffer a selection of [`Row`]
1153    ///
1154    /// ```
1155    /// # use std::sync::Arc;
1156    /// # use std::collections::HashSet;
1157    /// # use arrow_array::cast::AsArray;
1158    /// # use arrow_array::StringArray;
1159    /// # use arrow_row::{Row, RowConverter, SortField};
1160    /// # use arrow_schema::DataType;
1161    /// #
1162    /// let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
1163    /// let array = StringArray::from(vec!["hello", "world", "a", "a", "hello"]);
1164    ///
1165    /// // Convert to row format and deduplicate
1166    /// let converted = converter.convert_columns(&[Arc::new(array)]).unwrap();
1167    /// let mut distinct_rows = converter.empty_rows(3, 100);
1168    /// let mut dedup: HashSet<Row> = HashSet::with_capacity(3);
1169    /// converted.iter().filter(|row| dedup.insert(*row)).for_each(|row| distinct_rows.push(row));
1170    ///
1171    /// // Note: we could skip buffering and feed the filtered iterator directly
1172    /// // into convert_rows, this is done for demonstration purposes only
1173    /// let distinct = converter.convert_rows(&distinct_rows).unwrap();
1174    /// let values: Vec<_> = distinct[0].as_string::<i32>().iter().map(Option::unwrap).collect();
1175    /// assert_eq!(&values, &["hello", "world", "a"]);
1176    /// ```
1177    pub fn empty_rows(&self, row_capacity: usize, data_capacity: usize) -> Rows {
1178        let mut offsets = Vec::with_capacity(row_capacity.saturating_add(1));
1179        offsets.push(0);
1180
1181        Rows {
1182            offsets,
1183            buffer: Vec::with_capacity(data_capacity),
1184            config: RowConfig {
1185                fields: self.fields.clone(),
1186                validate_utf8: false,
1187            },
1188        }
1189    }
1190
1191    /// Create a new [Rows] instance from the given binary data.
1192    ///
1193    /// ```
1194    /// # use std::sync::Arc;
1195    /// # use std::collections::HashSet;
1196    /// # use arrow_array::cast::AsArray;
1197    /// # use arrow_array::StringArray;
1198    /// # use arrow_row::{OwnedRow, Row, RowConverter, RowParser, SortField};
1199    /// # use arrow_schema::DataType;
1200    /// #
1201    /// let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
1202    /// let array = StringArray::from(vec!["hello", "world", "a", "a", "hello"]);
1203    /// let rows = converter.convert_columns(&[Arc::new(array)]).unwrap();
1204    ///
1205    /// // We can convert rows into binary format and back in batch.
1206    /// let values: Vec<OwnedRow> = rows.iter().map(|r| r.owned()).collect();
1207    /// let binary = rows.try_into_binary().expect("known-small array");
1208    /// let converted = converter.from_binary(binary.clone());
1209    /// assert!(converted.iter().eq(values.iter().map(|r| r.row())));
1210    /// ```
1211    ///
1212    /// # Panics
1213    ///
1214    /// This function expects the passed [BinaryArray] to contain valid row data as produced by this
1215    /// [RowConverter]. It will panic if any rows are null. Operations on the returned [Rows] may
1216    /// panic if the data is malformed.
1217    pub fn from_binary(&self, array: BinaryArray) -> Rows {
1218        assert_eq!(
1219            array.null_count(),
1220            0,
1221            "can't construct Rows instance from array with nulls"
1222        );
1223        let (offsets, values, _) = array.into_parts();
1224        let offsets = offsets.iter().map(|&i| i.as_usize()).collect();
1225        // Try zero-copy, if it does not succeed, fall back to copying the values.
1226        let buffer = values.into_vec().unwrap_or_else(|values| values.to_vec());
1227        Rows {
1228            buffer,
1229            offsets,
1230            config: RowConfig {
1231                fields: Arc::clone(&self.fields),
1232                validate_utf8: true,
1233            },
1234        }
1235    }
1236
1237    /// Convert raw bytes into [`ArrayRef`]
1238    ///
1239    /// # Safety
1240    ///
1241    /// `rows` must contain valid data for this [`RowConverter`]
1242    unsafe fn convert_raw(
1243        &self,
1244        rows: &mut [&[u8]],
1245        validate_utf8: bool,
1246    ) -> Result<Vec<ArrayRef>, ArrowError> {
1247        self.fields
1248            .iter()
1249            .zip(&self.codecs)
1250            .map(|(field, codec)| unsafe { decode_column(field, rows, codec, validate_utf8) })
1251            .collect()
1252    }
1253
1254    /// Returns a [`RowParser`] that can be used to parse [`Row`] from bytes
1255    pub fn parser(&self) -> RowParser {
1256        RowParser::new(Arc::clone(&self.fields))
1257    }
1258
1259    /// Like [`Self::parser`] but skips UTF-8 validation on decode.
1260    ///
1261    /// # Safety
1262    /// The caller must ensure all row bytes contain valid UTF-8 for string columns.
1263    pub unsafe fn parser_skip_utf8_validation(&self) -> RowParser {
1264        unsafe { RowParser::with_skip_utf8_validate(Arc::clone(&self.fields)) }
1265    }
1266
1267    /// Returns the size of this instance in bytes
1268    ///
1269    /// Includes the size of `Self`.
1270    pub fn size(&self) -> usize {
1271        std::mem::size_of::<Self>()
1272            + self.fields.iter().map(|x| x.size()).sum::<usize>()
1273            + self.codecs.capacity() * std::mem::size_of::<Codec>()
1274            + self.codecs.iter().map(Codec::size).sum::<usize>()
1275    }
1276}
1277
1278/// A [`RowParser`] can be created from a [`RowConverter`] and used to parse bytes to [`Row`]
1279#[derive(Debug)]
1280pub struct RowParser {
1281    config: RowConfig,
1282}
1283
1284impl RowParser {
1285    fn new(fields: Arc<[SortField]>) -> Self {
1286        Self {
1287            config: RowConfig {
1288                fields,
1289                validate_utf8: true,
1290            },
1291        }
1292    }
1293    /// Like [`RowConverter::parser`] but skips UTF-8 validation on decode.
1294    ///
1295    /// # Safety
1296    /// The caller must ensure all row bytes contain valid UTF-8 for string columns.
1297    unsafe fn with_skip_utf8_validate(fields: Arc<[SortField]>) -> Self {
1298        Self {
1299            config: RowConfig {
1300                fields,
1301                validate_utf8: false,
1302            },
1303        }
1304    }
1305
1306    /// Creates a [`Row`] from the provided `bytes`.
1307    ///
1308    /// `bytes` must be a [`Row`] produced by the [`RowConverter`] associated with
1309    /// this [`RowParser`], otherwise subsequent operations with the produced [`Row`] may panic
1310    pub fn parse<'a>(&'a self, bytes: &'a [u8]) -> Row<'a> {
1311        Row {
1312            data: bytes,
1313            config: &self.config,
1314        }
1315    }
1316}
1317
1318/// The config of a given set of [`Row`]
1319#[derive(Debug, Clone)]
1320struct RowConfig {
1321    /// The schema for these rows
1322    fields: Arc<[SortField]>,
1323    /// Whether to run UTF-8 validation when converting to arrow arrays
1324    validate_utf8: bool,
1325}
1326
1327/// A row-oriented representation of arrow data, that is normalized for comparison.
1328///
1329/// See the [module level documentation](self) and [`RowConverter`] for more details.
1330#[derive(Debug, Clone)]
1331pub struct Rows {
1332    /// Underlying row bytes
1333    buffer: Vec<u8>,
1334    /// Row `i` has data `&buffer[offsets[i]..offsets[i+1]]`
1335    offsets: Vec<usize>,
1336    /// The config for these rows
1337    config: RowConfig,
1338}
1339
1340/// The iterator type for [`Rows::lengths`]
1341pub type RowLengthIter<'a> = Map<Windows<'a, usize>, fn(&'a [usize]) -> usize>;
1342
1343impl Rows {
1344    /// Append a [`Row`] to this [`Rows`]
1345    ///
1346    /// # Panics
1347    ///
1348    /// Panics if `row` was not produced by the same [`RowConverter`] as `self`
1349    pub fn push(&mut self, row: Row<'_>) {
1350        assert!(
1351            Arc::ptr_eq(&row.config.fields, &self.config.fields),
1352            "row was not produced by this RowConverter"
1353        );
1354        self.config.validate_utf8 |= row.config.validate_utf8;
1355        self.buffer.extend_from_slice(row.data);
1356        self.offsets.push(self.buffer.len())
1357    }
1358
1359    /// Reserve capacity for `row_capacity` rows with a total length of `data_capacity`
1360    pub fn reserve(&mut self, row_capacity: usize, data_capacity: usize) {
1361        self.buffer.reserve(data_capacity);
1362        self.offsets.reserve(row_capacity);
1363    }
1364
1365    /// Returns the row at index `row`
1366    ///
1367    /// # Panics
1368    ///
1369    /// Panics if `row >= self.num_rows()`
1370    pub fn row(&self, row: usize) -> Row<'_> {
1371        self.checked_row_end(row);
1372        unsafe { self.row_unchecked(row) }
1373    }
1374
1375    fn checked_row_end(&self, row: usize) -> usize {
1376        row.checked_add(1)
1377            .filter(|end| *end < self.offsets.len())
1378            .expect("row index out of bounds")
1379    }
1380
1381    /// Returns the row at `index` without bounds checking
1382    ///
1383    /// # Safety
1384    /// Caller must ensure that `index + 1` is less than the number of offsets (#rows + 1)
1385    pub unsafe fn row_unchecked(&self, index: usize) -> Row<'_> {
1386        let end = unsafe { self.offsets.get_unchecked(index + 1) };
1387        let start = unsafe { self.offsets.get_unchecked(index) };
1388        let data = unsafe { self.buffer.get_unchecked(*start..*end) };
1389        Row {
1390            data,
1391            config: &self.config,
1392        }
1393    }
1394
1395    /// Returns the number of bytes the row at index `row` is occupying,
1396    /// that is, what is the length of the returned [`Row::data`] will be.
1397    pub fn row_len(&self, row: usize) -> usize {
1398        let end = self.checked_row_end(row);
1399
1400        self.offsets[end] - self.offsets[row]
1401    }
1402
1403    /// Get an iterator over the lengths of each row in this [`Rows`]
1404    pub fn lengths(&self) -> RowLengthIter<'_> {
1405        self.offsets.windows(2).map(|w| w[1] - w[0])
1406    }
1407
1408    /// Sets the length of this [`Rows`] to 0
1409    pub fn clear(&mut self) {
1410        self.offsets.truncate(1);
1411        self.buffer.clear();
1412    }
1413
1414    /// Returns the number of [`Row`] in this [`Rows`]
1415    pub fn num_rows(&self) -> usize {
1416        self.offsets.len() - 1
1417    }
1418
1419    /// Returns an iterator over the [`Row`] in this [`Rows`]
1420    pub fn iter(&self) -> RowsIter<'_> {
1421        self.into_iter()
1422    }
1423
1424    /// Returns the size of this instance in bytes
1425    ///
1426    /// Includes the size of `Self`.
1427    pub fn size(&self) -> usize {
1428        // Size of fields is accounted for as part of RowConverter
1429        std::mem::size_of::<Self>()
1430            + self.buffer.capacity()
1431            + self.offsets.capacity() * std::mem::size_of::<usize>()
1432    }
1433
1434    /// Create a [BinaryArray] from the [Rows] data without reallocating the
1435    /// underlying bytes.
1436    ///
1437    ///
1438    /// ```
1439    /// # use std::sync::Arc;
1440    /// # use std::collections::HashSet;
1441    /// # use arrow_array::cast::AsArray;
1442    /// # use arrow_array::StringArray;
1443    /// # use arrow_row::{OwnedRow, Row, RowConverter, RowParser, SortField};
1444    /// # use arrow_schema::DataType;
1445    /// #
1446    /// let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
1447    /// let array = StringArray::from(vec!["hello", "world", "a", "a", "hello"]);
1448    /// let rows = converter.convert_columns(&[Arc::new(array)]).unwrap();
1449    ///
1450    /// // We can convert rows into binary format and back.
1451    /// let values: Vec<OwnedRow> = rows.iter().map(|r| r.owned()).collect();
1452    /// let binary = rows.try_into_binary().expect("known-small array");
1453    /// let parser = converter.parser();
1454    /// let parsed: Vec<OwnedRow> =
1455    ///   binary.iter().flatten().map(|b| parser.parse(b).owned()).collect();
1456    /// assert_eq!(values, parsed);
1457    /// ```
1458    ///
1459    /// # Errors
1460    ///
1461    /// This function will return an error if there is more data than can be stored in
1462    /// a [BinaryArray] -- i.e. if the total data size is more than 2GiB.
1463    pub fn try_into_binary(self) -> Result<BinaryArray, ArrowError> {
1464        if self.buffer.len() > i32::MAX as usize {
1465            return Err(ArrowError::InvalidArgumentError(format!(
1466                "{}-byte rows buffer too long to convert into a i32-indexed BinaryArray",
1467                self.buffer.len()
1468            )));
1469        }
1470        // We've checked that the buffer length fits in an i32; so all offsets into that buffer should fit as well.
1471        let offsets_scalar = ScalarBuffer::from_iter(self.offsets.into_iter().map(i32::usize_as));
1472        // SAFETY: offsets buffer is nonempty, monotonically increasing, and all represent valid indexes into buffer.
1473        let array = unsafe {
1474            BinaryArray::new_unchecked(
1475                OffsetBuffer::new_unchecked(offsets_scalar),
1476                Buffer::from_vec(self.buffer),
1477                None,
1478            )
1479        };
1480        Ok(array)
1481    }
1482}
1483
1484impl<'a> IntoIterator for &'a Rows {
1485    type Item = Row<'a>;
1486    type IntoIter = RowsIter<'a>;
1487
1488    fn into_iter(self) -> Self::IntoIter {
1489        RowsIter {
1490            rows: self,
1491            start: 0,
1492            end: self.num_rows(),
1493        }
1494    }
1495}
1496
1497/// An iterator over [`Rows`]
1498#[derive(Debug)]
1499pub struct RowsIter<'a> {
1500    rows: &'a Rows,
1501    start: usize,
1502    end: usize,
1503}
1504
1505impl<'a> Iterator for RowsIter<'a> {
1506    type Item = Row<'a>;
1507
1508    fn next(&mut self) -> Option<Self::Item> {
1509        if self.end == self.start {
1510            return None;
1511        }
1512
1513        // SAFETY: We have checked that `start` is less than `end`
1514        let row = unsafe { self.rows.row_unchecked(self.start) };
1515        self.start += 1;
1516        Some(row)
1517    }
1518
1519    fn size_hint(&self) -> (usize, Option<usize>) {
1520        let len = self.len();
1521        (len, Some(len))
1522    }
1523}
1524
1525impl ExactSizeIterator for RowsIter<'_> {
1526    fn len(&self) -> usize {
1527        self.end - self.start
1528    }
1529}
1530
1531impl DoubleEndedIterator for RowsIter<'_> {
1532    fn next_back(&mut self) -> Option<Self::Item> {
1533        if self.end == self.start {
1534            return None;
1535        }
1536
1537        self.end -= 1;
1538
1539        // Safety: By construction we create `end >= start`, so if `end` is not equal to `start` it cannot be less than `start`
1540        //          therefore `end - 1` is within range
1541        let row = unsafe { self.rows.row_unchecked(self.end) };
1542        Some(row)
1543    }
1544}
1545
1546/// A comparable representation of a row.
1547///
1548/// See the [module level documentation](self) for more details.
1549///
1550/// Two [`Row`] can only be compared if they both belong to [`Rows`]
1551/// returned by calls to [`RowConverter::convert_columns`] on the same
1552/// [`RowConverter`]. If different [`RowConverter`]s are used, any
1553/// ordering established by comparing the [`Row`] is arbitrary.
1554#[derive(Debug, Copy, Clone)]
1555pub struct Row<'a> {
1556    data: &'a [u8],
1557    config: &'a RowConfig,
1558}
1559
1560impl<'a> Row<'a> {
1561    /// Create owned version of the row to detach it from the shared [`Rows`].
1562    pub fn owned(&self) -> OwnedRow {
1563        OwnedRow {
1564            data: self.data.into(),
1565            config: self.config.clone(),
1566        }
1567    }
1568
1569    /// The row's bytes, with the lifetime of the underlying data.
1570    pub fn data(&self) -> &'a [u8] {
1571        self.data
1572    }
1573}
1574
1575// Manually derive these as don't wish to include `fields`
1576
1577impl PartialEq for Row<'_> {
1578    #[inline]
1579    fn eq(&self, other: &Self) -> bool {
1580        self.data.eq(other.data)
1581    }
1582}
1583
1584impl Eq for Row<'_> {}
1585
1586impl PartialOrd for Row<'_> {
1587    #[inline]
1588    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
1589        Some(self.cmp(other))
1590    }
1591}
1592
1593impl Ord for Row<'_> {
1594    #[inline]
1595    fn cmp(&self, other: &Self) -> Ordering {
1596        self.data.cmp(other.data)
1597    }
1598}
1599
1600impl Hash for Row<'_> {
1601    #[inline]
1602    fn hash<H: Hasher>(&self, state: &mut H) {
1603        self.data.hash(state)
1604    }
1605}
1606
1607impl AsRef<[u8]> for Row<'_> {
1608    #[inline]
1609    fn as_ref(&self) -> &[u8] {
1610        self.data
1611    }
1612}
1613
1614/// Owned version of a [`Row`] that can be moved/cloned freely.
1615///
1616/// This contains the data for the one specific row (not the entire buffer of all rows).
1617#[derive(Debug, Clone)]
1618pub struct OwnedRow {
1619    data: Box<[u8]>,
1620    config: RowConfig,
1621}
1622
1623impl OwnedRow {
1624    /// Get borrowed [`Row`] from owned version.
1625    ///
1626    /// This is helpful if you want to compare an [`OwnedRow`] with a [`Row`].
1627    pub fn row(&self) -> Row<'_> {
1628        Row {
1629            data: &self.data,
1630            config: &self.config,
1631        }
1632    }
1633}
1634
1635// Manually derive these as don't wish to include `fields`. Also we just want to use the same `Row` implementations here.
1636
1637impl PartialEq for OwnedRow {
1638    #[inline]
1639    fn eq(&self, other: &Self) -> bool {
1640        self.row().eq(&other.row())
1641    }
1642}
1643
1644impl Eq for OwnedRow {}
1645
1646impl PartialOrd for OwnedRow {
1647    #[inline]
1648    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
1649        Some(self.cmp(other))
1650    }
1651}
1652
1653impl Ord for OwnedRow {
1654    #[inline]
1655    fn cmp(&self, other: &Self) -> Ordering {
1656        self.row().cmp(&other.row())
1657    }
1658}
1659
1660impl Hash for OwnedRow {
1661    #[inline]
1662    fn hash<H: Hasher>(&self, state: &mut H) {
1663        self.row().hash(state)
1664    }
1665}
1666
1667impl AsRef<[u8]> for OwnedRow {
1668    #[inline]
1669    fn as_ref(&self) -> &[u8] {
1670        &self.data
1671    }
1672}
1673
1674/// Returns the null sentinel, negated if `invert` is true
1675#[inline]
1676fn null_sentinel(options: SortOptions) -> u8 {
1677    match options.nulls_first {
1678        true => 0,
1679        false => 0xFF,
1680    }
1681}
1682
1683/// Stores the lengths of the rows. Lazily materializes lengths for columns with fixed-size types.
1684enum LengthTracker {
1685    /// Fixed state: All rows have length `length`
1686    Fixed { length: usize, num_rows: usize },
1687    /// Variable state: The length of row `i` is `lengths[i] + fixed_length`
1688    Variable {
1689        fixed_length: usize,
1690        lengths: Vec<usize>,
1691    },
1692}
1693
1694impl LengthTracker {
1695    fn new(num_rows: usize) -> Self {
1696        Self::Fixed {
1697            length: 0,
1698            num_rows,
1699        }
1700    }
1701
1702    /// Adds a column of fixed-length elements, each of size `new_length` to the LengthTracker
1703    fn push_fixed(&mut self, new_length: usize) {
1704        match self {
1705            LengthTracker::Fixed { length, .. } => *length += new_length,
1706            LengthTracker::Variable { fixed_length, .. } => *fixed_length += new_length,
1707        }
1708    }
1709
1710    /// Adds a column of possibly variable-length elements, element `i` has length `new_lengths.nth(i)`
1711    fn push_variable(&mut self, new_lengths: impl ExactSizeIterator<Item = usize>) {
1712        match self {
1713            LengthTracker::Fixed { length, .. } => {
1714                *self = LengthTracker::Variable {
1715                    fixed_length: *length,
1716                    lengths: new_lengths.collect(),
1717                }
1718            }
1719            LengthTracker::Variable { lengths, .. } => {
1720                assert_eq!(lengths.len(), new_lengths.len());
1721                lengths
1722                    .iter_mut()
1723                    .zip(new_lengths)
1724                    .for_each(|(length, new_length)| *length += new_length);
1725            }
1726        }
1727    }
1728
1729    /// Returns the tracked row lengths as a slice
1730    fn materialized(&mut self) -> &mut [usize] {
1731        if let LengthTracker::Fixed { length, num_rows } = *self {
1732            *self = LengthTracker::Variable {
1733                fixed_length: length,
1734                lengths: vec![0; num_rows],
1735            };
1736        }
1737
1738        match self {
1739            LengthTracker::Variable { lengths, .. } => lengths,
1740            LengthTracker::Fixed { .. } => unreachable!(),
1741        }
1742    }
1743
1744    /// Initializes the offsets using the tracked lengths. Returns the sum of the
1745    /// lengths of the rows added.
1746    ///
1747    /// We initialize the offsets shifted down by one row index.
1748    ///
1749    /// As the rows are appended to the offsets will be incremented to match
1750    ///
1751    /// For example, consider the case of 3 rows of length 3, 4, and 6 respectively.
1752    /// The offsets would be initialized to `0, 0, 3, 7`
1753    ///
1754    /// Writing the first row entirely would yield `0, 3, 3, 7`
1755    /// The second, `0, 3, 7, 7`
1756    /// The third, `0, 3, 7, 13`
1757    //
1758    /// This would be the final offsets for reading
1759    //
1760    /// In this way offsets tracks the position during writing whilst eventually serving
1761    fn extend_offsets(&self, initial_offset: usize, offsets: &mut Vec<usize>) -> usize {
1762        match self {
1763            LengthTracker::Fixed { length, num_rows } => {
1764                offsets.extend((0..*num_rows).map(|i| initial_offset + i * length));
1765
1766                initial_offset + num_rows * length
1767            }
1768            LengthTracker::Variable {
1769                fixed_length,
1770                lengths,
1771            } => {
1772                let mut acc = initial_offset;
1773
1774                offsets.extend(lengths.iter().map(|length| {
1775                    let current = acc;
1776                    acc += length + fixed_length;
1777                    current
1778                }));
1779
1780                acc
1781            }
1782        }
1783    }
1784}
1785
1786/// Computes the length of each encoded [`Rows`] and returns an empty [`Rows`]
1787fn row_lengths(cols: &[ArrayRef], encoders: &[Encoder]) -> LengthTracker {
1788    use fixed::FixedLengthEncoding;
1789
1790    let num_rows = cols.first().map(|x| x.len()).unwrap_or(0);
1791    let mut tracker = LengthTracker::new(num_rows);
1792
1793    for (array, encoder) in cols.iter().zip(encoders) {
1794        match encoder {
1795            Encoder::Stateless => {
1796                downcast_primitive_array! {
1797                    array => tracker.push_fixed(fixed::encoded_len(array)),
1798                    DataType::Null => tracker.push_fixed(2)
1799                    DataType::Boolean => tracker.push_fixed(bool::ENCODED_LEN),
1800                    DataType::Binary => push_generic_byte_array_lengths(&mut tracker, as_generic_binary_array::<i32>(array)),
1801                    DataType::LargeBinary => push_generic_byte_array_lengths(&mut tracker, as_generic_binary_array::<i64>(array)),
1802                    DataType::BinaryView => push_byte_view_array_lengths(&mut tracker, array.as_binary_view()),
1803                    DataType::Utf8 => push_generic_byte_array_lengths(&mut tracker, array.as_string::<i32>()),
1804                    DataType::LargeUtf8 => push_generic_byte_array_lengths(&mut tracker, array.as_string::<i64>()),
1805                    DataType::Utf8View => push_byte_view_array_lengths(&mut tracker, array.as_string_view()),
1806                    DataType::FixedSizeBinary(len) => {
1807                        let len = len.to_usize().unwrap();
1808                        tracker.push_fixed(1 + len)
1809                    }
1810                    _ => unimplemented!("unsupported data type: {}", array.data_type()),
1811                }
1812            }
1813            Encoder::Dictionary(values, null) => {
1814                downcast_dictionary_array! {
1815                    array => {
1816                        tracker.push_variable(
1817                            array.keys().iter().map(|v| match v {
1818                                Some(k) => values.row_len(k.as_usize()),
1819                                None => null.data.len(),
1820                            })
1821                        )
1822                    }
1823                    _ => unreachable!(),
1824                }
1825            }
1826            Encoder::Struct(rows, null) => {
1827                let array = as_struct_array(array);
1828                if rows.num_rows() > 0 {
1829                    // Only calculate row length if there are rows
1830                    tracker.push_variable((0..array.len()).map(|idx| match array.is_valid(idx) {
1831                        true => 1 + rows.row_len(idx),
1832                        false => 1 + null.data.len(),
1833                    }));
1834                } else {
1835                    // Edge case for Struct([]) arrays (no child fields)
1836                    tracker.push_variable((0..array.len()).map(|idx| match array.is_valid(idx) {
1837                        true => 1,
1838                        false => 1 + null.data.len(),
1839                    }));
1840                }
1841            }
1842            Encoder::List(rows) => match array.data_type() {
1843                DataType::List(_) => {
1844                    list::compute_lengths(tracker.materialized(), rows, as_list_array(array))
1845                }
1846                DataType::LargeList(_) => {
1847                    list::compute_lengths(tracker.materialized(), rows, as_large_list_array(array))
1848                }
1849                DataType::ListView(_) => {
1850                    let list_view = array.as_list_view::<i32>();
1851                    let (min_offset, _) = compute_list_view_bounds(list_view);
1852                    list::compute_lengths_list_view(
1853                        tracker.materialized(),
1854                        rows,
1855                        list_view,
1856                        min_offset,
1857                    )
1858                }
1859                DataType::LargeListView(_) => {
1860                    let list_view = array.as_list_view::<i64>();
1861                    let (min_offset, _) = compute_list_view_bounds(list_view);
1862                    list::compute_lengths_list_view(
1863                        tracker.materialized(),
1864                        rows,
1865                        list_view,
1866                        min_offset,
1867                    )
1868                }
1869                DataType::FixedSizeList(_, _) => compute_lengths_fixed_size_list(
1870                    &mut tracker,
1871                    rows,
1872                    as_fixed_size_list_array(array),
1873                ),
1874                _ => unreachable!(),
1875            },
1876            Encoder::Map(rows) => {
1877                list::compute_lengths(tracker.materialized(), rows, as_map_array(array))
1878            }
1879            Encoder::RunEndEncoded(rows) => match array.data_type() {
1880                DataType::RunEndEncoded(r, _) => match r.data_type() {
1881                    DataType::Int16 => run::compute_lengths(
1882                        tracker.materialized(),
1883                        rows,
1884                        array.as_run::<Int16Type>(),
1885                    ),
1886                    DataType::Int32 => run::compute_lengths(
1887                        tracker.materialized(),
1888                        rows,
1889                        array.as_run::<Int32Type>(),
1890                    ),
1891                    DataType::Int64 => run::compute_lengths(
1892                        tracker.materialized(),
1893                        rows,
1894                        array.as_run::<Int64Type>(),
1895                    ),
1896                    _ => unreachable!("Unsupported run end index type: {r:?}"),
1897                },
1898                _ => unreachable!(),
1899            },
1900            Encoder::Union {
1901                child_rows,
1902                field_to_type_ids,
1903                type_ids,
1904                offsets,
1905            } => {
1906                let union_array = array
1907                    .as_any()
1908                    .downcast_ref::<UnionArray>()
1909                    .expect("expected UnionArray");
1910
1911                let mut type_id_to_field_idx = [0usize; 128];
1912                for (field_idx, &type_id) in field_to_type_ids.iter().enumerate() {
1913                    type_id_to_field_idx[type_id as usize] = field_idx;
1914                }
1915
1916                let lengths = (0..union_array.len()).map(|i| {
1917                    let type_id = type_ids[i];
1918                    let field_idx = type_id_to_field_idx[type_id as usize];
1919                    let child_row_i = offsets.as_ref().map(|o| o[i] as usize).unwrap_or(i);
1920                    let child_row_len = child_rows[field_idx].row_len(child_row_i);
1921
1922                    // length: 1 byte type_id + child row bytes
1923                    1 + child_row_len
1924                });
1925
1926                tracker.push_variable(lengths);
1927            }
1928        }
1929    }
1930
1931    tracker
1932}
1933
1934/// Add to [`LengthTracker`] the encoded length of each item in the [`GenericByteArray`]
1935fn push_generic_byte_array_lengths<T: ByteArrayType>(
1936    tracker: &mut LengthTracker,
1937    array: &GenericByteArray<T>,
1938) {
1939    if let Some(nulls) = array.nulls().filter(|n| n.null_count() > 0) {
1940        tracker.push_variable(
1941            array
1942                .offsets()
1943                .lengths()
1944                .zip(nulls.iter())
1945                .map(|(length, is_valid)| if is_valid { Some(length) } else { None })
1946                .map(variable::padded_length),
1947        )
1948    } else {
1949        tracker.push_variable(
1950            array
1951                .offsets()
1952                .lengths()
1953                .map(variable::non_null_padded_length),
1954        )
1955    }
1956}
1957
1958/// Add to [`LengthTracker`] the encoded length of each item in the [`GenericByteViewArray`]
1959fn push_byte_view_array_lengths<T: ByteViewType>(
1960    tracker: &mut LengthTracker,
1961    array: &GenericByteViewArray<T>,
1962) {
1963    if let Some(nulls) = array.nulls().filter(|n| n.null_count() > 0) {
1964        tracker.push_variable(
1965            array
1966                .lengths()
1967                .zip(nulls.iter())
1968                .map(|(length, is_valid)| {
1969                    if is_valid {
1970                        Some(length as usize)
1971                    } else {
1972                        None
1973                    }
1974                })
1975                .map(variable::padded_length),
1976        )
1977    } else {
1978        tracker.push_variable(
1979            array
1980                .lengths()
1981                .map(|len| variable::padded_length(Some(len as usize))),
1982        )
1983    }
1984}
1985
1986/// Encodes a column to the provided [`Rows`] incrementing the offsets as it progresses
1987fn encode_column(
1988    data: &mut [u8],
1989    offsets: &mut [usize],
1990    column: &dyn Array,
1991    opts: SortOptions,
1992    encoder: &Encoder<'_>,
1993) {
1994    match encoder {
1995        Encoder::Stateless => {
1996            downcast_primitive_array! {
1997                column => {
1998                    if let Some(nulls) = column.nulls().filter(|n| n.null_count() > 0){
1999                        fixed::encode(data, offsets, column.values(), nulls, opts)
2000                    } else {
2001                        fixed::encode_not_null(data, offsets, column.values(), opts)
2002                    }
2003                }
2004                DataType::Null => {
2005                    for offset in offsets.iter_mut().skip(1) {
2006                        variable::encode_null_value(&mut data[*offset..], opts);
2007                        *offset += 2;
2008                    }
2009                }
2010                DataType::Boolean => {
2011                    if let Some(nulls) = column.nulls().filter(|n| n.null_count() > 0){
2012                        fixed::encode_boolean(data, offsets, column.as_boolean().values(), nulls, opts)
2013                    } else {
2014                        fixed::encode_boolean_not_null(data, offsets, column.as_boolean().values(), opts)
2015                    }
2016                }
2017                DataType::Binary => {
2018                    variable::encode_generic_byte_array(data, offsets, as_generic_binary_array::<i32>(column), opts)
2019                }
2020                DataType::BinaryView => {
2021                    variable::encode(data, offsets, column.as_binary_view().iter(), opts)
2022                }
2023                DataType::LargeBinary => {
2024                    variable::encode_generic_byte_array(data, offsets, as_generic_binary_array::<i64>(column), opts)
2025                }
2026                DataType::Utf8 => variable::encode_generic_byte_array(
2027                    data, offsets,
2028                    column.as_string::<i32>(),
2029                    opts,
2030                ),
2031                DataType::LargeUtf8 => variable::encode_generic_byte_array(
2032                    data, offsets,
2033                    column.as_string::<i64>(),
2034                    opts,
2035                ),
2036                DataType::Utf8View => variable::encode(
2037                    data, offsets,
2038                    column.as_string_view().iter().map(|x| x.map(|x| x.as_bytes())),
2039                    opts,
2040                ),
2041                DataType::FixedSizeBinary(_) => {
2042                    let array = column.as_any().downcast_ref().unwrap();
2043                    fixed::encode_fixed_size_binary(data, offsets, array, opts)
2044                }
2045                _ => unimplemented!("unsupported data type: {}", column.data_type()),
2046            }
2047        }
2048        Encoder::Dictionary(values, nulls) => {
2049            downcast_dictionary_array! {
2050                column => encode_dictionary_values(data, offsets, column, values, nulls),
2051                _ => unreachable!()
2052            }
2053        }
2054        Encoder::Struct(rows, null) => {
2055            fn struct_encode_helper<const NO_CHILD_FIELDS: bool>(
2056                array: &StructArray,
2057                offsets: &mut [usize],
2058                null_sentinel: u8,
2059                rows: &Rows,
2060                null: &Row<'_>,
2061                data: &mut [u8],
2062            ) {
2063                let empty_row = Row {
2064                    data: &[],
2065                    config: &rows.config,
2066                };
2067
2068                offsets
2069                    .iter_mut()
2070                    .skip(1)
2071                    .enumerate()
2072                    .for_each(|(idx, offset)| {
2073                        let (row, sentinel) = match array.is_valid(idx) {
2074                            true => (
2075                                if NO_CHILD_FIELDS {
2076                                    empty_row
2077                                } else {
2078                                    rows.row(idx)
2079                                },
2080                                0x01,
2081                            ),
2082                            false => (*null, null_sentinel),
2083                        };
2084                        let end_offset = *offset + 1 + row.as_ref().len();
2085                        data[*offset] = sentinel;
2086                        data[*offset + 1..end_offset].copy_from_slice(row.as_ref());
2087                        *offset = end_offset;
2088                    })
2089            }
2090
2091            let array = as_struct_array(column);
2092            let null_sentinel = null_sentinel(opts);
2093            if rows.num_rows() == 0 {
2094                // Edge case for Struct([]) arrays (no child fields)
2095                struct_encode_helper::<true>(array, offsets, null_sentinel, rows, null, data);
2096            } else {
2097                struct_encode_helper::<false>(array, offsets, null_sentinel, rows, null, data);
2098            }
2099        }
2100        Encoder::List(rows) => match column.data_type() {
2101            DataType::List(_) => list::encode(data, offsets, rows, opts, as_list_array(column)),
2102            DataType::LargeList(_) => {
2103                list::encode(data, offsets, rows, opts, as_large_list_array(column))
2104            }
2105            DataType::ListView(_) => {
2106                let list_view = column.as_list_view::<i32>();
2107                let (min_offset, _) = compute_list_view_bounds(list_view);
2108                list::encode_list_view(data, offsets, rows, opts, list_view, min_offset)
2109            }
2110            DataType::LargeListView(_) => {
2111                let list_view = column.as_list_view::<i64>();
2112                let (min_offset, _) = compute_list_view_bounds(list_view);
2113                list::encode_list_view(data, offsets, rows, opts, list_view, min_offset)
2114            }
2115            DataType::FixedSizeList(_, _) => {
2116                encode_fixed_size_list(data, offsets, rows, opts, as_fixed_size_list_array(column))
2117            }
2118            _ => unreachable!(),
2119        },
2120        Encoder::Map(rows) => list::encode(data, offsets, rows, opts, as_map_array(column)),
2121        Encoder::RunEndEncoded(rows) => match column.data_type() {
2122            DataType::RunEndEncoded(r, _) => match r.data_type() {
2123                DataType::Int16 => {
2124                    run::encode(data, offsets, rows, opts, column.as_run::<Int16Type>())
2125                }
2126                DataType::Int32 => {
2127                    run::encode(data, offsets, rows, opts, column.as_run::<Int32Type>())
2128                }
2129                DataType::Int64 => {
2130                    run::encode(data, offsets, rows, opts, column.as_run::<Int64Type>())
2131                }
2132                _ => unreachable!("Unsupported run end index type: {r:?}"),
2133            },
2134            _ => unreachable!(),
2135        },
2136        Encoder::Union {
2137            child_rows,
2138            field_to_type_ids,
2139            type_ids,
2140            offsets: offsets_buf,
2141        } => {
2142            let mut type_id_to_field_idx = [0usize; 128];
2143            for (field_idx, &type_id) in field_to_type_ids.iter().enumerate() {
2144                type_id_to_field_idx[type_id as usize] = field_idx;
2145            }
2146
2147            offsets
2148                .iter_mut()
2149                .skip(1)
2150                .enumerate()
2151                .for_each(|(i, offset)| {
2152                    let type_id = type_ids[i];
2153                    let field_idx = type_id_to_field_idx[type_id as usize];
2154
2155                    let child_row_idx = offsets_buf.as_ref().map(|o| o[i] as usize).unwrap_or(i);
2156                    let child_row = child_rows[field_idx].row(child_row_idx);
2157                    let child_bytes = child_row.as_ref();
2158
2159                    let type_id_byte = if opts.descending {
2160                        !(type_id as u8)
2161                    } else {
2162                        type_id as u8
2163                    };
2164                    data[*offset] = type_id_byte;
2165
2166                    let child_start = *offset + 1;
2167                    let child_end = child_start + child_bytes.len();
2168                    data[child_start..child_end].copy_from_slice(child_bytes);
2169
2170                    *offset = child_end;
2171                });
2172        }
2173    }
2174}
2175
2176/// Encode dictionary values not preserving the dictionary encoding
2177pub fn encode_dictionary_values<K: ArrowDictionaryKeyType>(
2178    data: &mut [u8],
2179    offsets: &mut [usize],
2180    column: &DictionaryArray<K>,
2181    values: &Rows,
2182    null: &Row<'_>,
2183) {
2184    for (offset, k) in offsets.iter_mut().skip(1).zip(column.keys()) {
2185        let row = match k {
2186            Some(k) => values.row(k.as_usize()).data,
2187            None => null.data,
2188        };
2189        let end_offset = *offset + row.len();
2190        data[*offset..end_offset].copy_from_slice(row);
2191        *offset = end_offset;
2192    }
2193}
2194
2195macro_rules! decode_primitive_helper {
2196    ($t:ty, $rows:ident, $data_type:ident, $options:ident) => {
2197        Arc::new(decode_primitive::<$t>($rows, $data_type, $options))
2198    };
2199}
2200
2201/// Decodes a the provided `field` from `rows`
2202///
2203/// # Safety
2204///
2205/// Rows must contain valid data for the provided field
2206unsafe fn decode_column(
2207    field: &SortField,
2208    rows: &mut [&[u8]],
2209    codec: &Codec,
2210    validate_utf8: bool,
2211) -> Result<ArrayRef, ArrowError> {
2212    let options = field.options;
2213
2214    let array: ArrayRef = match codec {
2215        Codec::Stateless => {
2216            let data_type = field.data_type.clone();
2217            downcast_primitive! {
2218                data_type => (decode_primitive_helper, rows, data_type, options),
2219                DataType::Null => {
2220                    variable::decode_null_value(rows, options);
2221                    Arc::new(NullArray::new(rows.len()))
2222                }
2223                DataType::Boolean => Arc::new(decode_bool(rows, options)),
2224                DataType::Binary => Arc::new(decode_binary::<i32>(rows, options)),
2225                DataType::LargeBinary => Arc::new(decode_binary::<i64>(rows, options)),
2226                DataType::BinaryView => Arc::new(decode_binary_view(rows, options)),
2227                DataType::FixedSizeBinary(size) => Arc::new(decode_fixed_size_binary(rows, size, options)),
2228                DataType::Utf8 => Arc::new(unsafe{ decode_string::<i32>(rows, options, validate_utf8) }),
2229                DataType::LargeUtf8 => Arc::new(unsafe { decode_string::<i64>(rows, options, validate_utf8) }),
2230                DataType::Utf8View => Arc::new(unsafe { decode_string_view(rows, options, validate_utf8) }),
2231                _ => return Err(ArrowError::NotYetImplemented(format!("unsupported data type: {data_type}" )))
2232            }
2233        }
2234        Codec::Dictionary(converter, _) => {
2235            let cols = unsafe { converter.convert_raw(rows, validate_utf8) }?;
2236            cols.into_iter().next().unwrap()
2237        }
2238        Codec::Struct(converter, _) => {
2239            let nulls = fixed::decode_nulls(rows);
2240            rows.iter_mut().for_each(|row| *row = &row[1..]);
2241            let children = unsafe { converter.convert_raw(rows, validate_utf8) }?;
2242
2243            // Since RowConverter flattens certain data types (i.e. Dictionary),
2244            // we need to use updated data type instead of original field
2245            let corrected_fields: Vec<Field> = match &field.data_type {
2246                DataType::Struct(struct_fields) => struct_fields
2247                    .iter()
2248                    .zip(children.iter())
2249                    .map(|(orig_field, child_array)| {
2250                        orig_field
2251                            .as_ref()
2252                            .clone()
2253                            .with_data_type(child_array.data_type().clone())
2254                    })
2255                    .collect(),
2256                _ => unreachable!("Only Struct types should be corrected here"),
2257            };
2258
2259            Arc::new(unsafe {
2260                StructArray::new_unchecked_with_length(
2261                    corrected_fields.into(),
2262                    children,
2263                    nulls,
2264                    rows.len(),
2265                )
2266            })
2267        }
2268        Codec::List(converter) => match &field.data_type {
2269            DataType::List(_) => Arc::new(unsafe {
2270                list::decode::<GenericListArray<i32>>(converter, rows, field, validate_utf8)
2271            }?),
2272            DataType::LargeList(_) => Arc::new(unsafe {
2273                list::decode::<GenericListArray<i64>>(converter, rows, field, validate_utf8)
2274            }?),
2275            DataType::ListView(_) => Arc::new(unsafe {
2276                list::decode_list_view::<i32>(converter, rows, field, validate_utf8)
2277            }?),
2278            DataType::LargeListView(_) => Arc::new(unsafe {
2279                list::decode_list_view::<i64>(converter, rows, field, validate_utf8)
2280            }?),
2281            DataType::FixedSizeList(_, value_length) => Arc::new(unsafe {
2282                list::decode_fixed_size_list(
2283                    converter,
2284                    rows,
2285                    field,
2286                    validate_utf8,
2287                    value_length.as_usize(),
2288                )
2289            }?),
2290            _ => unreachable!(),
2291        },
2292        Codec::Map(converter) => {
2293            Arc::new(unsafe { list::decode::<MapArray>(converter, rows, field, validate_utf8) }?)
2294        }
2295        Codec::RunEndEncoded(converter) => match &field.data_type {
2296            DataType::RunEndEncoded(run_ends, _) => match run_ends.data_type() {
2297                DataType::Int16 => Arc::new(unsafe {
2298                    run::decode::<Int16Type>(converter, rows, field, validate_utf8)
2299                }?),
2300                DataType::Int32 => Arc::new(unsafe {
2301                    run::decode::<Int32Type>(converter, rows, field, validate_utf8)
2302                }?),
2303                DataType::Int64 => Arc::new(unsafe {
2304                    run::decode::<Int64Type>(converter, rows, field, validate_utf8)
2305                }?),
2306                _ => unreachable!(),
2307            },
2308            _ => unreachable!(),
2309        },
2310        Codec::Union(converters, field_to_type_ids, null_rows) => {
2311            let len = rows.len();
2312
2313            let DataType::Union(union_fields, mode) = &field.data_type else {
2314                unreachable!()
2315            };
2316
2317            let mut type_id_to_field_idx = [0usize; 128];
2318            for (field_idx, &type_id) in field_to_type_ids.iter().enumerate() {
2319                type_id_to_field_idx[type_id as usize] = field_idx;
2320            }
2321
2322            let mut type_ids = Vec::with_capacity(len);
2323            let mut rows_by_field: Vec<Vec<(usize, &[u8])>> = vec![Vec::new(); converters.len()];
2324
2325            for (idx, row) in rows.iter_mut().enumerate() {
2326                let type_id_byte = {
2327                    let id = row[0];
2328                    if options.descending { !id } else { id }
2329                };
2330
2331                let type_id = type_id_byte as i8;
2332                type_ids.push(type_id);
2333
2334                let field_idx = type_id_to_field_idx[type_id as usize];
2335
2336                let child_row = &row[1..];
2337                rows_by_field[field_idx].push((idx, child_row));
2338            }
2339
2340            let mut child_arrays: Vec<ArrayRef> = Vec::with_capacity(converters.len());
2341            let mut offsets = (*mode == UnionMode::Dense).then(|| Vec::with_capacity(len));
2342
2343            for (field_idx, converter) in converters.iter().enumerate() {
2344                let field_rows = &rows_by_field[field_idx];
2345
2346                match &mode {
2347                    UnionMode::Dense => {
2348                        if field_rows.is_empty() {
2349                            let (_, field) = union_fields.iter().nth(field_idx).unwrap();
2350                            child_arrays.push(arrow_array::new_empty_array(field.data_type()));
2351                            continue;
2352                        }
2353
2354                        let mut child_data = field_rows
2355                            .iter()
2356                            .map(|(_, bytes)| *bytes)
2357                            .collect::<Vec<_>>();
2358
2359                        let child_array =
2360                            unsafe { converter.convert_raw(&mut child_data, validate_utf8) }?;
2361
2362                        // advance row slices by the bytes consumed
2363                        for ((row_idx, original_bytes), remaining_bytes) in
2364                            field_rows.iter().zip(child_data)
2365                        {
2366                            let consumed_length = 1 + original_bytes.len() - remaining_bytes.len();
2367                            rows[*row_idx] = &rows[*row_idx][consumed_length..];
2368                        }
2369
2370                        child_arrays.push(child_array.into_iter().next().unwrap());
2371                    }
2372                    UnionMode::Sparse => {
2373                        let mut sparse_data: Vec<&[u8]> = Vec::with_capacity(len);
2374                        let mut field_row_iter = field_rows.iter().peekable();
2375                        let null_row_bytes: &[u8] = &null_rows[field_idx].data;
2376
2377                        for idx in 0..len {
2378                            if let Some((next_idx, bytes)) = field_row_iter.peek()
2379                                && *next_idx == idx
2380                            {
2381                                sparse_data.push(*bytes);
2382
2383                                field_row_iter.next();
2384                                continue;
2385                            }
2386                            sparse_data.push(null_row_bytes);
2387                        }
2388
2389                        let child_array =
2390                            unsafe { converter.convert_raw(&mut sparse_data, validate_utf8) }?;
2391
2392                        // advance row slices by the bytes consumed for rows that belong to this field
2393                        for (row_idx, child_row) in field_rows {
2394                            let remaining_len = sparse_data[*row_idx].len();
2395                            let consumed_length = 1 + child_row.len() - remaining_len;
2396                            rows[*row_idx] = &rows[*row_idx][consumed_length..];
2397                        }
2398
2399                        child_arrays.push(child_array.into_iter().next().unwrap());
2400                    }
2401                }
2402            }
2403
2404            // build offsets for dense unions
2405            if let Some(ref mut offsets_vec) = offsets {
2406                let mut count = vec![0i32; converters.len()];
2407                for type_id in &type_ids {
2408                    let field_idx = *type_id as usize;
2409                    offsets_vec.push(count[field_idx]);
2410
2411                    count[field_idx] += 1;
2412                }
2413            }
2414
2415            let type_ids_buffer = ScalarBuffer::from(type_ids);
2416            let offsets_buffer = offsets.map(ScalarBuffer::from);
2417
2418            let union_array = UnionArray::try_new(
2419                union_fields.clone(),
2420                type_ids_buffer,
2421                offsets_buffer,
2422                child_arrays,
2423            )?;
2424
2425            // note: union arrays don't support physical null buffers
2426            // nulls are represented logically though child arrays
2427            Arc::new(union_array)
2428        }
2429    };
2430    Ok(array)
2431}
2432
2433#[cfg(test)]
2434mod tests {
2435    use arrow_array::builder::*;
2436    use arrow_array::types::*;
2437    use arrow_buffer::{Buffer, OffsetBuffer};
2438    use arrow_buffer::{NullBuffer, i256};
2439    use arrow_cast::display::{ArrayFormatter, FormatOptions};
2440    use arrow_ord::sort::{LexicographicalComparator, SortColumn};
2441    use rand::distr::uniform::SampleUniform;
2442    use rand::distr::{Distribution, StandardUniform};
2443    use rand::prelude::StdRng;
2444    use rand::{RngExt, SeedableRng};
2445
2446    use super::*;
2447
2448    fn all_sort_options() -> [SortOptions; 4] {
2449        [
2450            SortOptions {
2451                descending: false,
2452                nulls_first: false,
2453            },
2454            SortOptions {
2455                descending: false,
2456                nulls_first: true,
2457            },
2458            SortOptions {
2459                descending: true,
2460                nulls_first: false,
2461            },
2462            SortOptions {
2463                descending: true,
2464                nulls_first: true,
2465            },
2466        ]
2467    }
2468
2469    #[test]
2470    fn test_fixed_width() {
2471        let cols = [
2472            Arc::new(Int16Array::from_iter([
2473                Some(1),
2474                Some(2),
2475                None,
2476                Some(-5),
2477                Some(2),
2478                Some(2),
2479                Some(0),
2480            ])) as ArrayRef,
2481            Arc::new(Float32Array::from_iter([
2482                Some(1.3),
2483                Some(2.5),
2484                None,
2485                Some(4.),
2486                Some(0.1),
2487                Some(-4.),
2488                Some(-0.),
2489            ])) as ArrayRef,
2490        ];
2491
2492        let converter = RowConverter::new(vec![
2493            SortField::new(DataType::Int16),
2494            SortField::new(DataType::Float32),
2495        ])
2496        .unwrap();
2497        let rows = converter.convert_columns(&cols).unwrap();
2498
2499        assert_eq!(rows.offsets, &[0, 8, 16, 24, 32, 40, 48, 56]);
2500        assert_eq!(
2501            rows.buffer,
2502            &[
2503                1, 128, 1, //
2504                1, 191, 166, 102, 102, //
2505                1, 128, 2, //
2506                1, 192, 32, 0, 0, //
2507                0, 0, 0, //
2508                0, 0, 0, 0, 0, //
2509                1, 127, 251, //
2510                1, 192, 128, 0, 0, //
2511                1, 128, 2, //
2512                1, 189, 204, 204, 205, //
2513                1, 128, 2, //
2514                1, 63, 127, 255, 255, //
2515                1, 128, 0, //
2516                1, 127, 255, 255, 255 //
2517            ]
2518        );
2519
2520        assert!(rows.row(3) < rows.row(6));
2521        assert!(rows.row(0) < rows.row(1));
2522        assert!(rows.row(3) < rows.row(0));
2523        assert!(rows.row(4) < rows.row(1));
2524        assert!(rows.row(5) < rows.row(4));
2525
2526        let back = converter.convert_rows(&rows).unwrap();
2527        for (expected, actual) in cols.iter().zip(&back) {
2528            assert_eq!(expected, actual);
2529        }
2530    }
2531
2532    fn test_roundtrip(sort_option: SortOptions, col: ArrayRef) {
2533        let converter = RowConverter::new(vec![SortField::new_with_options(
2534            col.data_type().clone(),
2535            sort_option,
2536        )])
2537        .unwrap();
2538        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2539        let back = converter.convert_rows(&rows).unwrap();
2540        assert_eq!(back.len(), 1);
2541        assert_eq!(&back[0], &col);
2542        back[0].to_data().validate_full().unwrap();
2543    }
2544
2545    #[test]
2546    fn test_zero_width_fixed_size_binary_roundtrip() {
2547        for sort_option in all_sort_options() {
2548            // With a zero byte width and no nulls, the decoded length cannot be
2549            // inferred from the value or null buffers and must come from the row count
2550            for with_null in [true, false] {
2551                let nulls = if with_null {
2552                    Some(NullBuffer::from(vec![true, false, true, false, true]))
2553                } else {
2554                    None
2555                };
2556                let col: ArrayRef = Arc::new(
2557                    FixedSizeBinaryArray::try_new_with_len(0, Buffer::default(), nulls, 5).unwrap(),
2558                );
2559
2560                test_roundtrip(sort_option, col);
2561            }
2562        }
2563    }
2564
2565    #[test]
2566    fn test_zero_width_fixed_size_list_roundtrip() {
2567        for sort_option in all_sort_options() {
2568            // With a zero byte width and no nulls, the decoded length cannot be
2569            // inferred from the value or null buffers and must come from the row count
2570            for with_null in [true, false] {
2571                let nulls = if with_null {
2572                    Some(NullBuffer::from(vec![true, false, true, false, true]))
2573                } else {
2574                    None
2575                };
2576                let col: ArrayRef = Arc::new(
2577                    FixedSizeListArray::try_new_with_length(
2578                        Arc::new(Field::new("item", DataType::Boolean, false)),
2579                        0,
2580                        new_empty_array(&DataType::Boolean),
2581                        nulls,
2582                        5,
2583                    )
2584                    .unwrap(),
2585                );
2586
2587                test_roundtrip(sort_option, col);
2588            }
2589        }
2590    }
2591
2592    #[test]
2593    fn test_decimal32() {
2594        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal32(
2595            DECIMAL32_MAX_PRECISION,
2596            7,
2597        ))])
2598        .unwrap();
2599        let col = Arc::new(
2600            Decimal32Array::from_iter([
2601                None,
2602                Some(i32::MIN),
2603                Some(-13),
2604                Some(46_i32),
2605                Some(5456_i32),
2606                Some(i32::MAX),
2607            ])
2608            .with_precision_and_scale(9, 7)
2609            .unwrap(),
2610        ) as ArrayRef;
2611
2612        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2613        for i in 0..rows.num_rows() - 1 {
2614            assert!(rows.row(i) < rows.row(i + 1));
2615        }
2616
2617        let back = converter.convert_rows(&rows).unwrap();
2618        assert_eq!(back.len(), 1);
2619        assert_eq!(col.as_ref(), back[0].as_ref())
2620    }
2621
2622    #[test]
2623    fn test_decimal64() {
2624        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal64(
2625            DECIMAL64_MAX_PRECISION,
2626            7,
2627        ))])
2628        .unwrap();
2629        let col = Arc::new(
2630            Decimal64Array::from_iter([
2631                None,
2632                Some(i64::MIN),
2633                Some(-13),
2634                Some(46_i64),
2635                Some(5456_i64),
2636                Some(i64::MAX),
2637            ])
2638            .with_precision_and_scale(18, 7)
2639            .unwrap(),
2640        ) as ArrayRef;
2641
2642        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2643        for i in 0..rows.num_rows() - 1 {
2644            assert!(rows.row(i) < rows.row(i + 1));
2645        }
2646
2647        let back = converter.convert_rows(&rows).unwrap();
2648        assert_eq!(back.len(), 1);
2649        assert_eq!(col.as_ref(), back[0].as_ref())
2650    }
2651
2652    #[test]
2653    fn test_decimal128() {
2654        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal128(
2655            DECIMAL128_MAX_PRECISION,
2656            7,
2657        ))])
2658        .unwrap();
2659        let col = Arc::new(
2660            Decimal128Array::from_iter([
2661                None,
2662                Some(i128::MIN),
2663                Some(-13),
2664                Some(46_i128),
2665                Some(5456_i128),
2666                Some(i128::MAX),
2667            ])
2668            .with_precision_and_scale(38, 7)
2669            .unwrap(),
2670        ) as ArrayRef;
2671
2672        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2673        for i in 0..rows.num_rows() - 1 {
2674            assert!(rows.row(i) < rows.row(i + 1));
2675        }
2676
2677        let back = converter.convert_rows(&rows).unwrap();
2678        assert_eq!(back.len(), 1);
2679        assert_eq!(col.as_ref(), back[0].as_ref())
2680    }
2681
2682    #[test]
2683    fn test_decimal256() {
2684        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal256(
2685            DECIMAL256_MAX_PRECISION,
2686            7,
2687        ))])
2688        .unwrap();
2689        let col = Arc::new(
2690            Decimal256Array::from_iter([
2691                None,
2692                Some(i256::MIN),
2693                Some(i256::from_parts(0, -1)),
2694                Some(i256::from_parts(u128::MAX, -1)),
2695                Some(i256::from_parts(u128::MAX, 0)),
2696                Some(i256::from_parts(0, 46_i128)),
2697                Some(i256::from_parts(5, 46_i128)),
2698                Some(i256::MAX),
2699            ])
2700            .with_precision_and_scale(DECIMAL256_MAX_PRECISION, 7)
2701            .unwrap(),
2702        ) as ArrayRef;
2703
2704        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2705        for i in 0..rows.num_rows() - 1 {
2706            assert!(rows.row(i) < rows.row(i + 1));
2707        }
2708
2709        let back = converter.convert_rows(&rows).unwrap();
2710        assert_eq!(back.len(), 1);
2711        assert_eq!(col.as_ref(), back[0].as_ref())
2712    }
2713
2714    #[test]
2715    fn test_bool() {
2716        let converter = RowConverter::new(vec![SortField::new(DataType::Boolean)]).unwrap();
2717
2718        let col = Arc::new(BooleanArray::from_iter([None, Some(false), Some(true)])) as ArrayRef;
2719
2720        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2721        assert!(rows.row(2) > rows.row(1));
2722        assert!(rows.row(2) > rows.row(0));
2723        assert!(rows.row(1) > rows.row(0));
2724
2725        let cols = converter.convert_rows(&rows).unwrap();
2726        assert_eq!(&cols[0], &col);
2727
2728        let converter = RowConverter::new(vec![SortField::new_with_options(
2729            DataType::Boolean,
2730            SortOptions::default().desc().with_nulls_first(false),
2731        )])
2732        .unwrap();
2733
2734        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2735        assert!(rows.row(2) < rows.row(1));
2736        assert!(rows.row(2) < rows.row(0));
2737        assert!(rows.row(1) < rows.row(0));
2738        let cols = converter.convert_rows(&rows).unwrap();
2739        assert_eq!(&cols[0], &col);
2740    }
2741
2742    #[test]
2743    fn test_timezone() {
2744        let a =
2745            TimestampNanosecondArray::from(vec![1, 2, 3, 4, 5]).with_timezone("+01:00".to_string());
2746        let d = a.data_type().clone();
2747
2748        let converter = RowConverter::new(vec![SortField::new(a.data_type().clone())]).unwrap();
2749        let rows = converter.convert_columns(&[Arc::new(a) as _]).unwrap();
2750        let back = converter.convert_rows(&rows).unwrap();
2751        assert_eq!(back.len(), 1);
2752        assert_eq!(back[0].data_type(), &d);
2753
2754        // Test dictionary
2755        let mut a = PrimitiveDictionaryBuilder::<Int32Type, TimestampNanosecondType>::new();
2756        a.append(34).unwrap();
2757        a.append_null();
2758        a.append(345).unwrap();
2759
2760        // Construct dictionary with a timezone
2761        let dict = a.finish();
2762        let values = TimestampNanosecondArray::from(dict.values().to_data());
2763        let dict_with_tz = dict.with_values(Arc::new(values.with_timezone("+02:00")));
2764        let v = DataType::Timestamp(TimeUnit::Nanosecond, Some("+02:00".into()));
2765        let d = DataType::Dictionary(Box::new(DataType::Int32), Box::new(v.clone()));
2766
2767        assert_eq!(dict_with_tz.data_type(), &d);
2768        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
2769        let rows = converter
2770            .convert_columns(&[Arc::new(dict_with_tz) as _])
2771            .unwrap();
2772        let back = converter.convert_rows(&rows).unwrap();
2773        assert_eq!(back.len(), 1);
2774        assert_eq!(back[0].data_type(), &v);
2775    }
2776
2777    #[test]
2778    fn test_null_encoding() {
2779        let col = Arc::new(NullArray::new(10));
2780        let converter = RowConverter::new(vec![SortField::new(DataType::Null)]).unwrap();
2781        let rows = converter.convert_columns(&[col]).unwrap();
2782        assert_eq!(rows.num_rows(), 10);
2783        // NULL element encoded as 2 bytes data
2784        assert_eq!(rows.row(1).data.len(), 2);
2785    }
2786
2787    #[test]
2788    fn test_variable_width() {
2789        let col = Arc::new(StringArray::from_iter([
2790            Some("hello"),
2791            Some("he"),
2792            None,
2793            Some("foo"),
2794            Some(""),
2795        ])) as ArrayRef;
2796
2797        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
2798        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2799
2800        assert!(rows.row(1) < rows.row(0));
2801        assert!(rows.row(2) < rows.row(4));
2802        assert!(rows.row(3) < rows.row(0));
2803        assert!(rows.row(3) < rows.row(1));
2804
2805        let cols = converter.convert_rows(&rows).unwrap();
2806        assert_eq!(&cols[0], &col);
2807
2808        let col = Arc::new(BinaryArray::from_iter([
2809            None,
2810            Some(vec![0_u8; 0]),
2811            Some(vec![0_u8; 6]),
2812            Some(vec![0_u8; variable::MINI_BLOCK_SIZE]),
2813            Some(vec![0_u8; variable::MINI_BLOCK_SIZE + 1]),
2814            Some(vec![0_u8; variable::BLOCK_SIZE]),
2815            Some(vec![0_u8; variable::BLOCK_SIZE + 1]),
2816            Some(vec![1_u8; 6]),
2817            Some(vec![1_u8; variable::MINI_BLOCK_SIZE]),
2818            Some(vec![1_u8; variable::MINI_BLOCK_SIZE + 1]),
2819            Some(vec![1_u8; variable::BLOCK_SIZE]),
2820            Some(vec![1_u8; variable::BLOCK_SIZE + 1]),
2821            Some(vec![0xFF_u8; 6]),
2822            Some(vec![0xFF_u8; variable::MINI_BLOCK_SIZE]),
2823            Some(vec![0xFF_u8; variable::MINI_BLOCK_SIZE + 1]),
2824            Some(vec![0xFF_u8; variable::BLOCK_SIZE]),
2825            Some(vec![0xFF_u8; variable::BLOCK_SIZE + 1]),
2826        ])) as ArrayRef;
2827
2828        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
2829        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2830
2831        for i in 0..rows.num_rows() {
2832            for j in i + 1..rows.num_rows() {
2833                assert!(
2834                    rows.row(i) < rows.row(j),
2835                    "{} < {} - {:?} < {:?}",
2836                    i,
2837                    j,
2838                    rows.row(i),
2839                    rows.row(j)
2840                );
2841            }
2842        }
2843
2844        let cols = converter.convert_rows(&rows).unwrap();
2845        assert_eq!(&cols[0], &col);
2846
2847        let converter = RowConverter::new(vec![SortField::new_with_options(
2848            DataType::Binary,
2849            SortOptions::default().desc().with_nulls_first(false),
2850        )])
2851        .unwrap();
2852        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2853
2854        for i in 0..rows.num_rows() {
2855            for j in i + 1..rows.num_rows() {
2856                assert!(
2857                    rows.row(i) > rows.row(j),
2858                    "{} > {} - {:?} > {:?}",
2859                    i,
2860                    j,
2861                    rows.row(i),
2862                    rows.row(j)
2863                );
2864            }
2865        }
2866
2867        let cols = converter.convert_rows(&rows).unwrap();
2868        assert_eq!(&cols[0], &col);
2869    }
2870
2871    /// If `exact` is false performs a logical comparison between a and dictionary-encoded b
2872    fn dictionary_eq(a: &dyn Array, b: &dyn Array) {
2873        match b.data_type() {
2874            DataType::Dictionary(_, v) => {
2875                assert_eq!(a.data_type(), v.as_ref());
2876                let b = arrow_cast::cast(b, v).unwrap();
2877                assert_eq!(a, b.as_ref())
2878            }
2879            _ => assert_eq!(a, b),
2880        }
2881    }
2882
2883    #[test]
2884    fn test_string_dictionary() {
2885        let a = Arc::new(DictionaryArray::<Int32Type>::from_iter([
2886            Some("foo"),
2887            Some("hello"),
2888            Some("he"),
2889            None,
2890            Some("hello"),
2891            Some(""),
2892            Some("hello"),
2893            Some("hello"),
2894        ])) as ArrayRef;
2895
2896        let field = SortField::new(a.data_type().clone());
2897        let converter = RowConverter::new(vec![field]).unwrap();
2898        let rows_a = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
2899
2900        assert!(rows_a.row(3) < rows_a.row(5));
2901        assert!(rows_a.row(2) < rows_a.row(1));
2902        assert!(rows_a.row(0) < rows_a.row(1));
2903        assert!(rows_a.row(3) < rows_a.row(0));
2904
2905        assert_eq!(rows_a.row(1), rows_a.row(4));
2906        assert_eq!(rows_a.row(1), rows_a.row(6));
2907        assert_eq!(rows_a.row(1), rows_a.row(7));
2908
2909        let cols = converter.convert_rows(&rows_a).unwrap();
2910        dictionary_eq(&cols[0], &a);
2911
2912        let b = Arc::new(DictionaryArray::<Int32Type>::from_iter([
2913            Some("hello"),
2914            None,
2915            Some("cupcakes"),
2916        ])) as ArrayRef;
2917
2918        let rows_b = converter.convert_columns(&[Arc::clone(&b)]).unwrap();
2919        assert_eq!(rows_a.row(1), rows_b.row(0));
2920        assert_eq!(rows_a.row(3), rows_b.row(1));
2921        assert!(rows_b.row(2) < rows_a.row(0));
2922
2923        let cols = converter.convert_rows(&rows_b).unwrap();
2924        dictionary_eq(&cols[0], &b);
2925
2926        let converter = RowConverter::new(vec![SortField::new_with_options(
2927            a.data_type().clone(),
2928            SortOptions::default().desc().with_nulls_first(false),
2929        )])
2930        .unwrap();
2931
2932        let rows_c = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
2933        assert!(rows_c.row(3) > rows_c.row(5));
2934        assert!(rows_c.row(2) > rows_c.row(1));
2935        assert!(rows_c.row(0) > rows_c.row(1));
2936        assert!(rows_c.row(3) > rows_c.row(0));
2937
2938        let cols = converter.convert_rows(&rows_c).unwrap();
2939        dictionary_eq(&cols[0], &a);
2940
2941        let converter = RowConverter::new(vec![SortField::new_with_options(
2942            a.data_type().clone(),
2943            SortOptions::default().desc().with_nulls_first(true),
2944        )])
2945        .unwrap();
2946
2947        let rows_c = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
2948        assert!(rows_c.row(3) < rows_c.row(5));
2949        assert!(rows_c.row(2) > rows_c.row(1));
2950        assert!(rows_c.row(0) > rows_c.row(1));
2951        assert!(rows_c.row(3) < rows_c.row(0));
2952
2953        let cols = converter.convert_rows(&rows_c).unwrap();
2954        dictionary_eq(&cols[0], &a);
2955    }
2956
2957    #[test]
2958    fn test_struct() {
2959        // Test basic
2960        let a = Arc::new(Int32Array::from(vec![1, 1, 2, 2])) as ArrayRef;
2961        let a_f = Arc::new(Field::new("int", DataType::Int32, false));
2962        let u = Arc::new(StringArray::from(vec!["a", "b", "c", "d"])) as ArrayRef;
2963        let u_f = Arc::new(Field::new("s", DataType::Utf8, false));
2964        let s1 = Arc::new(StructArray::from(vec![(a_f, a), (u_f, u)])) as ArrayRef;
2965
2966        let sort_fields = vec![SortField::new(s1.data_type().clone())];
2967        let converter = RowConverter::new(sort_fields).unwrap();
2968        let r1 = converter.convert_columns(&[Arc::clone(&s1)]).unwrap();
2969
2970        for (a, b) in r1.iter().zip(r1.iter().skip(1)) {
2971            assert!(a < b);
2972        }
2973
2974        let back = converter.convert_rows(&r1).unwrap();
2975        assert_eq!(back.len(), 1);
2976        assert_eq!(&back[0], &s1);
2977
2978        // Test struct nullability
2979        let data = s1
2980            .to_data()
2981            .into_builder()
2982            .null_bit_buffer(Some(Buffer::from_slice_ref([0b00001010])))
2983            .null_count(2)
2984            .build()
2985            .unwrap();
2986
2987        let s2 = Arc::new(StructArray::from(data)) as ArrayRef;
2988        let r2 = converter.convert_columns(&[Arc::clone(&s2)]).unwrap();
2989        assert_eq!(r2.row(0), r2.row(2)); // Nulls equal
2990        assert!(r2.row(0) < r2.row(1)); // Nulls first
2991        assert_ne!(r1.row(0), r2.row(0)); // Value does not equal null
2992        assert_eq!(r1.row(1), r2.row(1)); // Values equal
2993
2994        let back = converter.convert_rows(&r2).unwrap();
2995        assert_eq!(back.len(), 1);
2996        assert_eq!(&back[0], &s2);
2997
2998        back[0].to_data().validate_full().unwrap();
2999    }
3000
3001    #[test]
3002    fn test_dictionary_in_struct() {
3003        let builder = StringDictionaryBuilder::<Int32Type>::new();
3004        let mut struct_builder = StructBuilder::new(
3005            vec![Field::new_dictionary(
3006                "foo",
3007                DataType::Int32,
3008                DataType::Utf8,
3009                true,
3010            )],
3011            vec![Box::new(builder)],
3012        );
3013
3014        let dict_builder = struct_builder
3015            .field_builder::<StringDictionaryBuilder<Int32Type>>(0)
3016            .unwrap();
3017
3018        // Flattened: ["a", null, "a", "b"]
3019        dict_builder.append_value("a");
3020        dict_builder.append_null();
3021        dict_builder.append_value("a");
3022        dict_builder.append_value("b");
3023
3024        for _ in 0..4 {
3025            struct_builder.append(true);
3026        }
3027
3028        let s = Arc::new(struct_builder.finish()) as ArrayRef;
3029        let sort_fields = vec![SortField::new(s.data_type().clone())];
3030        let converter = RowConverter::new(sort_fields).unwrap();
3031        let r = converter.convert_columns(&[Arc::clone(&s)]).unwrap();
3032
3033        let back = converter.convert_rows(&r).unwrap();
3034        let [s2] = back.try_into().unwrap();
3035
3036        // RowConverter flattens Dictionary
3037        // s.ty = Struct("foo": Dictionary(Int32, Utf8)), s2.ty = Struct("foo": Utf8)
3038        assert_ne!(&s.data_type(), &s2.data_type());
3039        s2.to_data().validate_full().unwrap();
3040
3041        // Check if the logical data remains the same
3042        // Keys: [0, null, 0, 1]
3043        // Values: ["a", "b"]
3044        let s1_struct = s.as_struct();
3045        let s1_0 = s1_struct.column(0);
3046        let s1_idx_0 = s1_0.as_dictionary::<Int32Type>();
3047        let keys = s1_idx_0.keys();
3048        let values = s1_idx_0.values().as_string::<i32>();
3049        // Flattened: ["a", null, "a", "b"]
3050        let s2_struct = s2.as_struct();
3051        let s2_0 = s2_struct.column(0);
3052        let s2_idx_0 = s2_0.as_string::<i32>();
3053
3054        for i in 0..keys.len() {
3055            if keys.is_null(i) {
3056                assert!(s2_idx_0.is_null(i));
3057            } else {
3058                let dict_index = keys.value(i) as usize;
3059                assert_eq!(values.value(dict_index), s2_idx_0.value(i));
3060            }
3061        }
3062    }
3063
3064    #[test]
3065    fn test_dictionary_in_struct_empty() {
3066        let ty = DataType::Struct(
3067            vec![Field::new_dictionary(
3068                "foo",
3069                DataType::Int32,
3070                DataType::Int32,
3071                false,
3072            )]
3073            .into(),
3074        );
3075        let s = arrow_array::new_empty_array(&ty);
3076
3077        let sort_fields = vec![SortField::new(s.data_type().clone())];
3078        let converter = RowConverter::new(sort_fields).unwrap();
3079        let r = converter.convert_columns(&[Arc::clone(&s)]).unwrap();
3080
3081        let back = converter.convert_rows(&r).unwrap();
3082        let [s2] = back.try_into().unwrap();
3083
3084        // RowConverter flattens Dictionary
3085        // s.ty = Struct("foo": Dictionary(Int32, Int32)), s2.ty = Struct("foo": Int32)
3086        assert_ne!(&s.data_type(), &s2.data_type());
3087        s2.to_data().validate_full().unwrap();
3088        assert_eq!(s.len(), 0);
3089        assert_eq!(s2.len(), 0);
3090    }
3091
3092    #[test]
3093    fn test_list_of_string_dictionary() {
3094        let mut builder = ListBuilder::<StringDictionaryBuilder<Int32Type>>::default();
3095        // List[0] = ["a", "b", "zero", null, "c", "b", "d" (dict)]
3096        builder.values().append("a").unwrap();
3097        builder.values().append("b").unwrap();
3098        builder.values().append("zero").unwrap();
3099        builder.values().append_null();
3100        builder.values().append("c").unwrap();
3101        builder.values().append("b").unwrap();
3102        builder.values().append("d").unwrap();
3103        builder.append(true);
3104        // List[1] = null
3105        builder.append(false);
3106        // List[2] = ["e", "zero", "a" (dict)]
3107        builder.values().append("e").unwrap();
3108        builder.values().append("zero").unwrap();
3109        builder.values().append("a").unwrap();
3110        builder.append(true);
3111
3112        let a = Arc::new(builder.finish()) as ArrayRef;
3113        let data_type = a.data_type().clone();
3114
3115        let field = SortField::new(data_type.clone());
3116        let converter = RowConverter::new(vec![field]).unwrap();
3117        let rows = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
3118
3119        let back = converter.convert_rows(&rows).unwrap();
3120        assert_eq!(back.len(), 1);
3121        let [a2] = back.try_into().unwrap();
3122
3123        // RowConverter flattens Dictionary
3124        // a.ty: List(Dictionary(Int32, Utf8)), a2.ty: List(Utf8)
3125        assert_ne!(&a.data_type(), &a2.data_type());
3126
3127        a2.to_data().validate_full().unwrap();
3128
3129        let a2_list = a2.as_list::<i32>();
3130        let a1_list = a.as_list::<i32>();
3131
3132        // Check if the logical data remains the same
3133        // List[0] = ["a", "b", "zero", null, "c", "b", "d" (dict)]
3134        let a1_0 = a1_list.value(0);
3135        let a1_idx_0 = a1_0.as_dictionary::<Int32Type>();
3136        let keys = a1_idx_0.keys();
3137        let values = a1_idx_0.values().as_string::<i32>();
3138        let a2_0 = a2_list.value(0);
3139        let a2_idx_0 = a2_0.as_string::<i32>();
3140
3141        for i in 0..keys.len() {
3142            if keys.is_null(i) {
3143                assert!(a2_idx_0.is_null(i));
3144            } else {
3145                let dict_index = keys.value(i) as usize;
3146                assert_eq!(values.value(dict_index), a2_idx_0.value(i));
3147            }
3148        }
3149
3150        // List[1] = null
3151        assert!(a1_list.is_null(1));
3152        assert!(a2_list.is_null(1));
3153
3154        // List[2] = ["e", "zero", "a" (dict)]
3155        let a1_2 = a1_list.value(2);
3156        let a1_idx_2 = a1_2.as_dictionary::<Int32Type>();
3157        let keys = a1_idx_2.keys();
3158        let values = a1_idx_2.values().as_string::<i32>();
3159        let a2_2 = a2_list.value(2);
3160        let a2_idx_2 = a2_2.as_string::<i32>();
3161
3162        for i in 0..keys.len() {
3163            if keys.is_null(i) {
3164                assert!(a2_idx_2.is_null(i));
3165            } else {
3166                let dict_index = keys.value(i) as usize;
3167                assert_eq!(values.value(dict_index), a2_idx_2.value(i));
3168            }
3169        }
3170    }
3171
3172    #[test]
3173    fn test_primitive_dictionary() {
3174        let mut builder = PrimitiveDictionaryBuilder::<Int32Type, Int32Type>::new();
3175        builder.append(2).unwrap();
3176        builder.append(3).unwrap();
3177        builder.append(0).unwrap();
3178        builder.append_null();
3179        builder.append(5).unwrap();
3180        builder.append(3).unwrap();
3181        builder.append(-1).unwrap();
3182
3183        let a = builder.finish();
3184        let data_type = a.data_type().clone();
3185        let columns = [Arc::new(a) as ArrayRef];
3186
3187        let field = SortField::new(data_type.clone());
3188        let converter = RowConverter::new(vec![field]).unwrap();
3189        let rows = converter.convert_columns(&columns).unwrap();
3190        assert!(rows.row(0) < rows.row(1));
3191        assert!(rows.row(2) < rows.row(0));
3192        assert!(rows.row(3) < rows.row(2));
3193        assert!(rows.row(6) < rows.row(2));
3194        assert!(rows.row(3) < rows.row(6));
3195
3196        let back = converter.convert_rows(&rows).unwrap();
3197        assert_eq!(back.len(), 1);
3198        back[0].to_data().validate_full().unwrap();
3199    }
3200
3201    #[test]
3202    fn test_dictionary_nulls() {
3203        let values = Int32Array::from_iter([Some(1), Some(-1), None, Some(4), None]).into_data();
3204        let keys =
3205            Int32Array::from_iter([Some(0), Some(0), Some(1), Some(2), Some(4), None]).into_data();
3206
3207        let data_type = DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Int32));
3208        let data = keys
3209            .into_builder()
3210            .data_type(data_type.clone())
3211            .child_data(vec![values])
3212            .build()
3213            .unwrap();
3214
3215        let columns = [Arc::new(DictionaryArray::<Int32Type>::from(data)) as ArrayRef];
3216        let field = SortField::new(data_type.clone());
3217        let converter = RowConverter::new(vec![field]).unwrap();
3218        let rows = converter.convert_columns(&columns).unwrap();
3219
3220        assert_eq!(rows.row(0), rows.row(1));
3221        assert_eq!(rows.row(3), rows.row(4));
3222        assert_eq!(rows.row(4), rows.row(5));
3223        assert!(rows.row(3) < rows.row(0));
3224    }
3225
3226    #[test]
3227    fn test_from_binary_shared_buffer() {
3228        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
3229        let array = Arc::new(BinaryArray::from_iter_values([&[0xFF]])) as _;
3230        let rows = converter.convert_columns(&[array]).unwrap();
3231        let binary_rows = rows.try_into_binary().expect("known-small rows");
3232        let _binary_rows_shared_buffer = binary_rows.clone();
3233
3234        let parsed = converter.from_binary(binary_rows);
3235
3236        converter.convert_rows(parsed.iter()).unwrap();
3237    }
3238
3239    #[test]
3240    #[should_panic(expected = "Encountered non UTF-8 data")]
3241    fn test_invalid_utf8() {
3242        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
3243        let array = Arc::new(BinaryArray::from_iter_values([&[0xFF]])) as _;
3244        let rows = converter.convert_columns(&[array]).unwrap();
3245        let binary_row = rows.row(0);
3246
3247        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3248        let parser = converter.parser();
3249        let utf8_row = parser.parse(binary_row.as_ref());
3250
3251        converter.convert_rows(std::iter::once(utf8_row)).unwrap();
3252    }
3253
3254    #[test]
3255    #[should_panic(expected = "Encountered non UTF-8 data")]
3256    fn test_invalid_utf8_array() {
3257        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
3258        let array = Arc::new(BinaryArray::from_iter_values([&[0xFF]])) as _;
3259        let rows = converter.convert_columns(&[array]).unwrap();
3260        let binary_rows = rows.try_into_binary().expect("known-small rows");
3261
3262        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3263        let parsed = converter.from_binary(binary_rows);
3264
3265        converter.convert_rows(parsed.iter()).unwrap();
3266    }
3267
3268    #[test]
3269    #[should_panic(expected = "index out of bounds")]
3270    fn test_invalid_empty() {
3271        let binary_row: &[u8] = &[];
3272
3273        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3274        let parser = converter.parser();
3275        let utf8_row = parser.parse(binary_row.as_ref());
3276
3277        converter.convert_rows(std::iter::once(utf8_row)).unwrap();
3278    }
3279
3280    #[test]
3281    #[should_panic(expected = "index out of bounds")]
3282    fn test_invalid_empty_array() {
3283        let row: &[u8] = &[];
3284        let binary_rows = BinaryArray::from(vec![row]);
3285
3286        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3287        let parsed = converter.from_binary(binary_rows);
3288
3289        converter.convert_rows(parsed.iter()).unwrap();
3290    }
3291
3292    #[test]
3293    #[should_panic(expected = "index out of bounds")]
3294    fn test_invalid_truncated() {
3295        let binary_row: &[u8] = &[0x02];
3296
3297        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3298        let parser = converter.parser();
3299        let utf8_row = parser.parse(binary_row.as_ref());
3300
3301        converter.convert_rows(std::iter::once(utf8_row)).unwrap();
3302    }
3303
3304    #[test]
3305    #[should_panic(expected = "index out of bounds")]
3306    fn test_invalid_truncated_array() {
3307        let row: &[u8] = &[0x02];
3308        let binary_rows = BinaryArray::from(vec![row]);
3309
3310        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3311        let parsed = converter.from_binary(binary_rows);
3312
3313        converter.convert_rows(parsed.iter()).unwrap();
3314    }
3315
3316    #[test]
3317    #[should_panic(expected = "rows were not produced by this RowConverter")]
3318    fn test_different_converter() {
3319        let values = Arc::new(Int32Array::from_iter([Some(1), Some(-1)]));
3320        let converter = RowConverter::new(vec![SortField::new(DataType::Int32)]).unwrap();
3321        let rows = converter.convert_columns(&[values]).unwrap();
3322
3323        let converter = RowConverter::new(vec![SortField::new(DataType::Int32)]).unwrap();
3324        let _ = converter.convert_rows(&rows);
3325    }
3326
3327    fn test_single_list<O: OffsetSizeTrait>() {
3328        let mut builder = GenericListBuilder::<O, _>::new(Int32Builder::new());
3329        builder.values().append_value(32);
3330        builder.values().append_value(52);
3331        builder.values().append_value(32);
3332        builder.append(true);
3333        builder.values().append_value(32);
3334        builder.values().append_value(52);
3335        builder.values().append_value(12);
3336        builder.append(true);
3337        builder.values().append_value(32);
3338        builder.values().append_value(52);
3339        builder.append(true);
3340        builder.values().append_value(32); // MASKED
3341        builder.values().append_value(52); // MASKED
3342        builder.append(false);
3343        builder.values().append_value(32);
3344        builder.values().append_null();
3345        builder.append(true);
3346        builder.append(true);
3347        builder.values().append_value(17); // MASKED
3348        builder.values().append_null(); // MASKED
3349        builder.append(false);
3350
3351        let list = Arc::new(builder.finish()) as ArrayRef;
3352        let d = list.data_type().clone();
3353
3354        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3355
3356        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3357        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3358        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3359        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3360        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3361        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3362        assert!(rows.row(3) < rows.row(5)); // null < []
3363        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3364
3365        let back = converter.convert_rows(&rows).unwrap();
3366        assert_eq!(back.len(), 1);
3367        back[0].to_data().validate_full().unwrap();
3368        assert_eq!(&back[0], &list);
3369
3370        let options = SortOptions::default().asc().with_nulls_first(false);
3371        let field = SortField::new_with_options(d.clone(), options);
3372        let converter = RowConverter::new(vec![field]).unwrap();
3373        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3374
3375        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3376        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3377        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3378        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3379        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3380        assert!(rows.row(3) > rows.row(5)); // null > []
3381        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3382
3383        let back = converter.convert_rows(&rows).unwrap();
3384        assert_eq!(back.len(), 1);
3385        back[0].to_data().validate_full().unwrap();
3386        assert_eq!(&back[0], &list);
3387
3388        let options = SortOptions::default().desc().with_nulls_first(false);
3389        let field = SortField::new_with_options(d.clone(), options);
3390        let converter = RowConverter::new(vec![field]).unwrap();
3391        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3392
3393        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3394        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3395        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3396        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3397        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3398        assert!(rows.row(3) > rows.row(5)); // null > []
3399        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3400
3401        let back = converter.convert_rows(&rows).unwrap();
3402        assert_eq!(back.len(), 1);
3403        back[0].to_data().validate_full().unwrap();
3404        assert_eq!(&back[0], &list);
3405
3406        let options = SortOptions::default().desc().with_nulls_first(true);
3407        let field = SortField::new_with_options(d, options);
3408        let converter = RowConverter::new(vec![field]).unwrap();
3409        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3410
3411        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3412        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3413        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3414        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3415        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3416        assert!(rows.row(3) < rows.row(5)); // null < []
3417        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3418
3419        let back = converter.convert_rows(&rows).unwrap();
3420        assert_eq!(back.len(), 1);
3421        back[0].to_data().validate_full().unwrap();
3422        assert_eq!(&back[0], &list);
3423
3424        let sliced_list = list.slice(1, 5);
3425        let rows_on_sliced_list = converter
3426            .convert_columns(&[Arc::clone(&sliced_list)])
3427            .unwrap();
3428
3429        assert!(rows_on_sliced_list.row(1) > rows_on_sliced_list.row(0)); // [32, 52] > [32, 52, 12]
3430        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(1)); // null < [32, 52]
3431        assert!(rows_on_sliced_list.row(3) < rows_on_sliced_list.row(1)); // [32, null] < [32, 52]
3432        assert!(rows_on_sliced_list.row(4) > rows_on_sliced_list.row(1)); // [] > [32, 52]
3433        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(4)); // null < []
3434
3435        let back = converter.convert_rows(&rows_on_sliced_list).unwrap();
3436        assert_eq!(back.len(), 1);
3437        back[0].to_data().validate_full().unwrap();
3438        assert_eq!(&back[0], &sliced_list);
3439    }
3440
3441    fn test_nested_list<O: OffsetSizeTrait>() {
3442        let mut builder =
3443            GenericListBuilder::<O, _>::new(GenericListBuilder::<O, _>::new(Int32Builder::new()));
3444
3445        builder.values().values().append_value(1);
3446        builder.values().values().append_value(2);
3447        builder.values().append(true);
3448        builder.values().values().append_value(1);
3449        builder.values().values().append_null();
3450        builder.values().append(true);
3451        builder.append(true);
3452
3453        builder.values().values().append_value(1);
3454        builder.values().values().append_null();
3455        builder.values().append(true);
3456        builder.values().values().append_value(1);
3457        builder.values().values().append_null();
3458        builder.values().append(true);
3459        builder.append(true);
3460
3461        builder.values().values().append_value(1);
3462        builder.values().values().append_null();
3463        builder.values().append(true);
3464        builder.values().append(false);
3465        builder.append(true);
3466        builder.append(false);
3467
3468        builder.values().values().append_value(1);
3469        builder.values().values().append_value(2);
3470        builder.values().append(true);
3471        builder.append(true);
3472
3473        let list = Arc::new(builder.finish()) as ArrayRef;
3474        let d = list.data_type().clone();
3475
3476        // [
3477        //   [[1, 2], [1, null]],
3478        //   [[1, null], [1, null]],
3479        //   [[1, null], null]
3480        //   null
3481        //   [[1, 2]]
3482        // ]
3483        let options = SortOptions::default().asc().with_nulls_first(true);
3484        let field = SortField::new_with_options(d.clone(), options);
3485        let converter = RowConverter::new(vec![field]).unwrap();
3486        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3487
3488        assert!(rows.row(0) > rows.row(1));
3489        assert!(rows.row(1) > rows.row(2));
3490        assert!(rows.row(2) > rows.row(3));
3491        assert!(rows.row(4) < rows.row(0));
3492        assert!(rows.row(4) > rows.row(1));
3493
3494        let back = converter.convert_rows(&rows).unwrap();
3495        assert_eq!(back.len(), 1);
3496        back[0].to_data().validate_full().unwrap();
3497        assert_eq!(&back[0], &list);
3498
3499        let options = SortOptions::default().desc().with_nulls_first(true);
3500        let field = SortField::new_with_options(d.clone(), options);
3501        let converter = RowConverter::new(vec![field]).unwrap();
3502        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3503
3504        assert!(rows.row(0) > rows.row(1));
3505        assert!(rows.row(1) > rows.row(2));
3506        assert!(rows.row(2) > rows.row(3));
3507        assert!(rows.row(4) > rows.row(0));
3508        assert!(rows.row(4) > rows.row(1));
3509
3510        let back = converter.convert_rows(&rows).unwrap();
3511        assert_eq!(back.len(), 1);
3512        back[0].to_data().validate_full().unwrap();
3513        assert_eq!(&back[0], &list);
3514
3515        let options = SortOptions::default().desc().with_nulls_first(false);
3516        let field = SortField::new_with_options(d, options);
3517        let converter = RowConverter::new(vec![field]).unwrap();
3518        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3519
3520        assert!(rows.row(0) < rows.row(1));
3521        assert!(rows.row(1) < rows.row(2));
3522        assert!(rows.row(2) < rows.row(3));
3523        assert!(rows.row(4) > rows.row(0));
3524        assert!(rows.row(4) < rows.row(1));
3525
3526        let back = converter.convert_rows(&rows).unwrap();
3527        assert_eq!(back.len(), 1);
3528        back[0].to_data().validate_full().unwrap();
3529        assert_eq!(&back[0], &list);
3530
3531        let sliced_list = list.slice(1, 3);
3532        let rows = converter
3533            .convert_columns(&[Arc::clone(&sliced_list)])
3534            .unwrap();
3535
3536        assert!(rows.row(0) < rows.row(1));
3537        assert!(rows.row(1) < rows.row(2));
3538
3539        let back = converter.convert_rows(&rows).unwrap();
3540        assert_eq!(back.len(), 1);
3541        back[0].to_data().validate_full().unwrap();
3542        assert_eq!(&back[0], &sliced_list);
3543    }
3544
3545    #[test]
3546    fn test_list() {
3547        test_single_list::<i32>();
3548        test_nested_list::<i32>();
3549    }
3550
3551    #[test]
3552    fn test_large_list() {
3553        test_single_list::<i64>();
3554        test_nested_list::<i64>();
3555    }
3556
3557    fn test_single_list_view<O: OffsetSizeTrait>() {
3558        let mut builder = GenericListViewBuilder::<O, _>::new(Int32Builder::new());
3559        builder.values().append_value(32);
3560        builder.values().append_value(52);
3561        builder.values().append_value(32);
3562        builder.append(true);
3563        builder.values().append_value(32);
3564        builder.values().append_value(52);
3565        builder.values().append_value(12);
3566        builder.append(true);
3567        builder.values().append_value(32);
3568        builder.values().append_value(52);
3569        builder.append(true);
3570        builder.values().append_value(32); // MASKED
3571        builder.values().append_value(52); // MASKED
3572        builder.append(false);
3573        builder.values().append_value(32);
3574        builder.values().append_null();
3575        builder.append(true);
3576        builder.append(true);
3577        builder.values().append_value(17); // MASKED
3578        builder.values().append_null(); // MASKED
3579        builder.append(false);
3580
3581        let list = Arc::new(builder.finish()) as ArrayRef;
3582        let d = list.data_type().clone();
3583
3584        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3585
3586        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3587        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3588        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3589        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3590        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3591        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3592        assert!(rows.row(3) < rows.row(5)); // null < []
3593        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3594
3595        let back = converter.convert_rows(&rows).unwrap();
3596        assert_eq!(back.len(), 1);
3597        back[0].to_data().validate_full().unwrap();
3598
3599        // Verify the content matches (ListView may have different physical layout but same logical content)
3600        let back_list_view = back[0]
3601            .as_any()
3602            .downcast_ref::<GenericListViewArray<O>>()
3603            .unwrap();
3604        let orig_list_view = list
3605            .as_any()
3606            .downcast_ref::<GenericListViewArray<O>>()
3607            .unwrap();
3608
3609        assert_eq!(back_list_view.len(), orig_list_view.len());
3610        for i in 0..back_list_view.len() {
3611            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3612            if back_list_view.is_valid(i) {
3613                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3614            }
3615        }
3616
3617        let options = SortOptions::default().asc().with_nulls_first(false);
3618        let field = SortField::new_with_options(d.clone(), options);
3619        let converter = RowConverter::new(vec![field]).unwrap();
3620        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3621
3622        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3623        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3624        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3625        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3626        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3627        assert!(rows.row(3) > rows.row(5)); // null > []
3628        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3629
3630        let back = converter.convert_rows(&rows).unwrap();
3631        assert_eq!(back.len(), 1);
3632        back[0].to_data().validate_full().unwrap();
3633
3634        let options = SortOptions::default().desc().with_nulls_first(false);
3635        let field = SortField::new_with_options(d.clone(), options);
3636        let converter = RowConverter::new(vec![field]).unwrap();
3637        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3638
3639        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3640        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3641        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3642        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3643        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3644        assert!(rows.row(3) > rows.row(5)); // null > []
3645        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3646
3647        let back = converter.convert_rows(&rows).unwrap();
3648        assert_eq!(back.len(), 1);
3649        back[0].to_data().validate_full().unwrap();
3650
3651        let options = SortOptions::default().desc().with_nulls_first(true);
3652        let field = SortField::new_with_options(d, options);
3653        let converter = RowConverter::new(vec![field]).unwrap();
3654        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3655
3656        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3657        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3658        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3659        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3660        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3661        assert!(rows.row(3) < rows.row(5)); // null < []
3662        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3663
3664        let back = converter.convert_rows(&rows).unwrap();
3665        assert_eq!(back.len(), 1);
3666        back[0].to_data().validate_full().unwrap();
3667
3668        let sliced_list = list.slice(1, 5);
3669        let rows_on_sliced_list = converter
3670            .convert_columns(&[Arc::clone(&sliced_list)])
3671            .unwrap();
3672
3673        assert!(rows_on_sliced_list.row(1) > rows_on_sliced_list.row(0)); // [32, 52] > [32, 52, 12]
3674        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(1)); // null < [32, 52]
3675        assert!(rows_on_sliced_list.row(3) < rows_on_sliced_list.row(1)); // [32, null] < [32, 52]
3676        assert!(rows_on_sliced_list.row(4) > rows_on_sliced_list.row(1)); // [] > [32, 52]
3677        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(4)); // null < []
3678
3679        let back = converter.convert_rows(&rows_on_sliced_list).unwrap();
3680        assert_eq!(back.len(), 1);
3681        back[0].to_data().validate_full().unwrap();
3682    }
3683
3684    fn test_nested_list_view<O: OffsetSizeTrait>() {
3685        let mut builder = GenericListViewBuilder::<O, _>::new(GenericListViewBuilder::<O, _>::new(
3686            Int32Builder::new(),
3687        ));
3688
3689        // Row 0: [[1, 2], [1, null]]
3690        builder.values().values().append_value(1);
3691        builder.values().values().append_value(2);
3692        builder.values().append(true);
3693        builder.values().values().append_value(1);
3694        builder.values().values().append_null();
3695        builder.values().append(true);
3696        builder.append(true);
3697
3698        // Row 1: [[1, null], [1, null]]
3699        builder.values().values().append_value(1);
3700        builder.values().values().append_null();
3701        builder.values().append(true);
3702        builder.values().values().append_value(1);
3703        builder.values().values().append_null();
3704        builder.values().append(true);
3705        builder.append(true);
3706
3707        // Row 2: [[1, null], null]
3708        builder.values().values().append_value(1);
3709        builder.values().values().append_null();
3710        builder.values().append(true);
3711        builder.values().append(false);
3712        builder.append(true);
3713
3714        // Row 3: null
3715        builder.append(false);
3716
3717        // Row 4: [[1, 2]]
3718        builder.values().values().append_value(1);
3719        builder.values().values().append_value(2);
3720        builder.values().append(true);
3721        builder.append(true);
3722
3723        let list = Arc::new(builder.finish()) as ArrayRef;
3724        let d = list.data_type().clone();
3725
3726        // [
3727        //   [[1, 2], [1, null]],
3728        //   [[1, null], [1, null]],
3729        //   [[1, null], null]
3730        //   null
3731        //   [[1, 2]]
3732        // ]
3733        let options = SortOptions::default().asc().with_nulls_first(true);
3734        let field = SortField::new_with_options(d.clone(), options);
3735        let converter = RowConverter::new(vec![field]).unwrap();
3736        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3737
3738        assert!(rows.row(0) > rows.row(1));
3739        assert!(rows.row(1) > rows.row(2));
3740        assert!(rows.row(2) > rows.row(3));
3741        assert!(rows.row(4) < rows.row(0));
3742        assert!(rows.row(4) > rows.row(1));
3743
3744        let back = converter.convert_rows(&rows).unwrap();
3745        assert_eq!(back.len(), 1);
3746        back[0].to_data().validate_full().unwrap();
3747
3748        // Verify the content matches (ListView may have different physical layout but same logical content)
3749        let back_list_view = back[0]
3750            .as_any()
3751            .downcast_ref::<GenericListViewArray<O>>()
3752            .unwrap();
3753        let orig_list_view = list
3754            .as_any()
3755            .downcast_ref::<GenericListViewArray<O>>()
3756            .unwrap();
3757
3758        assert_eq!(back_list_view.len(), orig_list_view.len());
3759        for i in 0..back_list_view.len() {
3760            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3761            if back_list_view.is_valid(i) {
3762                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3763            }
3764        }
3765
3766        let options = SortOptions::default().desc().with_nulls_first(true);
3767        let field = SortField::new_with_options(d.clone(), options);
3768        let converter = RowConverter::new(vec![field]).unwrap();
3769        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3770
3771        assert!(rows.row(0) > rows.row(1));
3772        assert!(rows.row(1) > rows.row(2));
3773        assert!(rows.row(2) > rows.row(3));
3774        assert!(rows.row(4) > rows.row(0));
3775        assert!(rows.row(4) > rows.row(1));
3776
3777        let back = converter.convert_rows(&rows).unwrap();
3778        assert_eq!(back.len(), 1);
3779        back[0].to_data().validate_full().unwrap();
3780
3781        // Verify the content matches
3782        let back_list_view = back[0]
3783            .as_any()
3784            .downcast_ref::<GenericListViewArray<O>>()
3785            .unwrap();
3786
3787        assert_eq!(back_list_view.len(), orig_list_view.len());
3788        for i in 0..back_list_view.len() {
3789            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3790            if back_list_view.is_valid(i) {
3791                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3792            }
3793        }
3794
3795        let options = SortOptions::default().desc().with_nulls_first(false);
3796        let field = SortField::new_with_options(d.clone(), options);
3797        let converter = RowConverter::new(vec![field]).unwrap();
3798        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3799
3800        assert!(rows.row(0) < rows.row(1));
3801        assert!(rows.row(1) < rows.row(2));
3802        assert!(rows.row(2) < rows.row(3));
3803        assert!(rows.row(4) > rows.row(0));
3804        assert!(rows.row(4) < rows.row(1));
3805
3806        let back = converter.convert_rows(&rows).unwrap();
3807        assert_eq!(back.len(), 1);
3808        back[0].to_data().validate_full().unwrap();
3809
3810        // Verify the content matches
3811        let back_list_view = back[0]
3812            .as_any()
3813            .downcast_ref::<GenericListViewArray<O>>()
3814            .unwrap();
3815
3816        assert_eq!(back_list_view.len(), orig_list_view.len());
3817        for i in 0..back_list_view.len() {
3818            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3819            if back_list_view.is_valid(i) {
3820                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3821            }
3822        }
3823
3824        let sliced_list = list.slice(1, 3);
3825        let rows = converter
3826            .convert_columns(&[Arc::clone(&sliced_list)])
3827            .unwrap();
3828
3829        assert!(rows.row(0) < rows.row(1));
3830        assert!(rows.row(1) < rows.row(2));
3831
3832        let back = converter.convert_rows(&rows).unwrap();
3833        assert_eq!(back.len(), 1);
3834        back[0].to_data().validate_full().unwrap();
3835    }
3836
3837    #[test]
3838    fn test_list_view() {
3839        test_single_list_view::<i32>();
3840        test_nested_list_view::<i32>();
3841    }
3842
3843    #[test]
3844    fn test_large_list_view() {
3845        test_single_list_view::<i64>();
3846        test_nested_list_view::<i64>();
3847    }
3848
3849    fn test_list_view_with_shared_values<O: OffsetSizeTrait>() {
3850        // Create a values array: [1, 2, 3, 4, 5, 6, 7, 8]
3851        let values = Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8]);
3852        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
3853
3854        // Create a ListView where:
3855        // - Row 0: offset=0, size=3 -> [1, 2, 3]
3856        // - Row 1: offset=0, size=3 -> [1, 2, 3] (same offset+size as row 0)
3857        // - Row 2: offset=5, size=2 -> [6, 7] (non-monotonic offset)
3858        // - Row 3: offset=2, size=2 -> [3, 4] (offset goes back)
3859        // - Row 4: offset=1, size=4 -> [2, 3, 4, 5] (subset of values that contains row 3's range)
3860        // - Row 5: offset=2, size=1 -> [3] (subset of row 3 and row 4)
3861        let offsets = ScalarBuffer::<O>::from(vec![
3862            O::from_usize(0).unwrap(),
3863            O::from_usize(0).unwrap(),
3864            O::from_usize(5).unwrap(),
3865            O::from_usize(2).unwrap(),
3866            O::from_usize(1).unwrap(),
3867            O::from_usize(2).unwrap(),
3868        ]);
3869        let sizes = ScalarBuffer::<O>::from(vec![
3870            O::from_usize(3).unwrap(),
3871            O::from_usize(3).unwrap(),
3872            O::from_usize(2).unwrap(),
3873            O::from_usize(2).unwrap(),
3874            O::from_usize(4).unwrap(),
3875            O::from_usize(1).unwrap(),
3876        ]);
3877
3878        let list_view: GenericListViewArray<O> =
3879            GenericListViewArray::try_new(field, offsets, sizes, Arc::new(values), None).unwrap();
3880
3881        let d = list_view.data_type().clone();
3882        let list = Arc::new(list_view) as ArrayRef;
3883
3884        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3885        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3886
3887        // Row 0 and Row 1 have the same content [1, 2, 3], so they should be equal
3888        assert_eq!(rows.row(0), rows.row(1));
3889
3890        // [1, 2, 3] < [6, 7] (comparing first elements: 1 < 6)
3891        assert!(rows.row(0) < rows.row(2));
3892
3893        // [3, 4] > [1, 2, 3] (comparing first elements: 3 > 1)
3894        assert!(rows.row(3) > rows.row(0));
3895
3896        // [2, 3, 4, 5] > [1, 2, 3] (comparing first elements: 2 > 1)
3897        assert!(rows.row(4) > rows.row(0));
3898
3899        // [3] < [3, 4] (same prefix but shorter)
3900        assert!(rows.row(5) < rows.row(3));
3901
3902        // [3] < [2, 3, 4, 5] (comparing first elements: 3 > 2)
3903        assert!(rows.row(5) > rows.row(4));
3904
3905        // Round-trip conversion
3906        let back = converter.convert_rows(&rows).unwrap();
3907        assert_eq!(back.len(), 1);
3908        back[0].to_data().validate_full().unwrap();
3909
3910        // Verify logical content matches
3911        let back_list_view = back[0]
3912            .as_any()
3913            .downcast_ref::<GenericListViewArray<O>>()
3914            .unwrap();
3915        let orig_list_view = list
3916            .as_any()
3917            .downcast_ref::<GenericListViewArray<O>>()
3918            .unwrap();
3919
3920        assert_eq!(back_list_view.len(), orig_list_view.len());
3921        for i in 0..back_list_view.len() {
3922            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3923            if back_list_view.is_valid(i) {
3924                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3925            }
3926        }
3927
3928        // Test with descending order
3929        let options = SortOptions::default().desc();
3930        let field = SortField::new_with_options(d, options);
3931        let converter = RowConverter::new(vec![field]).unwrap();
3932        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3933
3934        // In descending order, comparisons are reversed
3935        assert_eq!(rows.row(0), rows.row(1)); // Equal rows stay equal
3936        assert!(rows.row(0) > rows.row(2)); // [1, 2, 3] > [6, 7] in desc
3937        assert!(rows.row(3) < rows.row(0)); // [3, 4] < [1, 2, 3] in desc
3938
3939        let back = converter.convert_rows(&rows).unwrap();
3940        assert_eq!(back.len(), 1);
3941        back[0].to_data().validate_full().unwrap();
3942    }
3943
3944    #[test]
3945    fn test_list_view_shared_values() {
3946        test_list_view_with_shared_values::<i32>();
3947    }
3948
3949    #[test]
3950    fn test_large_list_view_shared_values() {
3951        test_list_view_with_shared_values::<i64>();
3952    }
3953
3954    #[test]
3955    fn test_fixed_size_list() {
3956        let mut builder = FixedSizeListBuilder::new(Int32Builder::new(), 3);
3957        builder.values().append_value(32);
3958        builder.values().append_value(52);
3959        builder.values().append_value(32);
3960        builder.append(true);
3961        builder.values().append_value(32);
3962        builder.values().append_value(52);
3963        builder.values().append_value(12);
3964        builder.append(true);
3965        builder.values().append_value(32);
3966        builder.values().append_value(52);
3967        builder.values().append_null();
3968        builder.append(true);
3969        builder.values().append_value(32); // MASKED
3970        builder.values().append_value(52); // MASKED
3971        builder.values().append_value(13); // MASKED
3972        builder.append(false);
3973        builder.values().append_value(32);
3974        builder.values().append_null();
3975        builder.values().append_null();
3976        builder.append(true);
3977        builder.values().append_null();
3978        builder.values().append_null();
3979        builder.values().append_null();
3980        builder.append(true);
3981        builder.values().append_value(17); // MASKED
3982        builder.values().append_null(); // MASKED
3983        builder.values().append_value(77); // MASKED
3984        builder.append(false);
3985
3986        let list = Arc::new(builder.finish()) as ArrayRef;
3987        let d = list.data_type().clone();
3988
3989        // Default sorting (ascending, nulls first)
3990        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3991
3992        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3993        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3994        assert!(rows.row(2) < rows.row(1)); // [32, 52, null] < [32, 52, 12]
3995        assert!(rows.row(3) < rows.row(2)); // null < [32, 52, null]
3996        assert!(rows.row(4) < rows.row(2)); // [32, null, null] < [32, 52, null]
3997        assert!(rows.row(5) < rows.row(2)); // [null, null, null] < [32, 52, null]
3998        assert!(rows.row(3) < rows.row(5)); // null < [null, null, null]
3999        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
4000
4001        let back = converter.convert_rows(&rows).unwrap();
4002        assert_eq!(back.len(), 1);
4003        back[0].to_data().validate_full().unwrap();
4004        assert_eq!(&back[0], &list);
4005
4006        // Ascending, null last
4007        let options = SortOptions::default().asc().with_nulls_first(false);
4008        let field = SortField::new_with_options(d.clone(), options);
4009        let converter = RowConverter::new(vec![field]).unwrap();
4010        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
4011        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
4012        assert!(rows.row(2) > rows.row(1)); // [32, 52, null] > [32, 52, 12]
4013        assert!(rows.row(3) > rows.row(2)); // null > [32, 52, null]
4014        assert!(rows.row(4) > rows.row(2)); // [32, null, null] > [32, 52, null]
4015        assert!(rows.row(5) > rows.row(2)); // [null, null, null] > [32, 52, null]
4016        assert!(rows.row(3) > rows.row(5)); // null > [null, null, null]
4017        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
4018
4019        let back = converter.convert_rows(&rows).unwrap();
4020        assert_eq!(back.len(), 1);
4021        back[0].to_data().validate_full().unwrap();
4022        assert_eq!(&back[0], &list);
4023
4024        // Descending, nulls last
4025        let options = SortOptions::default().desc().with_nulls_first(false);
4026        let field = SortField::new_with_options(d.clone(), options);
4027        let converter = RowConverter::new(vec![field]).unwrap();
4028        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
4029        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
4030        assert!(rows.row(2) > rows.row(1)); // [32, 52, null] > [32, 52, 12]
4031        assert!(rows.row(3) > rows.row(2)); // null > [32, 52, null]
4032        assert!(rows.row(4) > rows.row(2)); // [32, null, null] > [32, 52, null]
4033        assert!(rows.row(5) > rows.row(2)); // [null, null, null] > [32, 52, null]
4034        assert!(rows.row(3) > rows.row(5)); // null > [null, null, null]
4035        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
4036
4037        let back = converter.convert_rows(&rows).unwrap();
4038        assert_eq!(back.len(), 1);
4039        back[0].to_data().validate_full().unwrap();
4040        assert_eq!(&back[0], &list);
4041
4042        // Descending, nulls first
4043        let options = SortOptions::default().desc().with_nulls_first(true);
4044        let field = SortField::new_with_options(d, options);
4045        let converter = RowConverter::new(vec![field]).unwrap();
4046        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
4047
4048        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
4049        assert!(rows.row(2) < rows.row(1)); // [32, 52, null] > [32, 52, 12]
4050        assert!(rows.row(3) < rows.row(2)); // null < [32, 52, null]
4051        assert!(rows.row(4) < rows.row(2)); // [32, null, null] < [32, 52, null]
4052        assert!(rows.row(5) < rows.row(2)); // [null, null, null] > [32, 52, null]
4053        assert!(rows.row(3) < rows.row(5)); // null < [null, null, null]
4054        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
4055
4056        let back = converter.convert_rows(&rows).unwrap();
4057        assert_eq!(back.len(), 1);
4058        back[0].to_data().validate_full().unwrap();
4059        assert_eq!(&back[0], &list);
4060
4061        let sliced_list = list.slice(1, 5);
4062        let rows_on_sliced_list = converter
4063            .convert_columns(&[Arc::clone(&sliced_list)])
4064            .unwrap();
4065
4066        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(1)); // null < [32, 52, null]
4067        assert!(rows_on_sliced_list.row(3) < rows_on_sliced_list.row(1)); // [32, null, null] < [32, 52, null]
4068        assert!(rows_on_sliced_list.row(4) < rows_on_sliced_list.row(1)); // [null, null, null] > [32, 52, null]
4069        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(4)); // null < [null, null, null]
4070
4071        let back = converter.convert_rows(&rows_on_sliced_list).unwrap();
4072        assert_eq!(back.len(), 1);
4073        back[0].to_data().validate_full().unwrap();
4074        assert_eq!(&back[0], &sliced_list);
4075    }
4076
4077    #[test]
4078    fn test_two_fixed_size_lists() {
4079        let mut first = FixedSizeListBuilder::new(UInt8Builder::new(), 1);
4080        // 0: [100]
4081        first.values().append_value(100);
4082        first.append(true);
4083        // 1: [101]
4084        first.values().append_value(101);
4085        first.append(true);
4086        // 2: [102]
4087        first.values().append_value(102);
4088        first.append(true);
4089        // 3: [null]
4090        first.values().append_null();
4091        first.append(true);
4092        // 4: null
4093        first.values().append_null(); // MASKED
4094        first.append(false);
4095        let first = Arc::new(first.finish()) as ArrayRef;
4096        let first_type = first.data_type().clone();
4097
4098        let mut second = FixedSizeListBuilder::new(UInt8Builder::new(), 1);
4099        // 0: [200]
4100        second.values().append_value(200);
4101        second.append(true);
4102        // 1: [201]
4103        second.values().append_value(201);
4104        second.append(true);
4105        // 2: [202]
4106        second.values().append_value(202);
4107        second.append(true);
4108        // 3: [null]
4109        second.values().append_null();
4110        second.append(true);
4111        // 4: null
4112        second.values().append_null(); // MASKED
4113        second.append(false);
4114        let second = Arc::new(second.finish()) as ArrayRef;
4115        let second_type = second.data_type().clone();
4116
4117        let converter = RowConverter::new(vec![
4118            SortField::new(first_type.clone()),
4119            SortField::new(second_type.clone()),
4120        ])
4121        .unwrap();
4122
4123        let rows = converter
4124            .convert_columns(&[Arc::clone(&first), Arc::clone(&second)])
4125            .unwrap();
4126
4127        let back = converter.convert_rows(&rows).unwrap();
4128        assert_eq!(back.len(), 2);
4129        back[0].to_data().validate_full().unwrap();
4130        assert_eq!(&back[0], &first);
4131        back[1].to_data().validate_full().unwrap();
4132        assert_eq!(&back[1], &second);
4133    }
4134
4135    #[test]
4136    fn test_fixed_size_list_with_variable_width_content() {
4137        let mut first = FixedSizeListBuilder::new(
4138            StructBuilder::from_fields(
4139                vec![
4140                    Field::new(
4141                        "timestamp",
4142                        DataType::Timestamp(TimeUnit::Microsecond, Some(Arc::from("UTC"))),
4143                        false,
4144                    ),
4145                    Field::new("offset_minutes", DataType::Int16, false),
4146                    Field::new("time_zone", DataType::Utf8, false),
4147                ],
4148                1,
4149            ),
4150            1,
4151        );
4152        // 0: null
4153        first
4154            .values()
4155            .field_builder::<TimestampMicrosecondBuilder>(0)
4156            .unwrap()
4157            .append_null();
4158        first
4159            .values()
4160            .field_builder::<Int16Builder>(1)
4161            .unwrap()
4162            .append_null();
4163        first
4164            .values()
4165            .field_builder::<StringBuilder>(2)
4166            .unwrap()
4167            .append_null();
4168        first.values().append(false);
4169        first.append(false);
4170        // 1: [null]
4171        first
4172            .values()
4173            .field_builder::<TimestampMicrosecondBuilder>(0)
4174            .unwrap()
4175            .append_null();
4176        first
4177            .values()
4178            .field_builder::<Int16Builder>(1)
4179            .unwrap()
4180            .append_null();
4181        first
4182            .values()
4183            .field_builder::<StringBuilder>(2)
4184            .unwrap()
4185            .append_null();
4186        first.values().append(false);
4187        first.append(true);
4188        // 2: [1970-01-01 00:00:00.000000 UTC]
4189        first
4190            .values()
4191            .field_builder::<TimestampMicrosecondBuilder>(0)
4192            .unwrap()
4193            .append_value(0);
4194        first
4195            .values()
4196            .field_builder::<Int16Builder>(1)
4197            .unwrap()
4198            .append_value(0);
4199        first
4200            .values()
4201            .field_builder::<StringBuilder>(2)
4202            .unwrap()
4203            .append_value("UTC");
4204        first.values().append(true);
4205        first.append(true);
4206        // 3: [2005-09-10 13:30:00.123456 Europe/Warsaw]
4207        first
4208            .values()
4209            .field_builder::<TimestampMicrosecondBuilder>(0)
4210            .unwrap()
4211            .append_value(1126351800123456);
4212        first
4213            .values()
4214            .field_builder::<Int16Builder>(1)
4215            .unwrap()
4216            .append_value(120);
4217        first
4218            .values()
4219            .field_builder::<StringBuilder>(2)
4220            .unwrap()
4221            .append_value("Europe/Warsaw");
4222        first.values().append(true);
4223        first.append(true);
4224        let first = Arc::new(first.finish()) as ArrayRef;
4225        let first_type = first.data_type().clone();
4226
4227        let mut second = StringBuilder::new();
4228        second.append_value("somewhere near");
4229        second.append_null();
4230        second.append_value("Greenwich");
4231        second.append_value("Warsaw");
4232        let second = Arc::new(second.finish()) as ArrayRef;
4233        let second_type = second.data_type().clone();
4234
4235        let converter = RowConverter::new(vec![
4236            SortField::new(first_type.clone()),
4237            SortField::new(second_type.clone()),
4238        ])
4239        .unwrap();
4240
4241        let rows = converter
4242            .convert_columns(&[Arc::clone(&first), Arc::clone(&second)])
4243            .unwrap();
4244
4245        let back = converter.convert_rows(&rows).unwrap();
4246        assert_eq!(back.len(), 2);
4247        back[0].to_data().validate_full().unwrap();
4248        assert_eq!(&back[0], &first);
4249        back[1].to_data().validate_full().unwrap();
4250        assert_eq!(&back[1], &second);
4251    }
4252
4253    #[test]
4254    fn test_single_map() {
4255        let mut builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new());
4256        // Entry 0: {"hello": 1, "world": 2}
4257        builder.keys().append_value("hello");
4258        builder.values().append_value(1);
4259        builder.keys().append_value("world");
4260        builder.values().append_value(2);
4261        builder.append(true).unwrap();
4262
4263        // Entry 1: {"foo": 3}
4264        builder.keys().append_value("foo");
4265        builder.values().append_value(3);
4266        builder.append(true).unwrap();
4267
4268        // Entry 2: {} (empty map)
4269        builder.append(true).unwrap();
4270
4271        // Entry 3: null (with masked data)
4272        builder.keys().append_value("masked_key");
4273        builder.values().append_value(999);
4274        builder.append(false).unwrap();
4275
4276        // Entry 4: null (with unmasked data)
4277        builder.append(false).unwrap();
4278
4279        // Entry 5: {"bar": null}
4280        builder.keys().append_value("bar");
4281        builder.values().append_null();
4282        builder.append(true).unwrap();
4283
4284        // Entry 6: null (with different masked data)
4285        builder.keys().append_value("other_masked");
4286        builder.values().append_value(0);
4287        builder.append(false).unwrap();
4288
4289        // Entry 7: {"a": 10, "b": 20, "c": 30}
4290        builder.keys().append_value("a");
4291        builder.values().append_value(10);
4292        builder.keys().append_value("b");
4293        builder.values().append_value(20);
4294        builder.keys().append_value("c");
4295        builder.values().append_value(30);
4296        builder.append(true).unwrap();
4297
4298        let map = Arc::new(builder.finish()) as ArrayRef;
4299        let d = map.data_type().clone();
4300
4301        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4302
4303        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4304
4305        // null = null (different masked values or masking vs non-masking)
4306        assert_eq!(rows.row(3), rows.row(4));
4307        assert_eq!(rows.row(4), rows.row(6));
4308
4309        let back = converter.convert_rows(&rows).unwrap();
4310        assert_eq!(back.len(), 1);
4311        back[0].to_data().validate_full().unwrap();
4312        assert_eq!(&back[0], &map);
4313
4314        let sliced_map = map.slice(1, map.len() - 2);
4315        let rows_on_sliced = converter
4316            .convert_columns(&[Arc::clone(&sliced_map)])
4317            .unwrap();
4318
4319        let back = converter.convert_rows(&rows_on_sliced).unwrap();
4320        assert_eq!(back.len(), 1);
4321        back[0].to_data().validate_full().unwrap();
4322        assert_eq!(&back[0], &sliced_map);
4323    }
4324
4325    #[test]
4326    fn two_maps_with_different_keys_order_should_sort_by_entry_order() {
4327        let map_1: ArrayRef =
4328            Arc::new(MapArray::from_vec_of_maps::<StringArray, Int32Array, _, _>(
4329                vec![Some(vec![("hello", Some(1)), ("world", Some(2))])],
4330                false,
4331            ));
4332        // { "world": 2, "hello": 1 }
4333        let map_2: ArrayRef =
4334            Arc::new(MapArray::from_vec_of_maps::<StringArray, Int32Array, _, _>(
4335                vec![Some(vec![("world", Some(2)), ("hello", Some(1))])],
4336                false,
4337            ));
4338
4339        let converter = RowConverter::new(vec![SortField::new(map_1.data_type().clone())]).unwrap();
4340
4341        let map_1_rows = converter.convert_columns(&[Arc::clone(&map_1)]).unwrap();
4342        let map_2_rows = converter.convert_columns(&[Arc::clone(&map_2)]).unwrap();
4343
4344        assert_ne!(map_1_rows.row(0), map_2_rows.row(0));
4345        assert!(map_1_rows.row(0) < map_2_rows.row(0));
4346
4347        let back_1 = converter.convert_rows(&map_1_rows).unwrap();
4348        let back_2 = converter.convert_rows(&map_2_rows).unwrap();
4349        assert_eq!(&back_1[0], &map_1);
4350        assert_eq!(&back_2[0], &map_2);
4351    }
4352
4353    #[test]
4354    fn test_nested_map() {
4355        // Map<Utf8, Map<Utf8, Int32>>
4356        let mut builder = MapBuilder::new(
4357            None,
4358            StringBuilder::new(),
4359            MapBuilder::new(None, StringBuilder::new(), Int32Builder::new()),
4360        );
4361
4362        // Entry 0: {"outer1": {"inner_a": 1, "inner_b": 2}, "outer2": {"inner_c": 3}}
4363        builder.keys().append_value("outer1");
4364        builder.values().keys().append_value("inner_a");
4365        builder.values().values().append_value(1);
4366        builder.values().keys().append_value("inner_b");
4367        builder.values().values().append_value(2);
4368        builder.values().append(true).unwrap();
4369        builder.keys().append_value("outer2");
4370        builder.values().keys().append_value("inner_c");
4371        builder.values().values().append_value(3);
4372        builder.values().append(true).unwrap();
4373        builder.append(true).unwrap();
4374
4375        // Entry 1: {"x": {}} (inner map is empty)
4376        builder.keys().append_value("x");
4377        builder.values().append(true).unwrap();
4378        builder.append(true).unwrap();
4379
4380        // Entry 2: {"y": null} (inner map is null)
4381        builder.keys().append_value("y");
4382        builder.values().keys().append_value("masked"); // MASKED
4383        builder.values().values().append_value(0); // MASKED
4384        builder.values().append(false).unwrap();
4385        builder.append(true).unwrap();
4386
4387        // Entry 3: {"y": null} (inner map is non masked null)
4388        builder.keys().append_value("y");
4389        builder.values().append(false).unwrap(); // not masked
4390        builder.append(true).unwrap();
4391
4392        // Entry 4: null (outer map is null)
4393        builder.keys().append_value("masked_outer"); // MASKED
4394        builder.values().keys().append_value("masked_inner"); // MASKED
4395        builder.values().values().append_value(0); // MASKED
4396        builder.values().append(true).unwrap(); // MASKED
4397        builder.append(false).unwrap();
4398
4399        // Entry 5: null (outer map is null with inner map non masked null)
4400        builder.keys().append_value("masked_outer"); // MASKED
4401        builder.values().append(false).unwrap(); // not masked
4402        builder.append(false).unwrap();
4403
4404        // Entry 6: non masked null (outer map is null)
4405        builder.append(false).unwrap(); // not masked
4406
4407        // Entry 7: {} (outer map is empty)
4408        builder.append(true).unwrap();
4409
4410        let map = Arc::new(builder.finish()) as ArrayRef;
4411        let d = map.data_type().clone();
4412
4413        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4414
4415        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4416
4417        let back = converter.convert_rows(&rows).unwrap();
4418        assert_eq!(back.len(), 1);
4419        back[0].to_data().validate_full().unwrap();
4420        assert_eq!(&back[0], &map);
4421
4422        let sliced_map = map.slice(1, 3);
4423        let rows_on_sliced = converter
4424            .convert_columns(&[Arc::clone(&sliced_map)])
4425            .unwrap();
4426
4427        let back = converter.convert_rows(&rows_on_sliced).unwrap();
4428        assert_eq!(back.len(), 1);
4429        back[0].to_data().validate_full().unwrap();
4430        assert_eq!(&back[0], &sliced_map);
4431    }
4432
4433    #[test]
4434    fn test_single_map_with_non_nullable_values() {
4435        // Use `with_values_field` on `MapBuilder` to set the values are not nullable
4436        let value_field = Arc::new(Field::new(
4437            Field::MAP_VALUE_FIELD_DEFAULT_NAME,
4438            DataType::Int32,
4439            false,
4440        ));
4441        let mut builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new())
4442            .with_values_field(value_field);
4443        // Entry 0: {"a": 1, "b": 2}
4444        builder.keys().append_value("a");
4445        builder.values().append_value(1);
4446        builder.keys().append_value("b");
4447        builder.values().append_value(2);
4448        builder.append(true).unwrap();
4449        // Entry 1: null
4450        builder.append(false).unwrap();
4451        // Entry 2: {"c": 3}
4452        builder.keys().append_value("c");
4453        builder.values().append_value(3);
4454        builder.append(true).unwrap();
4455        // Entry 3: {}
4456        builder.append(true).unwrap();
4457        // Entry 4: null
4458        builder.keys().append_value("masked"); // MASKED
4459        builder.values().append_value(0); // MASKED
4460        builder.append(false).unwrap();
4461
4462        let map = Arc::new(builder.finish()) as ArrayRef;
4463        let d = map.data_type().clone();
4464
4465        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4466
4467        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4468
4469        let back = converter.convert_rows(&rows).unwrap();
4470        assert_eq!(back.len(), 1);
4471        back[0].to_data().validate_full().unwrap();
4472        assert_eq!(&back[0], &map);
4473    }
4474
4475    #[test]
4476    fn test_single_map_with_non_nullable_map_but_with_nullable_values() {
4477        // Map column is non-nullable, but values are nullable
4478        let value_field = Arc::new(Field::new(
4479            Field::MAP_VALUE_FIELD_DEFAULT_NAME,
4480            DataType::Int32,
4481            true,
4482        ));
4483        let mut builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new())
4484            .with_values_field(value_field);
4485
4486        // Entry 0: {"a": 1, "b": null}
4487        builder.keys().append_value("a");
4488        builder.values().append_value(1);
4489        builder.keys().append_value("b");
4490        builder.values().append_null();
4491        builder.append(true).unwrap();
4492        // Entry 1: {"c": null, "d": null}
4493        builder.keys().append_value("c");
4494        builder.values().append_null();
4495        builder.keys().append_value("d");
4496        builder.values().append_null();
4497        builder.append(true).unwrap();
4498        // Entry 2: {}
4499        builder.append(true).unwrap();
4500        // Entry 3: {"e": 5}
4501        builder.keys().append_value("e");
4502        builder.values().append_value(5);
4503        builder.append(true).unwrap();
4504
4505        let map = Arc::new(builder.finish()) as ArrayRef;
4506        let d = map.data_type().clone();
4507
4508        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4509
4510        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4511
4512        let back = converter.convert_rows(&rows).unwrap();
4513        assert_eq!(back.len(), 1);
4514        back[0].to_data().validate_full().unwrap();
4515        assert_eq!(&back[0], &map);
4516    }
4517
4518    #[test]
4519    fn test_map_all_nulls() {
4520        let mut builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new());
4521        // All entries are null
4522        builder.keys().append_value("m1"); // MASKED
4523        builder.values().append_value(1); // MASKED
4524        builder.append(false).unwrap();
4525        builder.keys().append_value("m2"); // MASKED
4526        builder.values().append_value(2); // MASKED
4527        builder.append(false).unwrap();
4528
4529        builder.append(false).unwrap(); // non masked
4530
4531        builder.keys().append_value("m3"); // MASKED
4532        builder.values().append_value(3); // MASKED
4533        builder.append(false).unwrap();
4534
4535        let map = Arc::new(builder.finish()) as ArrayRef;
4536        let d = map.data_type().clone();
4537
4538        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4539
4540        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4541
4542        // All null rows should be equal
4543        rows.iter().for_each(|row| assert_eq!(row, rows.row(0)));
4544
4545        let back = converter.convert_rows(&rows).unwrap();
4546        assert_eq!(back.len(), 1);
4547        back[0].to_data().validate_full().unwrap();
4548        assert_eq!(&back[0], &map);
4549    }
4550
4551    #[test]
4552    fn test_map_all_empty() {
4553        let mut builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new());
4554        // All entries are empty maps
4555        builder.append(true).unwrap();
4556        builder.append(true).unwrap();
4557        builder.append(true).unwrap();
4558
4559        let map = Arc::new(builder.finish()) as ArrayRef;
4560        let d = map.data_type().clone();
4561
4562        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4563
4564        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4565
4566        // All empty maps should be equal
4567        rows.iter().for_each(|row| assert_eq!(row, rows.row(0)));
4568
4569        let back = converter.convert_rows(&rows).unwrap();
4570        assert_eq!(back.len(), 1);
4571        back[0].to_data().validate_full().unwrap();
4572        assert_eq!(&back[0], &map);
4573    }
4574
4575    #[test]
4576    fn test_map_empty_array() {
4577        // Zero-length map array
4578        let builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new());
4579        let map = Arc::new(builder.finish_cloned()) as ArrayRef;
4580        let d = map.data_type().clone();
4581
4582        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4583
4584        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4585
4586        let back = converter.convert_rows(&rows).unwrap();
4587        assert_eq!(back.len(), 1);
4588        back[0].to_data().validate_full().unwrap();
4589        assert_eq!(&back[0], &map);
4590    }
4591
4592    fn generate_primitive_array<K>(
4593        rng: &mut StdRng,
4594        len: usize,
4595        valid_percent: f64,
4596    ) -> PrimitiveArray<K>
4597    where
4598        K: ArrowPrimitiveType,
4599        StandardUniform: Distribution<K::Native>,
4600    {
4601        (0..len)
4602            .map(|_| rng.random_bool(valid_percent).then(|| rng.random()))
4603            .collect()
4604    }
4605
4606    fn generate_all_unique_primitive_array<K>(rng: &mut StdRng, len: usize) -> PrimitiveArray<K>
4607    where
4608        K: ArrowPrimitiveType,
4609        K::Native: Hash + Eq,
4610        StandardUniform: Distribution<K::Native>,
4611    {
4612        let possible_number_of_values = 2i32.saturating_pow(size_of::<K::Native>() as u32 * 8);
4613        assert!(
4614            len <= possible_number_of_values as usize,
4615            "len {len} is larger than the number of possible values {possible_number_of_values}"
4616        );
4617
4618        let mut seen = std::collections::HashSet::new();
4619        (0..len)
4620            .map(|_| {
4621                let mut value;
4622                loop {
4623                    value = rng.random();
4624
4625                    if seen.insert(value) {
4626                        break;
4627                    }
4628                }
4629
4630                Some(value)
4631            })
4632            .collect()
4633    }
4634
4635    fn generate_boolean_array(rng: &mut StdRng, len: usize, valid_percent: f64) -> BooleanArray {
4636        (0..len)
4637            .map(|_| rng.random_bool(valid_percent).then(|| rng.random_bool(0.5)))
4638            .collect()
4639    }
4640
4641    fn generate_strings<O: OffsetSizeTrait>(
4642        rng: &mut StdRng,
4643        len: usize,
4644        valid_percent: f64,
4645    ) -> GenericStringArray<O> {
4646        (0..len)
4647            .map(|_| {
4648                rng.random_bool(valid_percent).then(|| {
4649                    let len = rng.random_range(0..100);
4650                    let bytes = (0..len).map(|_| rng.random_range(0..128)).collect();
4651                    String::from_utf8(bytes).unwrap()
4652                })
4653            })
4654            .collect()
4655    }
4656
4657    fn generate_string_view(rng: &mut StdRng, len: usize, valid_percent: f64) -> StringViewArray {
4658        (0..len)
4659            .map(|_| {
4660                rng.random_bool(valid_percent).then(|| {
4661                    let len = rng.random_range(0..100);
4662                    let bytes = (0..len).map(|_| rng.random_range(0..128)).collect();
4663                    String::from_utf8(bytes).unwrap()
4664                })
4665            })
4666            .collect()
4667    }
4668
4669    fn generate_byte_view(rng: &mut StdRng, len: usize, valid_percent: f64) -> BinaryViewArray {
4670        (0..len)
4671            .map(|_| {
4672                rng.random_bool(valid_percent).then(|| {
4673                    let len = rng.random_range(0..100);
4674                    let bytes: Vec<_> = (0..len).map(|_| rng.random_range(0..128)).collect();
4675                    bytes
4676                })
4677            })
4678            .collect()
4679    }
4680
4681    fn generate_fixed_stringview_column(len: usize) -> StringViewArray {
4682        let edge_cases = vec![
4683            Some("bar".to_string()),
4684            Some("bar\0".to_string()),
4685            Some("LongerThan12Bytes".to_string()),
4686            Some("LongerThan12Bytez".to_string()),
4687            Some("LongerThan12Bytes\0".to_string()),
4688            Some("LongerThan12Byt".to_string()),
4689            Some("backend one".to_string()),
4690            Some("backend two".to_string()),
4691            Some("a".repeat(257)),
4692            Some("a".repeat(300)),
4693        ];
4694
4695        // Fill up to `len` by repeating edge cases and trimming
4696        let mut values = Vec::with_capacity(len);
4697        for i in 0..len {
4698            values.push(
4699                edge_cases
4700                    .get(i % edge_cases.len())
4701                    .cloned()
4702                    .unwrap_or(None),
4703            );
4704        }
4705
4706        StringViewArray::from(values)
4707    }
4708
4709    fn generate_dictionary<K>(
4710        rng: &mut StdRng,
4711        values: ArrayRef,
4712        len: usize,
4713        valid_percent: f64,
4714    ) -> DictionaryArray<K>
4715    where
4716        K: ArrowDictionaryKeyType,
4717        K::Native: SampleUniform,
4718    {
4719        let min_key = K::Native::from_usize(0).unwrap();
4720        let max_key = K::Native::from_usize(values.len()).unwrap();
4721        let keys: PrimitiveArray<K> = (0..len)
4722            .map(|_| {
4723                rng.random_bool(valid_percent)
4724                    .then(|| rng.random_range(min_key..max_key))
4725            })
4726            .collect();
4727
4728        let data_type =
4729            DataType::Dictionary(Box::new(K::DATA_TYPE), Box::new(values.data_type().clone()));
4730
4731        let data = keys
4732            .into_data()
4733            .into_builder()
4734            .data_type(data_type)
4735            .add_child_data(values.to_data())
4736            .build()
4737            .unwrap();
4738
4739        DictionaryArray::from(data)
4740    }
4741
4742    fn generate_fixed_size_binary(
4743        rng: &mut StdRng,
4744        len: usize,
4745        valid_percent: f64,
4746    ) -> FixedSizeBinaryArray {
4747        let width = rng.random_range(0..20);
4748        let mut builder = FixedSizeBinaryBuilder::new(width);
4749
4750        let mut b = vec![0; width as usize];
4751        for _ in 0..len {
4752            match rng.random_bool(valid_percent) {
4753                true => {
4754                    b.iter_mut().for_each(|x| *x = rng.random());
4755                    builder.append_value(&b).unwrap();
4756                }
4757                false => builder.append_null(),
4758            }
4759        }
4760
4761        builder.finish()
4762    }
4763
4764    fn generate_struct(rng: &mut StdRng, len: usize, valid_percent: f64) -> StructArray {
4765        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4766        let a = generate_primitive_array::<Int32Type>(rng, len, valid_percent);
4767        let b = generate_strings::<i32>(rng, len, valid_percent);
4768        let fields = Fields::from(vec![
4769            Field::new("a", DataType::Int32, true),
4770            Field::new("b", DataType::Utf8, true),
4771        ]);
4772        let values = vec![Arc::new(a) as _, Arc::new(b) as _];
4773        StructArray::new(fields, values, Some(nulls))
4774    }
4775
4776    fn generate_list<F>(rng: &mut StdRng, len: usize, valid_percent: f64, values: F) -> ListArray
4777    where
4778        F: FnOnce(&mut StdRng, usize) -> ArrayRef,
4779    {
4780        let offsets = OffsetBuffer::<i32>::from_lengths((0..len).map(|_| rng.random_range(0..10)));
4781        let values_len = offsets.last().as_usize();
4782        let values = values(rng, values_len);
4783        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4784        let field = Arc::new(Field::new_list_field(values.data_type().clone(), true));
4785        ListArray::new(field, offsets, values, Some(nulls))
4786    }
4787
4788    fn generate_list_view<F>(
4789        rng: &mut StdRng,
4790        len: usize,
4791        valid_percent: f64,
4792        values: F,
4793    ) -> ListViewArray
4794    where
4795        F: FnOnce(&mut StdRng, usize) -> ArrayRef,
4796    {
4797        // Generate sizes first, then create a values array large enough
4798        let sizes: Vec<i32> = (0..len).map(|_| rng.random_range(0..10)).collect();
4799        let values_len: usize = sizes.iter().map(|s| *s as usize).sum::<usize>().max(1);
4800        let values = values(rng, values_len);
4801
4802        // Generate offsets that can overlap, be non-monotonic, or share ranges
4803        let offsets: Vec<i32> = sizes
4804            .iter()
4805            .map(|&size| {
4806                if size == 0 {
4807                    0
4808                } else {
4809                    rng.random_range(0..=(values_len as i32 - size))
4810                }
4811            })
4812            .collect();
4813
4814        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4815        let field = Arc::new(Field::new_list_field(values.data_type().clone(), true));
4816        ListViewArray::new(
4817            field,
4818            ScalarBuffer::from(offsets),
4819            ScalarBuffer::from(sizes),
4820            values,
4821            Some(nulls),
4822        )
4823    }
4824
4825    fn generate_map<KeysFn, ValuesFn>(
4826        rng: &mut StdRng,
4827        len: usize,
4828        valid_percent: f64,
4829        gen_keys: KeysFn,
4830        gen_values: ValuesFn,
4831    ) -> MapArray
4832    where
4833        KeysFn: FnOnce(&mut StdRng, usize) -> ArrayRef,
4834        ValuesFn: FnOnce(&mut StdRng, usize) -> ArrayRef,
4835    {
4836        let offsets = OffsetBuffer::<i32>::from_lengths((0..len).map(|_| rng.random_range(0..10)));
4837        let entries_len = offsets.last().as_usize();
4838        let keys = gen_keys(rng, entries_len);
4839        let values = gen_values(rng, entries_len);
4840        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4841        let field = Arc::new(Field::new_map(
4842            "",
4843            Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
4844            Field::new(
4845                Field::MAP_KEY_FIELD_DEFAULT_NAME,
4846                keys.data_type().clone(),
4847                false,
4848            ),
4849            Field::new(
4850                Field::MAP_VALUE_FIELD_DEFAULT_NAME,
4851                values.data_type().clone(),
4852                true,
4853            ),
4854            false,
4855            true,
4856        ));
4857        let DataType::Map(struct_field, _) = field.data_type() else {
4858            unreachable!();
4859        };
4860
4861        let DataType::Struct(fields) = struct_field.data_type() else {
4862            unreachable!();
4863        };
4864
4865        let entries = StructArray::new(fields.clone(), vec![keys, values], None);
4866
4867        let map_array = MapArray::new(struct_field.clone(), offsets, entries, Some(nulls), false);
4868
4869        assert_valid_map(&map_array);
4870
4871        map_array
4872    }
4873
4874    /// Assert that the map is valid; this includes unique map keys
4875    ///
4876    /// Can be removed once https://github.com/apache/arrow-rs/issues/9475 is resolved and `MapArray`
4877    /// will not allow creation of invalid map arrays with duplicate keys.
4878    ///
4879    /// # Unique map keys
4880    /// According to [arrow specification][1], the keys of a map must be unique, so this asserts that
4881    ///
4882    /// [1]: https://github.com/apache/arrow/blob/cbe2618431e413f12aa16aeba88b3a98914f194b/format/Schema.fbs#L124
4883    fn assert_valid_map(array: &MapArray) {
4884        let keys_arrow_row_converter =
4885            RowConverter::new(vec![SortField::new(array.key_type().clone())]).unwrap();
4886
4887        array.iter().enumerate().filter_map(|(index, entry)| entry.map(|entry| (index, Arc::clone(entry.column(0))))).for_each(|(entry_index, keys)| {
4888            let keys_as_rows = keys_arrow_row_converter.convert_columns(&[Arc::clone(&keys)]).expect("should be able to convert keys");
4889
4890            for i in 0..keys_as_rows.num_rows() {
4891                for j in (i + 1)..keys_as_rows.num_rows() {
4892                    if keys_as_rows.row(i) == keys_as_rows.row(j) {
4893                        let key_i = keys.slice(i, 1);
4894                        let key_j = keys.slice(j, 1);
4895
4896                        assert_ne!(keys_as_rows.row(i), keys_as_rows.row(j), "map keys should be unique, but key {i} and key {j} are equal in entry {entry_index}. key {i} value is {key_i:?} and key {j} value is {key_j:?}");
4897                    }
4898                }
4899            }
4900        })
4901    }
4902
4903    fn generate_nulls(rng: &mut StdRng, len: usize) -> Option<NullBuffer> {
4904        Some(NullBuffer::from_iter(
4905            (0..len).map(|_| rng.random_bool(0.8)),
4906        ))
4907    }
4908
4909    fn change_underlying_null_values_for_primitive<T: ArrowPrimitiveType>(
4910        array: &PrimitiveArray<T>,
4911    ) -> PrimitiveArray<T> {
4912        let (dt, values, nulls) = array.clone().into_parts();
4913
4914        let new_values = ScalarBuffer::<T::Native>::from_iter(
4915            values
4916                .iter()
4917                .zip(nulls.as_ref().unwrap().iter())
4918                .map(|(val, is_valid)| {
4919                    if is_valid {
4920                        *val
4921                    } else {
4922                        val.add_wrapping(T::Native::usize_as(1))
4923                    }
4924                }),
4925        );
4926
4927        PrimitiveArray::new(new_values, nulls).with_data_type(dt)
4928    }
4929
4930    fn change_underline_null_values_for_byte_array<T: ByteArrayType>(
4931        array: &GenericByteArray<T>,
4932    ) -> GenericByteArray<T> {
4933        let (offsets, values, nulls) = array.clone().into_parts();
4934
4935        let new_offsets = OffsetBuffer::<T::Offset>::from_lengths(
4936            offsets
4937                .lengths()
4938                .zip(nulls.as_ref().unwrap().iter())
4939                .map(|(len, is_valid)| if is_valid { len } else { len + 1 }),
4940        );
4941
4942        let mut new_bytes = Vec::<u8>::with_capacity(new_offsets[new_offsets.len() - 1].as_usize());
4943
4944        offsets
4945            .windows(2)
4946            .zip(nulls.as_ref().unwrap().iter())
4947            .for_each(|(start_and_end, is_valid)| {
4948                let start = start_and_end[0].as_usize();
4949                let end = start_and_end[1].as_usize();
4950                new_bytes.extend_from_slice(&values.as_slice()[start..end]);
4951
4952                // add an extra byte
4953                if !is_valid {
4954                    new_bytes.push(b'c');
4955                }
4956            });
4957
4958        GenericByteArray::<T>::new(new_offsets, Buffer::from_vec(new_bytes), nulls)
4959    }
4960
4961    fn change_underline_null_values_for_list_array<O: OffsetSizeTrait>(
4962        array: &GenericListArray<O>,
4963    ) -> GenericListArray<O> {
4964        let (field, offsets, values, nulls) = array.clone().into_parts();
4965
4966        let (new_values, new_offsets) = {
4967            let concat_values = offsets
4968                .windows(2)
4969                .zip(nulls.as_ref().unwrap().iter())
4970                .map(|(start_and_end, is_valid)| {
4971                    let start = start_and_end[0].as_usize();
4972                    let end = start_and_end[1].as_usize();
4973                    if is_valid {
4974                        return (start, end - start);
4975                    }
4976
4977                    // If reached end, we take one less
4978                    if end == values.len() {
4979                        (start, (end - start).saturating_sub(1))
4980                    } else {
4981                        (start, end - start + 1)
4982                    }
4983                })
4984                .map(|(start, length)| values.slice(start, length))
4985                .collect::<Vec<_>>();
4986
4987            let new_offsets =
4988                OffsetBuffer::<O>::from_lengths(concat_values.iter().map(|s| s.len()));
4989
4990            let new_values = {
4991                let values = concat_values.iter().map(|a| a.as_ref()).collect::<Vec<_>>();
4992                arrow_select::concat::concat(&values).expect("should be able to concat")
4993            };
4994
4995            (new_values, new_offsets)
4996        };
4997
4998        GenericListArray::<O>::new(field, new_offsets, new_values, nulls)
4999    }
5000
5001    fn change_underline_null_values_for_map_array(array: &MapArray) -> MapArray {
5002        let (field, offsets, entries, nulls, ordered) = array.clone().into_parts();
5003        assert!(
5004            !ordered,
5005            "can't replace underlying null values for ordered map array as this can violate the ordering"
5006        );
5007
5008        let (new_entries, new_offsets) = {
5009            let concat_values = offsets
5010                .windows(2)
5011                .zip(nulls.as_ref().unwrap().iter())
5012                .map(|(start_and_end, is_valid)| {
5013                    let start = start_and_end[0].as_usize();
5014                    let end = start_and_end[1].as_usize();
5015                    if is_valid {
5016                        return (start, end - start);
5017                    }
5018
5019                    // If reached end, we take one less
5020                    if end == entries.len() {
5021                        (start, (end - start).saturating_sub(1))
5022                    } else {
5023                        // The keys may no longer be unique
5024                        (start, end - start + 1)
5025                    }
5026                })
5027                .map(|(start, length)| entries.slice(start, length))
5028                .collect::<Vec<_>>();
5029
5030            let new_offsets = OffsetBuffer::from_lengths(concat_values.iter().map(|s| s.len()));
5031
5032            let new_values = {
5033                let values = concat_values
5034                    .iter()
5035                    .map(|a| a as &dyn Array)
5036                    .collect::<Vec<_>>();
5037                arrow_select::concat::concat(&values).expect("should be able to concat")
5038            };
5039
5040            (new_values.as_struct().clone(), new_offsets)
5041        };
5042
5043        let new_map = MapArray::new(field, new_offsets, new_entries, nulls, ordered);
5044
5045        assert_valid_map(&new_map);
5046
5047        new_map
5048    }
5049
5050    fn change_underline_null_values(array: &ArrayRef) -> ArrayRef {
5051        if array.null_count() == 0 {
5052            return Arc::clone(array);
5053        }
5054
5055        downcast_primitive_array!(
5056            array => {
5057                let output = change_underlying_null_values_for_primitive(array);
5058
5059                Arc::new(output)
5060            }
5061
5062            DataType::Utf8 => {
5063                Arc::new(change_underline_null_values_for_byte_array(array.as_string::<i32>()))
5064            }
5065            DataType::LargeUtf8 => {
5066                Arc::new(change_underline_null_values_for_byte_array(array.as_string::<i64>()))
5067            }
5068            DataType::Binary => {
5069                Arc::new(change_underline_null_values_for_byte_array(array.as_binary::<i32>()))
5070            }
5071            DataType::LargeBinary => {
5072                Arc::new(change_underline_null_values_for_byte_array(array.as_binary::<i64>()))
5073            }
5074            DataType::List(_) => {
5075                Arc::new(change_underline_null_values_for_list_array(array.as_list::<i32>()))
5076            }
5077            DataType::LargeList(_) => {
5078                Arc::new(change_underline_null_values_for_list_array(array.as_list::<i64>()))
5079            }
5080            DataType::Map(_, _) => {
5081                Arc::new(change_underline_null_values_for_map_array(array.as_map()))
5082            }
5083            _ => {
5084                Arc::clone(array)
5085            }
5086        )
5087    }
5088
5089    fn generate_column(rng: &mut StdRng, len: usize) -> ArrayRef {
5090        match rng.random_range(0..24) {
5091            0 => Arc::new(generate_primitive_array::<Int32Type>(rng, len, 0.8)),
5092            1 => Arc::new(generate_primitive_array::<UInt32Type>(rng, len, 0.8)),
5093            2 => Arc::new(generate_primitive_array::<Int64Type>(rng, len, 0.8)),
5094            3 => Arc::new(generate_primitive_array::<UInt64Type>(rng, len, 0.8)),
5095            4 => Arc::new(generate_primitive_array::<Float32Type>(rng, len, 0.8)),
5096            5 => Arc::new(generate_primitive_array::<Float64Type>(rng, len, 0.8)),
5097            6 => Arc::new(generate_strings::<i32>(rng, len, 0.8)),
5098            7 => {
5099                let dict_values_len = rng.random_range(1..len);
5100                // Cannot test dictionaries containing null values because of #2687
5101                let strings = Arc::new(generate_strings::<i32>(rng, dict_values_len, 1.0));
5102                Arc::new(generate_dictionary::<Int64Type>(rng, strings, len, 0.8))
5103            }
5104            8 => {
5105                let dict_values_len = rng.random_range(1..len);
5106                // Cannot test dictionaries containing null values because of #2687
5107                let values = Arc::new(generate_primitive_array::<Int64Type>(
5108                    rng,
5109                    dict_values_len,
5110                    1.0,
5111                ));
5112                Arc::new(generate_dictionary::<Int64Type>(rng, values, len, 0.8))
5113            }
5114            9 => Arc::new(generate_fixed_size_binary(rng, len, 0.8)),
5115            10 => Arc::new(generate_struct(rng, len, 0.8)),
5116            11 => Arc::new(generate_list(rng, len, 0.8, |rng, values_len| {
5117                Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8))
5118            })),
5119            12 => Arc::new(generate_list(rng, len, 0.8, |rng, values_len| {
5120                Arc::new(generate_strings::<i32>(rng, values_len, 0.8))
5121            })),
5122            13 => Arc::new(generate_list(rng, len, 0.8, |rng, values_len| {
5123                Arc::new(generate_struct(rng, values_len, 0.8))
5124            })),
5125            14 => Arc::new(generate_string_view(rng, len, 0.8)),
5126            15 => Arc::new(generate_byte_view(rng, len, 0.8)),
5127            16 => Arc::new(generate_fixed_stringview_column(len)),
5128            17 => Arc::new(
5129                generate_list(rng, len + 1000, 0.8, |rng, values_len| {
5130                    Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8))
5131                })
5132                .slice(500, len),
5133            ),
5134            18 => Arc::new(generate_boolean_array(rng, len, 0.8)),
5135            19 => Arc::new(generate_list_view(rng, len, 0.8, |rng, values_len| {
5136                Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8))
5137            })),
5138            20 => Arc::new(generate_list_view(rng, len, 0.8, |rng, values_len| {
5139                Arc::new(generate_strings::<i32>(rng, values_len, 0.8))
5140            })),
5141            21 => Arc::new(generate_list_view(rng, len, 0.8, |rng, values_len| {
5142                Arc::new(generate_struct(rng, values_len, 0.8))
5143            })),
5144            22 => Arc::new(
5145                generate_list_view(rng, len + 1000, 0.8, |rng, values_len| {
5146                    Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8))
5147                })
5148                .slice(500, len),
5149            ),
5150            23 => Arc::new(generate_map(
5151                rng,
5152                len,
5153                0.9,
5154                // Need to generate all unique keys or make sure between each map every key is unique,
5155                |rng, keys_len| {
5156                    Arc::new(generate_all_unique_primitive_array::<Int64Type>(
5157                        rng, keys_len,
5158                    ))
5159                },
5160                |rng, values_len| Arc::new(generate_strings::<i32>(rng, values_len, 0.7)),
5161            )),
5162            _ => unreachable!(),
5163        }
5164    }
5165
5166    fn print_row(cols: &[SortColumn], row: usize) -> String {
5167        let t: Vec<_> = cols
5168            .iter()
5169            .map(|x| match x.values.is_valid(row) {
5170                true => {
5171                    let opts = FormatOptions::default().with_null("NULL");
5172                    let formatter = ArrayFormatter::try_new(x.values.as_ref(), &opts).unwrap();
5173                    formatter.value(row).to_string()
5174                }
5175                false => "NULL".to_string(),
5176            })
5177            .collect();
5178        t.join(",")
5179    }
5180
5181    fn print_col_types(cols: &[SortColumn]) -> String {
5182        let t: Vec<_> = cols
5183            .iter()
5184            .map(|x| x.values.data_type().to_string())
5185            .collect();
5186        t.join(",")
5187    }
5188
5189    #[derive(Debug, PartialEq)]
5190    enum Nulls {
5191        /// Keep the generated array as is
5192        AsIs,
5193
5194        /// Replace the null buffer with different null buffer to point to different positions as null
5195        Different,
5196
5197        /// Remove all nulls
5198        None,
5199    }
5200
5201    #[test]
5202    #[cfg_attr(miri, ignore)] // Takes too long
5203    fn fuzz_test() {
5204        let mut rng = StdRng::seed_from_u64(42);
5205        for _ in 0..100 {
5206            for null_behavior in [Nulls::AsIs, Nulls::Different, Nulls::None] {
5207                let num_columns = rng.random_range(1..5);
5208                let len = rng.random_range(5..100);
5209                let mut arrays: Vec<_> = (0..num_columns)
5210                    .map(|_| generate_column(&mut rng, len))
5211                    .collect();
5212
5213                match null_behavior {
5214                    Nulls::AsIs => {
5215                        // Keep as is
5216                    }
5217                    Nulls::Different => {
5218                        // Replace nulls with different nulls to allow for testing different underlying null values
5219                        arrays = arrays
5220                            .into_iter()
5221                            .map(|a| replace_array_nulls(a, generate_nulls(&mut rng, len)))
5222                            .collect()
5223                    }
5224                    Nulls::None => {
5225                        // Remove nulls
5226                        arrays = arrays
5227                            .into_iter()
5228                            .map(|a| replace_array_nulls(a, None))
5229                            .collect()
5230                    }
5231                }
5232
5233                let options: Vec<_> = (0..num_columns)
5234                    .map(|_| SortOptions {
5235                        descending: rng.random_bool(0.5),
5236                        nulls_first: rng.random_bool(0.5),
5237                    })
5238                    .collect();
5239
5240                let sort_columns: Vec<_> = options
5241                    .iter()
5242                    .zip(&arrays)
5243                    .map(|(o, c)| SortColumn {
5244                        values: Arc::clone(c),
5245                        options: Some(*o),
5246                    })
5247                    .collect();
5248
5249                let comparator = LexicographicalComparator::try_new(&sort_columns).unwrap();
5250
5251                let columns: Vec<SortField> = options
5252                    .into_iter()
5253                    .zip(&arrays)
5254                    .map(|(o, a)| SortField::new_with_options(a.data_type().clone(), o))
5255                    .collect();
5256
5257                let converter = RowConverter::new(columns).unwrap();
5258                let rows = converter.convert_columns(&arrays).unwrap();
5259
5260                // Assert that the underlying null values are not taken into account when converting
5261                // even for different inputs
5262                if !matches!(null_behavior, Nulls::None) {
5263                    assert_same_rows_when_changing_input_underlying_null_values(
5264                        &arrays, &converter, &rows,
5265                    );
5266                }
5267
5268                for i in 0..len {
5269                    for j in 0..len {
5270                        let row_i = rows.row(i);
5271                        let row_j = rows.row(j);
5272                        let row_cmp = row_i.cmp(&row_j);
5273                        let lex_cmp = comparator.compare(i, j);
5274                        assert_eq!(
5275                            row_cmp,
5276                            lex_cmp,
5277                            "({:?} vs {:?}) vs ({:?} vs {:?}) for types {}",
5278                            print_row(&sort_columns, i),
5279                            print_row(&sort_columns, j),
5280                            row_i,
5281                            row_j,
5282                            print_col_types(&sort_columns)
5283                        );
5284                    }
5285                }
5286
5287                // Validate rows length iterator
5288                {
5289                    let mut rows_iter = rows.iter();
5290                    let mut rows_lengths_iter = rows.lengths();
5291                    for (index, row) in rows_iter.by_ref().enumerate() {
5292                        let len = rows_lengths_iter
5293                            .next()
5294                            .expect("Reached end of length iterator while still have rows");
5295                        assert_eq!(
5296                            row.data.len(),
5297                            len,
5298                            "Row length mismatch: {} vs {}",
5299                            row.data.len(),
5300                            len
5301                        );
5302                        assert_eq!(
5303                            len,
5304                            rows.row_len(index),
5305                            "Row length mismatch at index {}: {} vs {}",
5306                            index,
5307                            len,
5308                            rows.row_len(index)
5309                        );
5310                    }
5311
5312                    assert_eq!(
5313                        rows_lengths_iter.next(),
5314                        None,
5315                        "Length iterator did not reach end"
5316                    );
5317                }
5318
5319                // Convert rows produced from convert_columns().
5320                // Note: validate_utf8 is set to false since Row is initialized through empty_rows()
5321                let back = converter.convert_rows(&rows).unwrap();
5322                for (actual, expected) in back.iter().zip(&arrays) {
5323                    actual.to_data().validate_full().unwrap();
5324                    dictionary_eq(actual, expected)
5325                }
5326
5327                // Check that we can convert rows into ByteArray and then parse, convert it back to array
5328                // Note: validate_utf8 is set to true since Row is initialized through RowParser
5329                let rows = rows.try_into_binary().expect("reasonable size");
5330                let parser = converter.parser();
5331                let back = converter
5332                    .convert_rows(rows.iter().map(|b| parser.parse(b.expect("valid bytes"))))
5333                    .unwrap();
5334                for (actual, expected) in back.iter().zip(&arrays) {
5335                    actual.to_data().validate_full().unwrap();
5336                    dictionary_eq(actual, expected)
5337                }
5338
5339                let rows = converter.from_binary(rows);
5340                let back = converter.convert_rows(&rows).unwrap();
5341                for (actual, expected) in back.iter().zip(&arrays) {
5342                    actual.to_data().validate_full().unwrap();
5343                    dictionary_eq(actual, expected)
5344                }
5345            }
5346        }
5347    }
5348
5349    fn replace_array_nulls(array: ArrayRef, new_nulls: Option<NullBuffer>) -> ArrayRef {
5350        make_array(
5351            array
5352                .into_data()
5353                .into_builder()
5354                // Replace the nulls
5355                .nulls(new_nulls)
5356                .build()
5357                .unwrap(),
5358        )
5359    }
5360
5361    fn assert_same_rows_when_changing_input_underlying_null_values(
5362        arrays: &[ArrayRef],
5363        converter: &RowConverter,
5364        rows: &Rows,
5365    ) {
5366        let arrays_with_different_data_behind_nulls = arrays
5367            .iter()
5368            .map(|arr| change_underline_null_values(arr))
5369            .collect::<Vec<_>>();
5370
5371        // Skip assertion if we did not change anything
5372        if arrays
5373            .iter()
5374            .zip(arrays_with_different_data_behind_nulls.iter())
5375            .all(|(a, b)| Arc::ptr_eq(a, b))
5376        {
5377            return;
5378        }
5379
5380        let rows_with_different_nulls = converter
5381            .convert_columns(&arrays_with_different_data_behind_nulls)
5382            .unwrap();
5383
5384        assert_eq!(
5385            rows.iter().collect::<Vec<_>>(),
5386            rows_with_different_nulls.iter().collect::<Vec<_>>(),
5387            "Different underlying nulls should not output different rows"
5388        )
5389    }
5390
5391    #[test]
5392    fn test_clear() {
5393        let converter = RowConverter::new(vec![SortField::new(DataType::Int32)]).unwrap();
5394        let mut rows = converter.empty_rows(3, 128);
5395
5396        let first = Int32Array::from(vec![None, Some(2), Some(4)]);
5397        let second = Int32Array::from(vec![Some(2), None, Some(4)]);
5398        let arrays = [Arc::new(first) as ArrayRef, Arc::new(second) as ArrayRef];
5399
5400        for array in &arrays {
5401            rows.clear();
5402            converter
5403                .append(&mut rows, std::slice::from_ref(array))
5404                .unwrap();
5405            let back = converter.convert_rows(&rows).unwrap();
5406            assert_eq!(&back[0], array);
5407        }
5408
5409        let mut rows_expected = converter.empty_rows(3, 128);
5410        converter.append(&mut rows_expected, &arrays[1..]).unwrap();
5411
5412        for (i, (actual, expected)) in rows.iter().zip(rows_expected.iter()).enumerate() {
5413            assert_eq!(
5414                actual, expected,
5415                "For row {i}: expected {expected:?}, actual: {actual:?}",
5416            );
5417        }
5418    }
5419
5420    #[test]
5421    fn test_append_codec_dictionary_binary() {
5422        use DataType::*;
5423        // Dictionary RowConverter
5424        let converter = RowConverter::new(vec![SortField::new(Dictionary(
5425            Box::new(Int32),
5426            Box::new(Binary),
5427        ))])
5428        .unwrap();
5429        let mut rows = converter.empty_rows(4, 128);
5430
5431        let keys = Int32Array::from_iter_values([0, 1, 2, 3]);
5432        let values = BinaryArray::from(vec![
5433            Some(b"a".as_slice()),
5434            Some(b"b"),
5435            Some(b"c"),
5436            Some(b"d"),
5437        ]);
5438        let dict_array = DictionaryArray::new(keys, Arc::new(values));
5439
5440        rows.clear();
5441        let array = Arc::new(dict_array) as ArrayRef;
5442        converter
5443            .append(&mut rows, std::slice::from_ref(&array))
5444            .unwrap();
5445        let back = converter.convert_rows(&rows).unwrap();
5446
5447        dictionary_eq(&back[0], &array);
5448    }
5449
5450    #[test]
5451    fn test_list_prefix() {
5452        let mut a = ListBuilder::new(Int8Builder::new());
5453        a.append_value([None]);
5454        a.append_value([None, None]);
5455        let a = a.finish();
5456
5457        let converter = RowConverter::new(vec![SortField::new(a.data_type().clone())]).unwrap();
5458        let rows = converter.convert_columns(&[Arc::new(a) as _]).unwrap();
5459        assert_eq!(rows.row(0).cmp(&rows.row(1)), Ordering::Less);
5460    }
5461
5462    #[test]
5463    fn test_utf8_validation_doesnt_affect_values_buffer_size() {
5464        fn assert_values_buffer_lens(col: ArrayRef) -> usize {
5465            // 1. Convert cols into rows
5466            let converter = RowConverter::new(vec![SortField::new(DataType::Utf8View)]).unwrap();
5467
5468            // 2a. Convert rows into cols (validate_utf8 = false)
5469            let rows = converter.convert_columns(&[col]).unwrap();
5470            let converted = converter.convert_rows(&rows).unwrap();
5471            let unchecked_values_len = converted[0].as_string_view().data_buffers()[0].len();
5472
5473            // 2b. Convert rows into cols (validate_utf8 = true since Row is initialized through RowParser)
5474            let rows = rows.try_into_binary().expect("reasonable size");
5475            let parser = converter.parser();
5476            let converted = converter
5477                .convert_rows(rows.iter().map(|b| parser.parse(b.expect("valid bytes"))))
5478                .unwrap();
5479            let checked_values_len = converted[0].as_string_view().data_buffers()[0].len();
5480            // Regardless of utf8 validation flag, we should always have minimal data in buffers
5481            assert_eq!(unchecked_values_len, checked_values_len);
5482            checked_values_len
5483        }
5484
5485        // Case1. StringViewArray with inline strings
5486        let col = Arc::new(StringViewArray::from_iter([
5487            Some("hello"), // short(5)
5488            None,          // null
5489            Some("short"), // short(5)
5490            Some("tiny"),  // short(4)
5491        ])) as ArrayRef;
5492
5493        let values_len = assert_values_buffer_lens(col);
5494        // Since there are no long (>12) strings, len of values buffer is 0
5495        assert_eq!(values_len, 0);
5496
5497        // Case2. StringViewArray with long(>12) strings
5498        let col = Arc::new(StringViewArray::from_iter([
5499            Some("1234567890123"),  // 13
5500            Some("12345678901234"), // 14
5501        ])) as ArrayRef;
5502
5503        let values_len = assert_values_buffer_lens(col);
5504        assert_eq!(values_len, 13 + 14);
5505
5506        // Case3. StringViewArray with both short and long strings
5507        let col = Arc::new(StringViewArray::from_iter([
5508            Some("tiny"),          // 4 (short)
5509            Some("thisisexact13"), // 13 (long)
5510            None,
5511            Some("short"), // 5 (short)
5512        ])) as ArrayRef;
5513
5514        let values_len = assert_values_buffer_lens(col);
5515        // Since there is single long string, len of values buffer is 13
5516        assert_eq!(values_len, 13);
5517    }
5518
5519    #[test]
5520    fn test_sparse_union() {
5521        // create a sparse union with Int32 (type_id = 0) and Utf8 (type_id = 1)
5522        let int_array = Int32Array::from(vec![Some(1), None, Some(3), None, Some(5)]);
5523        let str_array = StringArray::from(vec![None, Some("b"), None, Some("d"), None]);
5524
5525        // [1, "b", 3, "d", 5]
5526        let type_ids = vec![0, 1, 0, 1, 0].into();
5527
5528        let union_fields = [
5529            (0, Arc::new(Field::new("int", DataType::Int32, false))),
5530            (1, Arc::new(Field::new("str", DataType::Utf8, false))),
5531        ]
5532        .into_iter()
5533        .collect();
5534
5535        let union_array = UnionArray::try_new(
5536            union_fields,
5537            type_ids,
5538            None,
5539            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5540        )
5541        .unwrap();
5542
5543        let union_type = union_array.data_type().clone();
5544        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5545
5546        let rows = converter
5547            .convert_columns(&[Arc::new(union_array.clone())])
5548            .unwrap();
5549
5550        // round trip
5551        let back = converter.convert_rows(&rows).unwrap();
5552        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
5553
5554        assert_eq!(union_array.len(), back_union.len());
5555        for i in 0..union_array.len() {
5556            assert_eq!(union_array.type_id(i), back_union.type_id(i));
5557        }
5558    }
5559
5560    #[test]
5561    fn test_sparse_union_with_nulls() {
5562        // create a sparse union with Int32 (type_id = 0) and Utf8 (type_id = 1)
5563        let int_array = Int32Array::from(vec![Some(1), None, Some(3), None, Some(5)]);
5564        let str_array = StringArray::from(vec![None::<&str>; 5]);
5565
5566        // [1, null (both children null), 3, null (both children null), 5]
5567        let type_ids = vec![0, 1, 0, 1, 0].into();
5568
5569        let union_fields = [
5570            (0, Arc::new(Field::new("int", DataType::Int32, true))),
5571            (1, Arc::new(Field::new("str", DataType::Utf8, true))),
5572        ]
5573        .into_iter()
5574        .collect();
5575
5576        let union_array = UnionArray::try_new(
5577            union_fields,
5578            type_ids,
5579            None,
5580            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5581        )
5582        .unwrap();
5583
5584        let union_type = union_array.data_type().clone();
5585        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5586
5587        let rows = converter
5588            .convert_columns(&[Arc::new(union_array.clone())])
5589            .unwrap();
5590
5591        // round trip
5592        let back = converter.convert_rows(&rows).unwrap();
5593        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
5594
5595        assert_eq!(union_array.len(), back_union.len());
5596        for i in 0..union_array.len() {
5597            let expected_null = union_array.is_null(i);
5598            let actual_null = back_union.is_null(i);
5599            assert_eq!(expected_null, actual_null, "Null mismatch at index {i}");
5600            if !expected_null {
5601                assert_eq!(union_array.type_id(i), back_union.type_id(i));
5602            }
5603        }
5604    }
5605
5606    #[test]
5607    fn test_dense_union() {
5608        // create a dense union with Int32 (type_id = 0) and use Utf8 (type_id = 1)
5609        let int_array = Int32Array::from(vec![1, 3, 5]);
5610        let str_array = StringArray::from(vec!["a", "b"]);
5611
5612        let type_ids = vec![0, 1, 0, 1, 0].into();
5613
5614        // [1, "a", 3, "b", 5]
5615        let offsets = vec![0, 0, 1, 1, 2].into();
5616
5617        let union_fields = [
5618            (0, Arc::new(Field::new("int", DataType::Int32, false))),
5619            (1, Arc::new(Field::new("str", DataType::Utf8, false))),
5620        ]
5621        .into_iter()
5622        .collect();
5623
5624        let union_array = UnionArray::try_new(
5625            union_fields,
5626            type_ids,
5627            Some(offsets), // Dense mode
5628            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5629        )
5630        .unwrap();
5631
5632        let union_type = union_array.data_type().clone();
5633        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5634
5635        let rows = converter
5636            .convert_columns(&[Arc::new(union_array.clone())])
5637            .unwrap();
5638
5639        // round trip
5640        let back = converter.convert_rows(&rows).unwrap();
5641        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
5642
5643        assert_eq!(union_array.len(), back_union.len());
5644        for i in 0..union_array.len() {
5645            assert_eq!(union_array.type_id(i), back_union.type_id(i));
5646        }
5647    }
5648
5649    #[test]
5650    fn test_dense_union_with_nulls() {
5651        // create a dense union with Int32 (type_id = 0) and Utf8 (type_id = 1)
5652        let int_array = Int32Array::from(vec![Some(1), None, Some(5)]);
5653        let str_array = StringArray::from(vec![Some("a"), None]);
5654
5655        // [1, "a", 5, null (str null), null (int null)]
5656        let type_ids = vec![0, 1, 0, 1, 0].into();
5657        let offsets = vec![0, 0, 1, 1, 2].into();
5658
5659        let union_fields = [
5660            (0, Arc::new(Field::new("int", DataType::Int32, true))),
5661            (1, Arc::new(Field::new("str", DataType::Utf8, true))),
5662        ]
5663        .into_iter()
5664        .collect();
5665
5666        let union_array = UnionArray::try_new(
5667            union_fields,
5668            type_ids,
5669            Some(offsets),
5670            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5671        )
5672        .unwrap();
5673
5674        let union_type = union_array.data_type().clone();
5675        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5676
5677        let rows = converter
5678            .convert_columns(&[Arc::new(union_array.clone())])
5679            .unwrap();
5680
5681        // round trip
5682        let back = converter.convert_rows(&rows).unwrap();
5683        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
5684
5685        assert_eq!(union_array.len(), back_union.len());
5686        for i in 0..union_array.len() {
5687            let expected_null = union_array.is_null(i);
5688            let actual_null = back_union.is_null(i);
5689            assert_eq!(expected_null, actual_null, "Null mismatch at index {i}");
5690            if !expected_null {
5691                assert_eq!(union_array.type_id(i), back_union.type_id(i));
5692            }
5693        }
5694    }
5695
5696    #[test]
5697    fn test_union_ordering() {
5698        let int_array = Int32Array::from(vec![100, 5, 20]);
5699        let str_array = StringArray::from(vec!["z", "a"]);
5700
5701        // [100, "z", 5, "a", 20]
5702        let type_ids = vec![0, 1, 0, 1, 0].into();
5703        let offsets = vec![0, 0, 1, 1, 2].into();
5704
5705        let union_fields = [
5706            (0, Arc::new(Field::new("int", DataType::Int32, false))),
5707            (1, Arc::new(Field::new("str", DataType::Utf8, false))),
5708        ]
5709        .into_iter()
5710        .collect();
5711
5712        let union_array = UnionArray::try_new(
5713            union_fields,
5714            type_ids,
5715            Some(offsets),
5716            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5717        )
5718        .unwrap();
5719
5720        let union_type = union_array.data_type().clone();
5721        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5722
5723        let rows = converter.convert_columns(&[Arc::new(union_array)]).unwrap();
5724
5725        /*
5726        expected ordering
5727
5728        row 2: 5    - type_id 0
5729        row 4: 20   - type_id 0
5730        row 0: 100  - type id 0
5731        row 3: "a"  - type id 1
5732        row 1: "z"  - type id 1
5733        */
5734
5735        // 5 < "z"
5736        assert!(rows.row(2) < rows.row(1));
5737
5738        // 100 < "a"
5739        assert!(rows.row(0) < rows.row(3));
5740
5741        // among ints
5742        // 5 < 20
5743        assert!(rows.row(2) < rows.row(4));
5744        // 20 < 100
5745        assert!(rows.row(4) < rows.row(0));
5746
5747        // among strigns
5748        // "a" < "z"
5749        assert!(rows.row(3) < rows.row(1));
5750    }
5751
5752    #[test]
5753    fn test_row_converter_roundtrip_with_many_union_columns() {
5754        // col 1: Union(Int32, Utf8) [67, "hello"]
5755        let fields1 = UnionFields::try_new(
5756            vec![0, 1],
5757            vec![
5758                Field::new("int", DataType::Int32, true),
5759                Field::new("string", DataType::Utf8, true),
5760            ],
5761        )
5762        .unwrap();
5763
5764        let int_array1 = Int32Array::from(vec![Some(67), None]);
5765        let string_array1 = StringArray::from(vec![None::<&str>, Some("hello")]);
5766        let type_ids1 = vec![0i8, 1].into();
5767
5768        let union_array1 = UnionArray::try_new(
5769            fields1.clone(),
5770            type_ids1,
5771            None,
5772            vec![
5773                Arc::new(int_array1) as ArrayRef,
5774                Arc::new(string_array1) as ArrayRef,
5775            ],
5776        )
5777        .unwrap();
5778
5779        // col 2: Union(Int32, Utf8) [100, "world"]
5780        let fields2 = UnionFields::try_new(
5781            vec![0, 1],
5782            vec![
5783                Field::new("int", DataType::Int32, true),
5784                Field::new("string", DataType::Utf8, true),
5785            ],
5786        )
5787        .unwrap();
5788
5789        let int_array2 = Int32Array::from(vec![Some(100), None]);
5790        let string_array2 = StringArray::from(vec![None::<&str>, Some("world")]);
5791        let type_ids2 = vec![0i8, 1].into();
5792
5793        let union_array2 = UnionArray::try_new(
5794            fields2.clone(),
5795            type_ids2,
5796            None,
5797            vec![
5798                Arc::new(int_array2) as ArrayRef,
5799                Arc::new(string_array2) as ArrayRef,
5800            ],
5801        )
5802        .unwrap();
5803
5804        // create a row converter with 2 union columns
5805        let field1 = Field::new("col1", DataType::Union(fields1, UnionMode::Sparse), true);
5806        let field2 = Field::new("col2", DataType::Union(fields2, UnionMode::Sparse), true);
5807
5808        let sort_field1 = SortField::new(field1.data_type().clone());
5809        let sort_field2 = SortField::new(field2.data_type().clone());
5810
5811        let converter = RowConverter::new(vec![sort_field1, sort_field2]).unwrap();
5812
5813        let rows = converter
5814            .convert_columns(&[
5815                Arc::new(union_array1.clone()) as ArrayRef,
5816                Arc::new(union_array2.clone()) as ArrayRef,
5817            ])
5818            .unwrap();
5819
5820        // roundtrip
5821        let out = converter.convert_rows(&rows).unwrap();
5822
5823        let [col1, col2] = out.as_slice() else {
5824            panic!("expected 2 columns")
5825        };
5826
5827        let col1 = col1.as_any().downcast_ref::<UnionArray>().unwrap();
5828        let col2 = col2.as_any().downcast_ref::<UnionArray>().unwrap();
5829
5830        for (expected, got) in [union_array1, union_array2].iter().zip([col1, col2]) {
5831            assert_eq!(expected.len(), got.len());
5832            assert_eq!(expected.type_ids(), got.type_ids());
5833
5834            for i in 0..expected.len() {
5835                assert_eq!(expected.value(i).as_ref(), got.value(i).as_ref());
5836            }
5837        }
5838    }
5839
5840    #[test]
5841    fn test_row_converter_roundtrip_with_one_union_column() {
5842        let fields = UnionFields::try_new(
5843            vec![0, 1],
5844            vec![
5845                Field::new("int", DataType::Int32, true),
5846                Field::new("string", DataType::Utf8, true),
5847            ],
5848        )
5849        .unwrap();
5850
5851        let int_array = Int32Array::from(vec![Some(67), None]);
5852        let string_array = StringArray::from(vec![None::<&str>, Some("hello")]);
5853        let type_ids = vec![0i8, 1].into();
5854
5855        let union_array = UnionArray::try_new(
5856            fields.clone(),
5857            type_ids,
5858            None,
5859            vec![
5860                Arc::new(int_array) as ArrayRef,
5861                Arc::new(string_array) as ArrayRef,
5862            ],
5863        )
5864        .unwrap();
5865
5866        let field = Field::new("col", DataType::Union(fields, UnionMode::Sparse), true);
5867        let sort_field = SortField::new(field.data_type().clone());
5868        let converter = RowConverter::new(vec![sort_field]).unwrap();
5869
5870        let rows = converter
5871            .convert_columns(&[Arc::new(union_array.clone()) as ArrayRef])
5872            .unwrap();
5873
5874        // roundtrip
5875        let out = converter.convert_rows(&rows).unwrap();
5876
5877        let [col1] = out.as_slice() else {
5878            panic!("expected 1 column")
5879        };
5880
5881        let col = col1.as_any().downcast_ref::<UnionArray>().unwrap();
5882        assert_eq!(col.len(), union_array.len());
5883        assert_eq!(col.type_ids(), union_array.type_ids());
5884
5885        for i in 0..col.len() {
5886            assert_eq!(col.value(i).as_ref(), union_array.value(i).as_ref());
5887        }
5888    }
5889
5890    #[test]
5891    fn test_row_converter_roundtrip_with_non_default_union_type_ids() {
5892        // test with non-sequential type IDs (70, 85) instead of (0, 1)
5893        let fields = UnionFields::try_new(
5894            vec![70, 85],
5895            vec![
5896                Field::new("int", DataType::Int32, true),
5897                Field::new("string", DataType::Utf8, true),
5898            ],
5899        )
5900        .unwrap();
5901
5902        let int_array = Int32Array::from(vec![Some(67), None]);
5903        let string_array = StringArray::from(vec![None::<&str>, Some("hello")]);
5904        let type_ids = vec![70i8, 85].into();
5905
5906        let union_array = UnionArray::try_new(
5907            fields.clone(),
5908            type_ids,
5909            None,
5910            vec![
5911                Arc::new(int_array) as ArrayRef,
5912                Arc::new(string_array) as ArrayRef,
5913            ],
5914        )
5915        .unwrap();
5916
5917        let field = Field::new("col", DataType::Union(fields, UnionMode::Sparse), true);
5918        let sort_field = SortField::new(field.data_type().clone());
5919        let converter = RowConverter::new(vec![sort_field]).unwrap();
5920
5921        let rows = converter
5922            .convert_columns(&[Arc::new(union_array.clone()) as ArrayRef])
5923            .unwrap();
5924
5925        // roundtrip
5926        let out = converter.convert_rows(&rows).unwrap();
5927
5928        let [col1] = out.as_slice() else {
5929            panic!("expected 1 column")
5930        };
5931
5932        let col = col1.as_any().downcast_ref::<UnionArray>().unwrap();
5933        assert_eq!(col.len(), union_array.len());
5934        assert_eq!(col.type_ids(), union_array.type_ids());
5935
5936        for i in 0..col.len() {
5937            assert_eq!(col.value(i).as_ref(), union_array.value(i).as_ref());
5938        }
5939    }
5940
5941    #[test]
5942    fn rows_size_should_count_for_capacity() {
5943        let row_converter = RowConverter::new(vec![SortField::new(DataType::UInt8)]).unwrap();
5944
5945        let empty_rows_size_with_preallocate_rows_and_data = {
5946            let rows = row_converter.empty_rows(1000, 1000);
5947
5948            rows.size()
5949        };
5950        let empty_rows_size_with_preallocate_rows = {
5951            let rows = row_converter.empty_rows(1000, 0);
5952
5953            rows.size()
5954        };
5955        let empty_rows_size_with_preallocate_data = {
5956            let rows = row_converter.empty_rows(0, 1000);
5957
5958            rows.size()
5959        };
5960        let empty_rows_size_without_preallocate = {
5961            let rows = row_converter.empty_rows(0, 0);
5962
5963            rows.size()
5964        };
5965
5966        assert!(
5967            empty_rows_size_with_preallocate_rows_and_data > empty_rows_size_with_preallocate_rows,
5968            "{empty_rows_size_with_preallocate_rows_and_data} should be larger than {empty_rows_size_with_preallocate_rows}"
5969        );
5970        assert!(
5971            empty_rows_size_with_preallocate_rows_and_data > empty_rows_size_with_preallocate_data,
5972            "{empty_rows_size_with_preallocate_rows_and_data} should be larger than {empty_rows_size_with_preallocate_data}"
5973        );
5974        assert!(
5975            empty_rows_size_with_preallocate_rows > empty_rows_size_without_preallocate,
5976            "{empty_rows_size_with_preallocate_rows} should be larger than {empty_rows_size_without_preallocate}"
5977        );
5978        assert!(
5979            empty_rows_size_with_preallocate_data > empty_rows_size_without_preallocate,
5980            "{empty_rows_size_with_preallocate_data} should be larger than {empty_rows_size_without_preallocate}"
5981        );
5982    }
5983
5984    #[test]
5985    fn test_struct_no_child_fields() {
5986        fn run_test(array: ArrayRef) {
5987            let sort_fields = vec![SortField::new(array.data_type().clone())];
5988            let converter = RowConverter::new(sort_fields).unwrap();
5989            let r = converter.convert_columns(&[Arc::clone(&array)]).unwrap();
5990
5991            let back = converter.convert_rows(&r).unwrap();
5992            assert_eq!(back.len(), 1);
5993            assert_eq!(&back[0], &array);
5994        }
5995
5996        let s = Arc::new(StructArray::new_empty_fields(5, None)) as ArrayRef;
5997        run_test(s);
5998
5999        let s = Arc::new(StructArray::new_empty_fields(
6000            5,
6001            Some(vec![true, false, true, false, false].into()),
6002        )) as ArrayRef;
6003        run_test(s);
6004    }
6005
6006    #[test]
6007    fn reserve_should_increase_capacity_to_the_requested_size() {
6008        let row_converter = RowConverter::new(vec![SortField::new(DataType::UInt8)]).unwrap();
6009        let mut empty_rows = row_converter.empty_rows(0, 0);
6010        empty_rows.reserve(50, 50);
6011        let before_size = empty_rows.size();
6012        empty_rows.reserve(50, 50);
6013        assert_eq!(
6014            empty_rows.size(),
6015            before_size,
6016            "Size should not change when reserving already reserved space"
6017        );
6018        empty_rows.reserve(10, 20);
6019        assert_eq!(
6020            empty_rows.size(),
6021            before_size,
6022            "Size should not change when already have space for the expected reserved data"
6023        );
6024
6025        empty_rows.reserve(100, 20);
6026        assert!(
6027            empty_rows.size() > before_size,
6028            "Size should increase when reserving more space than previously reserved"
6029        );
6030
6031        let before_size = empty_rows.size();
6032
6033        empty_rows.reserve(20, 100);
6034        assert!(
6035            empty_rows.size() > before_size,
6036            "Size should increase when reserving more space than previously reserved"
6037        );
6038    }
6039
6040    #[test]
6041    fn empty_rows_should_return_empty_lengths_iterator() {
6042        let rows = RowConverter::new(vec![SortField::new(DataType::UInt8)])
6043            .unwrap()
6044            .empty_rows(0, 0);
6045        let mut lengths_iter = rows.lengths();
6046        assert_eq!(lengths_iter.next(), None);
6047    }
6048
6049    #[test]
6050    #[should_panic(expected = "row index out of bounds")]
6051    fn row_should_panic_on_overflowing_index() {
6052        let rows = RowConverter::new(vec![SortField::new(DataType::Int32)])
6053            .unwrap()
6054            .empty_rows(0, 0);
6055        rows.row(usize::MAX);
6056    }
6057
6058    #[test]
6059    #[should_panic(expected = "row index out of bounds")]
6060    fn row_len_should_panic_on_overflowing_index() {
6061        let rows = RowConverter::new(vec![SortField::new(DataType::Int32)])
6062            .unwrap()
6063            .empty_rows(0, 0);
6064        rows.row_len(usize::MAX);
6065    }
6066
6067    #[test]
6068    fn test_nested_null_list() {
6069        let null_array = Arc::new(NullArray::new(3));
6070        // [[NULL], [], [NULL, NULL]]
6071        let list: ArrayRef = Arc::new(ListArray::new(
6072            Field::new_list_field(DataType::Null, true).into(),
6073            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6074            null_array,
6075            None,
6076        ));
6077
6078        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6079        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6080        let back = converter.convert_rows(&rows).unwrap();
6081
6082        assert_eq!(&list, &back[0]);
6083    }
6084
6085    // Test case from original issue #9227: [[NULL]] - double nested List with Null
6086    #[test]
6087    fn test_double_nested_null_list() {
6088        let null_array = Arc::new(NullArray::new(1));
6089        // [NULL]
6090        let nested_field = Arc::new(Field::new_list_field(DataType::Null, true));
6091        let nested_list = Arc::new(ListArray::new(
6092            nested_field.clone(),
6093            OffsetBuffer::from_lengths(vec![1]),
6094            null_array,
6095            None,
6096        ));
6097        // [[NULL]]
6098        let list = Arc::new(ListArray::new(
6099            Field::new_list_field(DataType::List(nested_field), true).into(),
6100            OffsetBuffer::from_lengths(vec![1]),
6101            nested_list,
6102            None,
6103        )) as ArrayRef;
6104
6105        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6106        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6107        let back = converter.convert_rows(&rows).unwrap();
6108
6109        assert_eq!(&list, &back[0]);
6110    }
6111
6112    // Test LargeList<Null>
6113    #[test]
6114    fn test_large_list_null() {
6115        let null_array = Arc::new(NullArray::new(3));
6116        // [[NULL], [], [NULL, NULL]] as LargeList
6117        let list: ArrayRef = Arc::new(LargeListArray::new(
6118            Field::new_list_field(DataType::Null, true).into(),
6119            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6120            null_array,
6121            None,
6122        ));
6123
6124        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6125        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6126        let back = converter.convert_rows(&rows).unwrap();
6127
6128        assert_eq!(&list, &back[0]);
6129    }
6130
6131    // Test FixedSizeList<Null>
6132    #[test]
6133    fn test_fixed_size_list_null() {
6134        let null_array = Arc::new(NullArray::new(6));
6135        // [[NULL, NULL], [NULL, NULL], [NULL, NULL]] as FixedSizeList
6136        let list: ArrayRef = Arc::new(FixedSizeListArray::new(
6137            Arc::new(Field::new_list_field(DataType::Null, true)),
6138            2,
6139            null_array,
6140            None,
6141        ));
6142
6143        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6144        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6145        let back = converter.convert_rows(&rows).unwrap();
6146
6147        assert_eq!(&list, &back[0]);
6148    }
6149
6150    /// Ensure dictionaries nested within FixedSizeLists are not flattened
6151    #[test]
6152    fn test_fixed_size_list_of_dictionaries_round_trips() {
6153        // Build one row = ["a", "b"] as
6154        // `FixedSizeList<Dictionary<Int32, Utf8>, 2>`.
6155        let dict_dt = DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Utf8));
6156        let element_field = Arc::new(Field::new("item", dict_dt.clone(), true));
6157        let fsl_dt = DataType::FixedSizeList(Arc::clone(&element_field), 2);
6158
6159        let values = Arc::new(StringArray::from(vec!["a", "b"]));
6160        let keys = Int32Array::from(vec![0, 1]);
6161        let dict = DictionaryArray::<Int32Type>::try_new(keys, values).unwrap();
6162        let fsl: ArrayRef = Arc::new(FixedSizeListArray::new(
6163            Arc::clone(&element_field),
6164            2,
6165            Arc::new(dict),
6166            None,
6167        ));
6168
6169        assert!(RowConverter::supports_fields(&[SortField::new(
6170            fsl_dt.clone()
6171        )]));
6172
6173        let converter = RowConverter::new(vec![SortField::new(fsl_dt.clone())]).unwrap();
6174        let rows = converter.convert_columns(&[Arc::clone(&fsl)]).unwrap();
6175
6176        // Before the fix this panicked at the `.unwrap()` because
6177        // `convert_rows` returned `Err(InvalidArgumentError(...))`.
6178        let back = converter.convert_rows(&rows).unwrap();
6179        assert_eq!(back.len(), 1);
6180
6181        // The returned array is a `FixedSizeList` with a decoded
6182        // (flattened) child — same self-consistent shape the other
6183        // list-like decoders produce for dictionary children.
6184        let out = back[0]
6185            .as_any()
6186            .downcast_ref::<FixedSizeListArray>()
6187            .expect("decoded array must be a FixedSizeListArray");
6188        assert_eq!(out.len(), 1);
6189        assert_eq!(out.value_length(), 2);
6190        // Child data type is the flattened `Utf8`, not the declared
6191        // `Dictionary`. Callers that want the dictionary back need to
6192        // re-encode (see the module docs).
6193        assert_eq!(out.values().data_type(), &DataType::Utf8);
6194
6195        // Sanity: values survived the round trip.
6196        let values = out
6197            .values()
6198            .as_any()
6199            .downcast_ref::<StringArray>()
6200            .expect("child must be a StringArray after flattening");
6201        assert_eq!(values.value(0), "a");
6202        assert_eq!(values.value(1), "b");
6203    }
6204
6205    // Test List<Null> with various combinations of nulls and empty lists
6206    #[test]
6207    fn test_list_null_variations() {
6208        // Test case: [[NULL], [], [NULL, NULL]]
6209        let null_array = Arc::new(NullArray::new(3));
6210        let list: ArrayRef = Arc::new(ListArray::new(
6211            Field::new_list_field(DataType::Null, true).into(),
6212            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6213            null_array,
6214            None,
6215        ));
6216
6217        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6218        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6219        let back = converter.convert_rows(&rows).unwrap();
6220        assert_eq!(&list, &back[0]);
6221
6222        // Test case: [[NULL], null, [NULL, NULL]] - middle element is null
6223        let null_array = Arc::new(NullArray::new(3));
6224        let list: ArrayRef = Arc::new(ListArray::new(
6225            Field::new_list_field(DataType::Null, true).into(),
6226            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6227            null_array,
6228            Some(vec![true, false, true].into()),
6229        ));
6230
6231        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6232        let back = converter.convert_rows(&rows).unwrap();
6233        assert_eq!(&list, &back[0]);
6234
6235        // Test case: [] - empty list
6236        let null_array = Arc::new(NullArray::new(0));
6237        let list: ArrayRef = Arc::new(ListArray::new(
6238            Field::new_list_field(DataType::Null, true).into(),
6239            OffsetBuffer::from_lengths(vec![]),
6240            null_array,
6241            None,
6242        ));
6243
6244        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6245        let back = converter.convert_rows(&rows).unwrap();
6246        assert_eq!(&list, &back[0]);
6247
6248        // Test case: [[], [], []] - all empty sublists
6249        let null_array = Arc::new(NullArray::new(0));
6250        let list: ArrayRef = Arc::new(ListArray::new(
6251            Field::new_list_field(DataType::Null, true).into(),
6252            OffsetBuffer::from_lengths(vec![0, 0, 0]),
6253            null_array,
6254            None,
6255        ));
6256
6257        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6258        let back = converter.convert_rows(&rows).unwrap();
6259        assert_eq!(&list, &back[0]);
6260    }
6261
6262    // Test List<Null> with descending order
6263    #[test]
6264    fn test_list_null_descending() {
6265        let null_array = Arc::new(NullArray::new(3));
6266        // [[NULL], [], [NULL, NULL]]
6267        let list: ArrayRef = Arc::new(ListArray::new(
6268            Field::new_list_field(DataType::Null, true).into(),
6269            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6270            null_array,
6271            None,
6272        ));
6273
6274        let options = SortOptions::default().with_descending(true);
6275        let field = SortField::new_with_options(list.data_type().clone(), options);
6276        let converter = RowConverter::new(vec![field]).unwrap();
6277        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6278        let back = converter.convert_rows(&rows).unwrap();
6279
6280        assert_eq!(&list, &back[0]);
6281    }
6282
6283    // Test Struct with Null field
6284    #[test]
6285    fn test_struct_with_null_field() {
6286        // Struct { a: Null, b: Int32 }
6287        let null_array = Arc::new(NullArray::new(3));
6288        let int_array = Arc::new(Int32Array::from(vec![1, 2, 3]));
6289
6290        let struct_array: ArrayRef = Arc::new(StructArray::new(
6291            vec![
6292                Arc::new(Field::new("a", DataType::Null, true)),
6293                Arc::new(Field::new("b", DataType::Int32, true)),
6294            ]
6295            .into(),
6296            vec![null_array, int_array],
6297            Some(vec![true, true, false].into()), // validity bitmap
6298        ));
6299
6300        let converter =
6301            RowConverter::new(vec![SortField::new(struct_array.data_type().clone())]).unwrap();
6302        let rows = converter
6303            .convert_columns(&[Arc::clone(&struct_array)])
6304            .unwrap();
6305        let back = converter.convert_rows(&rows).unwrap();
6306
6307        assert_eq!(&struct_array, &back[0]);
6308    }
6309
6310    // Test nested Struct with Null
6311    #[test]
6312    fn test_nested_struct_with_null() {
6313        // Inner struct: { x: Null }
6314        let inner_null = Arc::new(NullArray::new(2));
6315        let inner_struct = Arc::new(StructArray::new(
6316            vec![Arc::new(Field::new("x", DataType::Null, true))].into(),
6317            vec![inner_null],
6318            None,
6319        ));
6320
6321        // Outer struct: { inner: Struct { x: Null }, y: Int32 }
6322        let y_array = Arc::new(Int32Array::from(vec![10, 20]));
6323        let outer_struct: ArrayRef = Arc::new(StructArray::new(
6324            vec![
6325                Arc::new(Field::new("inner", inner_struct.data_type().clone(), true)),
6326                Arc::new(Field::new("y", DataType::Int32, true)),
6327            ]
6328            .into(),
6329            vec![inner_struct, y_array],
6330            None,
6331        ));
6332
6333        let converter =
6334            RowConverter::new(vec![SortField::new(outer_struct.data_type().clone())]).unwrap();
6335        let rows = converter
6336            .convert_columns(&[Arc::clone(&outer_struct)])
6337            .unwrap();
6338        let back = converter.convert_rows(&rows).unwrap();
6339
6340        assert_eq!(&outer_struct, &back[0]);
6341    }
6342
6343    // Test Map<Utf8, Null> with various combinations of nulls and empty maps
6344    #[test]
6345    fn test_map_null_variations() {
6346        // Map with Null values: [{a: NULL}, {}, {b: NULL, c: NULL}]
6347        let keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6348        let null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6349
6350        let offsets = OffsetBuffer::new(vec![0, 1, 1, 3].into());
6351        let entries_fields = vec![
6352            Arc::new(Field::new(
6353                Field::MAP_KEY_FIELD_DEFAULT_NAME,
6354                DataType::Utf8,
6355                false,
6356            )),
6357            Arc::new(Field::new(
6358                Field::MAP_VALUE_FIELD_DEFAULT_NAME,
6359                DataType::Null,
6360                true,
6361            )),
6362        ];
6363        let struct_field = Arc::new(Field::new(
6364            Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
6365            DataType::Struct(entries_fields.clone().into()),
6366            false,
6367        ));
6368        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6369
6370        let map: ArrayRef = Arc::new(MapArray::new(
6371            struct_field.clone(),
6372            offsets,
6373            entries,
6374            None,
6375            false,
6376        ));
6377
6378        let converter = RowConverter::new(vec![SortField::new(map.data_type().clone())]).unwrap();
6379        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6380        let back = converter.convert_rows(&rows).unwrap();
6381        assert_eq!(back.len(), 1);
6382        back[0].to_data().validate_full().unwrap();
6383        assert_eq!(&map, &back[0]);
6384
6385        // Map with Null values and null map entries: [{a: NULL}, null, {b: NULL, c: NULL}]
6386        let keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6387        let null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6388
6389        let offsets = OffsetBuffer::new(vec![0, 1, 1, 3].into());
6390        let entries_fields = vec![
6391            Arc::new(Field::new(
6392                Field::MAP_KEY_FIELD_DEFAULT_NAME,
6393                DataType::Utf8,
6394                false,
6395            )),
6396            Arc::new(Field::new(
6397                Field::MAP_VALUE_FIELD_DEFAULT_NAME,
6398                DataType::Null,
6399                true,
6400            )),
6401        ];
6402        let struct_field = Arc::new(Field::new(
6403            Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
6404            DataType::Struct(entries_fields.clone().into()),
6405            false,
6406        ));
6407        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6408
6409        let map: ArrayRef = Arc::new(MapArray::new(
6410            struct_field.clone(),
6411            offsets,
6412            entries,
6413            Some(vec![true, false, true].into()),
6414            false,
6415        ));
6416
6417        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6418        let back = converter.convert_rows(&rows).unwrap();
6419        assert_eq!(back.len(), 1);
6420        back[0].to_data().validate_full().unwrap();
6421        assert_eq!(&map, &back[0]);
6422
6423        // Empty map array with Null value type
6424        let keys = Arc::new(StringArray::from(Vec::<&str>::new())) as ArrayRef;
6425        let null_values = Arc::new(NullArray::new(0)) as ArrayRef;
6426
6427        let offsets = OffsetBuffer::new(vec![0i32].into());
6428        let entries_fields = vec![
6429            Arc::new(Field::new(
6430                Field::MAP_KEY_FIELD_DEFAULT_NAME,
6431                DataType::Utf8,
6432                false,
6433            )),
6434            Arc::new(Field::new(
6435                Field::MAP_VALUE_FIELD_DEFAULT_NAME,
6436                DataType::Null,
6437                true,
6438            )),
6439        ];
6440        let struct_field = Arc::new(Field::new(
6441            Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
6442            DataType::Struct(entries_fields.clone().into()),
6443            false,
6444        ));
6445        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6446
6447        let map: ArrayRef = Arc::new(MapArray::new(struct_field, offsets, entries, None, false));
6448
6449        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6450        let back = converter.convert_rows(&rows).unwrap();
6451        assert_eq!(back.len(), 1);
6452        back[0].to_data().validate_full().unwrap();
6453        assert_eq!(&map, &back[0]);
6454    }
6455
6456    // Test Map<Utf8, Null> with descending order
6457    #[test]
6458    fn test_map_null_descending() {
6459        // [{a: NULL}, {}, {b: NULL, c: NULL}]
6460        let keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6461        let null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6462
6463        let offsets = OffsetBuffer::new(vec![0, 1, 1, 3].into());
6464        let entries_fields = vec![
6465            Arc::new(Field::new(
6466                Field::MAP_KEY_FIELD_DEFAULT_NAME,
6467                DataType::Utf8,
6468                false,
6469            )),
6470            Arc::new(Field::new(
6471                Field::MAP_VALUE_FIELD_DEFAULT_NAME,
6472                DataType::Null,
6473                true,
6474            )),
6475        ];
6476        let struct_field = Arc::new(Field::new(
6477            Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
6478            DataType::Struct(entries_fields.clone().into()),
6479            false,
6480        ));
6481        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6482
6483        let map: ArrayRef = Arc::new(MapArray::new(struct_field, offsets, entries, None, false));
6484
6485        let options = SortOptions::default().with_descending(true);
6486        let field = SortField::new_with_options(map.data_type().clone(), options);
6487        let converter = RowConverter::new(vec![field]).unwrap();
6488        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6489        let back = converter.convert_rows(&rows).unwrap();
6490        assert_eq!(back.len(), 1);
6491        back[0].to_data().validate_full().unwrap();
6492        assert_eq!(&map, &back[0]);
6493    }
6494
6495    // Test Map<Utf8, Null> all empty maps
6496    #[test]
6497    fn test_map_null_all_empty() {
6498        let keys = Arc::new(StringArray::from(Vec::<&str>::new())) as ArrayRef;
6499        let null_values = Arc::new(NullArray::new(0)) as ArrayRef;
6500
6501        let offsets = OffsetBuffer::new(vec![0, 0, 0, 0].into());
6502        let entries_fields = vec![
6503            Arc::new(Field::new(
6504                Field::MAP_KEY_FIELD_DEFAULT_NAME,
6505                DataType::Utf8,
6506                false,
6507            )),
6508            Arc::new(Field::new(
6509                Field::MAP_VALUE_FIELD_DEFAULT_NAME,
6510                DataType::Null,
6511                true,
6512            )),
6513        ];
6514        let struct_field = Arc::new(Field::new(
6515            Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
6516            DataType::Struct(entries_fields.clone().into()),
6517            false,
6518        ));
6519        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6520
6521        let map: ArrayRef = Arc::new(MapArray::new(struct_field, offsets, entries, None, false));
6522
6523        let converter = RowConverter::new(vec![SortField::new(map.data_type().clone())]).unwrap();
6524        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6525
6526        // All empty maps should be equal
6527        assert_eq!(rows.row(0), rows.row(1));
6528        assert_eq!(rows.row(1), rows.row(2));
6529
6530        let back = converter.convert_rows(&rows).unwrap();
6531        assert_eq!(back.len(), 1);
6532        back[0].to_data().validate_full().unwrap();
6533        assert_eq!(&map, &back[0]);
6534    }
6535
6536    // Test Map<Utf8, Map<Utf8, Null>> - nested map with Null leaf values
6537    #[test]
6538    fn test_nested_map_null() {
6539        // Inner map entries: {a: NULL, b: NULL, c: NULL}
6540        let inner_keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6541        let inner_null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6542
6543        let inner_entries_fields = vec![
6544            Arc::new(Field::new(
6545                Field::MAP_KEY_FIELD_DEFAULT_NAME,
6546                DataType::Utf8,
6547                false,
6548            )),
6549            Arc::new(Field::new(
6550                Field::MAP_VALUE_FIELD_DEFAULT_NAME,
6551                DataType::Null,
6552                true,
6553            )),
6554        ];
6555        let inner_struct_field = Arc::new(Field::new(
6556            Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
6557            DataType::Struct(inner_entries_fields.clone().into()),
6558            false,
6559        ));
6560        let inner_entries = StructArray::new(
6561            inner_entries_fields.clone().into(),
6562            vec![inner_keys, inner_null_values],
6563            None,
6564        );
6565
6566        // Inner maps: [{a: NULL}, {b: NULL, c: NULL}]
6567        let inner_map = Arc::new(MapArray::new(
6568            inner_struct_field.clone(),
6569            OffsetBuffer::new(vec![0, 1, 3].into()),
6570            inner_entries,
6571            None,
6572            false,
6573        )) as ArrayRef;
6574
6575        // Outer map entries
6576        let outer_keys = Arc::new(StringArray::from(vec!["x", "y"])) as ArrayRef;
6577
6578        let inner_map_type = DataType::Map(inner_struct_field.clone(), false);
6579        let outer_entries_fields = vec![
6580            Arc::new(Field::new(
6581                Field::MAP_KEY_FIELD_DEFAULT_NAME,
6582                DataType::Utf8,
6583                false,
6584            )),
6585            Arc::new(Field::new(
6586                Field::MAP_VALUE_FIELD_DEFAULT_NAME,
6587                inner_map_type,
6588                true,
6589            )),
6590        ];
6591        let outer_struct_field = Arc::new(Field::new(
6592            Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
6593            DataType::Struct(outer_entries_fields.clone().into()),
6594            false,
6595        ));
6596        let outer_entries = StructArray::new(
6597            outer_entries_fields.into(),
6598            vec![outer_keys, inner_map],
6599            None,
6600        );
6601
6602        // Outer map: [{x: {a: NULL}}, {y: {b: NULL, c: NULL}}]
6603        let map: ArrayRef = Arc::new(MapArray::new(
6604            outer_struct_field,
6605            OffsetBuffer::new(vec![0, 1, 2].into()),
6606            outer_entries,
6607            None,
6608            false,
6609        ));
6610
6611        let converter = RowConverter::new(vec![SortField::new(map.data_type().clone())]).unwrap();
6612        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6613        let back = converter.convert_rows(&rows).unwrap();
6614        assert_eq!(back.len(), 1);
6615        back[0].to_data().validate_full().unwrap();
6616        assert_eq!(&map, &back[0]);
6617    }
6618
6619    // Test List<Map<Utf8, Null>> - list containing maps with Null values
6620    #[test]
6621    fn test_list_of_map_null() {
6622        // Map entries: {a: NULL, b: NULL, c: NULL}
6623        let keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6624        let null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6625
6626        let entries_fields = vec![
6627            Arc::new(Field::new(
6628                Field::MAP_KEY_FIELD_DEFAULT_NAME,
6629                DataType::Utf8,
6630                false,
6631            )),
6632            Arc::new(Field::new(
6633                Field::MAP_VALUE_FIELD_DEFAULT_NAME,
6634                DataType::Null,
6635                true,
6636            )),
6637        ];
6638        let struct_field = Arc::new(Field::new(
6639            Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
6640            DataType::Struct(entries_fields.clone().into()),
6641            false,
6642        ));
6643        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6644
6645        // Maps: [{a: NULL}, {}, {b: NULL, c: NULL}]
6646        let map_array = Arc::new(MapArray::new(
6647            struct_field.clone(),
6648            OffsetBuffer::new(vec![0, 1, 1, 3].into()),
6649            entries,
6650            None,
6651            false,
6652        )) as ArrayRef;
6653
6654        let map_type = DataType::Map(struct_field, false);
6655        // List of maps: [[{a: NULL}], [{}, {b: NULL, c: NULL}]]
6656        let list: ArrayRef = Arc::new(ListArray::new(
6657            Arc::new(Field::new_list_field(map_type, true)),
6658            OffsetBuffer::new(vec![0, 1, 3].into()),
6659            map_array,
6660            None,
6661        ));
6662
6663        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6664        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6665        let back = converter.convert_rows(&rows).unwrap();
6666        assert_eq!(&list, &back[0]);
6667    }
6668
6669    // Test Map<Utf8, List<Null>> - map with list values containing Null
6670    #[test]
6671    fn test_map_of_list_null() {
6672        // Inner list values: [NULL, NULL, NULL]
6673        let null_array = Arc::new(NullArray::new(3)) as ArrayRef;
6674        // Lists: [[NULL], [], [NULL, NULL]]
6675        let list_array = Arc::new(ListArray::new(
6676            Arc::new(Field::new_list_field(DataType::Null, true)),
6677            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6678            null_array,
6679            None,
6680        )) as ArrayRef;
6681
6682        let keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6683
6684        let list_type = list_array.data_type().clone();
6685        let entries_fields = vec![
6686            Arc::new(Field::new(
6687                Field::MAP_KEY_FIELD_DEFAULT_NAME,
6688                DataType::Utf8,
6689                false,
6690            )),
6691            Arc::new(Field::new(
6692                Field::MAP_VALUE_FIELD_DEFAULT_NAME,
6693                list_type,
6694                true,
6695            )),
6696        ];
6697        let struct_field = Arc::new(Field::new(
6698            Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
6699            DataType::Struct(entries_fields.clone().into()),
6700            false,
6701        ));
6702        let entries = StructArray::new(entries_fields.into(), vec![keys, list_array], None);
6703
6704        // Map: [{a: [NULL], b: [], c: [NULL, NULL]}]
6705        let map: ArrayRef = Arc::new(MapArray::new(
6706            struct_field,
6707            OffsetBuffer::new(vec![0, 3].into()),
6708            entries,
6709            None,
6710            false,
6711        ));
6712
6713        let converter = RowConverter::new(vec![SortField::new(map.data_type().clone())]).unwrap();
6714        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6715        let back = converter.convert_rows(&rows).unwrap();
6716        assert_eq!(back.len(), 1);
6717        back[0].to_data().validate_full().unwrap();
6718        assert_eq!(&map, &back[0]);
6719    }
6720
6721    #[test]
6722    fn empty_row_iter_next_back() {
6723        let rows = RowConverter::new(vec![SortField::new(DataType::UInt8)])
6724            .unwrap()
6725            .empty_rows(0, 0);
6726        let mut rows_iter = rows.iter();
6727        assert_eq!(rows_iter.next_back(), None);
6728        assert_eq!(rows_iter.next_back(), None);
6729        assert_eq!(rows_iter.next_back(), None);
6730    }
6731
6732    /// Round-trip through `with_skip_utf8_validate` confirms skipping validation preserves values.
6733    #[test]
6734    fn test_row_parser_skip_utf8_validation_roundtrip() {
6735        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
6736        let array = StringArray::from(vec!["arrow", "rust"]);
6737        let rows = converter.convert_columns(&[Arc::new(array) as _]).unwrap();
6738        let binary = rows.try_into_binary().expect("fits in i32 offsets");
6739
6740        // SAFETY: bytes come from this RowConverter and are known-valid UTF-8.
6741        let parser = unsafe { RowParser::with_skip_utf8_validate(Arc::clone(&converter.fields)) };
6742
6743        let decoded = converter
6744            .convert_rows(binary.iter().map(|b| parser.parse(b.unwrap())))
6745            .unwrap();
6746        let got: Vec<_> = decoded[0].as_string::<i32>().iter().flatten().collect();
6747        assert_eq!(got, vec!["arrow", "rust"]);
6748    }
6749
6750    #[test]
6751    fn row_iter_next_back() {
6752        let row_converter = RowConverter::new(vec![SortField::new(DataType::UInt8)]).unwrap();
6753        let mut rng = StdRng::seed_from_u64(42);
6754        let array = generate_primitive_array::<UInt8Type>(&mut rng, 100, 0.8);
6755        let rows = row_converter.convert_columns(&[Arc::new(array)]).unwrap();
6756
6757        let mut rows_iter = rows.iter();
6758        let mut bytes: Vec<u8> = vec![];
6759
6760        while let Some(row) = rows_iter.next_back() {
6761            bytes.extend(row.data.iter().rev());
6762        }
6763
6764        bytes.reverse();
6765
6766        assert_eq!(
6767            bytes,
6768            &rows.buffer.as_slice()[..*rows.offsets.last().unwrap()]
6769        );
6770
6771        assert_eq!(rows_iter.next_back(), None);
6772        assert_eq!(rows_iter.next(), None);
6773    }
6774}