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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 colum in columns.iter().skip(1) {
1055            if colum.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                    colum.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    /// Returns the size of this instance in bytes
1260    ///
1261    /// Includes the size of `Self`.
1262    pub fn size(&self) -> usize {
1263        std::mem::size_of::<Self>()
1264            + self.fields.iter().map(|x| x.size()).sum::<usize>()
1265            + self.codecs.capacity() * std::mem::size_of::<Codec>()
1266            + self.codecs.iter().map(Codec::size).sum::<usize>()
1267    }
1268}
1269
1270/// A [`RowParser`] can be created from a [`RowConverter`] and used to parse bytes to [`Row`]
1271#[derive(Debug)]
1272pub struct RowParser {
1273    config: RowConfig,
1274}
1275
1276impl RowParser {
1277    fn new(fields: Arc<[SortField]>) -> Self {
1278        Self {
1279            config: RowConfig {
1280                fields,
1281                validate_utf8: true,
1282            },
1283        }
1284    }
1285
1286    /// Creates a [`Row`] from the provided `bytes`.
1287    ///
1288    /// `bytes` must be a [`Row`] produced by the [`RowConverter`] associated with
1289    /// this [`RowParser`], otherwise subsequent operations with the produced [`Row`] may panic
1290    pub fn parse<'a>(&'a self, bytes: &'a [u8]) -> Row<'a> {
1291        Row {
1292            data: bytes,
1293            config: &self.config,
1294        }
1295    }
1296}
1297
1298/// The config of a given set of [`Row`]
1299#[derive(Debug, Clone)]
1300struct RowConfig {
1301    /// The schema for these rows
1302    fields: Arc<[SortField]>,
1303    /// Whether to run UTF-8 validation when converting to arrow arrays
1304    validate_utf8: bool,
1305}
1306
1307/// A row-oriented representation of arrow data, that is normalized for comparison.
1308///
1309/// See the [module level documentation](self) and [`RowConverter`] for more details.
1310#[derive(Debug, Clone)]
1311pub struct Rows {
1312    /// Underlying row bytes
1313    buffer: Vec<u8>,
1314    /// Row `i` has data `&buffer[offsets[i]..offsets[i+1]]`
1315    offsets: Vec<usize>,
1316    /// The config for these rows
1317    config: RowConfig,
1318}
1319
1320/// The iterator type for [`Rows::lengths`]
1321pub type RowLengthIter<'a> = Map<Windows<'a, usize>, fn(&'a [usize]) -> usize>;
1322
1323impl Rows {
1324    /// Append a [`Row`] to this [`Rows`]
1325    pub fn push(&mut self, row: Row<'_>) {
1326        assert!(
1327            Arc::ptr_eq(&row.config.fields, &self.config.fields),
1328            "row was not produced by this RowConverter"
1329        );
1330        self.config.validate_utf8 |= row.config.validate_utf8;
1331        self.buffer.extend_from_slice(row.data);
1332        self.offsets.push(self.buffer.len())
1333    }
1334
1335    /// Reserve capacity for `row_capacity` rows with a total length of `data_capacity`
1336    pub fn reserve(&mut self, row_capacity: usize, data_capacity: usize) {
1337        self.buffer.reserve(data_capacity);
1338        self.offsets.reserve(row_capacity);
1339    }
1340
1341    /// Returns the row at index `row`
1342    pub fn row(&self, row: usize) -> Row<'_> {
1343        self.checked_row_end(row);
1344        unsafe { self.row_unchecked(row) }
1345    }
1346
1347    fn checked_row_end(&self, row: usize) -> usize {
1348        row.checked_add(1)
1349            .filter(|end| *end < self.offsets.len())
1350            .expect("row index out of bounds")
1351    }
1352
1353    /// Returns the row at `index` without bounds checking
1354    ///
1355    /// # Safety
1356    /// Caller must ensure that `index + 1` is less than the number of offsets (#rows + 1)
1357    pub unsafe fn row_unchecked(&self, index: usize) -> Row<'_> {
1358        let end = unsafe { self.offsets.get_unchecked(index + 1) };
1359        let start = unsafe { self.offsets.get_unchecked(index) };
1360        let data = unsafe { self.buffer.get_unchecked(*start..*end) };
1361        Row {
1362            data,
1363            config: &self.config,
1364        }
1365    }
1366
1367    /// Returns the number of bytes the row at index `row` is occupying,
1368    /// that is, what is the length of the returned [`Row::data`] will be.
1369    pub fn row_len(&self, row: usize) -> usize {
1370        let end = self.checked_row_end(row);
1371
1372        self.offsets[end] - self.offsets[row]
1373    }
1374
1375    /// Get an iterator over the lengths of each row in this [`Rows`]
1376    pub fn lengths(&self) -> RowLengthIter<'_> {
1377        self.offsets.windows(2).map(|w| w[1] - w[0])
1378    }
1379
1380    /// Sets the length of this [`Rows`] to 0
1381    pub fn clear(&mut self) {
1382        self.offsets.truncate(1);
1383        self.buffer.clear();
1384    }
1385
1386    /// Returns the number of [`Row`] in this [`Rows`]
1387    pub fn num_rows(&self) -> usize {
1388        self.offsets.len() - 1
1389    }
1390
1391    /// Returns an iterator over the [`Row`] in this [`Rows`]
1392    pub fn iter(&self) -> RowsIter<'_> {
1393        self.into_iter()
1394    }
1395
1396    /// Returns the size of this instance in bytes
1397    ///
1398    /// Includes the size of `Self`.
1399    pub fn size(&self) -> usize {
1400        // Size of fields is accounted for as part of RowConverter
1401        std::mem::size_of::<Self>()
1402            + self.buffer.capacity()
1403            + self.offsets.capacity() * std::mem::size_of::<usize>()
1404    }
1405
1406    /// Create a [BinaryArray] from the [Rows] data without reallocating the
1407    /// underlying bytes.
1408    ///
1409    ///
1410    /// ```
1411    /// # use std::sync::Arc;
1412    /// # use std::collections::HashSet;
1413    /// # use arrow_array::cast::AsArray;
1414    /// # use arrow_array::StringArray;
1415    /// # use arrow_row::{OwnedRow, Row, RowConverter, RowParser, SortField};
1416    /// # use arrow_schema::DataType;
1417    /// #
1418    /// let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
1419    /// let array = StringArray::from(vec!["hello", "world", "a", "a", "hello"]);
1420    /// let rows = converter.convert_columns(&[Arc::new(array)]).unwrap();
1421    ///
1422    /// // We can convert rows into binary format and back.
1423    /// let values: Vec<OwnedRow> = rows.iter().map(|r| r.owned()).collect();
1424    /// let binary = rows.try_into_binary().expect("known-small array");
1425    /// let parser = converter.parser();
1426    /// let parsed: Vec<OwnedRow> =
1427    ///   binary.iter().flatten().map(|b| parser.parse(b).owned()).collect();
1428    /// assert_eq!(values, parsed);
1429    /// ```
1430    ///
1431    /// # Errors
1432    ///
1433    /// This function will return an error if there is more data than can be stored in
1434    /// a [BinaryArray] -- i.e. if the total data size is more than 2GiB.
1435    pub fn try_into_binary(self) -> Result<BinaryArray, ArrowError> {
1436        if self.buffer.len() > i32::MAX as usize {
1437            return Err(ArrowError::InvalidArgumentError(format!(
1438                "{}-byte rows buffer too long to convert into a i32-indexed BinaryArray",
1439                self.buffer.len()
1440            )));
1441        }
1442        // We've checked that the buffer length fits in an i32; so all offsets into that buffer should fit as well.
1443        let offsets_scalar = ScalarBuffer::from_iter(self.offsets.into_iter().map(i32::usize_as));
1444        // SAFETY: offsets buffer is nonempty, monotonically increasing, and all represent valid indexes into buffer.
1445        let array = unsafe {
1446            BinaryArray::new_unchecked(
1447                OffsetBuffer::new_unchecked(offsets_scalar),
1448                Buffer::from_vec(self.buffer),
1449                None,
1450            )
1451        };
1452        Ok(array)
1453    }
1454}
1455
1456impl<'a> IntoIterator for &'a Rows {
1457    type Item = Row<'a>;
1458    type IntoIter = RowsIter<'a>;
1459
1460    fn into_iter(self) -> Self::IntoIter {
1461        RowsIter {
1462            rows: self,
1463            start: 0,
1464            end: self.num_rows(),
1465        }
1466    }
1467}
1468
1469/// An iterator over [`Rows`]
1470#[derive(Debug)]
1471pub struct RowsIter<'a> {
1472    rows: &'a Rows,
1473    start: usize,
1474    end: usize,
1475}
1476
1477impl<'a> Iterator for RowsIter<'a> {
1478    type Item = Row<'a>;
1479
1480    fn next(&mut self) -> Option<Self::Item> {
1481        if self.end == self.start {
1482            return None;
1483        }
1484
1485        // SAFETY: We have checked that `start` is less than `end`
1486        let row = unsafe { self.rows.row_unchecked(self.start) };
1487        self.start += 1;
1488        Some(row)
1489    }
1490
1491    fn size_hint(&self) -> (usize, Option<usize>) {
1492        let len = self.len();
1493        (len, Some(len))
1494    }
1495}
1496
1497impl ExactSizeIterator for RowsIter<'_> {
1498    fn len(&self) -> usize {
1499        self.end - self.start
1500    }
1501}
1502
1503impl DoubleEndedIterator for RowsIter<'_> {
1504    fn next_back(&mut self) -> Option<Self::Item> {
1505        if self.end == self.start {
1506            return None;
1507        }
1508
1509        self.end -= 1;
1510
1511        // Safety: By construction we create `end >= start`, so if `end` is not equal to `start` it cannot be less than `start`
1512        //          therefore `end - 1` is within range
1513        let row = unsafe { self.rows.row_unchecked(self.end) };
1514        Some(row)
1515    }
1516}
1517
1518/// A comparable representation of a row.
1519///
1520/// See the [module level documentation](self) for more details.
1521///
1522/// Two [`Row`] can only be compared if they both belong to [`Rows`]
1523/// returned by calls to [`RowConverter::convert_columns`] on the same
1524/// [`RowConverter`]. If different [`RowConverter`]s are used, any
1525/// ordering established by comparing the [`Row`] is arbitrary.
1526#[derive(Debug, Copy, Clone)]
1527pub struct Row<'a> {
1528    data: &'a [u8],
1529    config: &'a RowConfig,
1530}
1531
1532impl<'a> Row<'a> {
1533    /// Create owned version of the row to detach it from the shared [`Rows`].
1534    pub fn owned(&self) -> OwnedRow {
1535        OwnedRow {
1536            data: self.data.into(),
1537            config: self.config.clone(),
1538        }
1539    }
1540
1541    /// The row's bytes, with the lifetime of the underlying data.
1542    pub fn data(&self) -> &'a [u8] {
1543        self.data
1544    }
1545}
1546
1547// Manually derive these as don't wish to include `fields`
1548
1549impl PartialEq for Row<'_> {
1550    #[inline]
1551    fn eq(&self, other: &Self) -> bool {
1552        self.data.eq(other.data)
1553    }
1554}
1555
1556impl Eq for Row<'_> {}
1557
1558impl PartialOrd for Row<'_> {
1559    #[inline]
1560    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
1561        Some(self.cmp(other))
1562    }
1563}
1564
1565impl Ord for Row<'_> {
1566    #[inline]
1567    fn cmp(&self, other: &Self) -> Ordering {
1568        self.data.cmp(other.data)
1569    }
1570}
1571
1572impl Hash for Row<'_> {
1573    #[inline]
1574    fn hash<H: Hasher>(&self, state: &mut H) {
1575        self.data.hash(state)
1576    }
1577}
1578
1579impl AsRef<[u8]> for Row<'_> {
1580    #[inline]
1581    fn as_ref(&self) -> &[u8] {
1582        self.data
1583    }
1584}
1585
1586/// Owned version of a [`Row`] that can be moved/cloned freely.
1587///
1588/// This contains the data for the one specific row (not the entire buffer of all rows).
1589#[derive(Debug, Clone)]
1590pub struct OwnedRow {
1591    data: Box<[u8]>,
1592    config: RowConfig,
1593}
1594
1595impl OwnedRow {
1596    /// Get borrowed [`Row`] from owned version.
1597    ///
1598    /// This is helpful if you want to compare an [`OwnedRow`] with a [`Row`].
1599    pub fn row(&self) -> Row<'_> {
1600        Row {
1601            data: &self.data,
1602            config: &self.config,
1603        }
1604    }
1605}
1606
1607// Manually derive these as don't wish to include `fields`. Also we just want to use the same `Row` implementations here.
1608
1609impl PartialEq for OwnedRow {
1610    #[inline]
1611    fn eq(&self, other: &Self) -> bool {
1612        self.row().eq(&other.row())
1613    }
1614}
1615
1616impl Eq for OwnedRow {}
1617
1618impl PartialOrd for OwnedRow {
1619    #[inline]
1620    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
1621        Some(self.cmp(other))
1622    }
1623}
1624
1625impl Ord for OwnedRow {
1626    #[inline]
1627    fn cmp(&self, other: &Self) -> Ordering {
1628        self.row().cmp(&other.row())
1629    }
1630}
1631
1632impl Hash for OwnedRow {
1633    #[inline]
1634    fn hash<H: Hasher>(&self, state: &mut H) {
1635        self.row().hash(state)
1636    }
1637}
1638
1639impl AsRef<[u8]> for OwnedRow {
1640    #[inline]
1641    fn as_ref(&self) -> &[u8] {
1642        &self.data
1643    }
1644}
1645
1646/// Returns the null sentinel, negated if `invert` is true
1647#[inline]
1648fn null_sentinel(options: SortOptions) -> u8 {
1649    match options.nulls_first {
1650        true => 0,
1651        false => 0xFF,
1652    }
1653}
1654
1655/// Stores the lengths of the rows. Lazily materializes lengths for columns with fixed-size types.
1656enum LengthTracker {
1657    /// Fixed state: All rows have length `length`
1658    Fixed { length: usize, num_rows: usize },
1659    /// Variable state: The length of row `i` is `lengths[i] + fixed_length`
1660    Variable {
1661        fixed_length: usize,
1662        lengths: Vec<usize>,
1663    },
1664}
1665
1666impl LengthTracker {
1667    fn new(num_rows: usize) -> Self {
1668        Self::Fixed {
1669            length: 0,
1670            num_rows,
1671        }
1672    }
1673
1674    /// Adds a column of fixed-length elements, each of size `new_length` to the LengthTracker
1675    fn push_fixed(&mut self, new_length: usize) {
1676        match self {
1677            LengthTracker::Fixed { length, .. } => *length += new_length,
1678            LengthTracker::Variable { fixed_length, .. } => *fixed_length += new_length,
1679        }
1680    }
1681
1682    /// Adds a column of possibly variable-length elements, element `i` has length `new_lengths.nth(i)`
1683    fn push_variable(&mut self, new_lengths: impl ExactSizeIterator<Item = usize>) {
1684        match self {
1685            LengthTracker::Fixed { length, .. } => {
1686                *self = LengthTracker::Variable {
1687                    fixed_length: *length,
1688                    lengths: new_lengths.collect(),
1689                }
1690            }
1691            LengthTracker::Variable { lengths, .. } => {
1692                assert_eq!(lengths.len(), new_lengths.len());
1693                lengths
1694                    .iter_mut()
1695                    .zip(new_lengths)
1696                    .for_each(|(length, new_length)| *length += new_length);
1697            }
1698        }
1699    }
1700
1701    /// Returns the tracked row lengths as a slice
1702    fn materialized(&mut self) -> &mut [usize] {
1703        if let LengthTracker::Fixed { length, num_rows } = *self {
1704            *self = LengthTracker::Variable {
1705                fixed_length: length,
1706                lengths: vec![0; num_rows],
1707            };
1708        }
1709
1710        match self {
1711            LengthTracker::Variable { lengths, .. } => lengths,
1712            LengthTracker::Fixed { .. } => unreachable!(),
1713        }
1714    }
1715
1716    /// Initializes the offsets using the tracked lengths. Returns the sum of the
1717    /// lengths of the rows added.
1718    ///
1719    /// We initialize the offsets shifted down by one row index.
1720    ///
1721    /// As the rows are appended to the offsets will be incremented to match
1722    ///
1723    /// For example, consider the case of 3 rows of length 3, 4, and 6 respectively.
1724    /// The offsets would be initialized to `0, 0, 3, 7`
1725    ///
1726    /// Writing the first row entirely would yield `0, 3, 3, 7`
1727    /// The second, `0, 3, 7, 7`
1728    /// The third, `0, 3, 7, 13`
1729    //
1730    /// This would be the final offsets for reading
1731    //
1732    /// In this way offsets tracks the position during writing whilst eventually serving
1733    fn extend_offsets(&self, initial_offset: usize, offsets: &mut Vec<usize>) -> usize {
1734        match self {
1735            LengthTracker::Fixed { length, num_rows } => {
1736                offsets.extend((0..*num_rows).map(|i| initial_offset + i * length));
1737
1738                initial_offset + num_rows * length
1739            }
1740            LengthTracker::Variable {
1741                fixed_length,
1742                lengths,
1743            } => {
1744                let mut acc = initial_offset;
1745
1746                offsets.extend(lengths.iter().map(|length| {
1747                    let current = acc;
1748                    acc += length + fixed_length;
1749                    current
1750                }));
1751
1752                acc
1753            }
1754        }
1755    }
1756}
1757
1758/// Computes the length of each encoded [`Rows`] and returns an empty [`Rows`]
1759fn row_lengths(cols: &[ArrayRef], encoders: &[Encoder]) -> LengthTracker {
1760    use fixed::FixedLengthEncoding;
1761
1762    let num_rows = cols.first().map(|x| x.len()).unwrap_or(0);
1763    let mut tracker = LengthTracker::new(num_rows);
1764
1765    for (array, encoder) in cols.iter().zip(encoders) {
1766        match encoder {
1767            Encoder::Stateless => {
1768                downcast_primitive_array! {
1769                    array => tracker.push_fixed(fixed::encoded_len(array)),
1770                    DataType::Null => tracker.push_fixed(2)
1771                    DataType::Boolean => tracker.push_fixed(bool::ENCODED_LEN),
1772                    DataType::Binary => push_generic_byte_array_lengths(&mut tracker, as_generic_binary_array::<i32>(array)),
1773                    DataType::LargeBinary => push_generic_byte_array_lengths(&mut tracker, as_generic_binary_array::<i64>(array)),
1774                    DataType::BinaryView => push_byte_view_array_lengths(&mut tracker, array.as_binary_view()),
1775                    DataType::Utf8 => push_generic_byte_array_lengths(&mut tracker, array.as_string::<i32>()),
1776                    DataType::LargeUtf8 => push_generic_byte_array_lengths(&mut tracker, array.as_string::<i64>()),
1777                    DataType::Utf8View => push_byte_view_array_lengths(&mut tracker, array.as_string_view()),
1778                    DataType::FixedSizeBinary(len) => {
1779                        let len = len.to_usize().unwrap();
1780                        tracker.push_fixed(1 + len)
1781                    }
1782                    _ => unimplemented!("unsupported data type: {}", array.data_type()),
1783                }
1784            }
1785            Encoder::Dictionary(values, null) => {
1786                downcast_dictionary_array! {
1787                    array => {
1788                        tracker.push_variable(
1789                            array.keys().iter().map(|v| match v {
1790                                Some(k) => values.row_len(k.as_usize()),
1791                                None => null.data.len(),
1792                            })
1793                        )
1794                    }
1795                    _ => unreachable!(),
1796                }
1797            }
1798            Encoder::Struct(rows, null) => {
1799                let array = as_struct_array(array);
1800                if rows.num_rows() > 0 {
1801                    // Only calculate row length if there are rows
1802                    tracker.push_variable((0..array.len()).map(|idx| match array.is_valid(idx) {
1803                        true => 1 + rows.row_len(idx),
1804                        false => 1 + null.data.len(),
1805                    }));
1806                } else {
1807                    // Edge case for Struct([]) arrays (no child fields)
1808                    tracker.push_variable((0..array.len()).map(|idx| match array.is_valid(idx) {
1809                        true => 1,
1810                        false => 1 + null.data.len(),
1811                    }));
1812                }
1813            }
1814            Encoder::List(rows) => match array.data_type() {
1815                DataType::List(_) => {
1816                    list::compute_lengths(tracker.materialized(), rows, as_list_array(array))
1817                }
1818                DataType::LargeList(_) => {
1819                    list::compute_lengths(tracker.materialized(), rows, as_large_list_array(array))
1820                }
1821                DataType::ListView(_) => {
1822                    let list_view = array.as_list_view::<i32>();
1823                    let (min_offset, _) = compute_list_view_bounds(list_view);
1824                    list::compute_lengths_list_view(
1825                        tracker.materialized(),
1826                        rows,
1827                        list_view,
1828                        min_offset,
1829                    )
1830                }
1831                DataType::LargeListView(_) => {
1832                    let list_view = array.as_list_view::<i64>();
1833                    let (min_offset, _) = compute_list_view_bounds(list_view);
1834                    list::compute_lengths_list_view(
1835                        tracker.materialized(),
1836                        rows,
1837                        list_view,
1838                        min_offset,
1839                    )
1840                }
1841                DataType::FixedSizeList(_, _) => compute_lengths_fixed_size_list(
1842                    &mut tracker,
1843                    rows,
1844                    as_fixed_size_list_array(array),
1845                ),
1846                _ => unreachable!(),
1847            },
1848            Encoder::Map(rows) => {
1849                list::compute_lengths(tracker.materialized(), rows, as_map_array(array))
1850            }
1851            Encoder::RunEndEncoded(rows) => match array.data_type() {
1852                DataType::RunEndEncoded(r, _) => match r.data_type() {
1853                    DataType::Int16 => run::compute_lengths(
1854                        tracker.materialized(),
1855                        rows,
1856                        array.as_run::<Int16Type>(),
1857                    ),
1858                    DataType::Int32 => run::compute_lengths(
1859                        tracker.materialized(),
1860                        rows,
1861                        array.as_run::<Int32Type>(),
1862                    ),
1863                    DataType::Int64 => run::compute_lengths(
1864                        tracker.materialized(),
1865                        rows,
1866                        array.as_run::<Int64Type>(),
1867                    ),
1868                    _ => unreachable!("Unsupported run end index type: {r:?}"),
1869                },
1870                _ => unreachable!(),
1871            },
1872            Encoder::Union {
1873                child_rows,
1874                field_to_type_ids,
1875                type_ids,
1876                offsets,
1877            } => {
1878                let union_array = array
1879                    .as_any()
1880                    .downcast_ref::<UnionArray>()
1881                    .expect("expected UnionArray");
1882
1883                let mut type_id_to_field_idx = [0usize; 128];
1884                for (field_idx, &type_id) in field_to_type_ids.iter().enumerate() {
1885                    type_id_to_field_idx[type_id as usize] = field_idx;
1886                }
1887
1888                let lengths = (0..union_array.len()).map(|i| {
1889                    let type_id = type_ids[i];
1890                    let field_idx = type_id_to_field_idx[type_id as usize];
1891                    let child_row_i = offsets.as_ref().map(|o| o[i] as usize).unwrap_or(i);
1892                    let child_row_len = child_rows[field_idx].row_len(child_row_i);
1893
1894                    // length: 1 byte type_id + child row bytes
1895                    1 + child_row_len
1896                });
1897
1898                tracker.push_variable(lengths);
1899            }
1900        }
1901    }
1902
1903    tracker
1904}
1905
1906/// Add to [`LengthTracker`] the encoded length of each item in the [`GenericByteArray`]
1907fn push_generic_byte_array_lengths<T: ByteArrayType>(
1908    tracker: &mut LengthTracker,
1909    array: &GenericByteArray<T>,
1910) {
1911    if let Some(nulls) = array.nulls().filter(|n| n.null_count() > 0) {
1912        tracker.push_variable(
1913            array
1914                .offsets()
1915                .lengths()
1916                .zip(nulls.iter())
1917                .map(|(length, is_valid)| if is_valid { Some(length) } else { None })
1918                .map(variable::padded_length),
1919        )
1920    } else {
1921        tracker.push_variable(
1922            array
1923                .offsets()
1924                .lengths()
1925                .map(variable::non_null_padded_length),
1926        )
1927    }
1928}
1929
1930/// Add to [`LengthTracker`] the encoded length of each item in the [`GenericByteViewArray`]
1931fn push_byte_view_array_lengths<T: ByteViewType>(
1932    tracker: &mut LengthTracker,
1933    array: &GenericByteViewArray<T>,
1934) {
1935    if let Some(nulls) = array.nulls().filter(|n| n.null_count() > 0) {
1936        tracker.push_variable(
1937            array
1938                .lengths()
1939                .zip(nulls.iter())
1940                .map(|(length, is_valid)| {
1941                    if is_valid {
1942                        Some(length as usize)
1943                    } else {
1944                        None
1945                    }
1946                })
1947                .map(variable::padded_length),
1948        )
1949    } else {
1950        tracker.push_variable(
1951            array
1952                .lengths()
1953                .map(|len| variable::padded_length(Some(len as usize))),
1954        )
1955    }
1956}
1957
1958/// Encodes a column to the provided [`Rows`] incrementing the offsets as it progresses
1959fn encode_column(
1960    data: &mut [u8],
1961    offsets: &mut [usize],
1962    column: &dyn Array,
1963    opts: SortOptions,
1964    encoder: &Encoder<'_>,
1965) {
1966    match encoder {
1967        Encoder::Stateless => {
1968            downcast_primitive_array! {
1969                column => {
1970                    if let Some(nulls) = column.nulls().filter(|n| n.null_count() > 0){
1971                        fixed::encode(data, offsets, column.values(), nulls, opts)
1972                    } else {
1973                        fixed::encode_not_null(data, offsets, column.values(), opts)
1974                    }
1975                }
1976                DataType::Null => {
1977                    for offset in offsets.iter_mut().skip(1) {
1978                        variable::encode_null_value(&mut data[*offset..], opts);
1979                        *offset += 2;
1980                    }
1981                }
1982                DataType::Boolean => {
1983                    if let Some(nulls) = column.nulls().filter(|n| n.null_count() > 0){
1984                        fixed::encode_boolean(data, offsets, column.as_boolean().values(), nulls, opts)
1985                    } else {
1986                        fixed::encode_boolean_not_null(data, offsets, column.as_boolean().values(), opts)
1987                    }
1988                }
1989                DataType::Binary => {
1990                    variable::encode_generic_byte_array(data, offsets, as_generic_binary_array::<i32>(column), opts)
1991                }
1992                DataType::BinaryView => {
1993                    variable::encode(data, offsets, column.as_binary_view().iter(), opts)
1994                }
1995                DataType::LargeBinary => {
1996                    variable::encode_generic_byte_array(data, offsets, as_generic_binary_array::<i64>(column), opts)
1997                }
1998                DataType::Utf8 => variable::encode_generic_byte_array(
1999                    data, offsets,
2000                    column.as_string::<i32>(),
2001                    opts,
2002                ),
2003                DataType::LargeUtf8 => variable::encode_generic_byte_array(
2004                    data, offsets,
2005                    column.as_string::<i64>(),
2006                    opts,
2007                ),
2008                DataType::Utf8View => variable::encode(
2009                    data, offsets,
2010                    column.as_string_view().iter().map(|x| x.map(|x| x.as_bytes())),
2011                    opts,
2012                ),
2013                DataType::FixedSizeBinary(_) => {
2014                    let array = column.as_any().downcast_ref().unwrap();
2015                    fixed::encode_fixed_size_binary(data, offsets, array, opts)
2016                }
2017                _ => unimplemented!("unsupported data type: {}", column.data_type()),
2018            }
2019        }
2020        Encoder::Dictionary(values, nulls) => {
2021            downcast_dictionary_array! {
2022                column => encode_dictionary_values(data, offsets, column, values, nulls),
2023                _ => unreachable!()
2024            }
2025        }
2026        Encoder::Struct(rows, null) => {
2027            fn struct_encode_helper<const NO_CHILD_FIELDS: bool>(
2028                array: &StructArray,
2029                offsets: &mut [usize],
2030                null_sentinel: u8,
2031                rows: &Rows,
2032                null: &Row<'_>,
2033                data: &mut [u8],
2034            ) {
2035                let empty_row = Row {
2036                    data: &[],
2037                    config: &rows.config,
2038                };
2039
2040                offsets
2041                    .iter_mut()
2042                    .skip(1)
2043                    .enumerate()
2044                    .for_each(|(idx, offset)| {
2045                        let (row, sentinel) = match array.is_valid(idx) {
2046                            true => (
2047                                if NO_CHILD_FIELDS {
2048                                    empty_row
2049                                } else {
2050                                    rows.row(idx)
2051                                },
2052                                0x01,
2053                            ),
2054                            false => (*null, null_sentinel),
2055                        };
2056                        let end_offset = *offset + 1 + row.as_ref().len();
2057                        data[*offset] = sentinel;
2058                        data[*offset + 1..end_offset].copy_from_slice(row.as_ref());
2059                        *offset = end_offset;
2060                    })
2061            }
2062
2063            let array = as_struct_array(column);
2064            let null_sentinel = null_sentinel(opts);
2065            if rows.num_rows() == 0 {
2066                // Edge case for Struct([]) arrays (no child fields)
2067                struct_encode_helper::<true>(array, offsets, null_sentinel, rows, null, data);
2068            } else {
2069                struct_encode_helper::<false>(array, offsets, null_sentinel, rows, null, data);
2070            }
2071        }
2072        Encoder::List(rows) => match column.data_type() {
2073            DataType::List(_) => list::encode(data, offsets, rows, opts, as_list_array(column)),
2074            DataType::LargeList(_) => {
2075                list::encode(data, offsets, rows, opts, as_large_list_array(column))
2076            }
2077            DataType::ListView(_) => {
2078                let list_view = column.as_list_view::<i32>();
2079                let (min_offset, _) = compute_list_view_bounds(list_view);
2080                list::encode_list_view(data, offsets, rows, opts, list_view, min_offset)
2081            }
2082            DataType::LargeListView(_) => {
2083                let list_view = column.as_list_view::<i64>();
2084                let (min_offset, _) = compute_list_view_bounds(list_view);
2085                list::encode_list_view(data, offsets, rows, opts, list_view, min_offset)
2086            }
2087            DataType::FixedSizeList(_, _) => {
2088                encode_fixed_size_list(data, offsets, rows, opts, as_fixed_size_list_array(column))
2089            }
2090            _ => unreachable!(),
2091        },
2092        Encoder::Map(rows) => list::encode(data, offsets, rows, opts, as_map_array(column)),
2093        Encoder::RunEndEncoded(rows) => match column.data_type() {
2094            DataType::RunEndEncoded(r, _) => match r.data_type() {
2095                DataType::Int16 => {
2096                    run::encode(data, offsets, rows, opts, column.as_run::<Int16Type>())
2097                }
2098                DataType::Int32 => {
2099                    run::encode(data, offsets, rows, opts, column.as_run::<Int32Type>())
2100                }
2101                DataType::Int64 => {
2102                    run::encode(data, offsets, rows, opts, column.as_run::<Int64Type>())
2103                }
2104                _ => unreachable!("Unsupported run end index type: {r:?}"),
2105            },
2106            _ => unreachable!(),
2107        },
2108        Encoder::Union {
2109            child_rows,
2110            field_to_type_ids,
2111            type_ids,
2112            offsets: offsets_buf,
2113        } => {
2114            let mut type_id_to_field_idx = [0usize; 128];
2115            for (field_idx, &type_id) in field_to_type_ids.iter().enumerate() {
2116                type_id_to_field_idx[type_id as usize] = field_idx;
2117            }
2118
2119            offsets
2120                .iter_mut()
2121                .skip(1)
2122                .enumerate()
2123                .for_each(|(i, offset)| {
2124                    let type_id = type_ids[i];
2125                    let field_idx = type_id_to_field_idx[type_id as usize];
2126
2127                    let child_row_idx = offsets_buf.as_ref().map(|o| o[i] as usize).unwrap_or(i);
2128                    let child_row = child_rows[field_idx].row(child_row_idx);
2129                    let child_bytes = child_row.as_ref();
2130
2131                    let type_id_byte = if opts.descending {
2132                        !(type_id as u8)
2133                    } else {
2134                        type_id as u8
2135                    };
2136                    data[*offset] = type_id_byte;
2137
2138                    let child_start = *offset + 1;
2139                    let child_end = child_start + child_bytes.len();
2140                    data[child_start..child_end].copy_from_slice(child_bytes);
2141
2142                    *offset = child_end;
2143                });
2144        }
2145    }
2146}
2147
2148/// Encode dictionary values not preserving the dictionary encoding
2149pub fn encode_dictionary_values<K: ArrowDictionaryKeyType>(
2150    data: &mut [u8],
2151    offsets: &mut [usize],
2152    column: &DictionaryArray<K>,
2153    values: &Rows,
2154    null: &Row<'_>,
2155) {
2156    for (offset, k) in offsets.iter_mut().skip(1).zip(column.keys()) {
2157        let row = match k {
2158            Some(k) => values.row(k.as_usize()).data,
2159            None => null.data,
2160        };
2161        let end_offset = *offset + row.len();
2162        data[*offset..end_offset].copy_from_slice(row);
2163        *offset = end_offset;
2164    }
2165}
2166
2167macro_rules! decode_primitive_helper {
2168    ($t:ty, $rows:ident, $data_type:ident, $options:ident) => {
2169        Arc::new(decode_primitive::<$t>($rows, $data_type, $options))
2170    };
2171}
2172
2173/// Decodes a the provided `field` from `rows`
2174///
2175/// # Safety
2176///
2177/// Rows must contain valid data for the provided field
2178unsafe fn decode_column(
2179    field: &SortField,
2180    rows: &mut [&[u8]],
2181    codec: &Codec,
2182    validate_utf8: bool,
2183) -> Result<ArrayRef, ArrowError> {
2184    let options = field.options;
2185
2186    let array: ArrayRef = match codec {
2187        Codec::Stateless => {
2188            let data_type = field.data_type.clone();
2189            downcast_primitive! {
2190                data_type => (decode_primitive_helper, rows, data_type, options),
2191                DataType::Null => {
2192                    variable::decode_null_value(rows, options);
2193                    Arc::new(NullArray::new(rows.len()))
2194                }
2195                DataType::Boolean => Arc::new(decode_bool(rows, options)),
2196                DataType::Binary => Arc::new(decode_binary::<i32>(rows, options)),
2197                DataType::LargeBinary => Arc::new(decode_binary::<i64>(rows, options)),
2198                DataType::BinaryView => Arc::new(decode_binary_view(rows, options)),
2199                DataType::FixedSizeBinary(size) => Arc::new(decode_fixed_size_binary(rows, size, options)),
2200                DataType::Utf8 => Arc::new(unsafe{ decode_string::<i32>(rows, options, validate_utf8) }),
2201                DataType::LargeUtf8 => Arc::new(unsafe { decode_string::<i64>(rows, options, validate_utf8) }),
2202                DataType::Utf8View => Arc::new(unsafe { decode_string_view(rows, options, validate_utf8) }),
2203                _ => return Err(ArrowError::NotYetImplemented(format!("unsupported data type: {data_type}" )))
2204            }
2205        }
2206        Codec::Dictionary(converter, _) => {
2207            let cols = unsafe { converter.convert_raw(rows, validate_utf8) }?;
2208            cols.into_iter().next().unwrap()
2209        }
2210        Codec::Struct(converter, _) => {
2211            let nulls = fixed::decode_nulls(rows);
2212            rows.iter_mut().for_each(|row| *row = &row[1..]);
2213            let children = unsafe { converter.convert_raw(rows, validate_utf8) }?;
2214
2215            // Since RowConverter flattens certain data types (i.e. Dictionary),
2216            // we need to use updated data type instead of original field
2217            let corrected_fields: Vec<Field> = match &field.data_type {
2218                DataType::Struct(struct_fields) => struct_fields
2219                    .iter()
2220                    .zip(children.iter())
2221                    .map(|(orig_field, child_array)| {
2222                        orig_field
2223                            .as_ref()
2224                            .clone()
2225                            .with_data_type(child_array.data_type().clone())
2226                    })
2227                    .collect(),
2228                _ => unreachable!("Only Struct types should be corrected here"),
2229            };
2230
2231            Arc::new(unsafe {
2232                StructArray::new_unchecked_with_length(
2233                    corrected_fields.into(),
2234                    children,
2235                    nulls,
2236                    rows.len(),
2237                )
2238            })
2239        }
2240        Codec::List(converter) => match &field.data_type {
2241            DataType::List(_) => Arc::new(unsafe {
2242                list::decode::<GenericListArray<i32>>(converter, rows, field, validate_utf8)
2243            }?),
2244            DataType::LargeList(_) => Arc::new(unsafe {
2245                list::decode::<GenericListArray<i64>>(converter, rows, field, validate_utf8)
2246            }?),
2247            DataType::ListView(_) => Arc::new(unsafe {
2248                list::decode_list_view::<i32>(converter, rows, field, validate_utf8)
2249            }?),
2250            DataType::LargeListView(_) => Arc::new(unsafe {
2251                list::decode_list_view::<i64>(converter, rows, field, validate_utf8)
2252            }?),
2253            DataType::FixedSizeList(_, value_length) => Arc::new(unsafe {
2254                list::decode_fixed_size_list(
2255                    converter,
2256                    rows,
2257                    field,
2258                    validate_utf8,
2259                    value_length.as_usize(),
2260                )
2261            }?),
2262            _ => unreachable!(),
2263        },
2264        Codec::Map(converter) => {
2265            Arc::new(unsafe { list::decode::<MapArray>(converter, rows, field, validate_utf8) }?)
2266        }
2267        Codec::RunEndEncoded(converter) => match &field.data_type {
2268            DataType::RunEndEncoded(run_ends, _) => match run_ends.data_type() {
2269                DataType::Int16 => Arc::new(unsafe {
2270                    run::decode::<Int16Type>(converter, rows, field, validate_utf8)
2271                }?),
2272                DataType::Int32 => Arc::new(unsafe {
2273                    run::decode::<Int32Type>(converter, rows, field, validate_utf8)
2274                }?),
2275                DataType::Int64 => Arc::new(unsafe {
2276                    run::decode::<Int64Type>(converter, rows, field, validate_utf8)
2277                }?),
2278                _ => unreachable!(),
2279            },
2280            _ => unreachable!(),
2281        },
2282        Codec::Union(converters, field_to_type_ids, null_rows) => {
2283            let len = rows.len();
2284
2285            let DataType::Union(union_fields, mode) = &field.data_type else {
2286                unreachable!()
2287            };
2288
2289            let mut type_id_to_field_idx = [0usize; 128];
2290            for (field_idx, &type_id) in field_to_type_ids.iter().enumerate() {
2291                type_id_to_field_idx[type_id as usize] = field_idx;
2292            }
2293
2294            let mut type_ids = Vec::with_capacity(len);
2295            let mut rows_by_field: Vec<Vec<(usize, &[u8])>> = vec![Vec::new(); converters.len()];
2296
2297            for (idx, row) in rows.iter_mut().enumerate() {
2298                let type_id_byte = {
2299                    let id = row[0];
2300                    if options.descending { !id } else { id }
2301                };
2302
2303                let type_id = type_id_byte as i8;
2304                type_ids.push(type_id);
2305
2306                let field_idx = type_id_to_field_idx[type_id as usize];
2307
2308                let child_row = &row[1..];
2309                rows_by_field[field_idx].push((idx, child_row));
2310            }
2311
2312            let mut child_arrays: Vec<ArrayRef> = Vec::with_capacity(converters.len());
2313            let mut offsets = (*mode == UnionMode::Dense).then(|| Vec::with_capacity(len));
2314
2315            for (field_idx, converter) in converters.iter().enumerate() {
2316                let field_rows = &rows_by_field[field_idx];
2317
2318                match &mode {
2319                    UnionMode::Dense => {
2320                        if field_rows.is_empty() {
2321                            let (_, field) = union_fields.iter().nth(field_idx).unwrap();
2322                            child_arrays.push(arrow_array::new_empty_array(field.data_type()));
2323                            continue;
2324                        }
2325
2326                        let mut child_data = field_rows
2327                            .iter()
2328                            .map(|(_, bytes)| *bytes)
2329                            .collect::<Vec<_>>();
2330
2331                        let child_array =
2332                            unsafe { converter.convert_raw(&mut child_data, validate_utf8) }?;
2333
2334                        // advance row slices by the bytes consumed
2335                        for ((row_idx, original_bytes), remaining_bytes) in
2336                            field_rows.iter().zip(child_data)
2337                        {
2338                            let consumed_length = 1 + original_bytes.len() - remaining_bytes.len();
2339                            rows[*row_idx] = &rows[*row_idx][consumed_length..];
2340                        }
2341
2342                        child_arrays.push(child_array.into_iter().next().unwrap());
2343                    }
2344                    UnionMode::Sparse => {
2345                        let mut sparse_data: Vec<&[u8]> = Vec::with_capacity(len);
2346                        let mut field_row_iter = field_rows.iter().peekable();
2347                        let null_row_bytes: &[u8] = &null_rows[field_idx].data;
2348
2349                        for idx in 0..len {
2350                            if let Some((next_idx, bytes)) = field_row_iter.peek() {
2351                                if *next_idx == idx {
2352                                    sparse_data.push(*bytes);
2353
2354                                    field_row_iter.next();
2355                                    continue;
2356                                }
2357                            }
2358                            sparse_data.push(null_row_bytes);
2359                        }
2360
2361                        let child_array =
2362                            unsafe { converter.convert_raw(&mut sparse_data, validate_utf8) }?;
2363
2364                        // advance row slices by the bytes consumed for rows that belong to this field
2365                        for (row_idx, child_row) in field_rows.iter() {
2366                            let remaining_len = sparse_data[*row_idx].len();
2367                            let consumed_length = 1 + child_row.len() - remaining_len;
2368                            rows[*row_idx] = &rows[*row_idx][consumed_length..];
2369                        }
2370
2371                        child_arrays.push(child_array.into_iter().next().unwrap());
2372                    }
2373                }
2374            }
2375
2376            // build offsets for dense unions
2377            if let Some(ref mut offsets_vec) = offsets {
2378                let mut count = vec![0i32; converters.len()];
2379                for type_id in &type_ids {
2380                    let field_idx = *type_id as usize;
2381                    offsets_vec.push(count[field_idx]);
2382
2383                    count[field_idx] += 1;
2384                }
2385            }
2386
2387            let type_ids_buffer = ScalarBuffer::from(type_ids);
2388            let offsets_buffer = offsets.map(ScalarBuffer::from);
2389
2390            let union_array = UnionArray::try_new(
2391                union_fields.clone(),
2392                type_ids_buffer,
2393                offsets_buffer,
2394                child_arrays,
2395            )?;
2396
2397            // note: union arrays don't support physical null buffers
2398            // nulls are represented logically though child arrays
2399            Arc::new(union_array)
2400        }
2401    };
2402    Ok(array)
2403}
2404
2405#[cfg(test)]
2406mod tests {
2407    use arrow_array::builder::*;
2408    use arrow_array::types::*;
2409    use arrow_array::*;
2410    use arrow_buffer::{Buffer, OffsetBuffer};
2411    use arrow_buffer::{NullBuffer, i256};
2412    use arrow_cast::display::{ArrayFormatter, FormatOptions};
2413    use arrow_ord::sort::{LexicographicalComparator, SortColumn};
2414    use rand::distr::uniform::SampleUniform;
2415    use rand::distr::{Distribution, StandardUniform};
2416    use rand::prelude::StdRng;
2417    use rand::{Rng, RngCore, SeedableRng};
2418
2419    use super::*;
2420
2421    fn all_sort_options() -> [SortOptions; 4] {
2422        [
2423            SortOptions {
2424                descending: false,
2425                nulls_first: false,
2426            },
2427            SortOptions {
2428                descending: false,
2429                nulls_first: true,
2430            },
2431            SortOptions {
2432                descending: true,
2433                nulls_first: false,
2434            },
2435            SortOptions {
2436                descending: true,
2437                nulls_first: true,
2438            },
2439        ]
2440    }
2441
2442    #[test]
2443    fn test_fixed_width() {
2444        let cols = [
2445            Arc::new(Int16Array::from_iter([
2446                Some(1),
2447                Some(2),
2448                None,
2449                Some(-5),
2450                Some(2),
2451                Some(2),
2452                Some(0),
2453            ])) as ArrayRef,
2454            Arc::new(Float32Array::from_iter([
2455                Some(1.3),
2456                Some(2.5),
2457                None,
2458                Some(4.),
2459                Some(0.1),
2460                Some(-4.),
2461                Some(-0.),
2462            ])) as ArrayRef,
2463        ];
2464
2465        let converter = RowConverter::new(vec![
2466            SortField::new(DataType::Int16),
2467            SortField::new(DataType::Float32),
2468        ])
2469        .unwrap();
2470        let rows = converter.convert_columns(&cols).unwrap();
2471
2472        assert_eq!(rows.offsets, &[0, 8, 16, 24, 32, 40, 48, 56]);
2473        assert_eq!(
2474            rows.buffer,
2475            &[
2476                1, 128, 1, //
2477                1, 191, 166, 102, 102, //
2478                1, 128, 2, //
2479                1, 192, 32, 0, 0, //
2480                0, 0, 0, //
2481                0, 0, 0, 0, 0, //
2482                1, 127, 251, //
2483                1, 192, 128, 0, 0, //
2484                1, 128, 2, //
2485                1, 189, 204, 204, 205, //
2486                1, 128, 2, //
2487                1, 63, 127, 255, 255, //
2488                1, 128, 0, //
2489                1, 127, 255, 255, 255 //
2490            ]
2491        );
2492
2493        assert!(rows.row(3) < rows.row(6));
2494        assert!(rows.row(0) < rows.row(1));
2495        assert!(rows.row(3) < rows.row(0));
2496        assert!(rows.row(4) < rows.row(1));
2497        assert!(rows.row(5) < rows.row(4));
2498
2499        let back = converter.convert_rows(&rows).unwrap();
2500        for (expected, actual) in cols.iter().zip(&back) {
2501            assert_eq!(expected, actual);
2502        }
2503    }
2504
2505    fn test_roundtrip(sort_option: SortOptions, col: ArrayRef) {
2506        let converter = RowConverter::new(vec![SortField::new_with_options(
2507            col.data_type().clone(),
2508            sort_option,
2509        )])
2510        .unwrap();
2511        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2512        let back = converter.convert_rows(&rows).unwrap();
2513        assert_eq!(back.len(), 1);
2514        assert_eq!(&back[0], &col);
2515        back[0].to_data().validate_full().unwrap();
2516    }
2517
2518    #[test]
2519    fn test_zero_width_fixed_size_binary_roundtrip() {
2520        for sort_option in all_sort_options() {
2521            // With a zero byte width and no nulls, the decoded length cannot be
2522            // inferred from the value or null buffers and must come from the row count
2523            for with_null in [true, false] {
2524                let nulls = if with_null {
2525                    Some(NullBuffer::from(vec![true, false, true, false, true]))
2526                } else {
2527                    None
2528                };
2529                let col: ArrayRef = Arc::new(
2530                    FixedSizeBinaryArray::try_new_with_len(0, Buffer::default(), nulls, 5).unwrap(),
2531                );
2532
2533                test_roundtrip(sort_option, col);
2534            }
2535        }
2536    }
2537
2538    #[test]
2539    fn test_zero_width_fixed_size_list_roundtrip() {
2540        for sort_option in all_sort_options() {
2541            // With a zero byte width and no nulls, the decoded length cannot be
2542            // inferred from the value or null buffers and must come from the row count
2543            for with_null in [true, false] {
2544                let nulls = if with_null {
2545                    Some(NullBuffer::from(vec![true, false, true, false, true]))
2546                } else {
2547                    None
2548                };
2549                let col: ArrayRef = Arc::new(
2550                    FixedSizeListArray::try_new_with_length(
2551                        Arc::new(Field::new("item", DataType::Boolean, false)),
2552                        0,
2553                        new_empty_array(&DataType::Boolean),
2554                        nulls,
2555                        5,
2556                    )
2557                    .unwrap(),
2558                );
2559
2560                test_roundtrip(sort_option, col);
2561            }
2562        }
2563    }
2564
2565    #[test]
2566    fn test_decimal32() {
2567        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal32(
2568            DECIMAL32_MAX_PRECISION,
2569            7,
2570        ))])
2571        .unwrap();
2572        let col = Arc::new(
2573            Decimal32Array::from_iter([
2574                None,
2575                Some(i32::MIN),
2576                Some(-13),
2577                Some(46_i32),
2578                Some(5456_i32),
2579                Some(i32::MAX),
2580            ])
2581            .with_precision_and_scale(9, 7)
2582            .unwrap(),
2583        ) as ArrayRef;
2584
2585        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2586        for i in 0..rows.num_rows() - 1 {
2587            assert!(rows.row(i) < rows.row(i + 1));
2588        }
2589
2590        let back = converter.convert_rows(&rows).unwrap();
2591        assert_eq!(back.len(), 1);
2592        assert_eq!(col.as_ref(), back[0].as_ref())
2593    }
2594
2595    #[test]
2596    fn test_decimal64() {
2597        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal64(
2598            DECIMAL64_MAX_PRECISION,
2599            7,
2600        ))])
2601        .unwrap();
2602        let col = Arc::new(
2603            Decimal64Array::from_iter([
2604                None,
2605                Some(i64::MIN),
2606                Some(-13),
2607                Some(46_i64),
2608                Some(5456_i64),
2609                Some(i64::MAX),
2610            ])
2611            .with_precision_and_scale(18, 7)
2612            .unwrap(),
2613        ) as ArrayRef;
2614
2615        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2616        for i in 0..rows.num_rows() - 1 {
2617            assert!(rows.row(i) < rows.row(i + 1));
2618        }
2619
2620        let back = converter.convert_rows(&rows).unwrap();
2621        assert_eq!(back.len(), 1);
2622        assert_eq!(col.as_ref(), back[0].as_ref())
2623    }
2624
2625    #[test]
2626    fn test_decimal128() {
2627        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal128(
2628            DECIMAL128_MAX_PRECISION,
2629            7,
2630        ))])
2631        .unwrap();
2632        let col = Arc::new(
2633            Decimal128Array::from_iter([
2634                None,
2635                Some(i128::MIN),
2636                Some(-13),
2637                Some(46_i128),
2638                Some(5456_i128),
2639                Some(i128::MAX),
2640            ])
2641            .with_precision_and_scale(38, 7)
2642            .unwrap(),
2643        ) as ArrayRef;
2644
2645        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2646        for i in 0..rows.num_rows() - 1 {
2647            assert!(rows.row(i) < rows.row(i + 1));
2648        }
2649
2650        let back = converter.convert_rows(&rows).unwrap();
2651        assert_eq!(back.len(), 1);
2652        assert_eq!(col.as_ref(), back[0].as_ref())
2653    }
2654
2655    #[test]
2656    fn test_decimal256() {
2657        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal256(
2658            DECIMAL256_MAX_PRECISION,
2659            7,
2660        ))])
2661        .unwrap();
2662        let col = Arc::new(
2663            Decimal256Array::from_iter([
2664                None,
2665                Some(i256::MIN),
2666                Some(i256::from_parts(0, -1)),
2667                Some(i256::from_parts(u128::MAX, -1)),
2668                Some(i256::from_parts(u128::MAX, 0)),
2669                Some(i256::from_parts(0, 46_i128)),
2670                Some(i256::from_parts(5, 46_i128)),
2671                Some(i256::MAX),
2672            ])
2673            .with_precision_and_scale(DECIMAL256_MAX_PRECISION, 7)
2674            .unwrap(),
2675        ) as ArrayRef;
2676
2677        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2678        for i in 0..rows.num_rows() - 1 {
2679            assert!(rows.row(i) < rows.row(i + 1));
2680        }
2681
2682        let back = converter.convert_rows(&rows).unwrap();
2683        assert_eq!(back.len(), 1);
2684        assert_eq!(col.as_ref(), back[0].as_ref())
2685    }
2686
2687    #[test]
2688    fn test_bool() {
2689        let converter = RowConverter::new(vec![SortField::new(DataType::Boolean)]).unwrap();
2690
2691        let col = Arc::new(BooleanArray::from_iter([None, Some(false), Some(true)])) as ArrayRef;
2692
2693        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2694        assert!(rows.row(2) > rows.row(1));
2695        assert!(rows.row(2) > rows.row(0));
2696        assert!(rows.row(1) > rows.row(0));
2697
2698        let cols = converter.convert_rows(&rows).unwrap();
2699        assert_eq!(&cols[0], &col);
2700
2701        let converter = RowConverter::new(vec![SortField::new_with_options(
2702            DataType::Boolean,
2703            SortOptions::default().desc().with_nulls_first(false),
2704        )])
2705        .unwrap();
2706
2707        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2708        assert!(rows.row(2) < rows.row(1));
2709        assert!(rows.row(2) < rows.row(0));
2710        assert!(rows.row(1) < rows.row(0));
2711        let cols = converter.convert_rows(&rows).unwrap();
2712        assert_eq!(&cols[0], &col);
2713    }
2714
2715    #[test]
2716    fn test_timezone() {
2717        let a =
2718            TimestampNanosecondArray::from(vec![1, 2, 3, 4, 5]).with_timezone("+01:00".to_string());
2719        let d = a.data_type().clone();
2720
2721        let converter = RowConverter::new(vec![SortField::new(a.data_type().clone())]).unwrap();
2722        let rows = converter.convert_columns(&[Arc::new(a) as _]).unwrap();
2723        let back = converter.convert_rows(&rows).unwrap();
2724        assert_eq!(back.len(), 1);
2725        assert_eq!(back[0].data_type(), &d);
2726
2727        // Test dictionary
2728        let mut a = PrimitiveDictionaryBuilder::<Int32Type, TimestampNanosecondType>::new();
2729        a.append(34).unwrap();
2730        a.append_null();
2731        a.append(345).unwrap();
2732
2733        // Construct dictionary with a timezone
2734        let dict = a.finish();
2735        let values = TimestampNanosecondArray::from(dict.values().to_data());
2736        let dict_with_tz = dict.with_values(Arc::new(values.with_timezone("+02:00")));
2737        let v = DataType::Timestamp(TimeUnit::Nanosecond, Some("+02:00".into()));
2738        let d = DataType::Dictionary(Box::new(DataType::Int32), Box::new(v.clone()));
2739
2740        assert_eq!(dict_with_tz.data_type(), &d);
2741        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
2742        let rows = converter
2743            .convert_columns(&[Arc::new(dict_with_tz) as _])
2744            .unwrap();
2745        let back = converter.convert_rows(&rows).unwrap();
2746        assert_eq!(back.len(), 1);
2747        assert_eq!(back[0].data_type(), &v);
2748    }
2749
2750    #[test]
2751    fn test_null_encoding() {
2752        let col = Arc::new(NullArray::new(10));
2753        let converter = RowConverter::new(vec![SortField::new(DataType::Null)]).unwrap();
2754        let rows = converter.convert_columns(&[col]).unwrap();
2755        assert_eq!(rows.num_rows(), 10);
2756        // NULL element encoded as 2 bytes data
2757        assert_eq!(rows.row(1).data.len(), 2);
2758    }
2759
2760    #[test]
2761    fn test_variable_width() {
2762        let col = Arc::new(StringArray::from_iter([
2763            Some("hello"),
2764            Some("he"),
2765            None,
2766            Some("foo"),
2767            Some(""),
2768        ])) as ArrayRef;
2769
2770        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
2771        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2772
2773        assert!(rows.row(1) < rows.row(0));
2774        assert!(rows.row(2) < rows.row(4));
2775        assert!(rows.row(3) < rows.row(0));
2776        assert!(rows.row(3) < rows.row(1));
2777
2778        let cols = converter.convert_rows(&rows).unwrap();
2779        assert_eq!(&cols[0], &col);
2780
2781        let col = Arc::new(BinaryArray::from_iter([
2782            None,
2783            Some(vec![0_u8; 0]),
2784            Some(vec![0_u8; 6]),
2785            Some(vec![0_u8; variable::MINI_BLOCK_SIZE]),
2786            Some(vec![0_u8; variable::MINI_BLOCK_SIZE + 1]),
2787            Some(vec![0_u8; variable::BLOCK_SIZE]),
2788            Some(vec![0_u8; variable::BLOCK_SIZE + 1]),
2789            Some(vec![1_u8; 6]),
2790            Some(vec![1_u8; variable::MINI_BLOCK_SIZE]),
2791            Some(vec![1_u8; variable::MINI_BLOCK_SIZE + 1]),
2792            Some(vec![1_u8; variable::BLOCK_SIZE]),
2793            Some(vec![1_u8; variable::BLOCK_SIZE + 1]),
2794            Some(vec![0xFF_u8; 6]),
2795            Some(vec![0xFF_u8; variable::MINI_BLOCK_SIZE]),
2796            Some(vec![0xFF_u8; variable::MINI_BLOCK_SIZE + 1]),
2797            Some(vec![0xFF_u8; variable::BLOCK_SIZE]),
2798            Some(vec![0xFF_u8; variable::BLOCK_SIZE + 1]),
2799        ])) as ArrayRef;
2800
2801        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
2802        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2803
2804        for i in 0..rows.num_rows() {
2805            for j in i + 1..rows.num_rows() {
2806                assert!(
2807                    rows.row(i) < rows.row(j),
2808                    "{} < {} - {:?} < {:?}",
2809                    i,
2810                    j,
2811                    rows.row(i),
2812                    rows.row(j)
2813                );
2814            }
2815        }
2816
2817        let cols = converter.convert_rows(&rows).unwrap();
2818        assert_eq!(&cols[0], &col);
2819
2820        let converter = RowConverter::new(vec![SortField::new_with_options(
2821            DataType::Binary,
2822            SortOptions::default().desc().with_nulls_first(false),
2823        )])
2824        .unwrap();
2825        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2826
2827        for i in 0..rows.num_rows() {
2828            for j in i + 1..rows.num_rows() {
2829                assert!(
2830                    rows.row(i) > rows.row(j),
2831                    "{} > {} - {:?} > {:?}",
2832                    i,
2833                    j,
2834                    rows.row(i),
2835                    rows.row(j)
2836                );
2837            }
2838        }
2839
2840        let cols = converter.convert_rows(&rows).unwrap();
2841        assert_eq!(&cols[0], &col);
2842    }
2843
2844    /// If `exact` is false performs a logical comparison between a and dictionary-encoded b
2845    fn dictionary_eq(a: &dyn Array, b: &dyn Array) {
2846        match b.data_type() {
2847            DataType::Dictionary(_, v) => {
2848                assert_eq!(a.data_type(), v.as_ref());
2849                let b = arrow_cast::cast(b, v).unwrap();
2850                assert_eq!(a, b.as_ref())
2851            }
2852            _ => assert_eq!(a, b),
2853        }
2854    }
2855
2856    #[test]
2857    fn test_string_dictionary() {
2858        let a = Arc::new(DictionaryArray::<Int32Type>::from_iter([
2859            Some("foo"),
2860            Some("hello"),
2861            Some("he"),
2862            None,
2863            Some("hello"),
2864            Some(""),
2865            Some("hello"),
2866            Some("hello"),
2867        ])) as ArrayRef;
2868
2869        let field = SortField::new(a.data_type().clone());
2870        let converter = RowConverter::new(vec![field]).unwrap();
2871        let rows_a = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
2872
2873        assert!(rows_a.row(3) < rows_a.row(5));
2874        assert!(rows_a.row(2) < rows_a.row(1));
2875        assert!(rows_a.row(0) < rows_a.row(1));
2876        assert!(rows_a.row(3) < rows_a.row(0));
2877
2878        assert_eq!(rows_a.row(1), rows_a.row(4));
2879        assert_eq!(rows_a.row(1), rows_a.row(6));
2880        assert_eq!(rows_a.row(1), rows_a.row(7));
2881
2882        let cols = converter.convert_rows(&rows_a).unwrap();
2883        dictionary_eq(&cols[0], &a);
2884
2885        let b = Arc::new(DictionaryArray::<Int32Type>::from_iter([
2886            Some("hello"),
2887            None,
2888            Some("cupcakes"),
2889        ])) as ArrayRef;
2890
2891        let rows_b = converter.convert_columns(&[Arc::clone(&b)]).unwrap();
2892        assert_eq!(rows_a.row(1), rows_b.row(0));
2893        assert_eq!(rows_a.row(3), rows_b.row(1));
2894        assert!(rows_b.row(2) < rows_a.row(0));
2895
2896        let cols = converter.convert_rows(&rows_b).unwrap();
2897        dictionary_eq(&cols[0], &b);
2898
2899        let converter = RowConverter::new(vec![SortField::new_with_options(
2900            a.data_type().clone(),
2901            SortOptions::default().desc().with_nulls_first(false),
2902        )])
2903        .unwrap();
2904
2905        let rows_c = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
2906        assert!(rows_c.row(3) > rows_c.row(5));
2907        assert!(rows_c.row(2) > rows_c.row(1));
2908        assert!(rows_c.row(0) > rows_c.row(1));
2909        assert!(rows_c.row(3) > rows_c.row(0));
2910
2911        let cols = converter.convert_rows(&rows_c).unwrap();
2912        dictionary_eq(&cols[0], &a);
2913
2914        let converter = RowConverter::new(vec![SortField::new_with_options(
2915            a.data_type().clone(),
2916            SortOptions::default().desc().with_nulls_first(true),
2917        )])
2918        .unwrap();
2919
2920        let rows_c = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
2921        assert!(rows_c.row(3) < rows_c.row(5));
2922        assert!(rows_c.row(2) > rows_c.row(1));
2923        assert!(rows_c.row(0) > rows_c.row(1));
2924        assert!(rows_c.row(3) < rows_c.row(0));
2925
2926        let cols = converter.convert_rows(&rows_c).unwrap();
2927        dictionary_eq(&cols[0], &a);
2928    }
2929
2930    #[test]
2931    fn test_struct() {
2932        // Test basic
2933        let a = Arc::new(Int32Array::from(vec![1, 1, 2, 2])) as ArrayRef;
2934        let a_f = Arc::new(Field::new("int", DataType::Int32, false));
2935        let u = Arc::new(StringArray::from(vec!["a", "b", "c", "d"])) as ArrayRef;
2936        let u_f = Arc::new(Field::new("s", DataType::Utf8, false));
2937        let s1 = Arc::new(StructArray::from(vec![(a_f, a), (u_f, u)])) as ArrayRef;
2938
2939        let sort_fields = vec![SortField::new(s1.data_type().clone())];
2940        let converter = RowConverter::new(sort_fields).unwrap();
2941        let r1 = converter.convert_columns(&[Arc::clone(&s1)]).unwrap();
2942
2943        for (a, b) in r1.iter().zip(r1.iter().skip(1)) {
2944            assert!(a < b);
2945        }
2946
2947        let back = converter.convert_rows(&r1).unwrap();
2948        assert_eq!(back.len(), 1);
2949        assert_eq!(&back[0], &s1);
2950
2951        // Test struct nullability
2952        let data = s1
2953            .to_data()
2954            .into_builder()
2955            .null_bit_buffer(Some(Buffer::from_slice_ref([0b00001010])))
2956            .null_count(2)
2957            .build()
2958            .unwrap();
2959
2960        let s2 = Arc::new(StructArray::from(data)) as ArrayRef;
2961        let r2 = converter.convert_columns(&[Arc::clone(&s2)]).unwrap();
2962        assert_eq!(r2.row(0), r2.row(2)); // Nulls equal
2963        assert!(r2.row(0) < r2.row(1)); // Nulls first
2964        assert_ne!(r1.row(0), r2.row(0)); // Value does not equal null
2965        assert_eq!(r1.row(1), r2.row(1)); // Values equal
2966
2967        let back = converter.convert_rows(&r2).unwrap();
2968        assert_eq!(back.len(), 1);
2969        assert_eq!(&back[0], &s2);
2970
2971        back[0].to_data().validate_full().unwrap();
2972    }
2973
2974    #[test]
2975    fn test_dictionary_in_struct() {
2976        let builder = StringDictionaryBuilder::<Int32Type>::new();
2977        let mut struct_builder = StructBuilder::new(
2978            vec![Field::new_dictionary(
2979                "foo",
2980                DataType::Int32,
2981                DataType::Utf8,
2982                true,
2983            )],
2984            vec![Box::new(builder)],
2985        );
2986
2987        let dict_builder = struct_builder
2988            .field_builder::<StringDictionaryBuilder<Int32Type>>(0)
2989            .unwrap();
2990
2991        // Flattened: ["a", null, "a", "b"]
2992        dict_builder.append_value("a");
2993        dict_builder.append_null();
2994        dict_builder.append_value("a");
2995        dict_builder.append_value("b");
2996
2997        for _ in 0..4 {
2998            struct_builder.append(true);
2999        }
3000
3001        let s = Arc::new(struct_builder.finish()) as ArrayRef;
3002        let sort_fields = vec![SortField::new(s.data_type().clone())];
3003        let converter = RowConverter::new(sort_fields).unwrap();
3004        let r = converter.convert_columns(&[Arc::clone(&s)]).unwrap();
3005
3006        let back = converter.convert_rows(&r).unwrap();
3007        let [s2] = back.try_into().unwrap();
3008
3009        // RowConverter flattens Dictionary
3010        // s.ty = Struct("foo": Dictionary(Int32, Utf8)), s2.ty = Struct("foo": Utf8)
3011        assert_ne!(&s.data_type(), &s2.data_type());
3012        s2.to_data().validate_full().unwrap();
3013
3014        // Check if the logical data remains the same
3015        // Keys: [0, null, 0, 1]
3016        // Values: ["a", "b"]
3017        let s1_struct = s.as_struct();
3018        let s1_0 = s1_struct.column(0);
3019        let s1_idx_0 = s1_0.as_dictionary::<Int32Type>();
3020        let keys = s1_idx_0.keys();
3021        let values = s1_idx_0.values().as_string::<i32>();
3022        // Flattened: ["a", null, "a", "b"]
3023        let s2_struct = s2.as_struct();
3024        let s2_0 = s2_struct.column(0);
3025        let s2_idx_0 = s2_0.as_string::<i32>();
3026
3027        for i in 0..keys.len() {
3028            if keys.is_null(i) {
3029                assert!(s2_idx_0.is_null(i));
3030            } else {
3031                let dict_index = keys.value(i) as usize;
3032                assert_eq!(values.value(dict_index), s2_idx_0.value(i));
3033            }
3034        }
3035    }
3036
3037    #[test]
3038    fn test_dictionary_in_struct_empty() {
3039        let ty = DataType::Struct(
3040            vec![Field::new_dictionary(
3041                "foo",
3042                DataType::Int32,
3043                DataType::Int32,
3044                false,
3045            )]
3046            .into(),
3047        );
3048        let s = arrow_array::new_empty_array(&ty);
3049
3050        let sort_fields = vec![SortField::new(s.data_type().clone())];
3051        let converter = RowConverter::new(sort_fields).unwrap();
3052        let r = converter.convert_columns(&[Arc::clone(&s)]).unwrap();
3053
3054        let back = converter.convert_rows(&r).unwrap();
3055        let [s2] = back.try_into().unwrap();
3056
3057        // RowConverter flattens Dictionary
3058        // s.ty = Struct("foo": Dictionary(Int32, Int32)), s2.ty = Struct("foo": Int32)
3059        assert_ne!(&s.data_type(), &s2.data_type());
3060        s2.to_data().validate_full().unwrap();
3061        assert_eq!(s.len(), 0);
3062        assert_eq!(s2.len(), 0);
3063    }
3064
3065    #[test]
3066    fn test_list_of_string_dictionary() {
3067        let mut builder = ListBuilder::<StringDictionaryBuilder<Int32Type>>::default();
3068        // List[0] = ["a", "b", "zero", null, "c", "b", "d" (dict)]
3069        builder.values().append("a").unwrap();
3070        builder.values().append("b").unwrap();
3071        builder.values().append("zero").unwrap();
3072        builder.values().append_null();
3073        builder.values().append("c").unwrap();
3074        builder.values().append("b").unwrap();
3075        builder.values().append("d").unwrap();
3076        builder.append(true);
3077        // List[1] = null
3078        builder.append(false);
3079        // List[2] = ["e", "zero", "a" (dict)]
3080        builder.values().append("e").unwrap();
3081        builder.values().append("zero").unwrap();
3082        builder.values().append("a").unwrap();
3083        builder.append(true);
3084
3085        let a = Arc::new(builder.finish()) as ArrayRef;
3086        let data_type = a.data_type().clone();
3087
3088        let field = SortField::new(data_type.clone());
3089        let converter = RowConverter::new(vec![field]).unwrap();
3090        let rows = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
3091
3092        let back = converter.convert_rows(&rows).unwrap();
3093        assert_eq!(back.len(), 1);
3094        let [a2] = back.try_into().unwrap();
3095
3096        // RowConverter flattens Dictionary
3097        // a.ty: List(Dictionary(Int32, Utf8)), a2.ty: List(Utf8)
3098        assert_ne!(&a.data_type(), &a2.data_type());
3099
3100        a2.to_data().validate_full().unwrap();
3101
3102        let a2_list = a2.as_list::<i32>();
3103        let a1_list = a.as_list::<i32>();
3104
3105        // Check if the logical data remains the same
3106        // List[0] = ["a", "b", "zero", null, "c", "b", "d" (dict)]
3107        let a1_0 = a1_list.value(0);
3108        let a1_idx_0 = a1_0.as_dictionary::<Int32Type>();
3109        let keys = a1_idx_0.keys();
3110        let values = a1_idx_0.values().as_string::<i32>();
3111        let a2_0 = a2_list.value(0);
3112        let a2_idx_0 = a2_0.as_string::<i32>();
3113
3114        for i in 0..keys.len() {
3115            if keys.is_null(i) {
3116                assert!(a2_idx_0.is_null(i));
3117            } else {
3118                let dict_index = keys.value(i) as usize;
3119                assert_eq!(values.value(dict_index), a2_idx_0.value(i));
3120            }
3121        }
3122
3123        // List[1] = null
3124        assert!(a1_list.is_null(1));
3125        assert!(a2_list.is_null(1));
3126
3127        // List[2] = ["e", "zero", "a" (dict)]
3128        let a1_2 = a1_list.value(2);
3129        let a1_idx_2 = a1_2.as_dictionary::<Int32Type>();
3130        let keys = a1_idx_2.keys();
3131        let values = a1_idx_2.values().as_string::<i32>();
3132        let a2_2 = a2_list.value(2);
3133        let a2_idx_2 = a2_2.as_string::<i32>();
3134
3135        for i in 0..keys.len() {
3136            if keys.is_null(i) {
3137                assert!(a2_idx_2.is_null(i));
3138            } else {
3139                let dict_index = keys.value(i) as usize;
3140                assert_eq!(values.value(dict_index), a2_idx_2.value(i));
3141            }
3142        }
3143    }
3144
3145    #[test]
3146    fn test_primitive_dictionary() {
3147        let mut builder = PrimitiveDictionaryBuilder::<Int32Type, Int32Type>::new();
3148        builder.append(2).unwrap();
3149        builder.append(3).unwrap();
3150        builder.append(0).unwrap();
3151        builder.append_null();
3152        builder.append(5).unwrap();
3153        builder.append(3).unwrap();
3154        builder.append(-1).unwrap();
3155
3156        let a = builder.finish();
3157        let data_type = a.data_type().clone();
3158        let columns = [Arc::new(a) as ArrayRef];
3159
3160        let field = SortField::new(data_type.clone());
3161        let converter = RowConverter::new(vec![field]).unwrap();
3162        let rows = converter.convert_columns(&columns).unwrap();
3163        assert!(rows.row(0) < rows.row(1));
3164        assert!(rows.row(2) < rows.row(0));
3165        assert!(rows.row(3) < rows.row(2));
3166        assert!(rows.row(6) < rows.row(2));
3167        assert!(rows.row(3) < rows.row(6));
3168
3169        let back = converter.convert_rows(&rows).unwrap();
3170        assert_eq!(back.len(), 1);
3171        back[0].to_data().validate_full().unwrap();
3172    }
3173
3174    #[test]
3175    fn test_dictionary_nulls() {
3176        let values = Int32Array::from_iter([Some(1), Some(-1), None, Some(4), None]).into_data();
3177        let keys =
3178            Int32Array::from_iter([Some(0), Some(0), Some(1), Some(2), Some(4), None]).into_data();
3179
3180        let data_type = DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Int32));
3181        let data = keys
3182            .into_builder()
3183            .data_type(data_type.clone())
3184            .child_data(vec![values])
3185            .build()
3186            .unwrap();
3187
3188        let columns = [Arc::new(DictionaryArray::<Int32Type>::from(data)) as ArrayRef];
3189        let field = SortField::new(data_type.clone());
3190        let converter = RowConverter::new(vec![field]).unwrap();
3191        let rows = converter.convert_columns(&columns).unwrap();
3192
3193        assert_eq!(rows.row(0), rows.row(1));
3194        assert_eq!(rows.row(3), rows.row(4));
3195        assert_eq!(rows.row(4), rows.row(5));
3196        assert!(rows.row(3) < rows.row(0));
3197    }
3198
3199    #[test]
3200    fn test_from_binary_shared_buffer() {
3201        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
3202        let array = Arc::new(BinaryArray::from_iter_values([&[0xFF]])) as _;
3203        let rows = converter.convert_columns(&[array]).unwrap();
3204        let binary_rows = rows.try_into_binary().expect("known-small rows");
3205        let _binary_rows_shared_buffer = binary_rows.clone();
3206
3207        let parsed = converter.from_binary(binary_rows);
3208
3209        converter.convert_rows(parsed.iter()).unwrap();
3210    }
3211
3212    #[test]
3213    #[should_panic(expected = "Encountered non UTF-8 data")]
3214    fn test_invalid_utf8() {
3215        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
3216        let array = Arc::new(BinaryArray::from_iter_values([&[0xFF]])) as _;
3217        let rows = converter.convert_columns(&[array]).unwrap();
3218        let binary_row = rows.row(0);
3219
3220        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3221        let parser = converter.parser();
3222        let utf8_row = parser.parse(binary_row.as_ref());
3223
3224        converter.convert_rows(std::iter::once(utf8_row)).unwrap();
3225    }
3226
3227    #[test]
3228    #[should_panic(expected = "Encountered non UTF-8 data")]
3229    fn test_invalid_utf8_array() {
3230        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
3231        let array = Arc::new(BinaryArray::from_iter_values([&[0xFF]])) as _;
3232        let rows = converter.convert_columns(&[array]).unwrap();
3233        let binary_rows = rows.try_into_binary().expect("known-small rows");
3234
3235        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3236        let parsed = converter.from_binary(binary_rows);
3237
3238        converter.convert_rows(parsed.iter()).unwrap();
3239    }
3240
3241    #[test]
3242    #[should_panic(expected = "index out of bounds")]
3243    fn test_invalid_empty() {
3244        let binary_row: &[u8] = &[];
3245
3246        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3247        let parser = converter.parser();
3248        let utf8_row = parser.parse(binary_row.as_ref());
3249
3250        converter.convert_rows(std::iter::once(utf8_row)).unwrap();
3251    }
3252
3253    #[test]
3254    #[should_panic(expected = "index out of bounds")]
3255    fn test_invalid_empty_array() {
3256        let row: &[u8] = &[];
3257        let binary_rows = BinaryArray::from(vec![row]);
3258
3259        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3260        let parsed = converter.from_binary(binary_rows);
3261
3262        converter.convert_rows(parsed.iter()).unwrap();
3263    }
3264
3265    #[test]
3266    #[should_panic(expected = "index out of bounds")]
3267    fn test_invalid_truncated() {
3268        let binary_row: &[u8] = &[0x02];
3269
3270        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3271        let parser = converter.parser();
3272        let utf8_row = parser.parse(binary_row.as_ref());
3273
3274        converter.convert_rows(std::iter::once(utf8_row)).unwrap();
3275    }
3276
3277    #[test]
3278    #[should_panic(expected = "index out of bounds")]
3279    fn test_invalid_truncated_array() {
3280        let row: &[u8] = &[0x02];
3281        let binary_rows = BinaryArray::from(vec![row]);
3282
3283        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3284        let parsed = converter.from_binary(binary_rows);
3285
3286        converter.convert_rows(parsed.iter()).unwrap();
3287    }
3288
3289    #[test]
3290    #[should_panic(expected = "rows were not produced by this RowConverter")]
3291    fn test_different_converter() {
3292        let values = Arc::new(Int32Array::from_iter([Some(1), Some(-1)]));
3293        let converter = RowConverter::new(vec![SortField::new(DataType::Int32)]).unwrap();
3294        let rows = converter.convert_columns(&[values]).unwrap();
3295
3296        let converter = RowConverter::new(vec![SortField::new(DataType::Int32)]).unwrap();
3297        let _ = converter.convert_rows(&rows);
3298    }
3299
3300    fn test_single_list<O: OffsetSizeTrait>() {
3301        let mut builder = GenericListBuilder::<O, _>::new(Int32Builder::new());
3302        builder.values().append_value(32);
3303        builder.values().append_value(52);
3304        builder.values().append_value(32);
3305        builder.append(true);
3306        builder.values().append_value(32);
3307        builder.values().append_value(52);
3308        builder.values().append_value(12);
3309        builder.append(true);
3310        builder.values().append_value(32);
3311        builder.values().append_value(52);
3312        builder.append(true);
3313        builder.values().append_value(32); // MASKED
3314        builder.values().append_value(52); // MASKED
3315        builder.append(false);
3316        builder.values().append_value(32);
3317        builder.values().append_null();
3318        builder.append(true);
3319        builder.append(true);
3320        builder.values().append_value(17); // MASKED
3321        builder.values().append_null(); // MASKED
3322        builder.append(false);
3323
3324        let list = Arc::new(builder.finish()) as ArrayRef;
3325        let d = list.data_type().clone();
3326
3327        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3328
3329        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3330        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3331        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3332        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3333        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3334        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3335        assert!(rows.row(3) < rows.row(5)); // null < []
3336        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3337
3338        let back = converter.convert_rows(&rows).unwrap();
3339        assert_eq!(back.len(), 1);
3340        back[0].to_data().validate_full().unwrap();
3341        assert_eq!(&back[0], &list);
3342
3343        let options = SortOptions::default().asc().with_nulls_first(false);
3344        let field = SortField::new_with_options(d.clone(), options);
3345        let converter = RowConverter::new(vec![field]).unwrap();
3346        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3347
3348        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3349        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3350        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3351        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3352        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3353        assert!(rows.row(3) > rows.row(5)); // null > []
3354        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3355
3356        let back = converter.convert_rows(&rows).unwrap();
3357        assert_eq!(back.len(), 1);
3358        back[0].to_data().validate_full().unwrap();
3359        assert_eq!(&back[0], &list);
3360
3361        let options = SortOptions::default().desc().with_nulls_first(false);
3362        let field = SortField::new_with_options(d.clone(), options);
3363        let converter = RowConverter::new(vec![field]).unwrap();
3364        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3365
3366        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3367        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3368        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3369        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3370        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3371        assert!(rows.row(3) > rows.row(5)); // null > []
3372        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3373
3374        let back = converter.convert_rows(&rows).unwrap();
3375        assert_eq!(back.len(), 1);
3376        back[0].to_data().validate_full().unwrap();
3377        assert_eq!(&back[0], &list);
3378
3379        let options = SortOptions::default().desc().with_nulls_first(true);
3380        let field = SortField::new_with_options(d, options);
3381        let converter = RowConverter::new(vec![field]).unwrap();
3382        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3383
3384        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3385        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3386        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3387        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3388        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3389        assert!(rows.row(3) < rows.row(5)); // null < []
3390        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3391
3392        let back = converter.convert_rows(&rows).unwrap();
3393        assert_eq!(back.len(), 1);
3394        back[0].to_data().validate_full().unwrap();
3395        assert_eq!(&back[0], &list);
3396
3397        let sliced_list = list.slice(1, 5);
3398        let rows_on_sliced_list = converter
3399            .convert_columns(&[Arc::clone(&sliced_list)])
3400            .unwrap();
3401
3402        assert!(rows_on_sliced_list.row(1) > rows_on_sliced_list.row(0)); // [32, 52] > [32, 52, 12]
3403        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(1)); // null < [32, 52]
3404        assert!(rows_on_sliced_list.row(3) < rows_on_sliced_list.row(1)); // [32, null] < [32, 52]
3405        assert!(rows_on_sliced_list.row(4) > rows_on_sliced_list.row(1)); // [] > [32, 52]
3406        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(4)); // null < []
3407
3408        let back = converter.convert_rows(&rows_on_sliced_list).unwrap();
3409        assert_eq!(back.len(), 1);
3410        back[0].to_data().validate_full().unwrap();
3411        assert_eq!(&back[0], &sliced_list);
3412    }
3413
3414    fn test_nested_list<O: OffsetSizeTrait>() {
3415        let mut builder =
3416            GenericListBuilder::<O, _>::new(GenericListBuilder::<O, _>::new(Int32Builder::new()));
3417
3418        builder.values().values().append_value(1);
3419        builder.values().values().append_value(2);
3420        builder.values().append(true);
3421        builder.values().values().append_value(1);
3422        builder.values().values().append_null();
3423        builder.values().append(true);
3424        builder.append(true);
3425
3426        builder.values().values().append_value(1);
3427        builder.values().values().append_null();
3428        builder.values().append(true);
3429        builder.values().values().append_value(1);
3430        builder.values().values().append_null();
3431        builder.values().append(true);
3432        builder.append(true);
3433
3434        builder.values().values().append_value(1);
3435        builder.values().values().append_null();
3436        builder.values().append(true);
3437        builder.values().append(false);
3438        builder.append(true);
3439        builder.append(false);
3440
3441        builder.values().values().append_value(1);
3442        builder.values().values().append_value(2);
3443        builder.values().append(true);
3444        builder.append(true);
3445
3446        let list = Arc::new(builder.finish()) as ArrayRef;
3447        let d = list.data_type().clone();
3448
3449        // [
3450        //   [[1, 2], [1, null]],
3451        //   [[1, null], [1, null]],
3452        //   [[1, null], null]
3453        //   null
3454        //   [[1, 2]]
3455        // ]
3456        let options = SortOptions::default().asc().with_nulls_first(true);
3457        let field = SortField::new_with_options(d.clone(), options);
3458        let converter = RowConverter::new(vec![field]).unwrap();
3459        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3460
3461        assert!(rows.row(0) > rows.row(1));
3462        assert!(rows.row(1) > rows.row(2));
3463        assert!(rows.row(2) > rows.row(3));
3464        assert!(rows.row(4) < rows.row(0));
3465        assert!(rows.row(4) > rows.row(1));
3466
3467        let back = converter.convert_rows(&rows).unwrap();
3468        assert_eq!(back.len(), 1);
3469        back[0].to_data().validate_full().unwrap();
3470        assert_eq!(&back[0], &list);
3471
3472        let options = SortOptions::default().desc().with_nulls_first(true);
3473        let field = SortField::new_with_options(d.clone(), options);
3474        let converter = RowConverter::new(vec![field]).unwrap();
3475        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3476
3477        assert!(rows.row(0) > rows.row(1));
3478        assert!(rows.row(1) > rows.row(2));
3479        assert!(rows.row(2) > rows.row(3));
3480        assert!(rows.row(4) > rows.row(0));
3481        assert!(rows.row(4) > rows.row(1));
3482
3483        let back = converter.convert_rows(&rows).unwrap();
3484        assert_eq!(back.len(), 1);
3485        back[0].to_data().validate_full().unwrap();
3486        assert_eq!(&back[0], &list);
3487
3488        let options = SortOptions::default().desc().with_nulls_first(false);
3489        let field = SortField::new_with_options(d, options);
3490        let converter = RowConverter::new(vec![field]).unwrap();
3491        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3492
3493        assert!(rows.row(0) < rows.row(1));
3494        assert!(rows.row(1) < rows.row(2));
3495        assert!(rows.row(2) < rows.row(3));
3496        assert!(rows.row(4) > rows.row(0));
3497        assert!(rows.row(4) < rows.row(1));
3498
3499        let back = converter.convert_rows(&rows).unwrap();
3500        assert_eq!(back.len(), 1);
3501        back[0].to_data().validate_full().unwrap();
3502        assert_eq!(&back[0], &list);
3503
3504        let sliced_list = list.slice(1, 3);
3505        let rows = converter
3506            .convert_columns(&[Arc::clone(&sliced_list)])
3507            .unwrap();
3508
3509        assert!(rows.row(0) < rows.row(1));
3510        assert!(rows.row(1) < rows.row(2));
3511
3512        let back = converter.convert_rows(&rows).unwrap();
3513        assert_eq!(back.len(), 1);
3514        back[0].to_data().validate_full().unwrap();
3515        assert_eq!(&back[0], &sliced_list);
3516    }
3517
3518    #[test]
3519    fn test_list() {
3520        test_single_list::<i32>();
3521        test_nested_list::<i32>();
3522    }
3523
3524    #[test]
3525    fn test_large_list() {
3526        test_single_list::<i64>();
3527        test_nested_list::<i64>();
3528    }
3529
3530    fn test_single_list_view<O: OffsetSizeTrait>() {
3531        let mut builder = GenericListViewBuilder::<O, _>::new(Int32Builder::new());
3532        builder.values().append_value(32);
3533        builder.values().append_value(52);
3534        builder.values().append_value(32);
3535        builder.append(true);
3536        builder.values().append_value(32);
3537        builder.values().append_value(52);
3538        builder.values().append_value(12);
3539        builder.append(true);
3540        builder.values().append_value(32);
3541        builder.values().append_value(52);
3542        builder.append(true);
3543        builder.values().append_value(32); // MASKED
3544        builder.values().append_value(52); // MASKED
3545        builder.append(false);
3546        builder.values().append_value(32);
3547        builder.values().append_null();
3548        builder.append(true);
3549        builder.append(true);
3550        builder.values().append_value(17); // MASKED
3551        builder.values().append_null(); // MASKED
3552        builder.append(false);
3553
3554        let list = Arc::new(builder.finish()) as ArrayRef;
3555        let d = list.data_type().clone();
3556
3557        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3558
3559        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3560        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3561        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3562        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3563        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3564        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3565        assert!(rows.row(3) < rows.row(5)); // null < []
3566        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3567
3568        let back = converter.convert_rows(&rows).unwrap();
3569        assert_eq!(back.len(), 1);
3570        back[0].to_data().validate_full().unwrap();
3571
3572        // Verify the content matches (ListView may have different physical layout but same logical content)
3573        let back_list_view = back[0]
3574            .as_any()
3575            .downcast_ref::<GenericListViewArray<O>>()
3576            .unwrap();
3577        let orig_list_view = list
3578            .as_any()
3579            .downcast_ref::<GenericListViewArray<O>>()
3580            .unwrap();
3581
3582        assert_eq!(back_list_view.len(), orig_list_view.len());
3583        for i in 0..back_list_view.len() {
3584            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3585            if back_list_view.is_valid(i) {
3586                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3587            }
3588        }
3589
3590        let options = SortOptions::default().asc().with_nulls_first(false);
3591        let field = SortField::new_with_options(d.clone(), options);
3592        let converter = RowConverter::new(vec![field]).unwrap();
3593        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3594
3595        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3596        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3597        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3598        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3599        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3600        assert!(rows.row(3) > rows.row(5)); // null > []
3601        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3602
3603        let back = converter.convert_rows(&rows).unwrap();
3604        assert_eq!(back.len(), 1);
3605        back[0].to_data().validate_full().unwrap();
3606
3607        let options = SortOptions::default().desc().with_nulls_first(false);
3608        let field = SortField::new_with_options(d.clone(), options);
3609        let converter = RowConverter::new(vec![field]).unwrap();
3610        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3611
3612        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3613        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3614        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3615        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3616        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3617        assert!(rows.row(3) > rows.row(5)); // null > []
3618        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3619
3620        let back = converter.convert_rows(&rows).unwrap();
3621        assert_eq!(back.len(), 1);
3622        back[0].to_data().validate_full().unwrap();
3623
3624        let options = SortOptions::default().desc().with_nulls_first(true);
3625        let field = SortField::new_with_options(d, options);
3626        let converter = RowConverter::new(vec![field]).unwrap();
3627        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3628
3629        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3630        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3631        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3632        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3633        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3634        assert!(rows.row(3) < rows.row(5)); // null < []
3635        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3636
3637        let back = converter.convert_rows(&rows).unwrap();
3638        assert_eq!(back.len(), 1);
3639        back[0].to_data().validate_full().unwrap();
3640
3641        let sliced_list = list.slice(1, 5);
3642        let rows_on_sliced_list = converter
3643            .convert_columns(&[Arc::clone(&sliced_list)])
3644            .unwrap();
3645
3646        assert!(rows_on_sliced_list.row(1) > rows_on_sliced_list.row(0)); // [32, 52] > [32, 52, 12]
3647        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(1)); // null < [32, 52]
3648        assert!(rows_on_sliced_list.row(3) < rows_on_sliced_list.row(1)); // [32, null] < [32, 52]
3649        assert!(rows_on_sliced_list.row(4) > rows_on_sliced_list.row(1)); // [] > [32, 52]
3650        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(4)); // null < []
3651
3652        let back = converter.convert_rows(&rows_on_sliced_list).unwrap();
3653        assert_eq!(back.len(), 1);
3654        back[0].to_data().validate_full().unwrap();
3655    }
3656
3657    fn test_nested_list_view<O: OffsetSizeTrait>() {
3658        let mut builder = GenericListViewBuilder::<O, _>::new(GenericListViewBuilder::<O, _>::new(
3659            Int32Builder::new(),
3660        ));
3661
3662        // Row 0: [[1, 2], [1, null]]
3663        builder.values().values().append_value(1);
3664        builder.values().values().append_value(2);
3665        builder.values().append(true);
3666        builder.values().values().append_value(1);
3667        builder.values().values().append_null();
3668        builder.values().append(true);
3669        builder.append(true);
3670
3671        // Row 1: [[1, null], [1, null]]
3672        builder.values().values().append_value(1);
3673        builder.values().values().append_null();
3674        builder.values().append(true);
3675        builder.values().values().append_value(1);
3676        builder.values().values().append_null();
3677        builder.values().append(true);
3678        builder.append(true);
3679
3680        // Row 2: [[1, null], null]
3681        builder.values().values().append_value(1);
3682        builder.values().values().append_null();
3683        builder.values().append(true);
3684        builder.values().append(false);
3685        builder.append(true);
3686
3687        // Row 3: null
3688        builder.append(false);
3689
3690        // Row 4: [[1, 2]]
3691        builder.values().values().append_value(1);
3692        builder.values().values().append_value(2);
3693        builder.values().append(true);
3694        builder.append(true);
3695
3696        let list = Arc::new(builder.finish()) as ArrayRef;
3697        let d = list.data_type().clone();
3698
3699        // [
3700        //   [[1, 2], [1, null]],
3701        //   [[1, null], [1, null]],
3702        //   [[1, null], null]
3703        //   null
3704        //   [[1, 2]]
3705        // ]
3706        let options = SortOptions::default().asc().with_nulls_first(true);
3707        let field = SortField::new_with_options(d.clone(), options);
3708        let converter = RowConverter::new(vec![field]).unwrap();
3709        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3710
3711        assert!(rows.row(0) > rows.row(1));
3712        assert!(rows.row(1) > rows.row(2));
3713        assert!(rows.row(2) > rows.row(3));
3714        assert!(rows.row(4) < rows.row(0));
3715        assert!(rows.row(4) > rows.row(1));
3716
3717        let back = converter.convert_rows(&rows).unwrap();
3718        assert_eq!(back.len(), 1);
3719        back[0].to_data().validate_full().unwrap();
3720
3721        // Verify the content matches (ListView may have different physical layout but same logical content)
3722        let back_list_view = back[0]
3723            .as_any()
3724            .downcast_ref::<GenericListViewArray<O>>()
3725            .unwrap();
3726        let orig_list_view = list
3727            .as_any()
3728            .downcast_ref::<GenericListViewArray<O>>()
3729            .unwrap();
3730
3731        assert_eq!(back_list_view.len(), orig_list_view.len());
3732        for i in 0..back_list_view.len() {
3733            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3734            if back_list_view.is_valid(i) {
3735                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3736            }
3737        }
3738
3739        let options = SortOptions::default().desc().with_nulls_first(true);
3740        let field = SortField::new_with_options(d.clone(), options);
3741        let converter = RowConverter::new(vec![field]).unwrap();
3742        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3743
3744        assert!(rows.row(0) > rows.row(1));
3745        assert!(rows.row(1) > rows.row(2));
3746        assert!(rows.row(2) > rows.row(3));
3747        assert!(rows.row(4) > rows.row(0));
3748        assert!(rows.row(4) > rows.row(1));
3749
3750        let back = converter.convert_rows(&rows).unwrap();
3751        assert_eq!(back.len(), 1);
3752        back[0].to_data().validate_full().unwrap();
3753
3754        // Verify the content matches
3755        let back_list_view = back[0]
3756            .as_any()
3757            .downcast_ref::<GenericListViewArray<O>>()
3758            .unwrap();
3759
3760        assert_eq!(back_list_view.len(), orig_list_view.len());
3761        for i in 0..back_list_view.len() {
3762            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3763            if back_list_view.is_valid(i) {
3764                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3765            }
3766        }
3767
3768        let options = SortOptions::default().desc().with_nulls_first(false);
3769        let field = SortField::new_with_options(d.clone(), options);
3770        let converter = RowConverter::new(vec![field]).unwrap();
3771        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3772
3773        assert!(rows.row(0) < rows.row(1));
3774        assert!(rows.row(1) < rows.row(2));
3775        assert!(rows.row(2) < rows.row(3));
3776        assert!(rows.row(4) > rows.row(0));
3777        assert!(rows.row(4) < rows.row(1));
3778
3779        let back = converter.convert_rows(&rows).unwrap();
3780        assert_eq!(back.len(), 1);
3781        back[0].to_data().validate_full().unwrap();
3782
3783        // Verify the content matches
3784        let back_list_view = back[0]
3785            .as_any()
3786            .downcast_ref::<GenericListViewArray<O>>()
3787            .unwrap();
3788
3789        assert_eq!(back_list_view.len(), orig_list_view.len());
3790        for i in 0..back_list_view.len() {
3791            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3792            if back_list_view.is_valid(i) {
3793                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3794            }
3795        }
3796
3797        let sliced_list = list.slice(1, 3);
3798        let rows = converter
3799            .convert_columns(&[Arc::clone(&sliced_list)])
3800            .unwrap();
3801
3802        assert!(rows.row(0) < rows.row(1));
3803        assert!(rows.row(1) < rows.row(2));
3804
3805        let back = converter.convert_rows(&rows).unwrap();
3806        assert_eq!(back.len(), 1);
3807        back[0].to_data().validate_full().unwrap();
3808    }
3809
3810    #[test]
3811    fn test_list_view() {
3812        test_single_list_view::<i32>();
3813        test_nested_list_view::<i32>();
3814    }
3815
3816    #[test]
3817    fn test_large_list_view() {
3818        test_single_list_view::<i64>();
3819        test_nested_list_view::<i64>();
3820    }
3821
3822    fn test_list_view_with_shared_values<O: OffsetSizeTrait>() {
3823        // Create a values array: [1, 2, 3, 4, 5, 6, 7, 8]
3824        let values = Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8]);
3825        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
3826
3827        // Create a ListView where:
3828        // - Row 0: offset=0, size=3 -> [1, 2, 3]
3829        // - Row 1: offset=0, size=3 -> [1, 2, 3] (same offset+size as row 0)
3830        // - Row 2: offset=5, size=2 -> [6, 7] (non-monotonic offset)
3831        // - Row 3: offset=2, size=2 -> [3, 4] (offset goes back)
3832        // - Row 4: offset=1, size=4 -> [2, 3, 4, 5] (subset of values that contains row 3's range)
3833        // - Row 5: offset=2, size=1 -> [3] (subset of row 3 and row 4)
3834        let offsets = ScalarBuffer::<O>::from(vec![
3835            O::from_usize(0).unwrap(),
3836            O::from_usize(0).unwrap(),
3837            O::from_usize(5).unwrap(),
3838            O::from_usize(2).unwrap(),
3839            O::from_usize(1).unwrap(),
3840            O::from_usize(2).unwrap(),
3841        ]);
3842        let sizes = ScalarBuffer::<O>::from(vec![
3843            O::from_usize(3).unwrap(),
3844            O::from_usize(3).unwrap(),
3845            O::from_usize(2).unwrap(),
3846            O::from_usize(2).unwrap(),
3847            O::from_usize(4).unwrap(),
3848            O::from_usize(1).unwrap(),
3849        ]);
3850
3851        let list_view: GenericListViewArray<O> =
3852            GenericListViewArray::try_new(field, offsets, sizes, Arc::new(values), None).unwrap();
3853
3854        let d = list_view.data_type().clone();
3855        let list = Arc::new(list_view) as ArrayRef;
3856
3857        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3858        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3859
3860        // Row 0 and Row 1 have the same content [1, 2, 3], so they should be equal
3861        assert_eq!(rows.row(0), rows.row(1));
3862
3863        // [1, 2, 3] < [6, 7] (comparing first elements: 1 < 6)
3864        assert!(rows.row(0) < rows.row(2));
3865
3866        // [3, 4] > [1, 2, 3] (comparing first elements: 3 > 1)
3867        assert!(rows.row(3) > rows.row(0));
3868
3869        // [2, 3, 4, 5] > [1, 2, 3] (comparing first elements: 2 > 1)
3870        assert!(rows.row(4) > rows.row(0));
3871
3872        // [3] < [3, 4] (same prefix but shorter)
3873        assert!(rows.row(5) < rows.row(3));
3874
3875        // [3] < [2, 3, 4, 5] (comparing first elements: 3 > 2)
3876        assert!(rows.row(5) > rows.row(4));
3877
3878        // Round-trip conversion
3879        let back = converter.convert_rows(&rows).unwrap();
3880        assert_eq!(back.len(), 1);
3881        back[0].to_data().validate_full().unwrap();
3882
3883        // Verify logical content matches
3884        let back_list_view = back[0]
3885            .as_any()
3886            .downcast_ref::<GenericListViewArray<O>>()
3887            .unwrap();
3888        let orig_list_view = list
3889            .as_any()
3890            .downcast_ref::<GenericListViewArray<O>>()
3891            .unwrap();
3892
3893        assert_eq!(back_list_view.len(), orig_list_view.len());
3894        for i in 0..back_list_view.len() {
3895            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3896            if back_list_view.is_valid(i) {
3897                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3898            }
3899        }
3900
3901        // Test with descending order
3902        let options = SortOptions::default().desc();
3903        let field = SortField::new_with_options(d, options);
3904        let converter = RowConverter::new(vec![field]).unwrap();
3905        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3906
3907        // In descending order, comparisons are reversed
3908        assert_eq!(rows.row(0), rows.row(1)); // Equal rows stay equal
3909        assert!(rows.row(0) > rows.row(2)); // [1, 2, 3] > [6, 7] in desc
3910        assert!(rows.row(3) < rows.row(0)); // [3, 4] < [1, 2, 3] in desc
3911
3912        let back = converter.convert_rows(&rows).unwrap();
3913        assert_eq!(back.len(), 1);
3914        back[0].to_data().validate_full().unwrap();
3915    }
3916
3917    #[test]
3918    fn test_list_view_shared_values() {
3919        test_list_view_with_shared_values::<i32>();
3920    }
3921
3922    #[test]
3923    fn test_large_list_view_shared_values() {
3924        test_list_view_with_shared_values::<i64>();
3925    }
3926
3927    #[test]
3928    fn test_fixed_size_list() {
3929        let mut builder = FixedSizeListBuilder::new(Int32Builder::new(), 3);
3930        builder.values().append_value(32);
3931        builder.values().append_value(52);
3932        builder.values().append_value(32);
3933        builder.append(true);
3934        builder.values().append_value(32);
3935        builder.values().append_value(52);
3936        builder.values().append_value(12);
3937        builder.append(true);
3938        builder.values().append_value(32);
3939        builder.values().append_value(52);
3940        builder.values().append_null();
3941        builder.append(true);
3942        builder.values().append_value(32); // MASKED
3943        builder.values().append_value(52); // MASKED
3944        builder.values().append_value(13); // MASKED
3945        builder.append(false);
3946        builder.values().append_value(32);
3947        builder.values().append_null();
3948        builder.values().append_null();
3949        builder.append(true);
3950        builder.values().append_null();
3951        builder.values().append_null();
3952        builder.values().append_null();
3953        builder.append(true);
3954        builder.values().append_value(17); // MASKED
3955        builder.values().append_null(); // MASKED
3956        builder.values().append_value(77); // MASKED
3957        builder.append(false);
3958
3959        let list = Arc::new(builder.finish()) as ArrayRef;
3960        let d = list.data_type().clone();
3961
3962        // Default sorting (ascending, nulls first)
3963        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3964
3965        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3966        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3967        assert!(rows.row(2) < rows.row(1)); // [32, 52, null] < [32, 52, 12]
3968        assert!(rows.row(3) < rows.row(2)); // null < [32, 52, null]
3969        assert!(rows.row(4) < rows.row(2)); // [32, null, null] < [32, 52, null]
3970        assert!(rows.row(5) < rows.row(2)); // [null, null, null] < [32, 52, null]
3971        assert!(rows.row(3) < rows.row(5)); // null < [null, null, null]
3972        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3973
3974        let back = converter.convert_rows(&rows).unwrap();
3975        assert_eq!(back.len(), 1);
3976        back[0].to_data().validate_full().unwrap();
3977        assert_eq!(&back[0], &list);
3978
3979        // Ascending, null last
3980        let options = SortOptions::default().asc().with_nulls_first(false);
3981        let field = SortField::new_with_options(d.clone(), options);
3982        let converter = RowConverter::new(vec![field]).unwrap();
3983        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3984        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3985        assert!(rows.row(2) > rows.row(1)); // [32, 52, null] > [32, 52, 12]
3986        assert!(rows.row(3) > rows.row(2)); // null > [32, 52, null]
3987        assert!(rows.row(4) > rows.row(2)); // [32, null, null] > [32, 52, null]
3988        assert!(rows.row(5) > rows.row(2)); // [null, null, null] > [32, 52, null]
3989        assert!(rows.row(3) > rows.row(5)); // null > [null, null, null]
3990        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3991
3992        let back = converter.convert_rows(&rows).unwrap();
3993        assert_eq!(back.len(), 1);
3994        back[0].to_data().validate_full().unwrap();
3995        assert_eq!(&back[0], &list);
3996
3997        // Descending, nulls last
3998        let options = SortOptions::default().desc().with_nulls_first(false);
3999        let field = SortField::new_with_options(d.clone(), options);
4000        let converter = RowConverter::new(vec![field]).unwrap();
4001        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
4002        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
4003        assert!(rows.row(2) > rows.row(1)); // [32, 52, null] > [32, 52, 12]
4004        assert!(rows.row(3) > rows.row(2)); // null > [32, 52, null]
4005        assert!(rows.row(4) > rows.row(2)); // [32, null, null] > [32, 52, null]
4006        assert!(rows.row(5) > rows.row(2)); // [null, null, null] > [32, 52, null]
4007        assert!(rows.row(3) > rows.row(5)); // null > [null, null, null]
4008        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
4009
4010        let back = converter.convert_rows(&rows).unwrap();
4011        assert_eq!(back.len(), 1);
4012        back[0].to_data().validate_full().unwrap();
4013        assert_eq!(&back[0], &list);
4014
4015        // Descending, nulls first
4016        let options = SortOptions::default().desc().with_nulls_first(true);
4017        let field = SortField::new_with_options(d, options);
4018        let converter = RowConverter::new(vec![field]).unwrap();
4019        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
4020
4021        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
4022        assert!(rows.row(2) < rows.row(1)); // [32, 52, null] > [32, 52, 12]
4023        assert!(rows.row(3) < rows.row(2)); // null < [32, 52, null]
4024        assert!(rows.row(4) < rows.row(2)); // [32, null, null] < [32, 52, null]
4025        assert!(rows.row(5) < rows.row(2)); // [null, null, null] > [32, 52, null]
4026        assert!(rows.row(3) < rows.row(5)); // null < [null, null, null]
4027        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
4028
4029        let back = converter.convert_rows(&rows).unwrap();
4030        assert_eq!(back.len(), 1);
4031        back[0].to_data().validate_full().unwrap();
4032        assert_eq!(&back[0], &list);
4033
4034        let sliced_list = list.slice(1, 5);
4035        let rows_on_sliced_list = converter
4036            .convert_columns(&[Arc::clone(&sliced_list)])
4037            .unwrap();
4038
4039        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(1)); // null < [32, 52, null]
4040        assert!(rows_on_sliced_list.row(3) < rows_on_sliced_list.row(1)); // [32, null, null] < [32, 52, null]
4041        assert!(rows_on_sliced_list.row(4) < rows_on_sliced_list.row(1)); // [null, null, null] > [32, 52, null]
4042        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(4)); // null < [null, null, null]
4043
4044        let back = converter.convert_rows(&rows_on_sliced_list).unwrap();
4045        assert_eq!(back.len(), 1);
4046        back[0].to_data().validate_full().unwrap();
4047        assert_eq!(&back[0], &sliced_list);
4048    }
4049
4050    #[test]
4051    fn test_two_fixed_size_lists() {
4052        let mut first = FixedSizeListBuilder::new(UInt8Builder::new(), 1);
4053        // 0: [100]
4054        first.values().append_value(100);
4055        first.append(true);
4056        // 1: [101]
4057        first.values().append_value(101);
4058        first.append(true);
4059        // 2: [102]
4060        first.values().append_value(102);
4061        first.append(true);
4062        // 3: [null]
4063        first.values().append_null();
4064        first.append(true);
4065        // 4: null
4066        first.values().append_null(); // MASKED
4067        first.append(false);
4068        let first = Arc::new(first.finish()) as ArrayRef;
4069        let first_type = first.data_type().clone();
4070
4071        let mut second = FixedSizeListBuilder::new(UInt8Builder::new(), 1);
4072        // 0: [200]
4073        second.values().append_value(200);
4074        second.append(true);
4075        // 1: [201]
4076        second.values().append_value(201);
4077        second.append(true);
4078        // 2: [202]
4079        second.values().append_value(202);
4080        second.append(true);
4081        // 3: [null]
4082        second.values().append_null();
4083        second.append(true);
4084        // 4: null
4085        second.values().append_null(); // MASKED
4086        second.append(false);
4087        let second = Arc::new(second.finish()) as ArrayRef;
4088        let second_type = second.data_type().clone();
4089
4090        let converter = RowConverter::new(vec![
4091            SortField::new(first_type.clone()),
4092            SortField::new(second_type.clone()),
4093        ])
4094        .unwrap();
4095
4096        let rows = converter
4097            .convert_columns(&[Arc::clone(&first), Arc::clone(&second)])
4098            .unwrap();
4099
4100        let back = converter.convert_rows(&rows).unwrap();
4101        assert_eq!(back.len(), 2);
4102        back[0].to_data().validate_full().unwrap();
4103        assert_eq!(&back[0], &first);
4104        back[1].to_data().validate_full().unwrap();
4105        assert_eq!(&back[1], &second);
4106    }
4107
4108    #[test]
4109    fn test_fixed_size_list_with_variable_width_content() {
4110        let mut first = FixedSizeListBuilder::new(
4111            StructBuilder::from_fields(
4112                vec![
4113                    Field::new(
4114                        "timestamp",
4115                        DataType::Timestamp(TimeUnit::Microsecond, Some(Arc::from("UTC"))),
4116                        false,
4117                    ),
4118                    Field::new("offset_minutes", DataType::Int16, false),
4119                    Field::new("time_zone", DataType::Utf8, false),
4120                ],
4121                1,
4122            ),
4123            1,
4124        );
4125        // 0: null
4126        first
4127            .values()
4128            .field_builder::<TimestampMicrosecondBuilder>(0)
4129            .unwrap()
4130            .append_null();
4131        first
4132            .values()
4133            .field_builder::<Int16Builder>(1)
4134            .unwrap()
4135            .append_null();
4136        first
4137            .values()
4138            .field_builder::<StringBuilder>(2)
4139            .unwrap()
4140            .append_null();
4141        first.values().append(false);
4142        first.append(false);
4143        // 1: [null]
4144        first
4145            .values()
4146            .field_builder::<TimestampMicrosecondBuilder>(0)
4147            .unwrap()
4148            .append_null();
4149        first
4150            .values()
4151            .field_builder::<Int16Builder>(1)
4152            .unwrap()
4153            .append_null();
4154        first
4155            .values()
4156            .field_builder::<StringBuilder>(2)
4157            .unwrap()
4158            .append_null();
4159        first.values().append(false);
4160        first.append(true);
4161        // 2: [1970-01-01 00:00:00.000000 UTC]
4162        first
4163            .values()
4164            .field_builder::<TimestampMicrosecondBuilder>(0)
4165            .unwrap()
4166            .append_value(0);
4167        first
4168            .values()
4169            .field_builder::<Int16Builder>(1)
4170            .unwrap()
4171            .append_value(0);
4172        first
4173            .values()
4174            .field_builder::<StringBuilder>(2)
4175            .unwrap()
4176            .append_value("UTC");
4177        first.values().append(true);
4178        first.append(true);
4179        // 3: [2005-09-10 13:30:00.123456 Europe/Warsaw]
4180        first
4181            .values()
4182            .field_builder::<TimestampMicrosecondBuilder>(0)
4183            .unwrap()
4184            .append_value(1126351800123456);
4185        first
4186            .values()
4187            .field_builder::<Int16Builder>(1)
4188            .unwrap()
4189            .append_value(120);
4190        first
4191            .values()
4192            .field_builder::<StringBuilder>(2)
4193            .unwrap()
4194            .append_value("Europe/Warsaw");
4195        first.values().append(true);
4196        first.append(true);
4197        let first = Arc::new(first.finish()) as ArrayRef;
4198        let first_type = first.data_type().clone();
4199
4200        let mut second = StringBuilder::new();
4201        second.append_value("somewhere near");
4202        second.append_null();
4203        second.append_value("Greenwich");
4204        second.append_value("Warsaw");
4205        let second = Arc::new(second.finish()) as ArrayRef;
4206        let second_type = second.data_type().clone();
4207
4208        let converter = RowConverter::new(vec![
4209            SortField::new(first_type.clone()),
4210            SortField::new(second_type.clone()),
4211        ])
4212        .unwrap();
4213
4214        let rows = converter
4215            .convert_columns(&[Arc::clone(&first), Arc::clone(&second)])
4216            .unwrap();
4217
4218        let back = converter.convert_rows(&rows).unwrap();
4219        assert_eq!(back.len(), 2);
4220        back[0].to_data().validate_full().unwrap();
4221        assert_eq!(&back[0], &first);
4222        back[1].to_data().validate_full().unwrap();
4223        assert_eq!(&back[1], &second);
4224    }
4225
4226    #[test]
4227    fn test_single_map() {
4228        let mut builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new());
4229        // Entry 0: {"hello": 1, "world": 2}
4230        builder.keys().append_value("hello");
4231        builder.values().append_value(1);
4232        builder.keys().append_value("world");
4233        builder.values().append_value(2);
4234        builder.append(true).unwrap();
4235
4236        // Entry 1: {"foo": 3}
4237        builder.keys().append_value("foo");
4238        builder.values().append_value(3);
4239        builder.append(true).unwrap();
4240
4241        // Entry 2: {} (empty map)
4242        builder.append(true).unwrap();
4243
4244        // Entry 3: null (with masked data)
4245        builder.keys().append_value("masked_key");
4246        builder.values().append_value(999);
4247        builder.append(false).unwrap();
4248
4249        // Entry 4: null (with unmasked data)
4250        builder.append(false).unwrap();
4251
4252        // Entry 5: {"bar": null}
4253        builder.keys().append_value("bar");
4254        builder.values().append_null();
4255        builder.append(true).unwrap();
4256
4257        // Entry 6: null (with different masked data)
4258        builder.keys().append_value("other_masked");
4259        builder.values().append_value(0);
4260        builder.append(false).unwrap();
4261
4262        // Entry 7: {"a": 10, "b": 20, "c": 30}
4263        builder.keys().append_value("a");
4264        builder.values().append_value(10);
4265        builder.keys().append_value("b");
4266        builder.values().append_value(20);
4267        builder.keys().append_value("c");
4268        builder.values().append_value(30);
4269        builder.append(true).unwrap();
4270
4271        let map = Arc::new(builder.finish()) as ArrayRef;
4272        let d = map.data_type().clone();
4273
4274        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4275
4276        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4277
4278        // null = null (different masked values or masking vs non-masking)
4279        assert_eq!(rows.row(3), rows.row(4));
4280        assert_eq!(rows.row(4), rows.row(6));
4281
4282        let back = converter.convert_rows(&rows).unwrap();
4283        assert_eq!(back.len(), 1);
4284        back[0].to_data().validate_full().unwrap();
4285        assert_eq!(&back[0], &map);
4286
4287        let sliced_map = map.slice(1, map.len() - 2);
4288        let rows_on_sliced = converter
4289            .convert_columns(&[Arc::clone(&sliced_map)])
4290            .unwrap();
4291
4292        let back = converter.convert_rows(&rows_on_sliced).unwrap();
4293        assert_eq!(back.len(), 1);
4294        back[0].to_data().validate_full().unwrap();
4295        assert_eq!(&back[0], &sliced_map);
4296    }
4297
4298    #[test]
4299    fn two_maps_with_different_keys_order_should_sort_by_entry_order() {
4300        let map_1: ArrayRef =
4301            Arc::new(MapArray::from_vec_of_maps::<StringArray, Int32Array, _, _>(
4302                vec![Some(vec![("hello", Some(1)), ("world", Some(2))])],
4303                false,
4304            ));
4305        // { "world": 2, "hello": 1 }
4306        let map_2: ArrayRef =
4307            Arc::new(MapArray::from_vec_of_maps::<StringArray, Int32Array, _, _>(
4308                vec![Some(vec![("world", Some(2)), ("hello", Some(1))])],
4309                false,
4310            ));
4311
4312        let converter = RowConverter::new(vec![SortField::new(map_1.data_type().clone())]).unwrap();
4313
4314        let map_1_rows = converter.convert_columns(&[Arc::clone(&map_1)]).unwrap();
4315        let map_2_rows = converter.convert_columns(&[Arc::clone(&map_2)]).unwrap();
4316
4317        assert_ne!(map_1_rows.row(0), map_2_rows.row(0));
4318        assert!(map_1_rows.row(0) < map_2_rows.row(0));
4319
4320        let back_1 = converter.convert_rows(&map_1_rows).unwrap();
4321        let back_2 = converter.convert_rows(&map_2_rows).unwrap();
4322        assert_eq!(&back_1[0], &map_1);
4323        assert_eq!(&back_2[0], &map_2);
4324    }
4325
4326    #[test]
4327    fn test_nested_map() {
4328        // Map<Utf8, Map<Utf8, Int32>>
4329        let mut builder = MapBuilder::new(
4330            None,
4331            StringBuilder::new(),
4332            MapBuilder::new(None, StringBuilder::new(), Int32Builder::new()),
4333        );
4334
4335        // Entry 0: {"outer1": {"inner_a": 1, "inner_b": 2}, "outer2": {"inner_c": 3}}
4336        builder.keys().append_value("outer1");
4337        builder.values().keys().append_value("inner_a");
4338        builder.values().values().append_value(1);
4339        builder.values().keys().append_value("inner_b");
4340        builder.values().values().append_value(2);
4341        builder.values().append(true).unwrap();
4342        builder.keys().append_value("outer2");
4343        builder.values().keys().append_value("inner_c");
4344        builder.values().values().append_value(3);
4345        builder.values().append(true).unwrap();
4346        builder.append(true).unwrap();
4347
4348        // Entry 1: {"x": {}} (inner map is empty)
4349        builder.keys().append_value("x");
4350        builder.values().append(true).unwrap();
4351        builder.append(true).unwrap();
4352
4353        // Entry 2: {"y": null} (inner map is null)
4354        builder.keys().append_value("y");
4355        builder.values().keys().append_value("masked"); // MASKED
4356        builder.values().values().append_value(0); // MASKED
4357        builder.values().append(false).unwrap();
4358        builder.append(true).unwrap();
4359
4360        // Entry 3: {"y": null} (inner map is non masked null)
4361        builder.keys().append_value("y");
4362        builder.values().append(false).unwrap(); // not masked
4363        builder.append(true).unwrap();
4364
4365        // Entry 4: null (outer map is null)
4366        builder.keys().append_value("masked_outer"); // MASKED
4367        builder.values().keys().append_value("masked_inner"); // MASKED
4368        builder.values().values().append_value(0); // MASKED
4369        builder.values().append(true).unwrap(); // MASKED
4370        builder.append(false).unwrap();
4371
4372        // Entry 5: null (outer map is null with inner map non masked null)
4373        builder.keys().append_value("masked_outer"); // MASKED
4374        builder.values().append(false).unwrap(); // not masked
4375        builder.append(false).unwrap();
4376
4377        // Entry 6: non masked null (outer map is null)
4378        builder.append(false).unwrap(); // not masked
4379
4380        // Entry 7: {} (outer map is empty)
4381        builder.append(true).unwrap();
4382
4383        let map = Arc::new(builder.finish()) as ArrayRef;
4384        let d = map.data_type().clone();
4385
4386        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4387
4388        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4389
4390        let back = converter.convert_rows(&rows).unwrap();
4391        assert_eq!(back.len(), 1);
4392        back[0].to_data().validate_full().unwrap();
4393        assert_eq!(&back[0], &map);
4394
4395        let sliced_map = map.slice(1, 3);
4396        let rows_on_sliced = converter
4397            .convert_columns(&[Arc::clone(&sliced_map)])
4398            .unwrap();
4399
4400        let back = converter.convert_rows(&rows_on_sliced).unwrap();
4401        assert_eq!(back.len(), 1);
4402        back[0].to_data().validate_full().unwrap();
4403        assert_eq!(&back[0], &sliced_map);
4404    }
4405
4406    #[test]
4407    fn test_single_map_with_non_nullable_values() {
4408        // Use `with_values_field` on `MapBuilder` to set the values are not nullable
4409        let value_field = Arc::new(Field::new("values", DataType::Int32, false));
4410        let mut builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new())
4411            .with_values_field(value_field);
4412        // Entry 0: {"a": 1, "b": 2}
4413        builder.keys().append_value("a");
4414        builder.values().append_value(1);
4415        builder.keys().append_value("b");
4416        builder.values().append_value(2);
4417        builder.append(true).unwrap();
4418        // Entry 1: null
4419        builder.append(false).unwrap();
4420        // Entry 2: {"c": 3}
4421        builder.keys().append_value("c");
4422        builder.values().append_value(3);
4423        builder.append(true).unwrap();
4424        // Entry 3: {}
4425        builder.append(true).unwrap();
4426        // Entry 4: null
4427        builder.keys().append_value("masked"); // MASKED
4428        builder.values().append_value(0); // MASKED
4429        builder.append(false).unwrap();
4430
4431        let map = Arc::new(builder.finish()) as ArrayRef;
4432        let d = map.data_type().clone();
4433
4434        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4435
4436        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4437
4438        let back = converter.convert_rows(&rows).unwrap();
4439        assert_eq!(back.len(), 1);
4440        back[0].to_data().validate_full().unwrap();
4441        assert_eq!(&back[0], &map);
4442    }
4443
4444    #[test]
4445    fn test_single_map_with_non_nullable_map_but_with_nullable_values() {
4446        // Map column is non-nullable, but values are nullable
4447        let value_field = Arc::new(Field::new("values", DataType::Int32, true));
4448        let mut builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new())
4449            .with_values_field(value_field);
4450
4451        // Entry 0: {"a": 1, "b": null}
4452        builder.keys().append_value("a");
4453        builder.values().append_value(1);
4454        builder.keys().append_value("b");
4455        builder.values().append_null();
4456        builder.append(true).unwrap();
4457        // Entry 1: {"c": null, "d": null}
4458        builder.keys().append_value("c");
4459        builder.values().append_null();
4460        builder.keys().append_value("d");
4461        builder.values().append_null();
4462        builder.append(true).unwrap();
4463        // Entry 2: {}
4464        builder.append(true).unwrap();
4465        // Entry 3: {"e": 5}
4466        builder.keys().append_value("e");
4467        builder.values().append_value(5);
4468        builder.append(true).unwrap();
4469
4470        let map = Arc::new(builder.finish()) as ArrayRef;
4471        let d = map.data_type().clone();
4472
4473        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4474
4475        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4476
4477        let back = converter.convert_rows(&rows).unwrap();
4478        assert_eq!(back.len(), 1);
4479        back[0].to_data().validate_full().unwrap();
4480        assert_eq!(&back[0], &map);
4481    }
4482
4483    #[test]
4484    fn test_map_all_nulls() {
4485        let mut builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new());
4486        // All entries are null
4487        builder.keys().append_value("m1"); // MASKED
4488        builder.values().append_value(1); // MASKED
4489        builder.append(false).unwrap();
4490        builder.keys().append_value("m2"); // MASKED
4491        builder.values().append_value(2); // MASKED
4492        builder.append(false).unwrap();
4493
4494        builder.append(false).unwrap(); // non masked
4495
4496        builder.keys().append_value("m3"); // MASKED
4497        builder.values().append_value(3); // MASKED
4498        builder.append(false).unwrap();
4499
4500        let map = Arc::new(builder.finish()) as ArrayRef;
4501        let d = map.data_type().clone();
4502
4503        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4504
4505        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4506
4507        // All null rows should be equal
4508        rows.iter().for_each(|row| assert_eq!(row, rows.row(0)));
4509
4510        let back = converter.convert_rows(&rows).unwrap();
4511        assert_eq!(back.len(), 1);
4512        back[0].to_data().validate_full().unwrap();
4513        assert_eq!(&back[0], &map);
4514    }
4515
4516    #[test]
4517    fn test_map_all_empty() {
4518        let mut builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new());
4519        // All entries are empty maps
4520        builder.append(true).unwrap();
4521        builder.append(true).unwrap();
4522        builder.append(true).unwrap();
4523
4524        let map = Arc::new(builder.finish()) as ArrayRef;
4525        let d = map.data_type().clone();
4526
4527        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4528
4529        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4530
4531        // All empty maps should be equal
4532        rows.iter().for_each(|row| assert_eq!(row, rows.row(0)));
4533
4534        let back = converter.convert_rows(&rows).unwrap();
4535        assert_eq!(back.len(), 1);
4536        back[0].to_data().validate_full().unwrap();
4537        assert_eq!(&back[0], &map);
4538    }
4539
4540    #[test]
4541    fn test_map_empty_array() {
4542        // Zero-length map array
4543        let builder = MapBuilder::new(None, StringBuilder::new(), Int32Builder::new());
4544        let map = Arc::new(builder.finish_cloned()) as ArrayRef;
4545        let d = map.data_type().clone();
4546
4547        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
4548
4549        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
4550
4551        let back = converter.convert_rows(&rows).unwrap();
4552        assert_eq!(back.len(), 1);
4553        back[0].to_data().validate_full().unwrap();
4554        assert_eq!(&back[0], &map);
4555    }
4556
4557    fn generate_primitive_array<K>(
4558        rng: &mut impl RngCore,
4559        len: usize,
4560        valid_percent: f64,
4561    ) -> PrimitiveArray<K>
4562    where
4563        K: ArrowPrimitiveType,
4564        StandardUniform: Distribution<K::Native>,
4565    {
4566        (0..len)
4567            .map(|_| rng.random_bool(valid_percent).then(|| rng.random()))
4568            .collect()
4569    }
4570
4571    fn generate_all_unique_primitive_array<K>(
4572        rng: &mut impl RngCore,
4573        len: usize,
4574    ) -> PrimitiveArray<K>
4575    where
4576        K: ArrowPrimitiveType,
4577        K::Native: Hash + Eq,
4578        StandardUniform: Distribution<K::Native>,
4579    {
4580        let possible_number_of_values = 2i32.saturating_pow(size_of::<K::Native>() as u32 * 8);
4581        assert!(
4582            len <= possible_number_of_values as usize,
4583            "len {len} is larger than the number of possible values {possible_number_of_values}"
4584        );
4585
4586        let mut seen = std::collections::HashSet::new();
4587        (0..len)
4588            .map(|_| {
4589                let mut value;
4590                loop {
4591                    value = rng.random();
4592
4593                    if seen.insert(value) {
4594                        break;
4595                    }
4596                }
4597
4598                Some(value)
4599            })
4600            .collect()
4601    }
4602
4603    fn generate_boolean_array(
4604        rng: &mut impl RngCore,
4605        len: usize,
4606        valid_percent: f64,
4607    ) -> BooleanArray {
4608        (0..len)
4609            .map(|_| rng.random_bool(valid_percent).then(|| rng.random_bool(0.5)))
4610            .collect()
4611    }
4612
4613    fn generate_strings<O: OffsetSizeTrait>(
4614        rng: &mut impl RngCore,
4615        len: usize,
4616        valid_percent: f64,
4617    ) -> GenericStringArray<O> {
4618        (0..len)
4619            .map(|_| {
4620                rng.random_bool(valid_percent).then(|| {
4621                    let len = rng.random_range(0..100);
4622                    let bytes = (0..len).map(|_| rng.random_range(0..128)).collect();
4623                    String::from_utf8(bytes).unwrap()
4624                })
4625            })
4626            .collect()
4627    }
4628
4629    fn generate_string_view(
4630        rng: &mut impl RngCore,
4631        len: usize,
4632        valid_percent: f64,
4633    ) -> StringViewArray {
4634        (0..len)
4635            .map(|_| {
4636                rng.random_bool(valid_percent).then(|| {
4637                    let len = rng.random_range(0..100);
4638                    let bytes = (0..len).map(|_| rng.random_range(0..128)).collect();
4639                    String::from_utf8(bytes).unwrap()
4640                })
4641            })
4642            .collect()
4643    }
4644
4645    fn generate_byte_view(
4646        rng: &mut impl RngCore,
4647        len: usize,
4648        valid_percent: f64,
4649    ) -> BinaryViewArray {
4650        (0..len)
4651            .map(|_| {
4652                rng.random_bool(valid_percent).then(|| {
4653                    let len = rng.random_range(0..100);
4654                    let bytes: Vec<_> = (0..len).map(|_| rng.random_range(0..128)).collect();
4655                    bytes
4656                })
4657            })
4658            .collect()
4659    }
4660
4661    fn generate_fixed_stringview_column(len: usize) -> StringViewArray {
4662        let edge_cases = vec![
4663            Some("bar".to_string()),
4664            Some("bar\0".to_string()),
4665            Some("LongerThan12Bytes".to_string()),
4666            Some("LongerThan12Bytez".to_string()),
4667            Some("LongerThan12Bytes\0".to_string()),
4668            Some("LongerThan12Byt".to_string()),
4669            Some("backend one".to_string()),
4670            Some("backend two".to_string()),
4671            Some("a".repeat(257)),
4672            Some("a".repeat(300)),
4673        ];
4674
4675        // Fill up to `len` by repeating edge cases and trimming
4676        let mut values = Vec::with_capacity(len);
4677        for i in 0..len {
4678            values.push(
4679                edge_cases
4680                    .get(i % edge_cases.len())
4681                    .cloned()
4682                    .unwrap_or(None),
4683            );
4684        }
4685
4686        StringViewArray::from(values)
4687    }
4688
4689    fn generate_dictionary<K>(
4690        rng: &mut impl RngCore,
4691        values: ArrayRef,
4692        len: usize,
4693        valid_percent: f64,
4694    ) -> DictionaryArray<K>
4695    where
4696        K: ArrowDictionaryKeyType,
4697        K::Native: SampleUniform,
4698    {
4699        let min_key = K::Native::from_usize(0).unwrap();
4700        let max_key = K::Native::from_usize(values.len()).unwrap();
4701        let keys: PrimitiveArray<K> = (0..len)
4702            .map(|_| {
4703                rng.random_bool(valid_percent)
4704                    .then(|| rng.random_range(min_key..max_key))
4705            })
4706            .collect();
4707
4708        let data_type =
4709            DataType::Dictionary(Box::new(K::DATA_TYPE), Box::new(values.data_type().clone()));
4710
4711        let data = keys
4712            .into_data()
4713            .into_builder()
4714            .data_type(data_type)
4715            .add_child_data(values.to_data())
4716            .build()
4717            .unwrap();
4718
4719        DictionaryArray::from(data)
4720    }
4721
4722    fn generate_fixed_size_binary(
4723        rng: &mut impl RngCore,
4724        len: usize,
4725        valid_percent: f64,
4726    ) -> FixedSizeBinaryArray {
4727        let width = rng.random_range(0..20);
4728        let mut builder = FixedSizeBinaryBuilder::new(width);
4729
4730        let mut b = vec![0; width as usize];
4731        for _ in 0..len {
4732            match rng.random_bool(valid_percent) {
4733                true => {
4734                    b.iter_mut().for_each(|x| *x = rng.random());
4735                    builder.append_value(&b).unwrap();
4736                }
4737                false => builder.append_null(),
4738            }
4739        }
4740
4741        builder.finish()
4742    }
4743
4744    fn generate_struct(rng: &mut impl RngCore, len: usize, valid_percent: f64) -> StructArray {
4745        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4746        let a = generate_primitive_array::<Int32Type>(rng, len, valid_percent);
4747        let b = generate_strings::<i32>(rng, len, valid_percent);
4748        let fields = Fields::from(vec![
4749            Field::new("a", DataType::Int32, true),
4750            Field::new("b", DataType::Utf8, true),
4751        ]);
4752        let values = vec![Arc::new(a) as _, Arc::new(b) as _];
4753        StructArray::new(fields, values, Some(nulls))
4754    }
4755
4756    fn generate_list<R: RngCore, F>(
4757        rng: &mut R,
4758        len: usize,
4759        valid_percent: f64,
4760        values: F,
4761    ) -> ListArray
4762    where
4763        F: FnOnce(&mut R, usize) -> ArrayRef,
4764    {
4765        let offsets = OffsetBuffer::<i32>::from_lengths((0..len).map(|_| rng.random_range(0..10)));
4766        let values_len = offsets.last().unwrap().to_usize().unwrap();
4767        let values = values(rng, values_len);
4768        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4769        let field = Arc::new(Field::new_list_field(values.data_type().clone(), true));
4770        ListArray::new(field, offsets, values, Some(nulls))
4771    }
4772
4773    fn generate_list_view<F>(
4774        rng: &mut impl RngCore,
4775        len: usize,
4776        valid_percent: f64,
4777        values: F,
4778    ) -> ListViewArray
4779    where
4780        F: FnOnce(usize) -> ArrayRef,
4781    {
4782        // Generate sizes first, then create a values array large enough
4783        let sizes: Vec<i32> = (0..len).map(|_| rng.random_range(0..10)).collect();
4784        let values_len: usize = sizes.iter().map(|s| *s as usize).sum::<usize>().max(1);
4785        let values = values(values_len);
4786
4787        // Generate offsets that can overlap, be non-monotonic, or share ranges
4788        let offsets: Vec<i32> = sizes
4789            .iter()
4790            .map(|&size| {
4791                if size == 0 {
4792                    0
4793                } else {
4794                    rng.random_range(0..=(values_len as i32 - size))
4795                }
4796            })
4797            .collect();
4798
4799        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4800        let field = Arc::new(Field::new_list_field(values.data_type().clone(), true));
4801        ListViewArray::new(
4802            field,
4803            ScalarBuffer::from(offsets),
4804            ScalarBuffer::from(sizes),
4805            values,
4806            Some(nulls),
4807        )
4808    }
4809
4810    fn generate_map<R: RngCore, KeysFn, ValuesFn>(
4811        rng: &mut R,
4812        len: usize,
4813        valid_percent: f64,
4814        gen_keys: KeysFn,
4815        gen_values: ValuesFn,
4816    ) -> MapArray
4817    where
4818        KeysFn: FnOnce(&mut R, usize) -> ArrayRef,
4819        ValuesFn: FnOnce(&mut R, usize) -> ArrayRef,
4820    {
4821        let offsets = OffsetBuffer::<i32>::from_lengths((0..len).map(|_| rng.random_range(0..10)));
4822        let entries_len = offsets.last().unwrap().to_usize().unwrap();
4823        let keys = gen_keys(rng, entries_len);
4824        let values = gen_values(rng, entries_len);
4825        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4826        let field = Arc::new(Field::new_map(
4827            "",
4828            "entries",
4829            Field::new("keys", keys.data_type().clone(), false),
4830            Field::new("values", values.data_type().clone(), true),
4831            false,
4832            true,
4833        ));
4834        let DataType::Map(struct_field, _) = field.data_type() else {
4835            unreachable!();
4836        };
4837
4838        let DataType::Struct(fields) = struct_field.data_type() else {
4839            unreachable!();
4840        };
4841
4842        let entries = StructArray::new(fields.clone(), vec![keys, values], None);
4843
4844        let map_array = MapArray::new(struct_field.clone(), offsets, entries, Some(nulls), false);
4845
4846        assert_valid_map(&map_array);
4847
4848        map_array
4849    }
4850
4851    /// Assert that the map is valid; this includes unique map keys
4852    ///
4853    /// Can be removed once https://github.com/apache/arrow-rs/issues/9475 is resolved and `MapArray`
4854    /// will not allow creation of invalid map arrays with duplicate keys.
4855    ///
4856    /// # Unique map keys
4857    /// According to [arrow specification][1], the keys of a map must be unique, so this asserts that
4858    ///
4859    /// [1]: https://github.com/apache/arrow/blob/cbe2618431e413f12aa16aeba88b3a98914f194b/format/Schema.fbs#L124
4860    fn assert_valid_map(array: &MapArray) {
4861        let keys_arrow_row_converter =
4862            RowConverter::new(vec![SortField::new(array.key_type().clone())]).unwrap();
4863
4864        array.iter().enumerate().flat_map(|(index, entry)| entry.map(|entry| (index, Arc::clone(entry.column(0))))).for_each(|(entry_index, keys)| {
4865            let keys_as_rows = keys_arrow_row_converter.convert_columns(&[Arc::clone(&keys)]).expect("should be able to convert keys");
4866
4867            for i in 0..keys_as_rows.num_rows() {
4868                for j in (i + 1)..keys_as_rows.num_rows() {
4869                    if keys_as_rows.row(i) == keys_as_rows.row(j) {
4870                        let key_i = keys.slice(i, 1);
4871                        let key_j = keys.slice(j, 1);
4872
4873                        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:?}");
4874                    }
4875                }
4876            }
4877        })
4878    }
4879
4880    fn generate_nulls(rng: &mut impl RngCore, len: usize) -> Option<NullBuffer> {
4881        Some(NullBuffer::from_iter(
4882            (0..len).map(|_| rng.random_bool(0.8)),
4883        ))
4884    }
4885
4886    fn change_underlying_null_values_for_primitive<T: ArrowPrimitiveType>(
4887        array: &PrimitiveArray<T>,
4888    ) -> PrimitiveArray<T> {
4889        let (dt, values, nulls) = array.clone().into_parts();
4890
4891        let new_values = ScalarBuffer::<T::Native>::from_iter(
4892            values
4893                .iter()
4894                .zip(nulls.as_ref().unwrap().iter())
4895                .map(|(val, is_valid)| {
4896                    if is_valid {
4897                        *val
4898                    } else {
4899                        val.add_wrapping(T::Native::usize_as(1))
4900                    }
4901                }),
4902        );
4903
4904        PrimitiveArray::new(new_values, nulls).with_data_type(dt)
4905    }
4906
4907    fn change_underline_null_values_for_byte_array<T: ByteArrayType>(
4908        array: &GenericByteArray<T>,
4909    ) -> GenericByteArray<T> {
4910        let (offsets, values, nulls) = array.clone().into_parts();
4911
4912        let new_offsets = OffsetBuffer::<T::Offset>::from_lengths(
4913            offsets
4914                .lengths()
4915                .zip(nulls.as_ref().unwrap().iter())
4916                .map(|(len, is_valid)| if is_valid { len } else { len + 1 }),
4917        );
4918
4919        let mut new_bytes = Vec::<u8>::with_capacity(new_offsets[new_offsets.len() - 1].as_usize());
4920
4921        offsets
4922            .windows(2)
4923            .zip(nulls.as_ref().unwrap().iter())
4924            .for_each(|(start_and_end, is_valid)| {
4925                let start = start_and_end[0].as_usize();
4926                let end = start_and_end[1].as_usize();
4927                new_bytes.extend_from_slice(&values.as_slice()[start..end]);
4928
4929                // add an extra byte
4930                if !is_valid {
4931                    new_bytes.push(b'c');
4932                }
4933            });
4934
4935        GenericByteArray::<T>::new(new_offsets, Buffer::from_vec(new_bytes), nulls)
4936    }
4937
4938    fn change_underline_null_values_for_list_array<O: OffsetSizeTrait>(
4939        array: &GenericListArray<O>,
4940    ) -> GenericListArray<O> {
4941        let (field, offsets, values, nulls) = array.clone().into_parts();
4942
4943        let (new_values, new_offsets) = {
4944            let concat_values = offsets
4945                .windows(2)
4946                .zip(nulls.as_ref().unwrap().iter())
4947                .map(|(start_and_end, is_valid)| {
4948                    let start = start_and_end[0].as_usize();
4949                    let end = start_and_end[1].as_usize();
4950                    if is_valid {
4951                        return (start, end - start);
4952                    }
4953
4954                    // If reached end, we take one less
4955                    if end == values.len() {
4956                        (start, (end - start).saturating_sub(1))
4957                    } else {
4958                        (start, end - start + 1)
4959                    }
4960                })
4961                .map(|(start, length)| values.slice(start, length))
4962                .collect::<Vec<_>>();
4963
4964            let new_offsets =
4965                OffsetBuffer::<O>::from_lengths(concat_values.iter().map(|s| s.len()));
4966
4967            let new_values = {
4968                let values = concat_values.iter().map(|a| a.as_ref()).collect::<Vec<_>>();
4969                arrow_select::concat::concat(&values).expect("should be able to concat")
4970            };
4971
4972            (new_values, new_offsets)
4973        };
4974
4975        GenericListArray::<O>::new(field, new_offsets, new_values, nulls)
4976    }
4977
4978    fn change_underline_null_values_for_map_array(array: &MapArray) -> MapArray {
4979        let (field, offsets, entries, nulls, ordered) = array.clone().into_parts();
4980        assert!(
4981            !ordered,
4982            "can't replace underlying null values for ordered map array as this can violate the ordering"
4983        );
4984
4985        let (new_entries, new_offsets) = {
4986            let concat_values = offsets
4987                .windows(2)
4988                .zip(nulls.as_ref().unwrap().iter())
4989                .map(|(start_and_end, is_valid)| {
4990                    let start = start_and_end[0].as_usize();
4991                    let end = start_and_end[1].as_usize();
4992                    if is_valid {
4993                        return (start, end - start);
4994                    }
4995
4996                    // If reached end, we take one less
4997                    if end == entries.len() {
4998                        (start, (end - start).saturating_sub(1))
4999                    } else {
5000                        // The keys may no longer be unique
5001                        (start, end - start + 1)
5002                    }
5003                })
5004                .map(|(start, length)| entries.slice(start, length))
5005                .collect::<Vec<_>>();
5006
5007            let new_offsets = OffsetBuffer::from_lengths(concat_values.iter().map(|s| s.len()));
5008
5009            let new_values = {
5010                let values = concat_values
5011                    .iter()
5012                    .map(|a| a as &dyn Array)
5013                    .collect::<Vec<_>>();
5014                arrow_select::concat::concat(&values).expect("should be able to concat")
5015            };
5016
5017            (new_values.as_struct().clone(), new_offsets)
5018        };
5019
5020        let new_map = MapArray::new(field, new_offsets, new_entries, nulls, ordered);
5021
5022        assert_valid_map(&new_map);
5023
5024        new_map
5025    }
5026
5027    fn change_underline_null_values(array: &ArrayRef) -> ArrayRef {
5028        if array.null_count() == 0 {
5029            return Arc::clone(array);
5030        }
5031
5032        downcast_primitive_array!(
5033            array => {
5034                let output = change_underlying_null_values_for_primitive(array);
5035
5036                Arc::new(output)
5037            }
5038
5039            DataType::Utf8 => {
5040                Arc::new(change_underline_null_values_for_byte_array(array.as_string::<i32>()))
5041            }
5042            DataType::LargeUtf8 => {
5043                Arc::new(change_underline_null_values_for_byte_array(array.as_string::<i64>()))
5044            }
5045            DataType::Binary => {
5046                Arc::new(change_underline_null_values_for_byte_array(array.as_binary::<i32>()))
5047            }
5048            DataType::LargeBinary => {
5049                Arc::new(change_underline_null_values_for_byte_array(array.as_binary::<i64>()))
5050            }
5051            DataType::List(_) => {
5052                Arc::new(change_underline_null_values_for_list_array(array.as_list::<i32>()))
5053            }
5054            DataType::LargeList(_) => {
5055                Arc::new(change_underline_null_values_for_list_array(array.as_list::<i64>()))
5056            }
5057            DataType::Map(_, _) => {
5058                Arc::new(change_underline_null_values_for_map_array(array.as_map()))
5059            }
5060            _ => {
5061                Arc::clone(array)
5062            }
5063        )
5064    }
5065
5066    fn generate_column(rng: &mut (impl RngCore + Clone), len: usize) -> ArrayRef {
5067        match rng.random_range(0..24) {
5068            0 => Arc::new(generate_primitive_array::<Int32Type>(rng, len, 0.8)),
5069            1 => Arc::new(generate_primitive_array::<UInt32Type>(rng, len, 0.8)),
5070            2 => Arc::new(generate_primitive_array::<Int64Type>(rng, len, 0.8)),
5071            3 => Arc::new(generate_primitive_array::<UInt64Type>(rng, len, 0.8)),
5072            4 => Arc::new(generate_primitive_array::<Float32Type>(rng, len, 0.8)),
5073            5 => Arc::new(generate_primitive_array::<Float64Type>(rng, len, 0.8)),
5074            6 => Arc::new(generate_strings::<i32>(rng, len, 0.8)),
5075            7 => {
5076                let dict_values_len = rng.random_range(1..len);
5077                // Cannot test dictionaries containing null values because of #2687
5078                let strings = Arc::new(generate_strings::<i32>(rng, dict_values_len, 1.0));
5079                Arc::new(generate_dictionary::<Int64Type>(rng, strings, len, 0.8))
5080            }
5081            8 => {
5082                let dict_values_len = rng.random_range(1..len);
5083                // Cannot test dictionaries containing null values because of #2687
5084                let values = Arc::new(generate_primitive_array::<Int64Type>(
5085                    rng,
5086                    dict_values_len,
5087                    1.0,
5088                ));
5089                Arc::new(generate_dictionary::<Int64Type>(rng, values, len, 0.8))
5090            }
5091            9 => Arc::new(generate_fixed_size_binary(rng, len, 0.8)),
5092            10 => Arc::new(generate_struct(rng, len, 0.8)),
5093            11 => Arc::new(generate_list(rng, len, 0.8, |rng, values_len| {
5094                Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8))
5095            })),
5096            12 => Arc::new(generate_list(rng, len, 0.8, |rng, values_len| {
5097                Arc::new(generate_strings::<i32>(rng, values_len, 0.8))
5098            })),
5099            13 => Arc::new(generate_list(rng, len, 0.8, |rng, values_len| {
5100                Arc::new(generate_struct(rng, values_len, 0.8))
5101            })),
5102            14 => Arc::new(generate_string_view(rng, len, 0.8)),
5103            15 => Arc::new(generate_byte_view(rng, len, 0.8)),
5104            16 => Arc::new(generate_fixed_stringview_column(len)),
5105            17 => Arc::new(
5106                generate_list(&mut rng.clone(), len + 1000, 0.8, |rng, values_len| {
5107                    Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8))
5108                })
5109                .slice(500, len),
5110            ),
5111            18 => Arc::new(generate_boolean_array(rng, len, 0.8)),
5112            19 => Arc::new(generate_list_view(
5113                &mut rng.clone(),
5114                len,
5115                0.8,
5116                |values_len| Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8)),
5117            )),
5118            20 => Arc::new(generate_list_view(
5119                &mut rng.clone(),
5120                len,
5121                0.8,
5122                |values_len| Arc::new(generate_strings::<i32>(rng, values_len, 0.8)),
5123            )),
5124            21 => Arc::new(generate_list_view(
5125                &mut rng.clone(),
5126                len,
5127                0.8,
5128                |values_len| Arc::new(generate_struct(rng, values_len, 0.8)),
5129            )),
5130            22 => Arc::new(
5131                generate_list_view(&mut rng.clone(), len + 1000, 0.8, |values_len| {
5132                    Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8))
5133                })
5134                .slice(500, len),
5135            ),
5136            23 => Arc::new(generate_map(
5137                rng,
5138                len,
5139                0.9,
5140                // Need to generate all unique keys or make sure between each map every key is unique,
5141                |rng, keys_len| {
5142                    Arc::new(generate_all_unique_primitive_array::<Int64Type>(
5143                        rng, keys_len,
5144                    ))
5145                },
5146                |rng, values_len| Arc::new(generate_strings::<i32>(rng, values_len, 0.7)),
5147            )),
5148            _ => unreachable!(),
5149        }
5150    }
5151
5152    fn print_row(cols: &[SortColumn], row: usize) -> String {
5153        let t: Vec<_> = cols
5154            .iter()
5155            .map(|x| match x.values.is_valid(row) {
5156                true => {
5157                    let opts = FormatOptions::default().with_null("NULL");
5158                    let formatter = ArrayFormatter::try_new(x.values.as_ref(), &opts).unwrap();
5159                    formatter.value(row).to_string()
5160                }
5161                false => "NULL".to_string(),
5162            })
5163            .collect();
5164        t.join(",")
5165    }
5166
5167    fn print_col_types(cols: &[SortColumn]) -> String {
5168        let t: Vec<_> = cols
5169            .iter()
5170            .map(|x| x.values.data_type().to_string())
5171            .collect();
5172        t.join(",")
5173    }
5174
5175    #[derive(Debug, PartialEq)]
5176    enum Nulls {
5177        /// Keep the generated array as is
5178        AsIs,
5179
5180        /// Replace the null buffer with different null buffer to point to different positions as null
5181        Different,
5182
5183        /// Remove all nulls
5184        None,
5185    }
5186
5187    #[test]
5188    #[cfg_attr(miri, ignore)]
5189    fn fuzz_test() {
5190        let mut rng = StdRng::seed_from_u64(42);
5191        for _ in 0..100 {
5192            for null_behavior in [Nulls::AsIs, Nulls::Different, Nulls::None] {
5193                let num_columns = rng.random_range(1..5);
5194                let len = rng.random_range(5..100);
5195                let mut arrays: Vec<_> = (0..num_columns)
5196                    .map(|_| generate_column(&mut rng, len))
5197                    .collect();
5198
5199                match null_behavior {
5200                    Nulls::AsIs => {
5201                        // Keep as is
5202                    }
5203                    Nulls::Different => {
5204                        // Replace nulls with different nulls to allow for testing different underlying null values
5205                        arrays = arrays
5206                            .into_iter()
5207                            .map(|a| replace_array_nulls(a, generate_nulls(&mut rng, len)))
5208                            .collect()
5209                    }
5210                    Nulls::None => {
5211                        // Remove nulls
5212                        arrays = arrays
5213                            .into_iter()
5214                            .map(|a| replace_array_nulls(a, None))
5215                            .collect()
5216                    }
5217                }
5218
5219                let options: Vec<_> = (0..num_columns)
5220                    .map(|_| SortOptions {
5221                        descending: rng.random_bool(0.5),
5222                        nulls_first: rng.random_bool(0.5),
5223                    })
5224                    .collect();
5225
5226                let sort_columns: Vec<_> = options
5227                    .iter()
5228                    .zip(&arrays)
5229                    .map(|(o, c)| SortColumn {
5230                        values: Arc::clone(c),
5231                        options: Some(*o),
5232                    })
5233                    .collect();
5234
5235                let comparator = LexicographicalComparator::try_new(&sort_columns).unwrap();
5236
5237                let columns: Vec<SortField> = options
5238                    .into_iter()
5239                    .zip(&arrays)
5240                    .map(|(o, a)| SortField::new_with_options(a.data_type().clone(), o))
5241                    .collect();
5242
5243                let converter = RowConverter::new(columns).unwrap();
5244                let rows = converter.convert_columns(&arrays).unwrap();
5245
5246                // Assert that the underlying null values are not taken into account when converting
5247                // even for different inputs
5248                if !matches!(null_behavior, Nulls::None) {
5249                    assert_same_rows_when_changing_input_underlying_null_values(
5250                        &arrays, &converter, &rows,
5251                    );
5252                }
5253
5254                for i in 0..len {
5255                    for j in 0..len {
5256                        let row_i = rows.row(i);
5257                        let row_j = rows.row(j);
5258                        let row_cmp = row_i.cmp(&row_j);
5259                        let lex_cmp = comparator.compare(i, j);
5260                        assert_eq!(
5261                            row_cmp,
5262                            lex_cmp,
5263                            "({:?} vs {:?}) vs ({:?} vs {:?}) for types {}",
5264                            print_row(&sort_columns, i),
5265                            print_row(&sort_columns, j),
5266                            row_i,
5267                            row_j,
5268                            print_col_types(&sort_columns)
5269                        );
5270                    }
5271                }
5272
5273                // Validate rows length iterator
5274                {
5275                    let mut rows_iter = rows.iter();
5276                    let mut rows_lengths_iter = rows.lengths();
5277                    for (index, row) in rows_iter.by_ref().enumerate() {
5278                        let len = rows_lengths_iter
5279                            .next()
5280                            .expect("Reached end of length iterator while still have rows");
5281                        assert_eq!(
5282                            row.data.len(),
5283                            len,
5284                            "Row length mismatch: {} vs {}",
5285                            row.data.len(),
5286                            len
5287                        );
5288                        assert_eq!(
5289                            len,
5290                            rows.row_len(index),
5291                            "Row length mismatch at index {}: {} vs {}",
5292                            index,
5293                            len,
5294                            rows.row_len(index)
5295                        );
5296                    }
5297
5298                    assert_eq!(
5299                        rows_lengths_iter.next(),
5300                        None,
5301                        "Length iterator did not reach end"
5302                    );
5303                }
5304
5305                // Convert rows produced from convert_columns().
5306                // Note: validate_utf8 is set to false since Row is initialized through empty_rows()
5307                let back = converter.convert_rows(&rows).unwrap();
5308                for (actual, expected) in back.iter().zip(&arrays) {
5309                    actual.to_data().validate_full().unwrap();
5310                    dictionary_eq(actual, expected)
5311                }
5312
5313                // Check that we can convert rows into ByteArray and then parse, convert it back to array
5314                // Note: validate_utf8 is set to true since Row is initialized through RowParser
5315                let rows = rows.try_into_binary().expect("reasonable size");
5316                let parser = converter.parser();
5317                let back = converter
5318                    .convert_rows(rows.iter().map(|b| parser.parse(b.expect("valid bytes"))))
5319                    .unwrap();
5320                for (actual, expected) in back.iter().zip(&arrays) {
5321                    actual.to_data().validate_full().unwrap();
5322                    dictionary_eq(actual, expected)
5323                }
5324
5325                let rows = converter.from_binary(rows);
5326                let back = converter.convert_rows(&rows).unwrap();
5327                for (actual, expected) in back.iter().zip(&arrays) {
5328                    actual.to_data().validate_full().unwrap();
5329                    dictionary_eq(actual, expected)
5330                }
5331            }
5332        }
5333    }
5334
5335    fn replace_array_nulls(array: ArrayRef, new_nulls: Option<NullBuffer>) -> ArrayRef {
5336        make_array(
5337            array
5338                .into_data()
5339                .into_builder()
5340                // Replace the nulls
5341                .nulls(new_nulls)
5342                .build()
5343                .unwrap(),
5344        )
5345    }
5346
5347    fn assert_same_rows_when_changing_input_underlying_null_values(
5348        arrays: &[ArrayRef],
5349        converter: &RowConverter,
5350        rows: &Rows,
5351    ) {
5352        let arrays_with_different_data_behind_nulls = arrays
5353            .iter()
5354            .map(|arr| change_underline_null_values(arr))
5355            .collect::<Vec<_>>();
5356
5357        // Skip assertion if we did not change anything
5358        if arrays
5359            .iter()
5360            .zip(arrays_with_different_data_behind_nulls.iter())
5361            .all(|(a, b)| Arc::ptr_eq(a, b))
5362        {
5363            return;
5364        }
5365
5366        let rows_with_different_nulls = converter
5367            .convert_columns(&arrays_with_different_data_behind_nulls)
5368            .unwrap();
5369
5370        assert_eq!(
5371            rows.iter().collect::<Vec<_>>(),
5372            rows_with_different_nulls.iter().collect::<Vec<_>>(),
5373            "Different underlying nulls should not output different rows"
5374        )
5375    }
5376
5377    #[test]
5378    fn test_clear() {
5379        let converter = RowConverter::new(vec![SortField::new(DataType::Int32)]).unwrap();
5380        let mut rows = converter.empty_rows(3, 128);
5381
5382        let first = Int32Array::from(vec![None, Some(2), Some(4)]);
5383        let second = Int32Array::from(vec![Some(2), None, Some(4)]);
5384        let arrays = [Arc::new(first) as ArrayRef, Arc::new(second) as ArrayRef];
5385
5386        for array in arrays.iter() {
5387            rows.clear();
5388            converter
5389                .append(&mut rows, std::slice::from_ref(array))
5390                .unwrap();
5391            let back = converter.convert_rows(&rows).unwrap();
5392            assert_eq!(&back[0], array);
5393        }
5394
5395        let mut rows_expected = converter.empty_rows(3, 128);
5396        converter.append(&mut rows_expected, &arrays[1..]).unwrap();
5397
5398        for (i, (actual, expected)) in rows.iter().zip(rows_expected.iter()).enumerate() {
5399            assert_eq!(
5400                actual, expected,
5401                "For row {i}: expected {expected:?}, actual: {actual:?}",
5402            );
5403        }
5404    }
5405
5406    #[test]
5407    fn test_append_codec_dictionary_binary() {
5408        use DataType::*;
5409        // Dictionary RowConverter
5410        let converter = RowConverter::new(vec![SortField::new(Dictionary(
5411            Box::new(Int32),
5412            Box::new(Binary),
5413        ))])
5414        .unwrap();
5415        let mut rows = converter.empty_rows(4, 128);
5416
5417        let keys = Int32Array::from_iter_values([0, 1, 2, 3]);
5418        let values = BinaryArray::from(vec![
5419            Some("a".as_bytes()),
5420            Some(b"b"),
5421            Some(b"c"),
5422            Some(b"d"),
5423        ]);
5424        let dict_array = DictionaryArray::new(keys, Arc::new(values));
5425
5426        rows.clear();
5427        let array = Arc::new(dict_array) as ArrayRef;
5428        converter
5429            .append(&mut rows, std::slice::from_ref(&array))
5430            .unwrap();
5431        let back = converter.convert_rows(&rows).unwrap();
5432
5433        dictionary_eq(&back[0], &array);
5434    }
5435
5436    #[test]
5437    fn test_list_prefix() {
5438        let mut a = ListBuilder::new(Int8Builder::new());
5439        a.append_value([None]);
5440        a.append_value([None, None]);
5441        let a = a.finish();
5442
5443        let converter = RowConverter::new(vec![SortField::new(a.data_type().clone())]).unwrap();
5444        let rows = converter.convert_columns(&[Arc::new(a) as _]).unwrap();
5445        assert_eq!(rows.row(0).cmp(&rows.row(1)), Ordering::Less);
5446    }
5447
5448    #[test]
5449    fn test_values_buffer_smaller_when_utf8_validation_disabled() {
5450        fn get_values_buffer_len(col: ArrayRef) -> (usize, usize) {
5451            // 1. Convert cols into rows
5452            let converter = RowConverter::new(vec![SortField::new(DataType::Utf8View)]).unwrap();
5453
5454            // 2a. Convert rows into colsa (validate_utf8 = false)
5455            let rows = converter.convert_columns(&[col]).unwrap();
5456            let converted = converter.convert_rows(&rows).unwrap();
5457            let unchecked_values_len = converted[0].as_string_view().data_buffers()[0].len();
5458
5459            // 2b. Convert rows into cols (validate_utf8 = true since Row is initialized through RowParser)
5460            let rows = rows.try_into_binary().expect("reasonable size");
5461            let parser = converter.parser();
5462            let converted = converter
5463                .convert_rows(rows.iter().map(|b| parser.parse(b.expect("valid bytes"))))
5464                .unwrap();
5465            let checked_values_len = converted[0].as_string_view().data_buffers()[0].len();
5466            (unchecked_values_len, checked_values_len)
5467        }
5468
5469        // Case1. StringViewArray with inline strings
5470        let col = Arc::new(StringViewArray::from_iter([
5471            Some("hello"), // short(5)
5472            None,          // null
5473            Some("short"), // short(5)
5474            Some("tiny"),  // short(4)
5475        ])) as ArrayRef;
5476
5477        let (unchecked_values_len, checked_values_len) = get_values_buffer_len(col);
5478        // Since there are no long (>12) strings, len of values buffer is 0
5479        assert_eq!(unchecked_values_len, 0);
5480        // When utf8 validation enabled, values buffer includes inline strings (5+5+4)
5481        assert_eq!(checked_values_len, 14);
5482
5483        // Case2. StringViewArray with long(>12) strings
5484        let col = Arc::new(StringViewArray::from_iter([
5485            Some("this is a very long string over 12 bytes"),
5486            Some("another long string to test the buffer"),
5487        ])) as ArrayRef;
5488
5489        let (unchecked_values_len, checked_values_len) = get_values_buffer_len(col);
5490        // Since there are no inline strings, expected length of values buffer is the same
5491        assert!(unchecked_values_len > 0);
5492        assert_eq!(unchecked_values_len, checked_values_len);
5493
5494        // Case3. StringViewArray with both short and long strings
5495        let col = Arc::new(StringViewArray::from_iter([
5496            Some("tiny"),          // 4 (short)
5497            Some("thisisexact13"), // 13 (long)
5498            None,
5499            Some("short"), // 5 (short)
5500        ])) as ArrayRef;
5501
5502        let (unchecked_values_len, checked_values_len) = get_values_buffer_len(col);
5503        // Since there is single long string, len of values buffer is 13
5504        assert_eq!(unchecked_values_len, 13);
5505        assert!(checked_values_len > unchecked_values_len);
5506    }
5507
5508    #[test]
5509    fn test_sparse_union() {
5510        // create a sparse union with Int32 (type_id = 0) and Utf8 (type_id = 1)
5511        let int_array = Int32Array::from(vec![Some(1), None, Some(3), None, Some(5)]);
5512        let str_array = StringArray::from(vec![None, Some("b"), None, Some("d"), None]);
5513
5514        // [1, "b", 3, "d", 5]
5515        let type_ids = vec![0, 1, 0, 1, 0].into();
5516
5517        let union_fields = [
5518            (0, Arc::new(Field::new("int", DataType::Int32, false))),
5519            (1, Arc::new(Field::new("str", DataType::Utf8, false))),
5520        ]
5521        .into_iter()
5522        .collect();
5523
5524        let union_array = UnionArray::try_new(
5525            union_fields,
5526            type_ids,
5527            None,
5528            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5529        )
5530        .unwrap();
5531
5532        let union_type = union_array.data_type().clone();
5533        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5534
5535        let rows = converter
5536            .convert_columns(&[Arc::new(union_array.clone())])
5537            .unwrap();
5538
5539        // round trip
5540        let back = converter.convert_rows(&rows).unwrap();
5541        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
5542
5543        assert_eq!(union_array.len(), back_union.len());
5544        for i in 0..union_array.len() {
5545            assert_eq!(union_array.type_id(i), back_union.type_id(i));
5546        }
5547    }
5548
5549    #[test]
5550    fn test_sparse_union_with_nulls() {
5551        // create a sparse union with Int32 (type_id = 0) and Utf8 (type_id = 1)
5552        let int_array = Int32Array::from(vec![Some(1), None, Some(3), None, Some(5)]);
5553        let str_array = StringArray::from(vec![None::<&str>; 5]);
5554
5555        // [1, null (both children null), 3, null (both children null), 5]
5556        let type_ids = vec![0, 1, 0, 1, 0].into();
5557
5558        let union_fields = [
5559            (0, Arc::new(Field::new("int", DataType::Int32, true))),
5560            (1, Arc::new(Field::new("str", DataType::Utf8, true))),
5561        ]
5562        .into_iter()
5563        .collect();
5564
5565        let union_array = UnionArray::try_new(
5566            union_fields,
5567            type_ids,
5568            None,
5569            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5570        )
5571        .unwrap();
5572
5573        let union_type = union_array.data_type().clone();
5574        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5575
5576        let rows = converter
5577            .convert_columns(&[Arc::new(union_array.clone())])
5578            .unwrap();
5579
5580        // round trip
5581        let back = converter.convert_rows(&rows).unwrap();
5582        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
5583
5584        assert_eq!(union_array.len(), back_union.len());
5585        for i in 0..union_array.len() {
5586            let expected_null = union_array.is_null(i);
5587            let actual_null = back_union.is_null(i);
5588            assert_eq!(expected_null, actual_null, "Null mismatch at index {i}");
5589            if !expected_null {
5590                assert_eq!(union_array.type_id(i), back_union.type_id(i));
5591            }
5592        }
5593    }
5594
5595    #[test]
5596    fn test_dense_union() {
5597        // create a dense union with Int32 (type_id = 0) and use Utf8 (type_id = 1)
5598        let int_array = Int32Array::from(vec![1, 3, 5]);
5599        let str_array = StringArray::from(vec!["a", "b"]);
5600
5601        let type_ids = vec![0, 1, 0, 1, 0].into();
5602
5603        // [1, "a", 3, "b", 5]
5604        let offsets = vec![0, 0, 1, 1, 2].into();
5605
5606        let union_fields = [
5607            (0, Arc::new(Field::new("int", DataType::Int32, false))),
5608            (1, Arc::new(Field::new("str", DataType::Utf8, false))),
5609        ]
5610        .into_iter()
5611        .collect();
5612
5613        let union_array = UnionArray::try_new(
5614            union_fields,
5615            type_ids,
5616            Some(offsets), // Dense mode
5617            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5618        )
5619        .unwrap();
5620
5621        let union_type = union_array.data_type().clone();
5622        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5623
5624        let rows = converter
5625            .convert_columns(&[Arc::new(union_array.clone())])
5626            .unwrap();
5627
5628        // round trip
5629        let back = converter.convert_rows(&rows).unwrap();
5630        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
5631
5632        assert_eq!(union_array.len(), back_union.len());
5633        for i in 0..union_array.len() {
5634            assert_eq!(union_array.type_id(i), back_union.type_id(i));
5635        }
5636    }
5637
5638    #[test]
5639    fn test_dense_union_with_nulls() {
5640        // create a dense union with Int32 (type_id = 0) and Utf8 (type_id = 1)
5641        let int_array = Int32Array::from(vec![Some(1), None, Some(5)]);
5642        let str_array = StringArray::from(vec![Some("a"), None]);
5643
5644        // [1, "a", 5, null (str null), null (int null)]
5645        let type_ids = vec![0, 1, 0, 1, 0].into();
5646        let offsets = vec![0, 0, 1, 1, 2].into();
5647
5648        let union_fields = [
5649            (0, Arc::new(Field::new("int", DataType::Int32, true))),
5650            (1, Arc::new(Field::new("str", DataType::Utf8, true))),
5651        ]
5652        .into_iter()
5653        .collect();
5654
5655        let union_array = UnionArray::try_new(
5656            union_fields,
5657            type_ids,
5658            Some(offsets),
5659            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5660        )
5661        .unwrap();
5662
5663        let union_type = union_array.data_type().clone();
5664        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5665
5666        let rows = converter
5667            .convert_columns(&[Arc::new(union_array.clone())])
5668            .unwrap();
5669
5670        // round trip
5671        let back = converter.convert_rows(&rows).unwrap();
5672        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
5673
5674        assert_eq!(union_array.len(), back_union.len());
5675        for i in 0..union_array.len() {
5676            let expected_null = union_array.is_null(i);
5677            let actual_null = back_union.is_null(i);
5678            assert_eq!(expected_null, actual_null, "Null mismatch at index {i}");
5679            if !expected_null {
5680                assert_eq!(union_array.type_id(i), back_union.type_id(i));
5681            }
5682        }
5683    }
5684
5685    #[test]
5686    fn test_union_ordering() {
5687        let int_array = Int32Array::from(vec![100, 5, 20]);
5688        let str_array = StringArray::from(vec!["z", "a"]);
5689
5690        // [100, "z", 5, "a", 20]
5691        let type_ids = vec![0, 1, 0, 1, 0].into();
5692        let offsets = vec![0, 0, 1, 1, 2].into();
5693
5694        let union_fields = [
5695            (0, Arc::new(Field::new("int", DataType::Int32, false))),
5696            (1, Arc::new(Field::new("str", DataType::Utf8, false))),
5697        ]
5698        .into_iter()
5699        .collect();
5700
5701        let union_array = UnionArray::try_new(
5702            union_fields,
5703            type_ids,
5704            Some(offsets),
5705            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5706        )
5707        .unwrap();
5708
5709        let union_type = union_array.data_type().clone();
5710        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5711
5712        let rows = converter.convert_columns(&[Arc::new(union_array)]).unwrap();
5713
5714        /*
5715        expected ordering
5716
5717        row 2: 5    - type_id 0
5718        row 4: 20   - type_id 0
5719        row 0: 100  - type id 0
5720        row 3: "a"  - type id 1
5721        row 1: "z"  - type id 1
5722        */
5723
5724        // 5 < "z"
5725        assert!(rows.row(2) < rows.row(1));
5726
5727        // 100 < "a"
5728        assert!(rows.row(0) < rows.row(3));
5729
5730        // among ints
5731        // 5 < 20
5732        assert!(rows.row(2) < rows.row(4));
5733        // 20 < 100
5734        assert!(rows.row(4) < rows.row(0));
5735
5736        // among strigns
5737        // "a" < "z"
5738        assert!(rows.row(3) < rows.row(1));
5739    }
5740
5741    #[test]
5742    fn test_row_converter_roundtrip_with_many_union_columns() {
5743        // col 1: Union(Int32, Utf8) [67, "hello"]
5744        let fields1 = UnionFields::try_new(
5745            vec![0, 1],
5746            vec![
5747                Field::new("int", DataType::Int32, true),
5748                Field::new("string", DataType::Utf8, true),
5749            ],
5750        )
5751        .unwrap();
5752
5753        let int_array1 = Int32Array::from(vec![Some(67), None]);
5754        let string_array1 = StringArray::from(vec![None::<&str>, Some("hello")]);
5755        let type_ids1 = vec![0i8, 1].into();
5756
5757        let union_array1 = UnionArray::try_new(
5758            fields1.clone(),
5759            type_ids1,
5760            None,
5761            vec![
5762                Arc::new(int_array1) as ArrayRef,
5763                Arc::new(string_array1) as ArrayRef,
5764            ],
5765        )
5766        .unwrap();
5767
5768        // col 2: Union(Int32, Utf8) [100, "world"]
5769        let fields2 = UnionFields::try_new(
5770            vec![0, 1],
5771            vec![
5772                Field::new("int", DataType::Int32, true),
5773                Field::new("string", DataType::Utf8, true),
5774            ],
5775        )
5776        .unwrap();
5777
5778        let int_array2 = Int32Array::from(vec![Some(100), None]);
5779        let string_array2 = StringArray::from(vec![None::<&str>, Some("world")]);
5780        let type_ids2 = vec![0i8, 1].into();
5781
5782        let union_array2 = UnionArray::try_new(
5783            fields2.clone(),
5784            type_ids2,
5785            None,
5786            vec![
5787                Arc::new(int_array2) as ArrayRef,
5788                Arc::new(string_array2) as ArrayRef,
5789            ],
5790        )
5791        .unwrap();
5792
5793        // create a row converter with 2 union columns
5794        let field1 = Field::new("col1", DataType::Union(fields1, UnionMode::Sparse), true);
5795        let field2 = Field::new("col2", DataType::Union(fields2, UnionMode::Sparse), true);
5796
5797        let sort_field1 = SortField::new(field1.data_type().clone());
5798        let sort_field2 = SortField::new(field2.data_type().clone());
5799
5800        let converter = RowConverter::new(vec![sort_field1, sort_field2]).unwrap();
5801
5802        let rows = converter
5803            .convert_columns(&[
5804                Arc::new(union_array1.clone()) as ArrayRef,
5805                Arc::new(union_array2.clone()) as ArrayRef,
5806            ])
5807            .unwrap();
5808
5809        // roundtrip
5810        let out = converter.convert_rows(&rows).unwrap();
5811
5812        let [col1, col2] = out.as_slice() else {
5813            panic!("expected 2 columns")
5814        };
5815
5816        let col1 = col1.as_any().downcast_ref::<UnionArray>().unwrap();
5817        let col2 = col2.as_any().downcast_ref::<UnionArray>().unwrap();
5818
5819        for (expected, got) in [union_array1, union_array2].iter().zip([col1, col2]) {
5820            assert_eq!(expected.len(), got.len());
5821            assert_eq!(expected.type_ids(), got.type_ids());
5822
5823            for i in 0..expected.len() {
5824                assert_eq!(expected.value(i).as_ref(), got.value(i).as_ref());
5825            }
5826        }
5827    }
5828
5829    #[test]
5830    fn test_row_converter_roundtrip_with_one_union_column() {
5831        let fields = UnionFields::try_new(
5832            vec![0, 1],
5833            vec![
5834                Field::new("int", DataType::Int32, true),
5835                Field::new("string", DataType::Utf8, true),
5836            ],
5837        )
5838        .unwrap();
5839
5840        let int_array = Int32Array::from(vec![Some(67), None]);
5841        let string_array = StringArray::from(vec![None::<&str>, Some("hello")]);
5842        let type_ids = vec![0i8, 1].into();
5843
5844        let union_array = UnionArray::try_new(
5845            fields.clone(),
5846            type_ids,
5847            None,
5848            vec![
5849                Arc::new(int_array) as ArrayRef,
5850                Arc::new(string_array) as ArrayRef,
5851            ],
5852        )
5853        .unwrap();
5854
5855        let field = Field::new("col", DataType::Union(fields, UnionMode::Sparse), true);
5856        let sort_field = SortField::new(field.data_type().clone());
5857        let converter = RowConverter::new(vec![sort_field]).unwrap();
5858
5859        let rows = converter
5860            .convert_columns(&[Arc::new(union_array.clone()) as ArrayRef])
5861            .unwrap();
5862
5863        // roundtrip
5864        let out = converter.convert_rows(&rows).unwrap();
5865
5866        let [col1] = out.as_slice() else {
5867            panic!("expected 1 column")
5868        };
5869
5870        let col = col1.as_any().downcast_ref::<UnionArray>().unwrap();
5871        assert_eq!(col.len(), union_array.len());
5872        assert_eq!(col.type_ids(), union_array.type_ids());
5873
5874        for i in 0..col.len() {
5875            assert_eq!(col.value(i).as_ref(), union_array.value(i).as_ref());
5876        }
5877    }
5878
5879    #[test]
5880    fn test_row_converter_roundtrip_with_non_default_union_type_ids() {
5881        // test with non-sequential type IDs (70, 85) instead of (0, 1)
5882        let fields = UnionFields::try_new(
5883            vec![70, 85],
5884            vec![
5885                Field::new("int", DataType::Int32, true),
5886                Field::new("string", DataType::Utf8, true),
5887            ],
5888        )
5889        .unwrap();
5890
5891        let int_array = Int32Array::from(vec![Some(67), None]);
5892        let string_array = StringArray::from(vec![None::<&str>, Some("hello")]);
5893        let type_ids = vec![70i8, 85].into();
5894
5895        let union_array = UnionArray::try_new(
5896            fields.clone(),
5897            type_ids,
5898            None,
5899            vec![
5900                Arc::new(int_array) as ArrayRef,
5901                Arc::new(string_array) as ArrayRef,
5902            ],
5903        )
5904        .unwrap();
5905
5906        let field = Field::new("col", DataType::Union(fields, UnionMode::Sparse), true);
5907        let sort_field = SortField::new(field.data_type().clone());
5908        let converter = RowConverter::new(vec![sort_field]).unwrap();
5909
5910        let rows = converter
5911            .convert_columns(&[Arc::new(union_array.clone()) as ArrayRef])
5912            .unwrap();
5913
5914        // roundtrip
5915        let out = converter.convert_rows(&rows).unwrap();
5916
5917        let [col1] = out.as_slice() else {
5918            panic!("expected 1 column")
5919        };
5920
5921        let col = col1.as_any().downcast_ref::<UnionArray>().unwrap();
5922        assert_eq!(col.len(), union_array.len());
5923        assert_eq!(col.type_ids(), union_array.type_ids());
5924
5925        for i in 0..col.len() {
5926            assert_eq!(col.value(i).as_ref(), union_array.value(i).as_ref());
5927        }
5928    }
5929
5930    #[test]
5931    fn rows_size_should_count_for_capacity() {
5932        let row_converter = RowConverter::new(vec![SortField::new(DataType::UInt8)]).unwrap();
5933
5934        let empty_rows_size_with_preallocate_rows_and_data = {
5935            let rows = row_converter.empty_rows(1000, 1000);
5936
5937            rows.size()
5938        };
5939        let empty_rows_size_with_preallocate_rows = {
5940            let rows = row_converter.empty_rows(1000, 0);
5941
5942            rows.size()
5943        };
5944        let empty_rows_size_with_preallocate_data = {
5945            let rows = row_converter.empty_rows(0, 1000);
5946
5947            rows.size()
5948        };
5949        let empty_rows_size_without_preallocate = {
5950            let rows = row_converter.empty_rows(0, 0);
5951
5952            rows.size()
5953        };
5954
5955        assert!(
5956            empty_rows_size_with_preallocate_rows_and_data > empty_rows_size_with_preallocate_rows,
5957            "{empty_rows_size_with_preallocate_rows_and_data} should be larger than {empty_rows_size_with_preallocate_rows}"
5958        );
5959        assert!(
5960            empty_rows_size_with_preallocate_rows_and_data > empty_rows_size_with_preallocate_data,
5961            "{empty_rows_size_with_preallocate_rows_and_data} should be larger than {empty_rows_size_with_preallocate_data}"
5962        );
5963        assert!(
5964            empty_rows_size_with_preallocate_rows > empty_rows_size_without_preallocate,
5965            "{empty_rows_size_with_preallocate_rows} should be larger than {empty_rows_size_without_preallocate}"
5966        );
5967        assert!(
5968            empty_rows_size_with_preallocate_data > empty_rows_size_without_preallocate,
5969            "{empty_rows_size_with_preallocate_data} should be larger than {empty_rows_size_without_preallocate}"
5970        );
5971    }
5972
5973    #[test]
5974    fn test_struct_no_child_fields() {
5975        fn run_test(array: ArrayRef) {
5976            let sort_fields = vec![SortField::new(array.data_type().clone())];
5977            let converter = RowConverter::new(sort_fields).unwrap();
5978            let r = converter.convert_columns(&[Arc::clone(&array)]).unwrap();
5979
5980            let back = converter.convert_rows(&r).unwrap();
5981            assert_eq!(back.len(), 1);
5982            assert_eq!(&back[0], &array);
5983        }
5984
5985        let s = Arc::new(StructArray::new_empty_fields(5, None)) as ArrayRef;
5986        run_test(s);
5987
5988        let s = Arc::new(StructArray::new_empty_fields(
5989            5,
5990            Some(vec![true, false, true, false, false].into()),
5991        )) as ArrayRef;
5992        run_test(s);
5993    }
5994
5995    #[test]
5996    fn reserve_should_increase_capacity_to_the_requested_size() {
5997        let row_converter = RowConverter::new(vec![SortField::new(DataType::UInt8)]).unwrap();
5998        let mut empty_rows = row_converter.empty_rows(0, 0);
5999        empty_rows.reserve(50, 50);
6000        let before_size = empty_rows.size();
6001        empty_rows.reserve(50, 50);
6002        assert_eq!(
6003            empty_rows.size(),
6004            before_size,
6005            "Size should not change when reserving already reserved space"
6006        );
6007        empty_rows.reserve(10, 20);
6008        assert_eq!(
6009            empty_rows.size(),
6010            before_size,
6011            "Size should not change when already have space for the expected reserved data"
6012        );
6013
6014        empty_rows.reserve(100, 20);
6015        assert!(
6016            empty_rows.size() > before_size,
6017            "Size should increase when reserving more space than previously reserved"
6018        );
6019
6020        let before_size = empty_rows.size();
6021
6022        empty_rows.reserve(20, 100);
6023        assert!(
6024            empty_rows.size() > before_size,
6025            "Size should increase when reserving more space than previously reserved"
6026        );
6027    }
6028
6029    #[test]
6030    fn empty_rows_should_return_empty_lengths_iterator() {
6031        let rows = RowConverter::new(vec![SortField::new(DataType::UInt8)])
6032            .unwrap()
6033            .empty_rows(0, 0);
6034        let mut lengths_iter = rows.lengths();
6035        assert_eq!(lengths_iter.next(), None);
6036    }
6037
6038    #[test]
6039    #[should_panic(expected = "row index out of bounds")]
6040    fn row_should_panic_on_overflowing_index() {
6041        let rows = RowConverter::new(vec![SortField::new(DataType::Int32)])
6042            .unwrap()
6043            .empty_rows(0, 0);
6044        rows.row(usize::MAX);
6045    }
6046
6047    #[test]
6048    #[should_panic(expected = "row index out of bounds")]
6049    fn row_len_should_panic_on_overflowing_index() {
6050        let rows = RowConverter::new(vec![SortField::new(DataType::Int32)])
6051            .unwrap()
6052            .empty_rows(0, 0);
6053        rows.row_len(usize::MAX);
6054    }
6055
6056    #[test]
6057    fn test_nested_null_list() {
6058        let null_array = Arc::new(NullArray::new(3));
6059        // [[NULL], [], [NULL, NULL]]
6060        let list: ArrayRef = Arc::new(ListArray::new(
6061            Field::new_list_field(DataType::Null, true).into(),
6062            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6063            null_array,
6064            None,
6065        ));
6066
6067        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6068        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6069        let back = converter.convert_rows(&rows).unwrap();
6070
6071        assert_eq!(&list, &back[0]);
6072    }
6073
6074    // Test case from original issue #9227: [[NULL]] - double nested List with Null
6075    #[test]
6076    fn test_double_nested_null_list() {
6077        let null_array = Arc::new(NullArray::new(1));
6078        // [NULL]
6079        let nested_field = Arc::new(Field::new_list_field(DataType::Null, true));
6080        let nested_list = Arc::new(ListArray::new(
6081            nested_field.clone(),
6082            OffsetBuffer::from_lengths(vec![1]),
6083            null_array,
6084            None,
6085        ));
6086        // [[NULL]]
6087        let list = Arc::new(ListArray::new(
6088            Field::new_list_field(DataType::List(nested_field), true).into(),
6089            OffsetBuffer::from_lengths(vec![1]),
6090            nested_list,
6091            None,
6092        )) as ArrayRef;
6093
6094        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6095        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6096        let back = converter.convert_rows(&rows).unwrap();
6097
6098        assert_eq!(&list, &back[0]);
6099    }
6100
6101    // Test LargeList<Null>
6102    #[test]
6103    fn test_large_list_null() {
6104        let null_array = Arc::new(NullArray::new(3));
6105        // [[NULL], [], [NULL, NULL]] as LargeList
6106        let list: ArrayRef = Arc::new(LargeListArray::new(
6107            Field::new_list_field(DataType::Null, true).into(),
6108            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6109            null_array,
6110            None,
6111        ));
6112
6113        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6114        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6115        let back = converter.convert_rows(&rows).unwrap();
6116
6117        assert_eq!(&list, &back[0]);
6118    }
6119
6120    // Test FixedSizeList<Null>
6121    #[test]
6122    fn test_fixed_size_list_null() {
6123        let null_array = Arc::new(NullArray::new(6));
6124        // [[NULL, NULL], [NULL, NULL], [NULL, NULL]] as FixedSizeList
6125        let list: ArrayRef = Arc::new(FixedSizeListArray::new(
6126            Arc::new(Field::new_list_field(DataType::Null, true)),
6127            2,
6128            null_array,
6129            None,
6130        ));
6131
6132        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6133        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6134        let back = converter.convert_rows(&rows).unwrap();
6135
6136        assert_eq!(&list, &back[0]);
6137    }
6138
6139    // Test List<Null> with various combinations of nulls and empty lists
6140    #[test]
6141    fn test_list_null_variations() {
6142        // Test case: [[NULL], [], [NULL, NULL]]
6143        let null_array = Arc::new(NullArray::new(3));
6144        let list: ArrayRef = Arc::new(ListArray::new(
6145            Field::new_list_field(DataType::Null, true).into(),
6146            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6147            null_array,
6148            None,
6149        ));
6150
6151        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6152        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6153        let back = converter.convert_rows(&rows).unwrap();
6154        assert_eq!(&list, &back[0]);
6155
6156        // Test case: [[NULL], null, [NULL, NULL]] - middle element is null
6157        let null_array = Arc::new(NullArray::new(3));
6158        let list: ArrayRef = Arc::new(ListArray::new(
6159            Field::new_list_field(DataType::Null, true).into(),
6160            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6161            null_array,
6162            Some(vec![true, false, true].into()),
6163        ));
6164
6165        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6166        let back = converter.convert_rows(&rows).unwrap();
6167        assert_eq!(&list, &back[0]);
6168
6169        // Test case: [] - empty list
6170        let null_array = Arc::new(NullArray::new(0));
6171        let list: ArrayRef = Arc::new(ListArray::new(
6172            Field::new_list_field(DataType::Null, true).into(),
6173            OffsetBuffer::from_lengths(vec![]),
6174            null_array,
6175            None,
6176        ));
6177
6178        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6179        let back = converter.convert_rows(&rows).unwrap();
6180        assert_eq!(&list, &back[0]);
6181
6182        // Test case: [[], [], []] - all empty sublists
6183        let null_array = Arc::new(NullArray::new(0));
6184        let list: ArrayRef = Arc::new(ListArray::new(
6185            Field::new_list_field(DataType::Null, true).into(),
6186            OffsetBuffer::from_lengths(vec![0, 0, 0]),
6187            null_array,
6188            None,
6189        ));
6190
6191        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6192        let back = converter.convert_rows(&rows).unwrap();
6193        assert_eq!(&list, &back[0]);
6194    }
6195
6196    // Test List<Null> with descending order
6197    #[test]
6198    fn test_list_null_descending() {
6199        let null_array = Arc::new(NullArray::new(3));
6200        // [[NULL], [], [NULL, NULL]]
6201        let list: ArrayRef = Arc::new(ListArray::new(
6202            Field::new_list_field(DataType::Null, true).into(),
6203            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6204            null_array,
6205            None,
6206        ));
6207
6208        let options = SortOptions::default().with_descending(true);
6209        let field = SortField::new_with_options(list.data_type().clone(), options);
6210        let converter = RowConverter::new(vec![field]).unwrap();
6211        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6212        let back = converter.convert_rows(&rows).unwrap();
6213
6214        assert_eq!(&list, &back[0]);
6215    }
6216
6217    // Test Struct with Null field
6218    #[test]
6219    fn test_struct_with_null_field() {
6220        // Struct { a: Null, b: Int32 }
6221        let null_array = Arc::new(NullArray::new(3));
6222        let int_array = Arc::new(Int32Array::from(vec![1, 2, 3]));
6223
6224        let struct_array: ArrayRef = Arc::new(StructArray::new(
6225            vec![
6226                Arc::new(Field::new("a", DataType::Null, true)),
6227                Arc::new(Field::new("b", DataType::Int32, true)),
6228            ]
6229            .into(),
6230            vec![null_array, int_array],
6231            Some(vec![true, true, false].into()), // validity bitmap
6232        ));
6233
6234        let converter =
6235            RowConverter::new(vec![SortField::new(struct_array.data_type().clone())]).unwrap();
6236        let rows = converter
6237            .convert_columns(&[Arc::clone(&struct_array)])
6238            .unwrap();
6239        let back = converter.convert_rows(&rows).unwrap();
6240
6241        assert_eq!(&struct_array, &back[0]);
6242    }
6243
6244    // Test nested Struct with Null
6245    #[test]
6246    fn test_nested_struct_with_null() {
6247        // Inner struct: { x: Null }
6248        let inner_null = Arc::new(NullArray::new(2));
6249        let inner_struct = Arc::new(StructArray::new(
6250            vec![Arc::new(Field::new("x", DataType::Null, true))].into(),
6251            vec![inner_null],
6252            None,
6253        ));
6254
6255        // Outer struct: { inner: Struct { x: Null }, y: Int32 }
6256        let y_array = Arc::new(Int32Array::from(vec![10, 20]));
6257        let outer_struct: ArrayRef = Arc::new(StructArray::new(
6258            vec![
6259                Arc::new(Field::new("inner", inner_struct.data_type().clone(), true)),
6260                Arc::new(Field::new("y", DataType::Int32, true)),
6261            ]
6262            .into(),
6263            vec![inner_struct, y_array],
6264            None,
6265        ));
6266
6267        let converter =
6268            RowConverter::new(vec![SortField::new(outer_struct.data_type().clone())]).unwrap();
6269        let rows = converter
6270            .convert_columns(&[Arc::clone(&outer_struct)])
6271            .unwrap();
6272        let back = converter.convert_rows(&rows).unwrap();
6273
6274        assert_eq!(&outer_struct, &back[0]);
6275    }
6276
6277    // Test Map<Utf8, Null> with various combinations of nulls and empty maps
6278    #[test]
6279    fn test_map_null_variations() {
6280        // Map with Null values: [{a: NULL}, {}, {b: NULL, c: NULL}]
6281        let keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6282        let null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6283
6284        let offsets = OffsetBuffer::new(vec![0, 1, 1, 3].into());
6285        let entries_fields = vec![
6286            Arc::new(Field::new("keys", DataType::Utf8, false)),
6287            Arc::new(Field::new("values", DataType::Null, true)),
6288        ];
6289        let struct_field = Arc::new(Field::new(
6290            "entries",
6291            DataType::Struct(entries_fields.clone().into()),
6292            false,
6293        ));
6294        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6295
6296        let map: ArrayRef = Arc::new(MapArray::new(
6297            struct_field.clone(),
6298            offsets,
6299            entries,
6300            None,
6301            false,
6302        ));
6303
6304        let converter = RowConverter::new(vec![SortField::new(map.data_type().clone())]).unwrap();
6305        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6306        let back = converter.convert_rows(&rows).unwrap();
6307        assert_eq!(back.len(), 1);
6308        back[0].to_data().validate_full().unwrap();
6309        assert_eq!(&map, &back[0]);
6310
6311        // Map with Null values and null map entries: [{a: NULL}, null, {b: NULL, c: NULL}]
6312        let keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6313        let null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6314
6315        let offsets = OffsetBuffer::new(vec![0, 1, 1, 3].into());
6316        let entries_fields = vec![
6317            Arc::new(Field::new("keys", DataType::Utf8, false)),
6318            Arc::new(Field::new("values", DataType::Null, true)),
6319        ];
6320        let struct_field = Arc::new(Field::new(
6321            "entries",
6322            DataType::Struct(entries_fields.clone().into()),
6323            false,
6324        ));
6325        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6326
6327        let map: ArrayRef = Arc::new(MapArray::new(
6328            struct_field.clone(),
6329            offsets,
6330            entries,
6331            Some(vec![true, false, true].into()),
6332            false,
6333        ));
6334
6335        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6336        let back = converter.convert_rows(&rows).unwrap();
6337        assert_eq!(back.len(), 1);
6338        back[0].to_data().validate_full().unwrap();
6339        assert_eq!(&map, &back[0]);
6340
6341        // Empty map array with Null value type
6342        let keys = Arc::new(StringArray::from(Vec::<&str>::new())) as ArrayRef;
6343        let null_values = Arc::new(NullArray::new(0)) as ArrayRef;
6344
6345        let offsets = OffsetBuffer::new(vec![0i32].into());
6346        let entries_fields = vec![
6347            Arc::new(Field::new("keys", DataType::Utf8, false)),
6348            Arc::new(Field::new("values", DataType::Null, true)),
6349        ];
6350        let struct_field = Arc::new(Field::new(
6351            "entries",
6352            DataType::Struct(entries_fields.clone().into()),
6353            false,
6354        ));
6355        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6356
6357        let map: ArrayRef = Arc::new(MapArray::new(struct_field, offsets, entries, None, false));
6358
6359        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6360        let back = converter.convert_rows(&rows).unwrap();
6361        assert_eq!(back.len(), 1);
6362        back[0].to_data().validate_full().unwrap();
6363        assert_eq!(&map, &back[0]);
6364    }
6365
6366    // Test Map<Utf8, Null> with descending order
6367    #[test]
6368    fn test_map_null_descending() {
6369        // [{a: NULL}, {}, {b: NULL, c: NULL}]
6370        let keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6371        let null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6372
6373        let offsets = OffsetBuffer::new(vec![0, 1, 1, 3].into());
6374        let entries_fields = vec![
6375            Arc::new(Field::new("keys", DataType::Utf8, false)),
6376            Arc::new(Field::new("values", DataType::Null, true)),
6377        ];
6378        let struct_field = Arc::new(Field::new(
6379            "entries",
6380            DataType::Struct(entries_fields.clone().into()),
6381            false,
6382        ));
6383        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6384
6385        let map: ArrayRef = Arc::new(MapArray::new(struct_field, offsets, entries, None, false));
6386
6387        let options = SortOptions::default().with_descending(true);
6388        let field = SortField::new_with_options(map.data_type().clone(), options);
6389        let converter = RowConverter::new(vec![field]).unwrap();
6390        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6391        let back = converter.convert_rows(&rows).unwrap();
6392        assert_eq!(back.len(), 1);
6393        back[0].to_data().validate_full().unwrap();
6394        assert_eq!(&map, &back[0]);
6395    }
6396
6397    // Test Map<Null, Null> - both keys and values are Null type
6398    #[test]
6399    fn test_map_null_keys_and_null_values() {
6400        let null_keys = Arc::new(NullArray::new(3)) as ArrayRef;
6401        let null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6402
6403        let offsets = OffsetBuffer::new(vec![0, 1, 1, 3].into());
6404        let entries_fields = vec![
6405            Arc::new(Field::new("keys", DataType::Null, true)),
6406            Arc::new(Field::new("values", DataType::Null, true)),
6407        ];
6408        let struct_field = Arc::new(Field::new(
6409            "entries",
6410            DataType::Struct(entries_fields.clone().into()),
6411            false,
6412        ));
6413        let entries = StructArray::new(entries_fields.into(), vec![null_keys, null_values], None);
6414
6415        let map: ArrayRef = Arc::new(MapArray::new(struct_field, offsets, entries, None, false));
6416
6417        let converter = RowConverter::new(vec![SortField::new(map.data_type().clone())]).unwrap();
6418        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6419        let back = converter.convert_rows(&rows).unwrap();
6420        assert_eq!(back.len(), 1);
6421        back[0].to_data().validate_full().unwrap();
6422        assert_eq!(&map, &back[0]);
6423    }
6424
6425    // Test Map<Utf8, Null> all empty maps
6426    #[test]
6427    fn test_map_null_all_empty() {
6428        let keys = Arc::new(StringArray::from(Vec::<&str>::new())) as ArrayRef;
6429        let null_values = Arc::new(NullArray::new(0)) as ArrayRef;
6430
6431        let offsets = OffsetBuffer::new(vec![0, 0, 0, 0].into());
6432        let entries_fields = vec![
6433            Arc::new(Field::new("keys", DataType::Utf8, false)),
6434            Arc::new(Field::new("values", DataType::Null, true)),
6435        ];
6436        let struct_field = Arc::new(Field::new(
6437            "entries",
6438            DataType::Struct(entries_fields.clone().into()),
6439            false,
6440        ));
6441        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6442
6443        let map: ArrayRef = Arc::new(MapArray::new(struct_field, offsets, entries, None, false));
6444
6445        let converter = RowConverter::new(vec![SortField::new(map.data_type().clone())]).unwrap();
6446        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6447
6448        // All empty maps should be equal
6449        assert_eq!(rows.row(0), rows.row(1));
6450        assert_eq!(rows.row(1), rows.row(2));
6451
6452        let back = converter.convert_rows(&rows).unwrap();
6453        assert_eq!(back.len(), 1);
6454        back[0].to_data().validate_full().unwrap();
6455        assert_eq!(&map, &back[0]);
6456    }
6457
6458    // Test Map<Utf8, Map<Utf8, Null>> - nested map with Null leaf values
6459    #[test]
6460    fn test_nested_map_null() {
6461        // Inner map entries: {a: NULL, b: NULL, c: NULL}
6462        let inner_keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6463        let inner_null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6464
6465        let inner_entries_fields = vec![
6466            Arc::new(Field::new("keys", DataType::Utf8, false)),
6467            Arc::new(Field::new("values", DataType::Null, true)),
6468        ];
6469        let inner_struct_field = Arc::new(Field::new(
6470            "entries",
6471            DataType::Struct(inner_entries_fields.clone().into()),
6472            false,
6473        ));
6474        let inner_entries = StructArray::new(
6475            inner_entries_fields.clone().into(),
6476            vec![inner_keys, inner_null_values],
6477            None,
6478        );
6479
6480        // Inner maps: [{a: NULL}, {b: NULL, c: NULL}]
6481        let inner_map = Arc::new(MapArray::new(
6482            inner_struct_field.clone(),
6483            OffsetBuffer::new(vec![0, 1, 3].into()),
6484            inner_entries,
6485            None,
6486            false,
6487        )) as ArrayRef;
6488
6489        // Outer map entries
6490        let outer_keys = Arc::new(StringArray::from(vec!["x", "y"])) as ArrayRef;
6491
6492        let inner_map_type = DataType::Map(inner_struct_field.clone(), false);
6493        let outer_entries_fields = vec![
6494            Arc::new(Field::new("keys", DataType::Utf8, false)),
6495            Arc::new(Field::new("values", inner_map_type, true)),
6496        ];
6497        let outer_struct_field = Arc::new(Field::new(
6498            "entries",
6499            DataType::Struct(outer_entries_fields.clone().into()),
6500            false,
6501        ));
6502        let outer_entries = StructArray::new(
6503            outer_entries_fields.into(),
6504            vec![outer_keys, inner_map],
6505            None,
6506        );
6507
6508        // Outer map: [{x: {a: NULL}}, {y: {b: NULL, c: NULL}}]
6509        let map: ArrayRef = Arc::new(MapArray::new(
6510            outer_struct_field,
6511            OffsetBuffer::new(vec![0, 1, 2].into()),
6512            outer_entries,
6513            None,
6514            false,
6515        ));
6516
6517        let converter = RowConverter::new(vec![SortField::new(map.data_type().clone())]).unwrap();
6518        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6519        let back = converter.convert_rows(&rows).unwrap();
6520        assert_eq!(back.len(), 1);
6521        back[0].to_data().validate_full().unwrap();
6522        assert_eq!(&map, &back[0]);
6523    }
6524
6525    // Test List<Map<Utf8, Null>> - list containing maps with Null values
6526    #[test]
6527    fn test_list_of_map_null() {
6528        // Map entries: {a: NULL, b: NULL, c: NULL}
6529        let keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6530        let null_values = Arc::new(NullArray::new(3)) as ArrayRef;
6531
6532        let entries_fields = vec![
6533            Arc::new(Field::new("keys", DataType::Utf8, false)),
6534            Arc::new(Field::new("values", DataType::Null, true)),
6535        ];
6536        let struct_field = Arc::new(Field::new(
6537            "entries",
6538            DataType::Struct(entries_fields.clone().into()),
6539            false,
6540        ));
6541        let entries = StructArray::new(entries_fields.into(), vec![keys, null_values], None);
6542
6543        // Maps: [{a: NULL}, {}, {b: NULL, c: NULL}]
6544        let map_array = Arc::new(MapArray::new(
6545            struct_field.clone(),
6546            OffsetBuffer::new(vec![0, 1, 1, 3].into()),
6547            entries,
6548            None,
6549            false,
6550        )) as ArrayRef;
6551
6552        let map_type = DataType::Map(struct_field, false);
6553        // List of maps: [[{a: NULL}], [{}, {b: NULL, c: NULL}]]
6554        let list: ArrayRef = Arc::new(ListArray::new(
6555            Arc::new(Field::new_list_field(map_type, true)),
6556            OffsetBuffer::new(vec![0, 1, 3].into()),
6557            map_array,
6558            None,
6559        ));
6560
6561        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
6562        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
6563        let back = converter.convert_rows(&rows).unwrap();
6564        assert_eq!(&list, &back[0]);
6565    }
6566
6567    // Test Map<Utf8, List<Null>> - map with list values containing Null
6568    #[test]
6569    fn test_map_of_list_null() {
6570        // Inner list values: [NULL, NULL, NULL]
6571        let null_array = Arc::new(NullArray::new(3)) as ArrayRef;
6572        // Lists: [[NULL], [], [NULL, NULL]]
6573        let list_array = Arc::new(ListArray::new(
6574            Arc::new(Field::new_list_field(DataType::Null, true)),
6575            OffsetBuffer::from_lengths(vec![1, 0, 2]),
6576            null_array,
6577            None,
6578        )) as ArrayRef;
6579
6580        let keys = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
6581
6582        let list_type = list_array.data_type().clone();
6583        let entries_fields = vec![
6584            Arc::new(Field::new("keys", DataType::Utf8, false)),
6585            Arc::new(Field::new("values", list_type, true)),
6586        ];
6587        let struct_field = Arc::new(Field::new(
6588            "entries",
6589            DataType::Struct(entries_fields.clone().into()),
6590            false,
6591        ));
6592        let entries = StructArray::new(entries_fields.into(), vec![keys, list_array], None);
6593
6594        // Map: [{a: [NULL], b: [], c: [NULL, NULL]}]
6595        let map: ArrayRef = Arc::new(MapArray::new(
6596            struct_field,
6597            OffsetBuffer::new(vec![0, 3].into()),
6598            entries,
6599            None,
6600            false,
6601        ));
6602
6603        let converter = RowConverter::new(vec![SortField::new(map.data_type().clone())]).unwrap();
6604        let rows = converter.convert_columns(&[Arc::clone(&map)]).unwrap();
6605        let back = converter.convert_rows(&rows).unwrap();
6606        assert_eq!(back.len(), 1);
6607        back[0].to_data().validate_full().unwrap();
6608        assert_eq!(&map, &back[0]);
6609    }
6610
6611    #[test]
6612    fn empty_row_iter_next_back() {
6613        let rows = RowConverter::new(vec![SortField::new(DataType::UInt8)])
6614            .unwrap()
6615            .empty_rows(0, 0);
6616        let mut rows_iter = rows.iter();
6617        assert_eq!(rows_iter.next_back(), None);
6618        assert_eq!(rows_iter.next_back(), None);
6619        assert_eq!(rows_iter.next_back(), None);
6620    }
6621
6622    #[test]
6623    fn row_iter_next_back() {
6624        let row_converter = RowConverter::new(vec![SortField::new(DataType::UInt8)]).unwrap();
6625        let mut rng = StdRng::seed_from_u64(42);
6626        let array = generate_primitive_array::<UInt8Type>(&mut rng, 100, 0.8);
6627        let rows = row_converter.convert_columns(&[Arc::new(array)]).unwrap();
6628
6629        let mut rows_iter = rows.iter();
6630        let mut bytes: Vec<u8> = vec![];
6631
6632        while let Some(row) = rows_iter.next_back() {
6633            bytes.extend(row.data.iter().rev());
6634        }
6635
6636        bytes.reverse();
6637
6638        assert_eq!(
6639            bytes,
6640            &rows.buffer.as_slice()[..*rows.offsets.last().unwrap()]
6641        );
6642
6643        assert_eq!(rows_iter.next_back(), None);
6644        assert_eq!(rows_iter.next(), None);
6645    }
6646}