ailake_file/
reader.rs

1// SPDX-License-Identifier: MIT OR Apache-2.0
2use crate::footer::Precision;
3use ailake_core::{AilakeError, AilakeResult, Centroid, VectorMetric};
4use ailake_index::{AnyIndex, HnswIndex, IvfPqSerializer, MmapLoader};
5use ailake_parquet::ParquetVectorReader;
6use arrow_array::RecordBatch;
7use bytes::Bytes;
8
9use crate::footer::{
10    parquet_footer_start, AilakeHeader, AilakeTrailer, DistanceMetric, AILK_FTS_HEADER_SIZE,
11    AILK_FTS_MAGIC, FLAG_INDEX_IVF_PQ, HEADER_SIZE, KV_FTS_OFFSET, TRAILER_SIZE,
12};
13
14pub struct AilakeFileReader {
15    bytes: Bytes,
16    vector_column: String,
17    #[allow(dead_code)]
18    dim: u32,
19}
20
21impl AilakeFileReader {
22    pub fn new(bytes: Bytes, vector_column: &str, dim: u32) -> Self {
23        Self {
24            bytes,
25            vector_column: vector_column.to_string(),
26            dim,
27        }
28    }
29
30    /// Returns the absolute byte offset of the primary AILK section.
31    ///
32    /// Tries `ailake.footer_offset` from Parquet KV metadata first (files written
33    /// by `write()` / `write_multi()`). Falls back to `AilakeTrailer` bootstrap for
34    /// files produced by `write_single_pass()` / `write_multi_single_pass()`.
35    pub fn ailk_offset(&self) -> AilakeResult<u64> {
36        let reader = ParquetVectorReader::new(self.bytes.clone(), &self.vector_column);
37        if let Some(val) = reader.kv_metadata("ailake.footer_offset")? {
38            return val.parse::<u64>().map_err(|_| AilakeError::NotAnAilakeFile);
39        }
40        self.ailk_offset_from_trailer()
41    }
42
43    /// Returns the absolute byte offset of the AILK section for a named vector column.
44    ///
45    /// Resolution order:
46    ///   1. `ailake.{column}.footer_offset` KV (extra columns in multi-column files)
47    ///   2. `ailake.footer_offset` KV (primary column or single-column files)
48    ///   3. `AilakeTrailer` scan (streaming / single-pass files without KV injection)
49    pub fn ailk_offset_for_column(&self, column: &str) -> AilakeResult<u64> {
50        let reader = ParquetVectorReader::new(self.bytes.clone(), column);
51        let col_key = format!("ailake.{column}.footer_offset");
52        if let Some(val) = reader.kv_metadata(&col_key)? {
53            return val.parse::<u64>().map_err(|_| AilakeError::NotAnAilakeFile);
54        }
55        if let Some(val) = reader.kv_metadata("ailake.footer_offset")? {
56            return val.parse::<u64>().map_err(|_| AilakeError::NotAnAilakeFile);
57        }
58        self.ailk_offset_from_trailer()
59    }
60
61    /// Bootstrap AILK offset from the `AilakeTrailer` embedded just before the Parquet footer.
62    ///
63    /// The `AilakeTrailer` (24 bytes) ends immediately before the Parquet footer thrift
64    /// in every AI-Lake file. On S3, the trailer bytes are already present in the initial
65    /// footer range-GET (same GET that fetches the Parquet footer), so this bootstrap path
66    /// costs no additional I/O compared to the KV path.
67    fn ailk_offset_from_trailer(&self) -> AilakeResult<u64> {
68        let buf = self.bytes.as_ref();
69        let footer_start = parquet_footer_start(buf)?;
70        if footer_start < TRAILER_SIZE {
71            return Err(AilakeError::NotAnAilakeFile);
72        }
73        let trailer_start = footer_start - TRAILER_SIZE;
74        let trailer_bytes: &[u8; TRAILER_SIZE] = buf[trailer_start..footer_start]
75            .try_into()
76            .map_err(|_| AilakeError::NotAnAilakeFile)?;
77        let trailer = AilakeTrailer::from_bytes(trailer_bytes)?;
78        Ok(trailer.footer_offset)
79    }
80
81    /// Returns true if the file contains an embedded AILK section.
82    pub fn is_ailake_file(&self) -> bool {
83        self.ailk_offset().is_ok()
84    }
85
86    /// Parse the 64-byte AI-Lake header from the embedded AILK section.
87    pub fn read_header(&self) -> AilakeResult<AilakeHeader> {
88        self.read_header_at_offset(self.ailk_offset()?)
89    }
90
91    /// Parse the 64-byte AI-Lake header for a named vector column.
92    ///
93    /// Uses `ailake.{column}.footer_offset` for extra columns and falls back to
94    /// `ailake.footer_offset` for the primary column (single-column files).
95    pub fn read_header_for_column(&self, column: &str) -> AilakeResult<AilakeHeader> {
96        self.read_header_at_offset(self.ailk_offset_for_column(column)?)
97    }
98
99    fn read_header_at_offset(&self, offset: u64) -> AilakeResult<AilakeHeader> {
100        let offset = offset as usize;
101        if offset + HEADER_SIZE > self.bytes.len() {
102            return Err(AilakeError::NotAnAilakeFile);
103        }
104        let header_bytes: &[u8; HEADER_SIZE] = self.bytes[offset..offset + HEADER_SIZE]
105            .try_into()
106            .map_err(|_| AilakeError::NotAnAilakeFile)?;
107        AilakeHeader::from_bytes(header_bytes)
108    }
109
110    /// Read centroid + radius from the AILK section.
111    pub fn get_centroid(&self) -> AilakeResult<Centroid> {
112        let ailk_start = self.ailk_offset()? as usize;
113        let header = self.read_header()?;
114        let centroid_start = ailk_start + header.centroid_offset as usize;
115        let centroid_end = centroid_start + header.centroid_len as usize;
116
117        if centroid_end > self.bytes.len() {
118            return Err(AilakeError::NotAnAilakeFile);
119        }
120
121        let centroid_data = &self.bytes[centroid_start..centroid_end];
122        let dim = header.dim as usize;
123        let expected_len = dim * 4 + 4;
124        if centroid_data.len() != expected_len {
125            return Err(AilakeError::InvalidCentroidLength {
126                expected_dim: header.dim,
127                actual: centroid_data.len(),
128            });
129        }
130
131        let values: Vec<f32> = centroid_data[..dim * 4]
132            .chunks_exact(4)
133            .map(|b| f32::from_le_bytes(b.try_into().unwrap()))
134            .collect();
135        let radius = f32::from_le_bytes(centroid_data[dim * 4..].try_into().unwrap());
136        let metric = distance_metric_to_vector_metric(header.distance_metric);
137
138        Ok(Centroid {
139            values,
140            radius,
141            metric,
142        })
143    }
144
145    /// Load the HNSW index from the primary AILK section.
146    pub fn load_index(&self) -> AilakeResult<HnswIndex> {
147        self.load_index_for_column(&self.vector_column.clone())
148    }
149
150    /// Load the HNSW index for a specific vector column.
151    ///
152    /// Works for both single-column files (falls back to primary AILK) and
153    /// multi-column files written with `AilakeFileWriter::write_multi`.
154    pub fn load_index_for_column(&self, column: &str) -> AilakeResult<HnswIndex> {
155        let ailk_start = self.ailk_offset_for_column(column)? as usize;
156
157        if ailk_start + HEADER_SIZE > self.bytes.len() {
158            return Err(AilakeError::NotAnAilakeFile);
159        }
160        let header_bytes: &[u8; HEADER_SIZE] = self.bytes[ailk_start..ailk_start + HEADER_SIZE]
161            .try_into()
162            .map_err(|_| AilakeError::NotAnAilakeFile)?;
163        let header = AilakeHeader::from_bytes(header_bytes)?;
164
165        let hnsw_start = ailk_start + header.hnsw_offset as usize;
166        let hnsw_end = hnsw_start + header.hnsw_len as usize;
167
168        if hnsw_end > self.bytes.len() {
169            return Err(AilakeError::NotAnAilakeFile);
170        }
171        let mut idx = MmapLoader::from_bytes(&self.bytes[hnsw_start..hnsw_end])?;
172        if header.precision == Precision::F16 {
173            idx.quantize_to_f16();
174        }
175        Ok(idx)
176    }
177
178    /// Load primary index as `AnyIndex`, dispatching on header flags.
179    pub fn load_any_index(&self) -> AilakeResult<AnyIndex> {
180        self.load_any_index_for_column(&self.vector_column.clone())
181    }
182
183    /// Load index for a specific vector column as `AnyIndex`.
184    pub fn load_any_index_for_column(&self, column: &str) -> AilakeResult<AnyIndex> {
185        let ailk_start = self.ailk_offset_for_column(column)? as usize;
186
187        if ailk_start + HEADER_SIZE > self.bytes.len() {
188            return Err(AilakeError::NotAnAilakeFile);
189        }
190        let header_bytes: &[u8; HEADER_SIZE] = self.bytes[ailk_start..ailk_start + HEADER_SIZE]
191            .try_into()
192            .map_err(|_| AilakeError::NotAnAilakeFile)?;
193        let header = AilakeHeader::from_bytes(header_bytes)?;
194
195        let index_start = ailk_start + header.hnsw_offset as usize;
196        let index_end = index_start + header.hnsw_len as usize;
197
198        if index_end > self.bytes.len() {
199            return Err(AilakeError::NotAnAilakeFile);
200        }
201        let index_bytes = &self.bytes[index_start..index_end];
202
203        if header.flags & FLAG_INDEX_IVF_PQ != 0 {
204            let idx = IvfPqSerializer::from_bytes(index_bytes)?;
205            Ok(AnyIndex::IvfPq(idx))
206        } else {
207            let mut idx = MmapLoader::from_bytes(index_bytes)?;
208            if header.precision == Precision::F16 {
209                idx.quantize_to_f16();
210            }
211            Ok(AnyIndex::Hnsw(idx))
212        }
213    }
214
215    /// Read the Parquet section (tabular data + decoded embeddings).
216    /// The full file is valid Parquet; the AILK section is invisible to standard readers.
217    pub fn read_parquet(&self) -> AilakeResult<(RecordBatch, Vec<Vec<f32>>)> {
218        let reader = ParquetVectorReader::new(self.bytes.clone(), &self.vector_column);
219        reader.read_all()
220    }
221
222    /// Load the raw FTS blob from the AILK_FTS section, if present.
223    ///
224    /// Returns `Ok(None)` when the file has no FTS section (opt-in feature).
225    /// The returned bytes can be passed directly to `ailake_fts::FtsSearcher::from_blob`.
226    pub fn load_fts_blob(&self) -> AilakeResult<Option<Bytes>> {
227        let pq_reader = ParquetVectorReader::new(self.bytes.clone(), &self.vector_column);
228        let fts_offset_str = match pq_reader.kv_metadata(KV_FTS_OFFSET)? {
229            Some(s) => s,
230            None => return Ok(None),
231        };
232        let fts_abs: usize = fts_offset_str
233            .parse::<u64>()
234            .map_err(|_| AilakeError::NotAnAilakeFile)? as usize;
235
236        // Read AILK_FTS header: magic(4) | version(2) | reserved(2) | blob_len(8)
237        if fts_abs + AILK_FTS_HEADER_SIZE > self.bytes.len() {
238            return Err(AilakeError::Fts("AILK_FTS header out of bounds".into()));
239        }
240        let hdr = &self.bytes[fts_abs..fts_abs + AILK_FTS_HEADER_SIZE];
241        if hdr[0..4] != AILK_FTS_MAGIC {
242            return Err(AilakeError::Fts(format!(
243                "bad AILK_FTS magic: {:?}",
244                &hdr[0..4]
245            )));
246        }
247        let blob_len = u64::from_le_bytes(hdr[8..16].try_into().unwrap()) as usize;
248        let blob_start = fts_abs + AILK_FTS_HEADER_SIZE;
249        let blob_end = blob_start + blob_len;
250        if blob_end > self.bytes.len() {
251            return Err(AilakeError::Fts("AILK_FTS blob out of bounds".into()));
252        }
253        Ok(Some(self.bytes.slice(blob_start..blob_end)))
254    }
255
256    /// Verify the positional invariant: Parquet record_count == HNSW node_count.
257    pub fn verify_integrity(&self) -> AilakeResult<()> {
258        let header = self.read_header()?;
259        let index = self.load_index()?;
260        let reader = ParquetVectorReader::new(self.bytes.clone(), &self.vector_column);
261        let parquet_count = reader.record_count()?;
262
263        if parquet_count != index.node_count() {
264            return Err(AilakeError::RowCountMismatch {
265                parquet: parquet_count,
266                hnsw: index.node_count(),
267            });
268        }
269        if parquet_count != header.record_count {
270            return Err(AilakeError::RowCountMismatch {
271                parquet: parquet_count,
272                hnsw: header.record_count,
273            });
274        }
275        Ok(())
276    }
277}
278
279fn distance_metric_to_vector_metric(dm: DistanceMetric) -> VectorMetric {
280    match dm {
281        DistanceMetric::Cosine => VectorMetric::Cosine,
282        DistanceMetric::Euclidean => VectorMetric::Euclidean,
283        DistanceMetric::DotProduct => VectorMetric::DotProduct,
284        DistanceMetric::NormalizedCosine => VectorMetric::NormalizedCosine,
285    }
286}
287
288#[cfg(test)]
289mod tests {
290    use super::*;
291    use crate::writer::AilakeFileWriter;
292    use ailake_core::{VectorMetric, VectorPrecision, VectorStoragePolicy};
293    use arrow_array::{Int32Array, RecordBatch};
294    use arrow_schema::{DataType, Field, Schema};
295    use std::sync::Arc;
296
297    fn make_policy(dim: u32) -> VectorStoragePolicy {
298        VectorStoragePolicy {
299            column_name: "embedding".to_string(),
300            dim,
301            metric: VectorMetric::Cosine,
302            precision: VectorPrecision::F16,
303            pq: None,
304            keep_raw_for_reranking: true,
305            pre_normalize: false,
306            hnsw_m: None,
307            hnsw_ef_construction: None,
308            ivf_residual: false,
309            embedding_model: None,
310            modality: None,
311            partition_by: None,
312            partition_value: None,
313            partition_column_type: None,
314            partition_fields: vec![],
315        }
316    }
317
318    fn write_file(rows: usize, dim: u32) -> Bytes {
319        let schema = Arc::new(Schema::new(vec![Field::new("id", DataType::Int32, false)]));
320        let ids: Vec<i32> = (0..rows as i32).collect();
321        let batch = RecordBatch::try_new(schema, vec![Arc::new(Int32Array::from(ids))]).unwrap();
322        let embs: Vec<Vec<f32>> = (0..rows)
323            .map(|i| {
324                let mut v = vec![0.0f32; dim as usize];
325                v[i % dim as usize] = 1.0;
326                v
327            })
328            .collect();
329        AilakeFileWriter::new(make_policy(dim))
330            .write(&batch, &embs)
331            .unwrap()
332    }
333
334    #[test]
335    fn is_ailake_file() {
336        let file = write_file(3, 4);
337        let reader = AilakeFileReader::new(file, "embedding", 4);
338        assert!(reader.is_ailake_file());
339    }
340
341    #[test]
342    fn integrity_check_passes() {
343        let file = write_file(10, 8);
344        let reader = AilakeFileReader::new(file, "embedding", 8);
345        reader.verify_integrity().unwrap();
346    }
347
348    #[test]
349    fn centroid_has_correct_dim() {
350        let file = write_file(5, 4);
351        let reader = AilakeFileReader::new(file, "embedding", 4);
352        let centroid = reader.get_centroid().unwrap();
353        assert_eq!(centroid.values.len(), 4);
354    }
355
356    #[test]
357    fn search_finds_nearest() {
358        let dim = 4u32;
359        let file = write_file(4, dim);
360        let reader = AilakeFileReader::new(file, "embedding", dim);
361        let index = reader.load_index().unwrap();
362        let query = vec![1.0f32, 0.0, 0.0, 0.0];
363        let results = index.search(&query, 1, 50);
364        assert_eq!(results.len(), 1);
365        assert_eq!(results[0].0, ailake_core::RowId::new(0));
366    }
367
368    #[test]
369    fn parquet_read_returns_tabular_data() {
370        let file = write_file(3, 4);
371        let reader = AilakeFileReader::new(file, "embedding", 4);
372        let (batch, embs) = reader.read_parquet().unwrap();
373        assert_eq!(batch.num_rows(), 3);
374        assert_eq!(embs.len(), 3);
375    }
376}
ailake_file/reader.rs

ailake_file/
reader.rs
