File IndexIVFFlat.h¶
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namespace faiss
Copyright (c) Facebook, Inc. and its affiliates.
This source code is licensed under the MIT license found in the LICENSE file in the root directory of this source tree.
Throughout the library, vectors are provided as float * pointers. Most algorithms can be optimized when several vectors are processed (added/searched) together in a batch. In this case, they are passed in as a matrix. When n vectors of size d are provided as float * x, component j of vector i is
x[ i * d + j ]
where 0 <= i < n and 0 <= j < d. In other words, matrices are always compact. When specifying the size of the matrix, we call it an n*d matrix, which implies a row-major storage.
Copyright (c) Facebook, Inc. and its affiliates.
This source code is licensed under the MIT license found in the LICENSE file in the root directory of this source tree. I/O functions can read/write to a filename, a file handle or to an object that abstracts the medium.
The read functions return objects that should be deallocated with delete. All references within these objectes are owned by the object.
Copyright (c) Facebook, Inc. and its affiliates.
This source code is licensed under the MIT license found in the LICENSE file in the root directory of this source tree. Definition of inverted lists + a few common classes that implement the interface.
Copyright (c) Facebook, Inc. and its affiliates.
This source code is licensed under the MIT license found in the LICENSE file in the root directory of this source tree. Since IVF (inverted file) indexes are of so much use for large-scale use cases, we group a few functions related to them in this small library. Most functions work both on IndexIVFs and IndexIVFs embedded within an IndexPreTransform.
Copyright (c) Facebook, Inc. and its affiliates.
This source code is licensed under the MIT license found in the LICENSE file in the root directory of this source tree. In this file are the implementations of extra metrics beyond L2 and inner product
Copyright (c) Facebook, Inc. and its affiliates.
This source code is licensed under the MIT license found in the LICENSE file in the root directory of this source tree. Defines a few objects that apply transformations to a set of vectors Often these are pre-processing steps.
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struct IndexIVFFlat : public faiss::IndexIVF¶
- #include <IndexIVFFlat.h>
Inverted file with stored vectors. Here the inverted file pre-selects the vectors to be searched, but they are not otherwise encoded, the code array just contains the raw float entries.
Subclassed by faiss::IndexIVFFlatDedup
Public Functions
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IndexIVFFlat(Index *quantizer, size_t d, size_t nlist_, MetricType = METRIC_L2)¶
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virtual void add_core(idx_t n, const float *x, const idx_t *xids, const idx_t *precomputed_idx) override¶
Implementation of vector addition where the vector assignments are predefined. The default implementation hands over the code extraction to encode_vectors.
- Parameters:
precomputed_idx – quantization indices for the input vectors (size n)
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virtual void encode_vectors(idx_t n, const float *x, const idx_t *list_nos, uint8_t *codes, bool include_listnos = false) const override¶
Encodes a set of vectors as they would appear in the inverted lists
- Parameters:
list_nos – inverted list ids as returned by the quantizer (size n). -1s are ignored.
codes – output codes, size n * code_size
include_listno – include the list ids in the code (in this case add ceil(log8(nlist)) to the code size)
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virtual InvertedListScanner *get_InvertedListScanner(bool store_pairs, const IDSelector *sel) const override¶
Get a scanner for this index (store_pairs means ignore labels)
The default search implementation uses this to compute the distances
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virtual void reconstruct_from_offset(int64_t list_no, int64_t offset, float *recons) const override¶
Reconstruct a vector given the location in terms of (inv list index + inv list offset) instead of the id.
Useful for reconstructing when the direct_map is not maintained and the inv list offset is computed by search_preassigned() with
store_pairs
set.
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virtual void sa_decode(idx_t n, const uint8_t *bytes, float *x) const override¶
decode a set of vectors
- Parameters:
n – number of vectors
bytes – input encoded vectors, size n * sa_code_size()
x – output vectors, size n * d
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inline IndexIVFFlat()¶
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IndexIVFFlat(Index *quantizer, size_t d, size_t nlist_, MetricType = METRIC_L2)¶
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struct IndexIVFFlatDedup : public faiss::IndexIVFFlat¶
Public Functions
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IndexIVFFlatDedup(Index *quantizer, size_t d, size_t nlist_, MetricType = METRIC_L2)¶
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virtual void add_with_ids(idx_t n, const float *x, const idx_t *xids) override¶
implemented for all IndexIVF* classes
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virtual void search_preassigned(idx_t n, const float *x, idx_t k, const idx_t *assign, const float *centroid_dis, float *distances, idx_t *labels, bool store_pairs, const IVFSearchParameters *params = nullptr, IndexIVFStats *stats = nullptr) const override¶
search a set of vectors, that are pre-quantized by the IVF quantizer. Fill in the corresponding heaps with the query results. The default implementation uses InvertedListScanners to do the search.
- Parameters:
n – nb of vectors to query
x – query vectors, size nx * d
assign – coarse quantization indices, size nx * nprobe
centroid_dis – distances to coarse centroids, size nx * nprobe
distance – output distances, size n * k
labels – output labels, size n * k
store_pairs – store inv list index + inv list offset instead in upper/lower 32 bit of result, instead of ids (used for reranking).
params – used to override the object’s search parameters
stats – search stats to be updated (can be null)
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virtual size_t remove_ids(const IDSelector &sel) override¶
Dataset manipulation functions.
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virtual void range_search(idx_t n, const float *x, float radius, RangeSearchResult *result, const SearchParameters *params = nullptr) const override¶
not implemented
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virtual void reconstruct_from_offset(int64_t list_no, int64_t offset, float *recons) const override¶
not implemented
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inline IndexIVFFlatDedup()¶
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virtual void add_core(idx_t n, const float *x, const idx_t *xids, const idx_t *precomputed_idx) override¶
Implementation of vector addition where the vector assignments are predefined. The default implementation hands over the code extraction to encode_vectors.
- Parameters:
precomputed_idx – quantization indices for the input vectors (size n)
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virtual void encode_vectors(idx_t n, const float *x, const idx_t *list_nos, uint8_t *codes, bool include_listnos = false) const override¶
Encodes a set of vectors as they would appear in the inverted lists
- Parameters:
list_nos – inverted list ids as returned by the quantizer (size n). -1s are ignored.
codes – output codes, size n * code_size
include_listno – include the list ids in the code (in this case add ceil(log8(nlist)) to the code size)
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virtual InvertedListScanner *get_InvertedListScanner(bool store_pairs, const IDSelector *sel) const override¶
Get a scanner for this index (store_pairs means ignore labels)
The default search implementation uses this to compute the distances
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virtual void sa_decode(idx_t n, const uint8_t *bytes, float *x) const override¶
decode a set of vectors
- Parameters:
n – number of vectors
bytes – input encoded vectors, size n * sa_code_size()
x – output vectors, size n * d
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IndexIVFFlatDedup(Index *quantizer, size_t d, size_t nlist_, MetricType = METRIC_L2)¶
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struct IndexIVFFlat : public faiss::IndexIVF¶