mirror of
https://github.com/facebookresearch/faiss.git
synced 2025-06-03 21:54:02 +08:00
e1adde0d84
Summary: This diff streamlines the code that collects results for brute force distance computations for the L2 / IP and range search / knn search combinations. It introduces a `ResultHandler` template class that abstracts what happens with the computed distances and ids. In addition to the heap result handler and the range search result handler, it introduces a reservoir result handler that improves the search speed for large k (>=100). Benchmark results (https://fb.quip.com/y0g1ACLEqJXx#OCaACA2Gm45) show that on small datasets (10k) search is 10-50% faster (improvements are larger for small k). There is room for improvement in the reservoir implementation, whose implementation is quite naive currently, but the diff is already useful in its current form. Experiments on precomputed db vector norms for L2 distance computations were not very concluding performance-wise, so the implementation is removed from IndexFlatL2. This diff also removes IndexL2BaseShift, which was never used. Pull Request resolved: https://github.com/facebookresearch/faiss/pull/1502 Test Plan: ``` buck test //faiss/tests/:test_product_quantizer buck test //faiss/tests/:test_index -- TestIndexFlat ``` Reviewed By: wickedfoo Differential Revision: D24705464 Pulled By: mdouze fbshipit-source-id: 270e10b19f3c89ed7b607ec30549aca0ac5027fe
108 lines
3.0 KiB
C
108 lines
3.0 KiB
C
/**
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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// Copyright 2004-present Facebook. All Rights Reserved
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// -*- c -*-
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#ifndef FAISS_INDEX_FLAT_C_H
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#define FAISS_INDEX_FLAT_C_H
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#include "Index_c.h"
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#include "faiss_c.h"
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#ifdef __cplusplus
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extern "C" {
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#endif
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// forward declaration
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typedef enum FaissMetricType FaissMetricType;
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/** Opaque type for IndexFlat */
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FAISS_DECLARE_CLASS_INHERITED(IndexFlat, Index)
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int faiss_IndexFlat_new(FaissIndexFlat** p_index);
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int faiss_IndexFlat_new_with(FaissIndexFlat** p_index, idx_t d, FaissMetricType metric);
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/** get a pointer to the index's internal data (the `xb` field). The outputs
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* become invalid after any data addition or removal operation.
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*
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* @param index opaque pointer to index object
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* @param p_xb output, the pointer to the beginning of `xb`.
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* @param p_size output, the current size of `sb` in number of float values.
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*/
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void faiss_IndexFlat_xb(FaissIndexFlat* index, float** p_xb, size_t* p_size);
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/** attempt a dynamic cast to a flat index, thus checking
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* check whether the underlying index type is `IndexFlat`.
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*
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* @param index opaque pointer to index object
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* @return the same pointer if the index is a flat index, NULL otherwise
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*/
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FAISS_DECLARE_INDEX_DOWNCAST(IndexFlat)
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FAISS_DECLARE_DESTRUCTOR(IndexFlat)
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/** compute distance with a subset of vectors
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*
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* @param index opaque pointer to index object
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* @param x query vectors, size n * d
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* @param labels indices of the vectors that should be compared
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* for each query vector, size n * k
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* @param distances
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* corresponding output distances, size n * k
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*/
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int faiss_IndexFlat_compute_distance_subset(
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FaissIndex *index,
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idx_t n,
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const float *x,
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idx_t k,
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float *distances,
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const idx_t *labels);
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/** Opaque type for IndexFlatIP */
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FAISS_DECLARE_CLASS_INHERITED(IndexFlatIP, Index)
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int faiss_IndexFlatIP_new(FaissIndexFlatIP** p_index);
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int faiss_IndexFlatIP_new_with(FaissIndexFlatIP** p_index, idx_t d);
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/** Opaque type for IndexFlatL2 */
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FAISS_DECLARE_CLASS_INHERITED(IndexFlatL2, Index)
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int faiss_IndexFlatL2_new(FaissIndexFlatL2** p_index);
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int faiss_IndexFlatL2_new_with(FaissIndexFlatL2** p_index, idx_t d);
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/** Opaque type for IndexRefineFlat
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*
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* Index that queries in a base_index (a fast one) and refines the
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* results with an exact search, hopefully improving the results.
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*/
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FAISS_DECLARE_CLASS_INHERITED(IndexRefineFlat, Index)
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int faiss_IndexRefineFlat_new(FaissIndexRefineFlat** p_index, FaissIndex* base_index);
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FAISS_DECLARE_DESTRUCTOR(IndexRefineFlat)
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/** Opaque type for IndexFlat1D
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*
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* optimized version for 1D "vectors"
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*/
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FAISS_DECLARE_CLASS_INHERITED(IndexFlat1D, Index)
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int faiss_IndexFlat1D_new(FaissIndexFlat1D** p_index);
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int faiss_IndexFlat1D_new_with(FaissIndexFlat1D** p_index, int continuous_update);
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int faiss_IndexFlat1D_update_permutation(FaissIndexFlat1D* index);
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#ifdef __cplusplus
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}
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#endif
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#endif
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