File DistanceComputer.h
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namespace faiss
Implementation of k-means clustering with many variants.
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.
IDSelector is intended to define a subset of vectors to handle (for removal or as subset to search)
PQ4 SIMD packing and accumulation functions
The basic kernel accumulates nq query vectors with bbs = nb * 2 * 16 vectors and produces an output matrix for that. It is interesting for nq * nb <= 4, otherwise register spilling becomes too large.
The implementation of these functions is spread over 3 cpp files to reduce parallel compile times. Templates are instantiated explicitly.
This file contains callbacks for kernels that compute distances.
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.
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.
Definition of inverted lists + a few common classes that implement the interface.
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.
In this file are the implementations of extra metrics beyond L2 and inner product
Implements a few neural net layers, mainly to support QINCo
Defines a few objects that apply transformations to a set of vectors Often these are pre-processing steps.
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struct DistanceComputer
Subclassed by faiss::FlatCodesDistanceComputer, faiss::NegativeDistanceComputer
Public Functions
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virtual void set_query(const float *x) = 0
called before computing distances. Pointer x should remain valid while operator () is called
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inline virtual void distances_batch_4(const idx_t idx0, const idx_t idx1, const idx_t idx2, const idx_t idx3, float &dis0, float &dis1, float &dis2, float &dis3)
compute distances of current query to 4 stored vectors. certain DistanceComputer implementations may benefit heavily from this.
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inline virtual ~DistanceComputer()
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virtual void set_query(const float *x) = 0
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struct NegativeDistanceComputer : public faiss::DistanceComputer
Public Functions
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inline explicit NegativeDistanceComputer(DistanceComputer *basedis)
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inline virtual void set_query(const float *x) override
called before computing distances. Pointer x should remain valid while operator () is called
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inline virtual void distances_batch_4(const idx_t idx0, const idx_t idx1, const idx_t idx2, const idx_t idx3, float &dis0, float &dis1, float &dis2, float &dis3) override
compute distances of current query to 4 stored vectors. certain DistanceComputer implementations may benefit heavily from this.
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inline virtual float symmetric_dis(idx_t i, idx_t j) override
compute distance between two stored vectors
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inline virtual ~NegativeDistanceComputer()
Public Members
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DistanceComputer *basedis
owned by this
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inline explicit NegativeDistanceComputer(DistanceComputer *basedis)
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struct FlatCodesDistanceComputer : public faiss::DistanceComputer
Subclassed by faiss::ScalarQuantizer::SQDistanceComputer
Public Functions
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inline FlatCodesDistanceComputer(const uint8_t *codes, size_t code_size)
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inline FlatCodesDistanceComputer()
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virtual float distance_to_code(const uint8_t *code) = 0
compute distance of current query to an encoded vector
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inline virtual ~FlatCodesDistanceComputer()
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virtual void set_query(const float *x) = 0
called before computing distances. Pointer x should remain valid while operator () is called
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inline FlatCodesDistanceComputer(const uint8_t *codes, size_t code_size)
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struct DistanceComputer