86 lines
2.0 KiB
C
86 lines
2.0 KiB
C
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/**
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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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// -*- c++ -*-
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#pragma once
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#include <vector>
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#include <faiss/IndexPQ.h>
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#include <faiss/IndexIVF.h>
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namespace faiss {
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struct IndexIVFPQ;
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/** Same as an IndexIVFPQ without the inverted lists: codes are stored sequentially
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*
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* The class is mainly inteded to store encoded vectors that can be
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* accessed randomly, the search function is not implemented.
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*/
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struct Index2Layer: Index {
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/// first level quantizer
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Level1Quantizer q1;
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/// second level quantizer is always a PQ
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ProductQuantizer pq;
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/// Codes. Size ntotal * code_size.
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std::vector<uint8_t> codes;
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/// size of the code for the first level (ceil(log8(q1.nlist)))
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size_t code_size_1;
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/// size of the code for the second level
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size_t code_size_2;
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/// code_size_1 + code_size_2
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size_t code_size;
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Index2Layer (Index * quantizer, size_t nlist,
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int M, int nbit = 8,
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MetricType metric = METRIC_L2);
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Index2Layer ();
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~Index2Layer ();
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void train(idx_t n, const float* x) override;
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void add(idx_t n, const float* x) override;
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/// not implemented
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void search(
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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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idx_t* labels) const override;
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void reconstruct_n(idx_t i0, idx_t ni, float* recons) const override;
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void reconstruct(idx_t key, float* recons) const override;
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void reset() override;
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DistanceComputer * get_distance_computer() const override;
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/// transfer the flat codes to an IVFPQ index
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void transfer_to_IVFPQ(IndexIVFPQ & other) const;
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/* The standalone codec interface */
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size_t sa_code_size () const override;
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void sa_encode (idx_t n, const float *x, uint8_t *bytes) const override;
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void sa_decode (idx_t n, const uint8_t *bytes, float *x) const override;
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};
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} // namespace faiss
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