faiss/gpu/GpuIndexIVFScalarQuantizer.h

101 lines
2.9 KiB
C++

/**
* 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.
*/
#pragma once
#include <faiss/gpu/GpuIndexIVF.h>
#include <faiss/IndexScalarQuantizer.h>
namespace faiss { namespace gpu {
class IVFFlat;
class GpuIndexFlat;
struct GpuIndexIVFScalarQuantizerConfig : public GpuIndexIVFConfig {
};
/// Wrapper around the GPU implementation that looks like
/// faiss::IndexIVFScalarQuantizer
class GpuIndexIVFScalarQuantizer : public GpuIndexIVF {
public:
/// Construct from a pre-existing faiss::IndexIVFScalarQuantizer instance,
/// copying data over to the given GPU, if the input index is trained.
GpuIndexIVFScalarQuantizer(
GpuResources* resources,
const faiss::IndexIVFScalarQuantizer* index,
GpuIndexIVFScalarQuantizerConfig config =
GpuIndexIVFScalarQuantizerConfig());
/// Constructs a new instance with an empty flat quantizer; the user
/// provides the number of lists desired.
GpuIndexIVFScalarQuantizer(
GpuResources* resources,
int dims,
int nlist,
faiss::ScalarQuantizer::QuantizerType qtype,
faiss::MetricType metric = MetricType::METRIC_L2,
bool encodeResidual = true,
GpuIndexIVFScalarQuantizerConfig config =
GpuIndexIVFScalarQuantizerConfig());
~GpuIndexIVFScalarQuantizer() override;
/// Reserve GPU memory in our inverted lists for this number of vectors
void reserveMemory(size_t numVecs);
/// Initialize ourselves from the given CPU index; will overwrite
/// all data in ourselves
void copyFrom(const faiss::IndexIVFScalarQuantizer* index);
/// Copy ourselves to the given CPU index; will overwrite all data
/// in the index instance
void copyTo(faiss::IndexIVFScalarQuantizer* index) const;
/// After adding vectors, one can call this to reclaim device memory
/// to exactly the amount needed. Returns space reclaimed in bytes
size_t reclaimMemory();
void reset() override;
void train(Index::idx_t n, const float* x) override;
protected:
/// Called from GpuIndex for add/add_with_ids
void addImpl_(int n,
const float* x,
const Index::idx_t* ids) override;
/// Called from GpuIndex for search
void searchImpl_(int n,
const float* x,
int k,
float* distances,
Index::idx_t* labels) const override;
/// Called from train to handle SQ residual training
void trainResiduals_(Index::idx_t n, const float* x);
public:
/// Exposed like the CPU version
faiss::ScalarQuantizer sq;
/// Exposed like the CPU version
bool by_residual;
private:
GpuIndexIVFScalarQuantizerConfig ivfSQConfig_;
/// Desired inverted list memory reservation
size_t reserveMemoryVecs_;
/// Instance that we own; contains the inverted list
IVFFlat* index_;
};
} } // namespace