faiss/MetaIndexes.h

127 lines
3.4 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.
*/
// -*- c++ -*-
#ifndef META_INDEXES_H
#define META_INDEXES_H
#include <vector>
#include <unordered_map>
#include <faiss/Index.h>
#include <faiss/IndexShards.h>
#include <faiss/IndexReplicas.h>
namespace faiss {
/** Index that translates search results to ids */
template <typename IndexT>
struct IndexIDMapTemplate : IndexT {
using idx_t = typename IndexT::idx_t;
using component_t = typename IndexT::component_t;
using distance_t = typename IndexT::distance_t;
IndexT * index; ///! the sub-index
bool own_fields; ///! whether pointers are deleted in destructo
std::vector<idx_t> id_map;
explicit IndexIDMapTemplate (IndexT *index);
/// @param xids if non-null, ids to store for the vectors (size n)
void add_with_ids(idx_t n, const component_t* x, const idx_t* xids) override;
/// this will fail. Use add_with_ids
void add(idx_t n, const component_t* x) override;
void search(
idx_t n, const component_t* x, idx_t k,
distance_t* distances,
idx_t* labels) const override;
void train(idx_t n, const component_t* x) override;
void reset() override;
/// remove ids adapted to IndexFlat
size_t remove_ids(const IDSelector& sel) override;
void range_search (idx_t n, const component_t *x, distance_t radius,
RangeSearchResult *result) const override;
~IndexIDMapTemplate () override;
IndexIDMapTemplate () {own_fields=false; index=nullptr; }
};
using IndexIDMap = IndexIDMapTemplate<Index>;
using IndexBinaryIDMap = IndexIDMapTemplate<IndexBinary>;
/** same as IndexIDMap but also provides an efficient reconstruction
* implementation via a 2-way index */
template <typename IndexT>
struct IndexIDMap2Template : IndexIDMapTemplate<IndexT> {
using idx_t = typename IndexT::idx_t;
using component_t = typename IndexT::component_t;
using distance_t = typename IndexT::distance_t;
std::unordered_map<idx_t, idx_t> rev_map;
explicit IndexIDMap2Template (IndexT *index);
/// make the rev_map from scratch
void construct_rev_map ();
void add_with_ids(idx_t n, const component_t* x, const idx_t* xids) override;
size_t remove_ids(const IDSelector& sel) override;
void reconstruct (idx_t key, component_t * recons) const override;
~IndexIDMap2Template() override {}
IndexIDMap2Template () {}
};
using IndexIDMap2 = IndexIDMap2Template<Index>;
using IndexBinaryIDMap2 = IndexIDMap2Template<IndexBinary>;
/** splits input vectors in segments and assigns each segment to a sub-index
* used to distribute a MultiIndexQuantizer
*/
struct IndexSplitVectors: Index {
bool own_fields;
bool threaded;
std::vector<Index*> sub_indexes;
idx_t sum_d; /// sum of dimensions seen so far
explicit IndexSplitVectors (idx_t d, bool threaded = false);
void add_sub_index (Index *);
void sync_with_sub_indexes ();
void add(idx_t n, const float* x) override;
void search(
idx_t n,
const float* x,
idx_t k,
float* distances,
idx_t* labels) const override;
void train(idx_t n, const float* x) override;
void reset() override;
~IndexSplitVectors() override;
};
} // namespace faiss
#endif