File IndexFlatCodes.h

namespace faiss

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.

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.

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. 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.

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. Definition of inverted lists + a few common classes that implement the interface.

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. 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.

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. In this file are the implementations of extra metrics beyond L2 and inner product

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. Defines a few objects that apply transformations to a set of vectors Often these are pre-processing steps.

struct IndexFlatCodes : public faiss::Index
#include <IndexFlatCodes.h>

Index that encodes all vectors as fixed-size codes (size code_size). Storage is in the codes vector

Subclassed by faiss::Index2Layer, faiss::IndexAdditiveQuantizer, faiss::IndexFlat, faiss::IndexLSH, faiss::IndexPQ, faiss::IndexScalarQuantizer

Public Functions

IndexFlatCodes()
IndexFlatCodes(size_t code_size, idx_t d, MetricType metric = METRIC_L2)
virtual void add(idx_t n, const float *x) override

default add uses sa_encode

virtual void reset() override

removes all elements from the database.

virtual void reconstruct_n(idx_t i0, idx_t ni, float *recons) const override

reconstruction using the codec interface

virtual void reconstruct(idx_t key, float *recons) const override

Reconstruct a stored vector (or an approximation if lossy coding)

this function may not be defined for some indexes

Parameters
  • key – id of the vector to reconstruct

  • recons – reconstucted vector (size d)

virtual size_t sa_code_size() const override

size of the produced codes in bytes

virtual size_t remove_ids(const IDSelector &sel) override

remove some ids. NB that Because of the structure of the indexing structure, the semantics of this operation are different from the usual ones: the new ids are shifted

virtual FlatCodesDistanceComputer *get_FlatCodesDistanceComputer() const

a FlatCodesDistanceComputer offers a distance_to_code method

inline virtual DistanceComputer *get_distance_computer() const override

Get a DistanceComputer (defined in AuxIndexStructures) object for this kind of index.

DistanceComputer is implemented for indexes that support random access of their vectors.

Public Members

size_t code_size
std::vector<uint8_t> codes

encoded dataset, size ntotal * code_size