Struct faiss::IndexShardsTemplate

template<typename IndexT>
struct IndexShardsTemplate : public faiss::ThreadedIndex<IndexT>

Index that concatenates the results from several sub-indexes

Subclassed by faiss::IndexShardsIVF

Public Types

using component_t = typename IndexT::component_t
using distance_t = typename IndexT::distance_t

Public Functions

explicit IndexShardsTemplate(bool threaded = false, bool successive_ids = true)

The dimension that all sub-indices must share will be the dimension of the first sub-index added

Parameters:

  • threaded – do we use one thread per sub_index or do queries sequentially?

  • successive_ids – should we shift the returned ids by the size of each sub-index or return them as they are?

explicit IndexShardsTemplate(idx_t d, bool threaded = false, bool successive_ids = true)
Parameters:

  • threaded – do we use one thread per sub_index or do queries sequentially?

  • successive_ids – should we shift the returned ids by the size of each sub-index or return them as they are?

explicit IndexShardsTemplate(int d, bool threaded = false, bool successive_ids = true)

int version due to the implicit bool conversion ambiguity of int as dimension

inline void add_shard(IndexT *index)

Alias for addIndex()

inline void remove_shard(IndexT *index)

Alias for removeIndex()

void add(idx_t n, const component_t *x) override

supported only for sub-indices that implement add_with_ids

void add_with_ids(idx_t n, const component_t *x, const idx_t *xids) override

Cases (successive_ids, xids):

  • true, non-NULL ERROR: it makes no sense to pass in ids and request them to be shifted

  • true, NULL OK: but should be called only once (calls add() on sub-indexes).

  • false, non-NULL OK: will call add_with_ids with passed in xids distributed evenly over shards

  • false, NULL OK: will call add_with_ids on each sub-index, starting at ntotal

void search(idx_t n, const component_t *x, idx_t k, distance_t *distances, idx_t *labels, const SearchParameters *params = nullptr) const override
void train(idx_t n, const component_t *x) override
virtual void syncWithSubIndexes()

Synchronize the top-level index (IndexShards) with data in the sub-indices

virtual void addIndex(IndexT *index)

override an index that is managed by ourselves. WARNING: once an index is added, it becomes unsafe to touch it from any other thread than that on which is managing it, until we are shut down. Use runOnIndex to perform work on it instead.

void removeIndex(IndexT *index)

Remove an index that is managed by ourselves. This will flush all pending work on that index, and then shut down its managing thread, and will remove the index.

void runOnIndex(std::function<void(int, IndexT*)> f)

Run a function on all indices, in the thread that the index is managed in. Function arguments are (index in collection, index pointer)

void runOnIndex(std::function<void(int, const IndexT*)> f) const
void reset() override

faiss::Index API All indices receive the same call

inline int count() const

Returns the number of sub-indices.

inline IndexT *at(size_t i)

Returns the i-th sub-index.

inline const IndexT *at(size_t i) const

Returns the i-th sub-index (const version)

Public Members

bool successive_ids
bool own_indices = false

Whether or not we are responsible for deleting our contained indices.

Protected Functions

virtual void onAfterAddIndex(IndexT *index) override

Called just after an index is added.

virtual void onAfterRemoveIndex(IndexT *index) override

Called just after an index is removed.

Protected Attributes

std::vector<std::pair<IndexT*, std::unique_ptr<WorkerThread>>> indices_

Collection of Index instances, with their managing worker thread if any.

bool isThreaded_

Is this index multi-threaded?

Protected Static Functions

static void waitAndHandleFutures(std::vector<std::future<bool>> &v)