Summary:
Added a few functions in contrib to:
- run range searches by batches on the query or the database side
- emulate range search on GPU: search on GPU with k=1024, if the farthest neighbor is still within range, re-perform search on CPU
- as reference implementations for precision-recall on range search datasets
- optimized code to plot precision-recall plots (ie. sweep over thresholds)
The new functions are mainly in a new `evaluation.py`
Reviewed By: wickedfoo
Differential Revision: D25627619
fbshipit-source-id: 58f90654c32c925557d7bbf8083efbb710712e03
Bugfixes:
- slow scanning of inverted lists (#836).
Features:
- add basic support for 6 new metrics in CPU `IndexFlat` and `IndexHNSW` (#848);
- add support for `IndexIDMap`/`IndexIDMap2` with binary indexes (#780).
Misc:
- throw python exception for OOM (#758);
- make `DistanceComputer` available for all random access indexes;
- gradually moving from `long` to `int64_t` for portability.