pvfmm
RoaringBitmap
| pvfmm | RoaringBitmap | |
|---|---|---|
| 1 | 24 | |
| 49 | 3,390 | |
| - | 0.9% | |
| 6.0 | 8.5 | |
| 8 months ago | 13 days ago | |
| C++ | Java | |
| GNU Lesser General Public License v3.0 only | Apache License 2.0 |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
pvfmm
RoaringBitmap
-
Iterating over Bit Sets Quickly
I was recently reading about Roaring https://roaringbitmap.org/ which is a highly optimized compressed bitset implementation. I reccomend reading about it if you are interested in this sort of thing. The talk at https://roaringbitmap.org/talks/ is especially good.
- Roaring Bitmaps
- Roaring bitmaps are compressed bitmaps, can be 100x faster
-
What feature would you like to remove in C++26?
However, I would love compressed (not just packed) bitsets too, which is something different to me. I would make it another class with a similar interface, based on something like roaring. It doesn't need to be in the standard, but it would be nice if the API was a such that one could easily swap implementations.
-
Jaccard Index
As an aside if you find yourself having to compute them on the fly, know that the Roaring Bitmaps libraries is the way to go [1]. The bitmaps are compressed, and can be streamed directly into SIMD computations (batching XORs and popcnts 256 bits wide!). The Jaccard index is just intersection_len / union_len [2] away
[1] https://roaringbitmap.org/
[2] https://roaringbitmap.readthedocs.io/en/latest/#roaringbitma...
-
Looking for fast, space-efficient key-lookup
Use a two stage approach, with a bloom/cuckoo filter stored as a https://roaringbitmap.org/ in memory. Then a secondary key/value store on disk (bolt or anything else).
-
BitSet Vs BigInteger
As an aside, if you're dealing with large bit sets, you might also want to evaluate Roaring Bitmaps.
-
Negative Incentives in Academic Research
Sidetracking a bit the conversation. What a coincidence that the author (Lemire) is also represented on Today's #1 "Ask HN: What are some cool but obscure data structures you know about?" as he is the main contributor of RoaringBitmap https://github.com/RoaringBitmap/RoaringBitmap and one of the main authors of the data structure.
- Ask HN: What are some 'cool' but obscure data structures you know about?
- Roaring bitmaps: A better compressed bitset
What are some alternatives?
PSI - Private Set Intersection Cardinality protocol based on ECDH and Bloom Filters
HyperMinHash-java - Union, intersection, and set cardinality in loglog space
asami - A graph store for Clojure and ClojureScript
lucene - Apache Lucene open-source search software
RVS_Generic_Swift_Toolbox - A Collection Of Various Swift Tools, Like Extensions and Utilities
CQEngine - Ultra-fast SQL-like queries on Java collections
entt - Gaming meets modern C++ - a fast and reliable entity component system (ECS) and much more
Primes - Prime Number Projects in C#/C++/Python
Folly - An open-source C++ library developed and used at Facebook.
Feign - Feign makes writing java http clients easier
us - An alternative interface to Sia
maven-compiler-plugin - Apache Maven Compiler Plugin