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diff --git a/src/xxHash/README.md b/src/xxHash/README.md new file mode 100644 index 000000000..e2ec2b8e6 --- /dev/null +++ b/src/xxHash/README.md @@ -0,0 +1,75 @@ +xxHash - Extremely fast hash algorithm +====================================== + +xxHash is an Extremely fast Hash algorithm, running at RAM speed limits. +It successfully completes the [SMHasher](http://code.google.com/p/smhasher/wiki/SMHasher) test suite +which evaluates collision, dispersion and randomness qualities of hash functions. + +|Branch |Status | +|------------|---------| +|master | [](https://travis-ci.org/Cyan4973/xxHash?branch=master) | +|dev | [](https://travis-ci.org/Cyan4973/xxHash?branch=dev) | + +> **Branch Policy:** + +> - The "master" branch is considered stable, at all times. +> - The "dev" branch is the one where all contributions must be merged + before being promoted to master. +> + If you plan to propose a patch, please commit into the "dev" branch, + or its own feature branch. + Direct commit to "master" are not permitted. + + +Benchmarks +------------------------- + +The benchmark uses SMHasher speed test, compiled with Visual 2010 on a Windows Seven 32-bits box. +The reference system uses a Core 2 Duo @3GHz + + +| Name | Speed | Quality | Author | +|---------------|----------|:-------:|------------------| +| [xxHash] | 5.4 GB/s | 10 | Y.C. | +| MurmurHash 3a | 2.7 GB/s | 10 | Austin Appleby | +| SBox | 1.4 GB/s | 9 | Bret Mulvey | +| Lookup3 | 1.2 GB/s | 9 | Bob Jenkins | +| CityHash64 | 1.05 GB/s| 10 | Pike & Alakuijala| +| FNV | 0.55 GB/s| 5 | Fowler, Noll, Vo | +| CRC32 | 0.43 GB/s| 9 | | +| MD5-32 | 0.33 GB/s| 10 | Ronald L.Rivest | +| SHA1-32 | 0.28 GB/s| 10 | | + +[xxHash]: http://www.xxhash.com + +Q.Score is a measure of quality of the hash function. +It depends on successfully passing SMHasher test set. +10 is a perfect score. +Algorithms with a score < 5 are not listed on this table. + +A new version, XXH64, has been created thanks to [Mathias Westerdahl]'s contribution, +which offers superior speed and dispersion for 64-bits systems. +Note however that 32-bits applications will still run faster using the 32-bits version. +[Mathias Westerdahl]: https://github.com/JCash + +SMHasher speed test, compiled using GCC 4.8.2, on Linux Mint 64-bits. +The reference system uses a Core i5-3340M @2.7GHz + +| Version | Speed on 64-bits | Speed on 32-bits | +|------------|------------------|------------------| +| XXH64 | 13.8 GB/s | 1.9 GB/s | +| XXH32 | 6.8 GB/s | 6.0 GB/s | + + +### License + +The library files `xxhash.c` and `xxhash.h` are BSD licensed. +The utility `xxhsum` is GPL licensed. + + +### Other languages + +Beyond the C reference version, +xxHash is also available on many programming languages, +thanks to great contributors. +They are [listed here](http://www.xxhash.com/#other-languages). + |