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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).
|
