https://github.com/juliastring/murmurhash3.jl
Port of MurmurHash3 to pure Julia, adding support for hashing any AbstractString without converting first
https://github.com/juliastring/murmurhash3.jl
hacktoberfest julia murmurhash3
Last synced: 8 months ago
JSON representation
Port of MurmurHash3 to pure Julia, adding support for hashing any AbstractString without converting first
- Host: GitHub
- URL: https://github.com/juliastring/murmurhash3.jl
- Owner: JuliaString
- License: mit
- Created: 2018-05-24T13:07:38.000Z (almost 8 years ago)
- Default Branch: master
- Last Pushed: 2021-05-18T12:34:24.000Z (almost 5 years ago)
- Last Synced: 2025-05-26T22:07:20.676Z (9 months ago)
- Topics: hacktoberfest, julia, murmurhash3
- Language: Julia
- Homepage:
- Size: 38.1 KB
- Stars: 5
- Watchers: 1
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# MurmurHash3: a pure Julia implementation of the MurmurHash3 functions
[pkg-url]: https://github.com/JuliaString/MurmurHash3.jl.git
[julia-url]: https://github.com/JuliaLang/Julia
[julia-release]:https://img.shields.io/github/release/JuliaLang/julia.svg
[release]: https://img.shields.io/github/release/JuliaString/MurmurHash3.jl.svg
[release-date]: https://img.shields.io/github/release-date/JuliaString/MurmurHash3.jl.svg
[license-img]: http://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat
[license-url]: LICENSE.md
[gitter-img]: https://badges.gitter.im/Join%20Chat.svg
[gitter-url]: https://gitter.im/JuliaString/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge
[travis-url]: https://travis-ci.org/JuliaString/MurmurHash3.jl
[travis-s-img]: https://travis-ci.org/JuliaString/MurmurHash3.jl.svg
[travis-m-img]: https://travis-ci.org/JuliaString/MurmurHash3.jl.svg?branch=master
[codecov-url]: https://codecov.io/gh/JuliaString/MurmurHash3.jl
[codecov-img]: https://codecov.io/gh/JuliaString/MurmurHash3.jl/branch/master/graph/badge.svg
[contrib]: https://img.shields.io/badge/contributions-welcome-brightgreen.svg?style=flat
[![][release]][pkg-url] [![][release-date]][pkg-url] [![][license-img]][license-url] [![contributions welcome][contrib]](https://github.com/JuliaString/MurmurHash3.jl/issues)
| **Julia Version** | **Unit Tests** | **Coverage** |
|:------------------:|:------------------:|:---------------------:|
| [![][julia-release]][julia-url] | [![][travis-s-img]][travis-url] | [![][codecov-img]][codecov-url]
| Julia Latest | [![][travis-m-img]][travis-url] | [![][codecov-img]][codecov-url]
Note: this can be used to replace the C MurmurHash library used by base Julia,
to implement a `hash` function that gives compatible results.
This provides the following functions (written in pure Julia):
`mmhash128` which hashes a UTF-8 (or ASCII, which is compatible) string
`mmhash128_c` which can be used to hash an generic abstract string (by converting to UTF-8 on the fly, without having to allocate the string, working a few characters at a time)
Note that the hashes on 64-bit systems are *not* the same as on 32-bit systems
(this is true for base Julia `hash` as well)
`mmhash32` which creates a 32 bit hash from a UTF-8/ASCII string
(this works for `String`, as well as some of the `Str` types, such as `ASCIIStr`, `UTF8Str`, `Binary`, `Text1Str` can all be hashed directly)
(note, there is no mmhash32_c yet, so other strings have to be converted to `String` type before hashing)
Julia uses the following code to create a hash using the C MurmurHash library:
```
const memhash = UInt === UInt64 ? :memhash_seed : :memhash32_seed
const memhash_seed = UInt === UInt64 ? 0x71e729fd56419c81 : 0x56419c81
function hash(s::String, h::UInt)
h += memhash_seed
ccall(memhash, UInt, (Ptr{UInt8}, Csize_t, UInt32), s, sizeof(s), h % UInt32) + h
end
```
similar code, such as that in `JuliaString/StrBase.jl/src/hash.jl`, implements the
`hash` function for all of the `Str` types, but is specialized for performance based on the type of the string and whether or not it is aligned in memory.