Endpoint MurmurHash3
WHO WHAT WHY WHEN HOW
What
a non crypto hash function that is pretty dar random except for repetitions or something.
hosted at https://murmurhash3.pages.dev
Who
Who
tanjent
March 3 2008, 13:31
MurmurHash, final version. UPDATE - If you're reading this via a link from Google or Reddit, please go here - http://murmurhash.googlepages.com. All future updates about MurmurHash will be posted there.
UPDATEUPDATE - MurmurHash is now at version 2.0. The new version uses a different mix function than the below that is much faster & mixes better. Code is on the website linked above.
OK, I'm done with this for the time being. Figured out a clever way to generate and test mixing constants and found a much better one, replaced the "h ^= data" with "h += data" (very slightly better collision resistance), and ended up removing the rotate instruction and replacing with a shift-xor (should I rename it MusxmusxHash?).
This version passes Jenkin's frog.c torture-test up to 2^25 keypairs (beats Hsieh's 2^17; previous Murmur failed after 2^9), distribution is still excellent (only 3 collisions on the SCOWL english-words.95 list vs. Hsieh's 41), and still runs faster than Hsieh and Jenkins at 1300 mb/sec vs. their ~900 mb/sec.
You should be able to use this hash function anywhere you like with very good results. I'll work on getting it posted up to interesting places this week.
Performance results from Hsieh's test app -
CRC32 : 4.7810s
oneAtATimeHash : 3.5470s
alphaNumHash : 2.2500s
FNVHash : 2.1870s
Jenkins lookup3 : 1.2650s
SuperFastHash : 1.2970s
MurmurHash : 0.9060s
-tanjent
//-------------------------------------------------------------------
unsigned int MurmurHash ( const unsigned char * data, int len, unsigned int h )
{
const unsigned int m = 0x7fd652ad;
const int r = 16;
h += 0xdeadbeef;
while(len >= 4)
{
h += *(unsigned int *)data;
h *= m;
h ^= h >> r;
data += 4;
len -= 4;
}
switch(len)
{
case 3:
h += data[2] << 16;
case 2:
h += data[1] << 8;
case 1:
h += data[0];
h *= m;
h ^= h >> r;
};
h *= m;
h ^= h >> 10;
h *= m;
h ^= h >> 17;
return h;
}
Why
because we liked the name murmur
When
MurmurHash3 was created by Austin Appleby and completed on April 3, 2011.
How
Ok I read his blog and it sounded like he wanted a hash function in 10 instructions of asembaly
so how the need for speed made a function thats fast.
maybe that is the why also
Guide to how to use this package
apt install nodejs npm
mkdir -p myapp
cd myapp
npm init -y
npm install endpoint-murmurhash3
mkdir -p src
nano src/script.js
node src/script.js
Original Readme Of MurMurhash TS project
your milage may very
git clone this repo
cd murmurHash3
npm install
npm run build
nice blog on mmh3
Original Readme
v1 deploy
https://ad214310.murmurhash3.pages.dev/dist/cjs/index.js
https://ad214310.murmurhash3.pages.dev/dist/esm/index.js
MurmurHash3 (TS)
Usage
> const murmurHash3 = require('murmurhash3.js');
// Return a 32bit hash as an unsigned integer:
> murmurHash3.x86.hash32("I will not buy this record, it is scratched.");
2832214938
// Return a 128bit hash as a hexadecimal string:
> murmurHash3.x86.hash128("I will not buy this tobacconist's, it is scratched.");
'9b5b7ba2ef3f7866889adeaf00f3f98e'
> murmurHash3.x64.hash128("I will not buy this tobacconist's, it is scratched.");
'd30654abbd8227e367d73523f0079673'
// Specify a starting seed (defaults to 0x0):
> murmurHash3.x86.hash32("My hovercraft is full of eels.", 25);
2520298415
// Hash buffers:
> const buf = new Uint8Array(Array.from({ length: 256}, (_, i) => i));
> murmurHash3.x86.hash32(buf);
3825864278
> murmurHash3.x86.hash128(buf);
Uint8Array [44, 86, 200, 143, 219, 69, 3, 223, 211, 82, 178, 26, 73, 76, 162, 192];
// Progressively hash streams of data as either buffers or strings:
> const state32 = murmurHash3.x86.hash32(buf.slice(0, 127), 0x0, false);
> murmurHash3.x86.hash32(buf.slice(127), state32, true);
3825864278
> const state128 = murmurHash3.x86.hash128(buf.slice(0, 127), 0x0, false);
> murmurHash3.x86.hash128(buf.slice(127), state128, true);
Uint8Array [44, 86, 200, 143, 219, 69, 3, 223, 211, 82, 178, 26, 73, 76, 162, 192];
API
murmurHash3 = {
strToBuf: (str: string = ""
):
Uint8Array,
bufToHex
:
(buf: Uint8Array = new Uint8Array(0)
):
string,
x86
:
{
hash32: (
buf: Uint8Array | string = new Uint8Array(0),
state
:
U32 | X86Hash32State = 0x0,
finalize
:
boolean = true,
):
U32 | X86Hash32State,
hash128
:
(
buf: Uint8Array | string = new Uint8Array(0),
state
:
U32 | X86Hash128State = 0x0,
finalize
:
boolean = true
):
Uint8Array | string | X86Hash128State,
}
,
x64: {
hash128: (
buf: Uint8Array | string = new Uint8Array(0),
state
:
U32 | X64Hash128State = 0x0,
finalize
:
boolean = true
):
Uint8Array | string | X64Hash128State,
}
,
}
- - -
Requires [`TextEncoder`](https://caniuse.com/#feat=textencoder),
[Typed Arrays & `DataView`](https://caniuse.com/#feat=typedarrays), and additional
[es6/es2015](https://caniuse.com/#feat=es6) features; bring your own transpiler and
polyfills to target the past.