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/**
* Jenkins hash implementation which yeilds 32-bit and 64-bit hashes.
*
* See https://github.com/vkandy/jenkins-hash-js
*/
class Jenkins {
constructor() {
/**
* Default first initial seed.
*/
this.pc = 0;
/**
* Default second initial seed.
*/
this.pb = 0;
}
// --------------------------------------------------
// Public access
// --------------------------------------------------
/**
* Computes and returns 32-bit hash of given message.
*/
hash32(msg) {
var h = lookup3(msg, this.pc, this.pb);
return (h.c).toString(16);
}
hash32ToBinary(msg) {
var h = lookup3(msg, this.pc, this.pb);
return (h.c).toString(2);
}
/**
* Computes and returns 32-bit hash of given message.
*/
hash64(msg) {
var h = lookup3(msg, this.pc, this.pb);
return (h.b).toString(16) + (h.c).toString(16);
}
hash64ToBinary(msg) {
var h = lookup3(msg, this.pc, this.pb);
return (h.b).toString(2) + (h.c).toString(2);
}
}
/**
* Implementation of lookup3 algorithm.
*/
function lookup3(k, pc, pb) {
var length = k.length;
var a, b, c;
a = b = c = 0xdeadbeef + length + pc;
c += pb;
var offset = 0;
while (length > 12) {
a += k.charCodeAt(offset + 0);
a += k.charCodeAt(offset + 1) << 8;
a += k.charCodeAt(offset + 2) << 16;
a += k.charCodeAt(offset + 3) << 24;
b += k.charCodeAt(offset + 4);
b += k.charCodeAt(offset + 5) << 8;
b += k.charCodeAt(offset + 6) << 16;
b += k.charCodeAt(offset + 7) << 24;
c += k.charCodeAt(offset + 8);
c += k.charCodeAt(offset + 9) << 8;
c += k.charCodeAt(offset + 10) << 16;
c += k.charCodeAt(offset + 11) << 24;
mixed = mix(a, b, c);
a = mixed.a;
b = mixed.b;
c = mixed.c;
length -= 12;
offset += 12;
}
switch (length) {
case 12:
c += k.charCodeAt(offset + 11) << 24;
case 11:
c += k.charCodeAt(offset + 10) << 16;
case 10:
c += k.charCodeAt(offset + 9) << 8;
case 9:
c += k.charCodeAt(offset + 8);
case 8:
b += k.charCodeAt(offset + 7) << 24;
case 7:
b += k.charCodeAt(offset + 6) << 16;
case 6:
b += k.charCodeAt(offset + 5) << 8;
case 5:
b += k.charCodeAt(offset + 4);
case 4:
a += k.charCodeAt(offset + 3) << 24;
case 3:
a += k.charCodeAt(offset + 2) << 16;
case 2:
a += k.charCodeAt(offset + 1) << 8;
case 1:
a += k.charCodeAt(offset + 0);
break;
case 0:
return { c: c >>> 0, b: b >>> 0 };
}
// Final mixing of three 32-bit values in to c
mixed = finalMix(a, b, c)
a = mixed.a;
b = mixed.b;
c = mixed.c;
return { c: c >>> 0, b: b >>> 0 };
};
/**
* Mixes 3 32-bit integers reversibly but fast.
*/
function mix(a, b, c) {
a -= c;
a ^= rot(c, 4);
c += b;
b -= a;
b ^= rot(a, 6);
a += c;
c -= b;
c ^= rot(b, 8);
b += a;
a -= c;
a ^= rot(c, 16);
c += b;
b -= a;
b ^= rot(a, 19);
a += c;
c -= b;
c ^= rot(b, 4);
b += a;
return { a: a, b: b, c: c };
};
/**
* Final mixing of 3 32-bit values (a,b,c) into c
*/
function finalMix(a, b, c) {
c ^= b;
c -= rot(b, 14);
a ^= c;
a -= rot(c, 11);
b ^= a;
b -= rot(a, 25);
c ^= b;
c -= rot(b, 16);
a ^= c;
a -= rot(c, 4);
b ^= a;
b -= rot(a, 14);
c ^= b;
c -= rot(b, 24);
return { a: a, b: b, c: c };
};
/**
* Rotate x by k distance.
*/
function rot(x, k) {
return (((x) << (k)) | ((x) >> (32 - (k))));
};
module.exports.Jenkins = Jenkins;
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