enigma-bbs/core/fnv1a.js

53 lines
1.2 KiB
JavaScript

/* jslint node: true */
'use strict';
const { Errors } = require('./enig_error.js');
const _ = require('lodash');
// FNV-1a based on work here: https://github.com/wiedi/node-fnv
module.exports = class FNV1a {
constructor(data) {
this.hash = 0x811c9dc5;
if(!_.isUndefined(data)) {
this.update(data);
}
}
update(data) {
if(_.isNumber(data)) {
data = data.toString();
}
if(_.isString(data)) {
data = Buffer.from(data);
}
if(!Buffer.isBuffer(data)) {
throw Errors.Invalid('data must be String or Buffer!');
}
for(let b of data) {
this.hash = this.hash ^ b;
this.hash +=
(this.hash << 24) + (this.hash << 8) + (this.hash << 7) +
(this.hash << 4) + (this.hash << 1);
}
return this;
}
digest(encoding) {
encoding = encoding || 'binary';
const buf = Buffer.alloc(4);
buf.writeInt32BE(this.hash & 0xffffffff, 0);
return buf.toString(encoding);
}
get value() {
return this.hash & 0xffffffff;
}
};