You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

59 lines
1.2 KiB

'use strict';
function pad (hash, len) {
while (hash.length < len) {
hash = '0' + hash;
}
return hash;
}
function fold (hash, text) {
var i;
var chr;
var len;
if (text.length === 0) {
return hash;
}
for (i = 0, len = text.length; i < len; i++) {
chr = text.charCodeAt(i);
hash = ((hash << 5) - hash) + chr;
hash |= 0;
}
return hash < 0 ? hash * -2 : hash;
}
function foldObject (hash, o, seen) {
return Object.keys(o).sort().reduce(foldKey, hash);
function foldKey (hash, key) {
return foldValue(hash, o[key], key, seen);
}
}
function foldValue (input, value, key, seen) {
var hash = fold(fold(fold(input, key), toString(value)), typeof value);
if (value === null) {
return fold(hash, 'null');
}
if (value === undefined) {
return fold(hash, 'undefined');
}
if (typeof value === 'object') {
if (seen.indexOf(value) !== -1) {
return fold(hash, '[Circular]' + key);
}
seen.push(value);
return foldObject(hash, value, seen);
}
return fold(hash, value.toString());
}
function toString (o) {
return Object.prototype.toString.call(o);
}
function sum (o) {
return pad(foldValue(0, o, '', []).toString(16), 8);
}
module.exports = sum;