70 lines
1.5 KiB
JavaScript
70 lines
1.5 KiB
JavaScript
'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' || typeof value === 'function') {
|
|
if (seen.indexOf(value) !== -1) {
|
|
return fold(hash, '[Circular]' + key);
|
|
}
|
|
seen.push(value);
|
|
|
|
var objHash = foldObject(hash, value, seen)
|
|
|
|
if (!('valueOf' in value) || typeof value.valueOf !== 'function') {
|
|
return objHash;
|
|
}
|
|
|
|
try {
|
|
return fold(objHash, String(value.valueOf()))
|
|
} catch (err) {
|
|
return fold(objHash, '[valueOf exception]' + (err.stack || err.message))
|
|
}
|
|
}
|
|
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;
|