You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
33 lines
888 B
TypeScript
33 lines
888 B
TypeScript
import * as crypto from 'crypto';
|
|
|
|
const hashes = Object.create(null);
|
|
|
|
//TODO shorter?
|
|
const hash_length = 12;
|
|
|
|
export function safeBase64Hash(input: string) {
|
|
if (hashes[input]) {
|
|
return hashes[input];
|
|
}
|
|
//TODO if performance really matters, use a faster one like xx-hash etc.
|
|
// should be evenly distributed because short input length and similarities in paths could cause collisions otherwise
|
|
// OR DON'T USE A HASH AT ALL, what about a simple counter?
|
|
const md5 = crypto.createHash('md5');
|
|
md5.update(input);
|
|
const hash = toSafe(md5.digest('base64')).slice(0, hash_length);
|
|
hashes[input] = hash;
|
|
return hash;
|
|
}
|
|
|
|
const replacements: { [key: string]: string } = {
|
|
'+': '-',
|
|
'/': '_',
|
|
'=': ''
|
|
};
|
|
|
|
const replaceRE = new RegExp(`[${Object.keys(replacements).join('')}]`, 'g');
|
|
|
|
function toSafe(base64: string) {
|
|
return base64.replace(replaceRE, (x) => replacements[x]);
|
|
}
|