Urara-Blog/node_modules/.pnpm-store/v3/files/0c/aa022bf67cdec4a39092c6b22d949755eefbc3bf9222ac1d62d9b88a7366385af57da9d6f2cc2457c5929bc36c2f3541d37821faf81db3328a2ea488f626b8
2022-08-14 01:14:53 +08:00

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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]);
}