uuid v5

uuidv5.js

/*! https://psn.hatenablog.jp/entry/2018/05/28/235801 */
export const generateUUIDv5 = (namespace, data) => {
    const parseUUID = (namespace) => {
        namespace = namespace.replaceAll('-', '');
        const output = new Uint8Array(Math.ceil(namespace.length / 2)); // 16 octets
        for (let i = 0, pointer = 0; i < output.length; i++) {
            output.set([parseInt(namespace.substring(pointer, pointer + 2), 16)], i);
            pointer += 2;
        }
        return output;
    };
    const formatUUID = (hash) => {
        const chars = 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'.split('');
        const hashView = new Uint8Array(hash);
        hashView[6] = (hashView[6] & 0x0f) | 0x50; // version(5) : [6]=xxxx yyyy => 0101 yyyy
        hashView[8] = (hashView[8] & 0x3f) | 0x80; // variant(8) : [8]=xxxx yyyy => 10xx yyyy
        const hashArray = Array.from(hashView).map(b => b.toString(16).padStart(2, '0')).join('').split('');
        for (let i = 0, p = 0; i < chars.length; i++) {
            if (chars[i] === 'x') {
                chars[i] = hashArray[p];
                p++;
            }
        }
        return chars.join('');
    };
    const nsUint8 = parseUUID(namespace);
    const dataUint8 = new TextEncoder().encode(data);
    const digestData = new Uint8Array(nsUint8.length + dataUint8.length);
    digestData.set(nsUint8);
    digestData.set(dataUint8, nsUint8.length);
    return crypto.subtle.digest('SHA-1', digestData).then(hash => {
        return formatUUID(hash);
    });
};