source: frontend/node_modules/webpack/lib/util/generateDebugId.js

/*
        MIT License http://www.opensource.org/licenses/mit-license.php
        Author Alexander Akait @alexander-akait
*/

"use strict";

const createHash = require("./createHash");

/**
 * Returns generated debug id.
 * @param {string | Buffer} content content
 * @param {string} file file
 * @returns {string} generated debug id
 */
module.exports = (content, file) => {
        // We need a uuid which is 128 bits so we need 2x 64 bit hashes.
        // The first 64 bits is a hash of the source.
        const sourceHash = createHash("xxhash64").update(content).digest("hex");
        // The next 64 bits is a hash of the filename and sourceHash
        const hash128 = `${sourceHash}${createHash("xxhash64")
                .update(file)
                .update(sourceHash)
                .digest("hex")}`;

        return [
                hash128.slice(0, 8),
                hash128.slice(8, 12),
                `4${hash128.slice(12, 15)}`,
                ((Number.parseInt(hash128.slice(15, 16), 16) & 3) | 8).toString(16) +
                        hash128.slice(17, 20),
                hash128.slice(20, 32)
        ].join("-");
};