Method _readContextHash

lib/FileSystemInfo.js:4058–4124

* @private * @type {Processor<string, ContextHash>}

(path, callback)

	 * @type {Processor<string, ContextHash>}
	 */
	_readContextHash(path, callback) {
		this._readContext(
			{
				path,
				fromImmutablePath: () => /** @type {ContextHash | ""} */ (""),
				fromManagedItem: (info) => info || "",
				fromSymlink: (file, target, callback) => {
					callback(
						null,
						/** @type {ContextHash} */
						({
							hash: target,
							symlinks: new Set([target])
						})
					);
				},
				fromFile: (file, stat, callback) =>
					this.getFileHash(file, (err, hash) => {
						callback(err, hash || "");
					}),
				fromDirectory: (directory, stat, callback) => {
					this.contextHashQueue.increaseParallelism();
					this._getUnresolvedContextHash(directory, (err, hash) => {
						this.contextHashQueue.decreaseParallelism();
						callback(err, hash || "");
					});
				},
				/**
				 * Returns reduced hash.
				 * @param {string[]} files files
				 * @param {(string | ContextHash)[]} fileHashes hashes
				 * @returns {ContextHash} reduced hash
				 */
				reduce: (files, fileHashes) => {
					/** @type {undefined | Symlinks} */
					let symlinks;
					const hash = createHash(this._hashFunction);

					for (const file of files) hash.update(file);
					for (const entry of fileHashes) {
						if (typeof entry === "string") {
							hash.update(entry);
						} else {
							hash.update(entry.hash);
							if (entry.symlinks) {
								if (symlinks === undefined) symlinks = new Set();
								addAll(entry.symlinks, symlinks);
							}
						}
					}

					/** @type {ContextHash} */
					const result = {
						hash: hash.digest("hex")
					};
					if (symlinks) result.symlinks = symlinks;
					return result;
				}