webpack/lib/util/hash/BatchedHash.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

const Hash = require("../Hash");
const MAX_SHORT_STRING = require("./wasm-hash").MAX_SHORT_STRING;

class BatchedHash extends Hash {
	constructor(hash) {
		super();
		this.string = undefined;
		this.encoding = undefined;
		this.hash = hash;
	}

	/**
	 * Update hash {@link https://nodejs.org/api/crypto.html#crypto_hash_update_data_inputencoding}
	 * @param {string|Buffer} data data
	 * @param {string=} inputEncoding data encoding
	 * @returns {this} updated hash
	 */
	update(data, inputEncoding) {
		if (this.string !== undefined) {
			if (
				typeof data === "string" &&
				inputEncoding === this.encoding &&
				this.string.length + data.length < MAX_SHORT_STRING
			) {
				this.string += data;
				return this;
			}
			this.hash.update(this.string, this.encoding);
			this.string = undefined;
		}
		if (typeof data === "string") {
			if (
				data.length < MAX_SHORT_STRING &&
				// base64 encoding is not valid since it may contain padding chars
				(!inputEncoding || !inputEncoding.startsWith("ba"))
			) {
				this.string = data;
				this.encoding = inputEncoding;
			} else {
				this.hash.update(data, inputEncoding);
			}
		} else {
			this.hash.update(data);
		}
		return this;
	}

	/**
	 * Calculates the digest {@link https://nodejs.org/api/crypto.html#crypto_hash_digest_encoding}
	 * @param {string=} encoding encoding of the return value
	 * @returns {string|Buffer} digest
	 */
	digest(encoding) {
		if (this.string !== undefined) {
			this.hash.update(this.string, this.encoding);
		}
		return this.hash.digest(encoding);
	}
}

module.exports = BatchedHash;