1 files changed, 92 insertions, 0 deletions
diff --git a/node_modules/webpack/lib/util/createHash.js b/node_modules/webpack/lib/util/createHash.js
new file mode 100644
index 00000000..bb5062c6
--- /dev/null
+++ b/node_modules/webpack/lib/util/createHash.js
@@ -0,0 +1,92 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+"use strict";
+
+/** @typedef {{new(): Hash}} HashConstructor */
+/**
+ * @typedef {Object} Hash
+ * @property {function(string|Buffer, string=): Hash} update
+ * @property {function(string): string} digest
+ */
+
+const BULK_SIZE = 1000;
+
+/**
+ * @implements {Hash}
+ */
+class BulkUpdateDecorator {
+	constructor(hash) {
+		this.hash = hash;
+		this.buffer = "";
+	}
+
+	update(data, inputEncoding) {
+		if (
+			inputEncoding !== undefined ||
+			typeof data !== "string" ||
+			data.length > BULK_SIZE
+		) {
+			if (this.buffer.length > 0) {
+				this.hash.update(this.buffer);
+				this.buffer = "";
+			}
+			this.hash.update(data, inputEncoding);
+		} else {
+			this.buffer += data;
+			if (this.buffer.length > BULK_SIZE) {
+				this.hash.update(this.buffer);
+				this.buffer = "";
+			}
+		}
+		return this;
+	}
+
+	digest(encoding) {
+		if (this.buffer.length > 0) {
+			this.hash.update(this.buffer);
+		}
+		var digestResult = this.hash.digest(encoding);
+		return typeof digestResult === "string"
+			? digestResult
+			: digestResult.toString();
+	}
+}
+
+/* istanbul ignore next */
+class DebugHash {
+	constructor() {
+		this.string = "";
+	}
+
+	update(data, inputEncoding) {
+		if (typeof data !== "string") data = data.toString("utf-8");
+		this.string += data;
+		return this;
+	}
+
+	digest(encoding) {
+		return this.string.replace(/[^a-z0-9]+/gi, m =>
+			Buffer.from(m).toString("hex")
+		);
+	}
+}
+
+/**
+ * Creates a hash by name or function
+ * @param {string | HashConstructor} algorithm the algorithm name or a constructor creating a hash
+ * @returns {Hash} the hash
+ */
+module.exports = algorithm => {
+	if (typeof algorithm === "function") {
+		return new BulkUpdateDecorator(new algorithm());
+	}
+	switch (algorithm) {
+		// TODO add non-cryptographic algorithm here
+		case "debug":
+			return new DebugHash();
+		default:
+			return new BulkUpdateDecorator(require("crypto").createHash(algorithm));
+	}
+};