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node_modules/webpack/lib/util/hash/wasm-hash.js

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+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+// 65536 is the size of a wasm memory page
+// 64 is the maximum chunk size for every possible wasm hash implementation
+// 4 is the maximum number of bytes per char for string encoding (max is utf-8)
+// ~3 makes sure that it's always a block of 4 chars, so avoid partially encoded bytes for base64
+const MAX_SHORT_STRING = Math.floor((65536 - 64) / 4) & ~3;
+
+class WasmHash {
+	/**
+	 * @param {WebAssembly.Instance} instance wasm instance
+	 * @param {WebAssembly.Instance[]} instancesPool pool of instances
+	 * @param {number} chunkSize size of data chunks passed to wasm
+	 * @param {number} digestSize size of digest returned by wasm
+	 */
+	constructor(instance, instancesPool, chunkSize, digestSize) {
+		const exports = /** @type {any} */ (instance.exports);
+		exports.init();
+		this.exports = exports;
+		this.mem = Buffer.from(exports.memory.buffer, 0, 65536);
+		this.buffered = 0;
+		this.instancesPool = instancesPool;
+		this.chunkSize = chunkSize;
+		this.digestSize = digestSize;
+	}
+
+	reset() {
+		this.buffered = 0;
+		this.exports.init();
+	}
+
+	/**
+	 * @param {Buffer | string} data data
+	 * @param {BufferEncoding=} encoding encoding
+	 * @returns {this} itself
+	 */
+	update(data, encoding) {
+		if (typeof data === "string") {
+			while (data.length > MAX_SHORT_STRING) {
+				this._updateWithShortString(data.slice(0, MAX_SHORT_STRING), encoding);
+				data = data.slice(MAX_SHORT_STRING);
+			}
+			this._updateWithShortString(data, encoding);
+			return this;
+		}
+		this._updateWithBuffer(data);
+		return this;
+	}
+
+	/**
+	 * @param {string} data data
+	 * @param {BufferEncoding=} encoding encoding
+	 * @returns {void}
+	 */
+	_updateWithShortString(data, encoding) {
+		const { exports, buffered, mem, chunkSize } = this;
+		let endPos;
+		if (data.length < 70) {
+			if (!encoding || encoding === "utf-8" || encoding === "utf8") {
+				endPos = buffered;
+				for (let i = 0; i < data.length; i++) {
+					const cc = data.charCodeAt(i);
+					if (cc < 0x80) mem[endPos++] = cc;
+					else if (cc < 0x800) {
+						mem[endPos] = (cc >> 6) | 0xc0;
+						mem[endPos + 1] = (cc & 0x3f) | 0x80;
+						endPos += 2;
+					} else {
+						// bail-out for weird chars
+						endPos += mem.write(data.slice(i), endPos, encoding);
+						break;
+					}
+				}
+			} else if (encoding === "latin1") {
+				endPos = buffered;
+				for (let i = 0; i < data.length; i++) {
+					const cc = data.charCodeAt(i);
+					mem[endPos++] = cc;
+				}
+			} else {
+				endPos = buffered + mem.write(data, buffered, encoding);
+			}
+		} else {
+			endPos = buffered + mem.write(data, buffered, encoding);
+		}
+		if (endPos < chunkSize) {
+			this.buffered = endPos;
+		} else {
+			const l = endPos & ~(this.chunkSize - 1);
+			exports.update(l);
+			const newBuffered = endPos - l;
+			this.buffered = newBuffered;
+			if (newBuffered > 0) mem.copyWithin(0, l, endPos);
+		}
+	}
+
+	/**
+	 * @param {Buffer} data data
+	 * @returns {void}
+	 */
+	_updateWithBuffer(data) {
+		const { exports, buffered, mem } = this;
+		const length = data.length;
+		if (buffered + length < this.chunkSize) {
+			data.copy(mem, buffered, 0, length);
+			this.buffered += length;
+		} else {
+			const l = (buffered + length) & ~(this.chunkSize - 1);
+			if (l > 65536) {
+				let i = 65536 - buffered;
+				data.copy(mem, buffered, 0, i);
+				exports.update(65536);
+				const stop = l - buffered - 65536;
+				while (i < stop) {
+					data.copy(mem, 0, i, i + 65536);
+					exports.update(65536);
+					i += 65536;
+				}
+				data.copy(mem, 0, i, l - buffered);
+				exports.update(l - buffered - i);
+			} else {
+				data.copy(mem, buffered, 0, l - buffered);
+				exports.update(l);
+			}
+			const newBuffered = length + buffered - l;
+			this.buffered = newBuffered;
+			if (newBuffered > 0) data.copy(mem, 0, length - newBuffered, length);
+		}
+	}
+
+	digest(type) {
+		const { exports, buffered, mem, digestSize } = this;
+		exports.final(buffered);
+		this.instancesPool.push(this);
+		const hex = mem.toString("latin1", 0, digestSize);
+		if (type === "hex") return hex;
+		if (type === "binary" || !type) return Buffer.from(hex, "hex");
+		return Buffer.from(hex, "hex").toString(type);
+	}
+}
+
+const create = (wasmModule, instancesPool, chunkSize, digestSize) => {
+	if (instancesPool.length > 0) {
+		const old = instancesPool.pop();
+		old.reset();
+		return old;
+	} else {
+		return new WasmHash(
+			new WebAssembly.Instance(wasmModule),
+			instancesPool,
+			chunkSize,
+			digestSize
+		);
+	}
+};
+
+module.exports = create;
+module.exports.MAX_SHORT_STRING = MAX_SHORT_STRING;