Big Change Update

uBlock0.chromium/lib/lz4/lz4-block-codec-wasm.js

@@ -0,0 +1,195 @@
+/*******************************************************************************
+
+    lz4-block-codec-wasm.js
+        A javascript wrapper around a WebAssembly implementation of
+        LZ4 block format codec.
+    Copyright (C) 2018 Raymond Hill
+
+    BSD-2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions are
+    met:
+
+    1. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    2. Redistributions in binary form must reproduce the above
+    copyright notice, this list of conditions and the following disclaimer
+    in the documentation and/or other materials provided with the
+    distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+    Home: https://github.com/gorhill/lz4-wasm
+
+    I used the same license as the one picked by creator of LZ4 out of respect
+    for his creation, see https://lz4.github.io/lz4/
+
+*/
+
+/* global WebAssembly */
+
+'use strict';
+
+/******************************************************************************/
+
+(function(context) {                    // >>>> Start of private namespace
+
+/******************************************************************************/
+
+const wd = (function() {
+    let url = document.currentScript.src;
+    let match = /[^\/]+$/.exec(url);
+    return match !== null ?
+        url.slice(0, match.index) :
+        '';
+})();
+
+const growMemoryTo = function(wasmInstance, byteLength) {
+    let lz4api = wasmInstance.exports;
+    let neededByteLength = lz4api.getLinearMemoryOffset() + byteLength;
+    let pageCountBefore = lz4api.memory.buffer.byteLength >>> 16;
+    let pageCountAfter = (neededByteLength + 65535) >>> 16;
+    if ( pageCountAfter > pageCountBefore ) {
+        lz4api.memory.grow(pageCountAfter - pageCountBefore);
+    }
+    return lz4api.memory.buffer;
+};
+
+const encodeBlock = function(wasmInstance, inputArray, outputOffset) {
+    let lz4api = wasmInstance.exports;
+    let mem0 = lz4api.getLinearMemoryOffset();
+    let hashTableSize = 65536 * 4;
+    let inputSize = inputArray.byteLength;
+    if ( inputSize >= 0x7E000000 ) { throw new RangeError(); }
+    let memSize =
+        hashTableSize +
+        inputSize +
+        outputOffset + lz4api.lz4BlockEncodeBound(inputSize);
+    let memBuffer = growMemoryTo(wasmInstance, memSize);
+    let hashTable = new Int32Array(memBuffer, mem0, 65536);
+    hashTable.fill(-65536, 0, 65536);
+    let inputMem = new Uint8Array(memBuffer, mem0 + hashTableSize, inputSize);
+    inputMem.set(inputArray);
+    let outputSize = lz4api.lz4BlockEncode(
+        mem0 + hashTableSize,
+        inputSize,
+        mem0 + hashTableSize + inputSize + outputOffset
+    );
+    if ( outputSize === 0 ) { return; }
+    let outputArray = new Uint8Array(
+        memBuffer,
+        mem0 + hashTableSize + inputSize,
+        outputOffset + outputSize
+    );
+    return outputArray;
+};
+
+const decodeBlock = function(wasmInstance, inputArray, inputOffset, outputSize) {
+    let inputSize = inputArray.byteLength;
+    let lz4api = wasmInstance.exports;
+    let mem0 = lz4api.getLinearMemoryOffset();
+    let memSize = inputSize + outputSize;
+    let memBuffer = growMemoryTo(wasmInstance, memSize);
+    let inputArea = new Uint8Array(memBuffer, mem0, inputSize);
+    inputArea.set(inputArray);
+    outputSize = lz4api.lz4BlockDecode(
+        mem0 + inputOffset,
+        inputSize - inputOffset,
+        mem0 + inputSize
+    );
+    if ( outputSize === 0 ) { return; }
+    return new Uint8Array(memBuffer, mem0 + inputSize, outputSize);
+};
+
+/******************************************************************************/
+
+context.LZ4BlockWASM = function() {
+    this.lz4wasmInstance = undefined;
+};
+
+context.LZ4BlockWASM.prototype = {
+    flavor: 'wasm',
+
+    init: function() {
+        if (
+            typeof WebAssembly !== 'object' ||
+            typeof WebAssembly.instantiateStreaming !== 'function'
+        ) {
+            this.lz4wasmInstance = null;
+        }
+        if ( this.lz4wasmInstance === null ) {
+            return Promise.resolve(false);
+        }
+        if ( this.lz4wasmInstance instanceof WebAssembly.Instance ) {
+            return Promise.resolve(true);
+        }
+        if ( this.lz4wasmInstance === undefined ) {
+            this.lz4wasmInstance = fetch(
+                wd + 'lz4-block-codec.wasm',
+                { mode: 'same-origin' }
+            ).then(
+                WebAssembly.instantiateStreaming
+            ).then(result => {
+                this.lz4wasmInstance = result && result.instance || null;
+            }).catch(reason => {
+                this.lz4wasmInstance = null;
+                console.info(reason);
+            }).then(( ) =>
+                this.lz4wasmInstance !== null
+            );
+        }
+        return this.lz4wasmInstance;
+    },
+
+    reset: function() {
+        this.lz4wasmInstance = undefined;
+    },
+
+    bytesInUse: function() {
+        return this.lz4wasmInstance instanceof WebAssembly.Instance ?
+            this.lz4wasmInstance.exports.memory.buffer.byteLength :
+            0;
+    },
+
+    encodeBlock: function(input, outputOffset) {
+        if ( this.lz4wasmInstance instanceof WebAssembly.Instance === false ) {
+            throw new Error('LZ4BlockWASM: not initialized');
+        }
+        if ( input instanceof ArrayBuffer ) {
+            input = new Uint8Array(input);
+        } else if ( input instanceof Uint8Array === false ) {
+            throw new TypeError();
+        }
+        return encodeBlock(this.lz4wasmInstance, input, outputOffset);
+    },
+
+    decodeBlock: function(input, inputOffset, outputSize) {
+        if ( this.lz4wasmInstance instanceof WebAssembly.Instance === false ) {
+            throw new Error('LZ4BlockWASM: not initialized');
+        }
+        if ( input instanceof ArrayBuffer ) {
+            input = new Uint8Array(input);
+        } else if ( input instanceof Uint8Array === false ) {
+            throw new TypeError();
+        }
+        return decodeBlock(this.lz4wasmInstance, input, inputOffset, outputSize);
+    }
+};
+
+/******************************************************************************/
+
+})(this || self);                       // <<<< End of private namespace
+
+/******************************************************************************/