JezK
Edit File: sparse-array-reverse.js
// Copyright 2008 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * 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. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // 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. /** * @fileoverview Test reverse on small * and large arrays. */ var VERYLARGE = 4000000000; // Nicer for firefox 1.5. Unless you uncomment the following line, // smjs will appear to hang on this file. //var VERYLARGE = 40000; // Simple test of reverse on sparse array. var a = []; a.length = 2000; a[15] = 'a'; a[30] = 'b'; Array.prototype[30] = 'B'; // Should be hidden by a[30]. a[40] = 'c'; a[50] = 'deleted'; delete a[50]; // Should leave no trace once deleted. a[1959] = 'd'; // Swapped with a[40] when reversing. a[1999] = 'e'; assertEquals("abcde", a.join('')); a.reverse(); delete Array.prototype[30]; assertEquals("edcba", a.join('')); var seed = 43; // CONG pseudo random number generator. Used for fuzzing the sparse array // reverse code. function DoOrDont() { seed = (69069 * seed + 1234567) % 0x100000000; return (seed & 0x100000) != 0; } var sizes = [140, 40000, VERYLARGE]; var poses = [0, 10, 50, 69]; // Fuzzing test of reverse on sparse array. for (var iterations = 0; iterations < 20; iterations++) { for (var size_pos = 0; size_pos < sizes.length; size_pos++) { var size = sizes[size_pos]; var to_delete = []; var a; // Make sure we test both array-backed and hash-table backed // arrays. if (size < 1000) { a = new Array(size); } else { a = new Array(); a.length = size; } var expected = ''; var expected_reversed = ''; for (var pos_pos = 0; pos_pos < poses.length; pos_pos++) { var pos = poses[pos_pos]; var letter = String.fromCharCode(97 + pos_pos); if (DoOrDont()) { a[pos] = letter; expected += letter; expected_reversed = letter + expected_reversed; } else if (DoOrDont()) { Array.prototype[pos] = letter; expected += letter; expected_reversed = letter + expected_reversed; to_delete.push(pos); } } var expected2 = ''; var expected_reversed2 = ''; for (var pos_pos = poses.length - 1; pos_pos >= 0; pos_pos--) { var letter = String.fromCharCode(110 + pos_pos); var pos = size - poses[pos_pos] - 1; if (DoOrDont()) { a[pos] = letter; expected2 += letter; expected_reversed2 = letter + expected_reversed2; } else if (DoOrDont()) { Array.prototype[pos] = letter; expected2 += letter; expected_reversed2 = letter + expected_reversed2; to_delete.push(pos); } } assertEquals(expected + expected2, a.join(''), 'join' + size); a.reverse(); while (to_delete.length != 0) { var pos = to_delete.pop(); delete(Array.prototype[pos]); } assertEquals(expected_reversed2 + expected_reversed, a.join(''), 'reverse then join' + size); } }