diff -r 000000000000 -r 6474c204b198 js/src/parjs-benchmarks/seedrandom.js
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/parjs-benchmarks/seedrandom.js Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,299 @@
+// seedrandom.js version 2.1.
+// Author: David Bau
+// Date: 2013 Mar 16
+//
+// Defines a method Math.seedrandom() that, when called, substitutes
+// an explicitly seeded RC4-based algorithm for Math.random(). Also
+// supports automatic seeding from local or network sources of entropy.
+//
+// http://davidbau.com/encode/seedrandom.js
+// http://davidbau.com/encode/seedrandom-min.js
+//
+// Usage:
+//
+//
+//
+// Math.seedrandom('yay.'); Sets Math.random to a function that is
+// initialized using the given explicit seed.
+//
+// Math.seedrandom(); Sets Math.random to a function that is
+// seeded using the current time, dom state,
+// and other accumulated local entropy.
+// The generated seed string is returned.
+//
+// Math.seedrandom('yowza.', true);
+// Seeds using the given explicit seed mixed
+// together with accumulated entropy.
+//
+// Seeds using urandom bits from a server.
+//
+// More advanced examples:
+//
+// Math.seedrandom("hello."); // Use "hello." as the seed.
+// document.write(Math.random()); // Always 0.9282578795792454
+// document.write(Math.random()); // Always 0.3752569768646784
+// var rng1 = Math.random; // Remember the current prng.
+//
+// var autoseed = Math.seedrandom(); // New prng with an automatic seed.
+// document.write(Math.random()); // Pretty much unpredictable x.
+//
+// Math.random = rng1; // Continue "hello." prng sequence.
+// document.write(Math.random()); // Always 0.7316977468919549
+//
+// Math.seedrandom(autoseed); // Restart at the previous seed.
+// document.write(Math.random()); // Repeat the 'unpredictable' x.
+//
+// function reseed(event, count) { // Define a custom entropy collector.
+// var t = [];
+// function w(e) {
+// t.push([e.pageX, e.pageY, +new Date]);
+// if (t.length < count) { return; }
+// document.removeEventListener(event, w);
+// Math.seedrandom(t, true); // Mix in any previous entropy.
+// }
+// document.addEventListener(event, w);
+// }
+// reseed('mousemove', 100); // Reseed after 100 mouse moves.
+//
+// Version notes:
+//
+// The random number sequence is the same as version 1.0 for string seeds.
+// Version 2.0 changed the sequence for non-string seeds.
+// Version 2.1 speeds seeding and uses window.crypto to autoseed if present.
+//
+// The standard ARC4 key scheduler cycles short keys, which means that
+// seedrandom('ab') is equivalent to seedrandom('abab') and 'ababab'.
+// Therefore it is a good idea to add a terminator to avoid trivial
+// equivalences on short string seeds, e.g., Math.seedrandom(str + '\0').
+// Starting with version 2.0, a terminator is added automatically for
+// non-string seeds, so seeding with the number 111 is the same as seeding
+// with '111\0'.
+//
+// When seedrandom() is called with zero args, it uses a seed
+// drawn from the browser crypto object if present. If there is no
+// crypto support, seedrandom() uses the current time, the native rng,
+// and a walk of several DOM objects to collect a few bits of entropy.
+//
+// Each time the one- or two-argument forms of seedrandom are called,
+// entropy from the passed seed is accumulated in a pool to help generate
+// future seeds for the zero- and two-argument forms of seedrandom.
+//
+// On speed - This javascript implementation of Math.random() is about
+// 3-10x slower than the built-in Math.random() because it is not native
+// code, but that is typically fast enough. Some details (timings on
+// Chrome 25 on a 2010 vintage macbook):
+//
+// seeded Math.random() - avg less than 0.0002 milliseconds per call
+// seedrandom('explicit.') - avg less than 0.2 milliseconds per call
+// seedrandom('explicit.', true) - avg less than 0.2 milliseconds per call
+// seedrandom() with crypto - avg less than 0.2 milliseconds per call
+// seedrandom() without crypto - avg about 12 milliseconds per call
+//
+// On a 2012 windows 7 1.5ghz i5 laptop, Chrome, Firefox 19, IE 10, and
+// Opera have similarly fast timings. Slowest numbers are on Opera, with
+// about 0.0005 milliseconds per seeded Math.random() and 15 milliseconds
+// for autoseeding.
+//
+// LICENSE (BSD):
+//
+// Copyright 2013 David Bau, all rights reserved.
+//
+// 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.
+//
+// 3. Neither the name of this module 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.
+//
+/**
+ * All code is in an anonymous closure to keep the global namespace clean.
+ */
+(function (
+ global, pool, math, width, chunks, digits) {
+
+//
+// The following constants are related to IEEE 754 limits.
+//
+var startdenom = math.pow(width, chunks),
+ significance = math.pow(2, digits),
+ overflow = significance * 2,
+ mask = width - 1;
+
+//
+// seedrandom()
+// This is the seedrandom function described above.
+//
+math['seedrandom'] = function(seed, use_entropy) {
+ var key = [];
+
+ // Flatten the seed string or build one from local entropy if needed.
+ var shortseed = mixkey(flatten(
+ use_entropy ? [seed, tostring(pool)] :
+ 0 in arguments ? seed : autoseed(), 3), key);
+
+ // Use the seed to initialize an ARC4 generator.
+ var arc4 = new ARC4(key);
+
+ // Mix the randomness into accumulated entropy.
+ mixkey(tostring(arc4.S), pool);
+
+ // Override Math.random
+
+ // This function returns a random double in [0, 1) that contains
+ // randomness in every bit of the mantissa of the IEEE 754 value.
+
+ math['random'] = function() { // Closure to return a random double:
+ var n = arc4.g(chunks), // Start with a numerator n < 2 ^ 48
+ d = startdenom, // and denominator d = 2 ^ 48.
+ x = 0; // and no 'extra last byte'.
+ while (n < significance) { // Fill up all significant digits by
+ n = (n + x) * width; // shifting numerator and
+ d *= width; // denominator and generating a
+ x = arc4.g(1); // new least-significant-byte.
+ }
+ while (n >= overflow) { // To avoid rounding up, before adding
+ n /= 2; // last byte, shift everything
+ d /= 2; // right using integer math until
+ x >>>= 1; // we have exactly the desired bits.
+ }
+ return (n + x) / d; // Form the number within [0, 1).
+ };
+
+ // Return the seed that was used
+ return shortseed;
+};
+
+//
+// ARC4
+//
+// An ARC4 implementation. The constructor takes a key in the form of
+// an array of at most (width) integers that should be 0 <= x < (width).
+//
+// The g(count) method returns a pseudorandom integer that concatenates
+// the next (count) outputs from ARC4. Its return value is a number x
+// that is in the range 0 <= x < (width ^ count).
+//
+/** @constructor */
+function ARC4(key) {
+ var t, keylen = key.length,
+ me = this, i = 0, j = me.i = me.j = 0, s = me.S = [];
+
+ // The empty key [] is treated as [0].
+ if (!keylen) { key = [keylen++]; }
+
+ // Set up S using the standard key scheduling algorithm.
+ while (i < width) {
+ s[i] = i++;
+ }
+ for (i = 0; i < width; i++) {
+ s[i] = s[j = mask & (j + key[i % keylen] + (t = s[i]))];
+ s[j] = t;
+ }
+
+ // The "g" method returns the next (count) outputs as one number.
+ (me.g = function(count) {
+ // Using instance members instead of closure state nearly doubles speed.
+ var t, r = 0,
+ i = me.i, j = me.j, s = me.S;
+ while (count--) {
+ t = s[i = mask & (i + 1)];
+ r = r * width + s[mask & ((s[i] = s[j = mask & (j + t)]) + (s[j] = t))];
+ }
+ me.i = i; me.j = j;
+ return r;
+ // For robust unpredictability discard an initial batch of values.
+ // See http://www.rsa.com/rsalabs/node.asp?id=2009
+ })(width);
+}
+
+//
+// flatten()
+// Converts an object tree to nested arrays of strings.
+//
+function flatten(obj, depth) {
+ var result = [], typ = (typeof obj)[0], prop;
+ if (depth && typ == 'o') {
+ for (prop in obj) {
+ if (obj.hasOwnProperty(prop)) {
+ try { result.push(flatten(obj[prop], depth - 1)); } catch (e) {}
+ }
+ }
+ }
+ return (result.length ? result : typ == 's' ? obj : obj + '\0');
+}
+
+//
+// mixkey()
+// Mixes a string seed into a key that is an array of integers, and
+// returns a shortened string seed that is equivalent to the result key.
+//
+function mixkey(seed, key) {
+ var stringseed = seed + '', smear, j = 0;
+ while (j < stringseed.length) {
+ key[mask & j] =
+ mask & ((smear ^= key[mask & j] * 19) + stringseed.charCodeAt(j++));
+ }
+ return tostring(key);
+}
+
+//
+// autoseed()
+// Returns an object for autoseeding, using window.crypto if available.
+//
+/** @param {Uint8Array=} seed */
+function autoseed(seed) {
+ try {
+ global.crypto.getRandomValues(seed = new Uint8Array(width));
+ return tostring(seed);
+ } catch (e) {
+ return [+new Date, global.document, global.history,
+ global.navigator, global.screen, tostring(pool)];
+ }
+}
+
+//
+// tostring()
+// Converts an array of charcodes to a string
+//
+function tostring(a) {
+ return String.fromCharCode.apply(0, a);
+}
+
+//
+// When seedrandom.js is loaded, we immediately mix a few bits
+// from the built-in RNG into the entropy pool. Because we do
+// not want to intefere with determinstic PRNG state later,
+// seedrandom will not call math.random on its own again after
+// initialization.
+//
+mixkey(math.random(), pool);
+
+// End anonymous scope, and pass initial values.
+})(
+ this, // global window object
+ [], // pool: entropy pool starts empty
+ Math, // math: package containing random, pow, and seedrandom
+ 256, // width: each RC4 output is 0 <= x < 256
+ 6, // chunks: at least six RC4 outputs for each double
+ 52 // digits: there are 52 significant digits in a double
+);