1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/devtools/jint/v8/deltablue.js Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,1196 @@
1.4 +// Copyright 2008 the V8 project authors. All rights reserved.
1.5 +// Redistribution and use in source and binary forms, with or without
1.6 +// modification, are permitted provided that the following conditions are
1.7 +// met:
1.8 +//
1.9 +// * Redistributions of source code must retain the above copyright
1.10 +// notice, this list of conditions and the following disclaimer.
1.11 +// * Redistributions in binary form must reproduce the above
1.12 +// copyright notice, this list of conditions and the following
1.13 +// disclaimer in the documentation and/or other materials provided
1.14 +// with the distribution.
1.15 +// * Neither the name of Google Inc. nor the names of its
1.16 +// contributors may be used to endorse or promote products derived
1.17 +// from this software without specific prior written permission.
1.18 +//
1.19 +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.20 +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.21 +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1.22 +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1.23 +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1.24 +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1.25 +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1.26 +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1.27 +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.28 +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1.29 +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.30 +
1.31 +
1.32 +// Simple framework for running the benchmark suites and
1.33 +// computing a score based on the timing measurements.
1.34 +
1.35 +
1.36 +// A benchmark has a name (string) and a function that will be run to
1.37 +// do the performance measurement. The optional setup and tearDown
1.38 +// arguments are functions that will be invoked before and after
1.39 +// running the benchmark, but the running time of these functions will
1.40 +// not be accounted for in the benchmark score.
1.41 +function Benchmark(name, run, setup, tearDown) {
1.42 + this.name = name;
1.43 + this.run = run;
1.44 + this.Setup = setup ? setup : function() { };
1.45 + this.TearDown = tearDown ? tearDown : function() { };
1.46 +}
1.47 +
1.48 +
1.49 +// Benchmark results hold the benchmark and the measured time used to
1.50 +// run the benchmark. The benchmark score is computed later once a
1.51 +// full benchmark suite has run to completion.
1.52 +function BenchmarkResult(benchmark, time) {
1.53 + this.benchmark = benchmark;
1.54 + this.time = time;
1.55 +}
1.56 +
1.57 +
1.58 +// Automatically convert results to numbers. Used by the geometric
1.59 +// mean computation.
1.60 +BenchmarkResult.prototype.valueOf = function() {
1.61 + return this.time;
1.62 +}
1.63 +
1.64 +
1.65 +// Suites of benchmarks consist of a name and the set of benchmarks in
1.66 +// addition to the reference timing that the final score will be based
1.67 +// on. This way, all scores are relative to a reference run and higher
1.68 +// scores implies better performance.
1.69 +function BenchmarkSuite(name, reference, benchmarks) {
1.70 + this.name = name;
1.71 + this.reference = reference;
1.72 + this.benchmarks = benchmarks;
1.73 + BenchmarkSuite.suites.push(this);
1.74 +}
1.75 +
1.76 +
1.77 +// Keep track of all declared benchmark suites.
1.78 +BenchmarkSuite.suites = [];
1.79 +
1.80 +
1.81 +// Scores are not comparable across versions. Bump the version if
1.82 +// you're making changes that will affect that scores, e.g. if you add
1.83 +// a new benchmark or change an existing one.
1.84 +BenchmarkSuite.version = '5';
1.85 +
1.86 +
1.87 +// To make the benchmark results predictable, we replace Math.random
1.88 +// with a 100% deterministic alternative.
1.89 +Math.random = (function() {
1.90 + var seed = 49734321;
1.91 + return function() {
1.92 + // Robert Jenkins' 32 bit integer hash function.
1.93 + seed = ((seed + 0x7ed55d16) + (seed << 12)) & 0xffffffff;
1.94 + seed = ((seed ^ 0xc761c23c) ^ (seed >>> 19)) & 0xffffffff;
1.95 + seed = ((seed + 0x165667b1) + (seed << 5)) & 0xffffffff;
1.96 + seed = ((seed + 0xd3a2646c) ^ (seed << 9)) & 0xffffffff;
1.97 + seed = ((seed + 0xfd7046c5) + (seed << 3)) & 0xffffffff;
1.98 + seed = ((seed ^ 0xb55a4f09) ^ (seed >>> 16)) & 0xffffffff;
1.99 + return (seed & 0xfffffff) / 0x10000000;
1.100 + };
1.101 +})();
1.102 +
1.103 +
1.104 +// Runs all registered benchmark suites and optionally yields between
1.105 +// each individual benchmark to avoid running for too long in the
1.106 +// context of browsers. Once done, the final score is reported to the
1.107 +// runner.
1.108 +BenchmarkSuite.RunSuites = function(runner) {
1.109 + var continuation = null;
1.110 + var suites = BenchmarkSuite.suites;
1.111 + var length = suites.length;
1.112 + BenchmarkSuite.scores = [];
1.113 + var index = 0;
1.114 + function RunStep() {
1.115 + while (continuation || index < length) {
1.116 + if (continuation) {
1.117 + continuation = continuation();
1.118 + } else {
1.119 + var suite = suites[index++];
1.120 + if (runner.NotifyStart) runner.NotifyStart(suite.name);
1.121 + continuation = suite.RunStep(runner);
1.122 + }
1.123 + if (continuation && typeof window != 'undefined' && window.setTimeout) {
1.124 + window.setTimeout(RunStep, 25);
1.125 + return;
1.126 + }
1.127 + }
1.128 + if (runner.NotifyScore) {
1.129 + var score = BenchmarkSuite.GeometricMean(BenchmarkSuite.scores);
1.130 + var formatted = BenchmarkSuite.FormatScore(100 * score);
1.131 + runner.NotifyScore(formatted);
1.132 + }
1.133 + }
1.134 + RunStep();
1.135 +}
1.136 +
1.137 +
1.138 +// Counts the total number of registered benchmarks. Useful for
1.139 +// showing progress as a percentage.
1.140 +BenchmarkSuite.CountBenchmarks = function() {
1.141 + var result = 0;
1.142 + var suites = BenchmarkSuite.suites;
1.143 + for (var i = 0; i < suites.length; i++) {
1.144 + result += suites[i].benchmarks.length;
1.145 + }
1.146 + return result;
1.147 +}
1.148 +
1.149 +
1.150 +// Computes the geometric mean of a set of numbers.
1.151 +BenchmarkSuite.GeometricMean = function(numbers) {
1.152 + var log = 0;
1.153 + for (var i = 0; i < numbers.length; i++) {
1.154 + log += Math.log(numbers[i]);
1.155 + }
1.156 + return Math.pow(Math.E, log / numbers.length);
1.157 +}
1.158 +
1.159 +
1.160 +// Converts a score value to a string with at least three significant
1.161 +// digits.
1.162 +BenchmarkSuite.FormatScore = function(value) {
1.163 + if (value > 100) {
1.164 + return value.toFixed(0);
1.165 + } else {
1.166 + return value.toPrecision(3);
1.167 + }
1.168 +}
1.169 +
1.170 +// Notifies the runner that we're done running a single benchmark in
1.171 +// the benchmark suite. This can be useful to report progress.
1.172 +BenchmarkSuite.prototype.NotifyStep = function(result) {
1.173 + this.results.push(result);
1.174 + if (this.runner.NotifyStep) this.runner.NotifyStep(result.benchmark.name);
1.175 +}
1.176 +
1.177 +
1.178 +// Notifies the runner that we're done with running a suite and that
1.179 +// we have a result which can be reported to the user if needed.
1.180 +BenchmarkSuite.prototype.NotifyResult = function() {
1.181 + var mean = BenchmarkSuite.GeometricMean(this.results);
1.182 + var score = this.reference / mean;
1.183 + BenchmarkSuite.scores.push(score);
1.184 + if (this.runner.NotifyResult) {
1.185 + var formatted = BenchmarkSuite.FormatScore(100 * score);
1.186 + this.runner.NotifyResult(this.name, formatted);
1.187 + }
1.188 +}
1.189 +
1.190 +
1.191 +// Notifies the runner that running a benchmark resulted in an error.
1.192 +BenchmarkSuite.prototype.NotifyError = function(error) {
1.193 + if (this.runner.NotifyError) {
1.194 + this.runner.NotifyError(this.name, error);
1.195 + }
1.196 + if (this.runner.NotifyStep) {
1.197 + this.runner.NotifyStep(this.name);
1.198 + }
1.199 +}
1.200 +
1.201 +
1.202 +// Runs a single benchmark for at least a second and computes the
1.203 +// average time it takes to run a single iteration.
1.204 +BenchmarkSuite.prototype.RunSingleBenchmark = function(benchmark) {
1.205 + var elapsed = 0;
1.206 + var start = new Date();
1.207 + for (var n = 0; elapsed < 200; n++) {
1.208 + benchmark.run();
1.209 + elapsed = new Date() - start;
1.210 + }
1.211 + var usec = (elapsed * 1000) / n;
1.212 + this.NotifyStep(new BenchmarkResult(benchmark, usec));
1.213 +}
1.214 +
1.215 +
1.216 +// This function starts running a suite, but stops between each
1.217 +// individual benchmark in the suite and returns a continuation
1.218 +// function which can be invoked to run the next benchmark. Once the
1.219 +// last benchmark has been executed, null is returned.
1.220 +BenchmarkSuite.prototype.RunStep = function(runner) {
1.221 + this.results = [];
1.222 + this.runner = runner;
1.223 + var length = this.benchmarks.length;
1.224 + var index = 0;
1.225 + var suite = this;
1.226 +
1.227 + // Run the setup, the actual benchmark, and the tear down in three
1.228 + // separate steps to allow the framework to yield between any of the
1.229 + // steps.
1.230 +
1.231 + function RunNextSetup() {
1.232 + if (index < length) {
1.233 + try {
1.234 + suite.benchmarks[index].Setup();
1.235 + } catch (e) {
1.236 + suite.NotifyError(e);
1.237 + return null;
1.238 + }
1.239 + return RunNextBenchmark;
1.240 + }
1.241 + suite.NotifyResult();
1.242 + return null;
1.243 + }
1.244 +
1.245 + function RunNextBenchmark() {
1.246 + try {
1.247 + suite.RunSingleBenchmark(suite.benchmarks[index]);
1.248 + } catch (e) {
1.249 + suite.NotifyError(e);
1.250 + return null;
1.251 + }
1.252 + return RunNextTearDown;
1.253 + }
1.254 +
1.255 + function RunNextTearDown() {
1.256 + try {
1.257 + suite.benchmarks[index++].TearDown();
1.258 + } catch (e) {
1.259 + suite.NotifyError(e);
1.260 + return null;
1.261 + }
1.262 + return RunNextSetup;
1.263 + }
1.264 +
1.265 + // Start out running the setup.
1.266 + return RunNextSetup();
1.267 +}
1.268 +
1.269 +
1.270 +// Copyright 2008 Google Inc. All Rights Reserved.
1.271 +// Copyright 1996 John Maloney and Mario Wolczko.
1.272 +
1.273 +// This program is free software; you can redistribute it and/or modify
1.274 +// it under the terms of the GNU General Public License as published by
1.275 +// the Free Software Foundation; either version 2 of the License, or
1.276 +// (at your option) any later version.
1.277 +//
1.278 +// This program is distributed in the hope that it will be useful,
1.279 +// but WITHOUT ANY WARRANTY; without even the implied warranty of
1.280 +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1.281 +// GNU General Public License for more details.
1.282 +//
1.283 +// You should have received a copy of the GNU General Public License
1.284 +// along with this program; if not, write to the Free Software
1.285 +// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
1.286 +
1.287 +
1.288 +// This implementation of the DeltaBlue benchmark is derived
1.289 +// from the Smalltalk implementation by John Maloney and Mario
1.290 +// Wolczko. Some parts have been translated directly, whereas
1.291 +// others have been modified more aggresively to make it feel
1.292 +// more like a JavaScript program.
1.293 +
1.294 +
1.295 +var DeltaBlue = new BenchmarkSuite('DeltaBlue', 71104, [
1.296 + new Benchmark('DeltaBlue', deltaBlue)
1.297 +]);
1.298 +
1.299 +
1.300 +/**
1.301 + * A JavaScript implementation of the DeltaBlue constrain-solving
1.302 + * algorithm, as described in:
1.303 + *
1.304 + * "The DeltaBlue Algorithm: An Incremental Constraint Hierarchy Solver"
1.305 + * Bjorn N. Freeman-Benson and John Maloney
1.306 + * January 1990 Communications of the ACM,
1.307 + * also available as University of Washington TR 89-08-06.
1.308 + *
1.309 + * Beware: this benchmark is written in a grotesque style where
1.310 + * the constraint model is built by side-effects from constructors.
1.311 + * I've kept it this way to avoid deviating too much from the original
1.312 + * implementation.
1.313 + */
1.314 +
1.315 +
1.316 +/* --- O b j e c t M o d e l --- */
1.317 +
1.318 +Object.prototype.inherits = function (shuper) {
1.319 + function Inheriter() { }
1.320 + Inheriter.prototype = shuper.prototype;
1.321 + this.prototype = new Inheriter();
1.322 + this.superConstructor = shuper;
1.323 +}
1.324 +
1.325 +function OrderedCollection() {
1.326 + this.elms = new Array();
1.327 +}
1.328 +
1.329 +OrderedCollection.prototype.add = function (elm) {
1.330 + this.elms.push(elm);
1.331 +}
1.332 +
1.333 +OrderedCollection.prototype.at = function (index) {
1.334 + return this.elms[index];
1.335 +}
1.336 +
1.337 +OrderedCollection.prototype.size = function () {
1.338 + return this.elms.length;
1.339 +}
1.340 +
1.341 +OrderedCollection.prototype.removeFirst = function () {
1.342 + return this.elms.pop();
1.343 +}
1.344 +
1.345 +OrderedCollection.prototype.remove = function (elm) {
1.346 + var index = 0, skipped = 0;
1.347 + /* BEGIN LOOP */
1.348 + for (var i = 0; i < this.elms.length; i++) {
1.349 + var value = this.elms[i];
1.350 + if (value != elm) {
1.351 + this.elms[index] = value;
1.352 + index++;
1.353 + } else {
1.354 + skipped++;
1.355 + }
1.356 + }
1.357 + /* END LOOP */
1.358 + /* BEGIN LOOP */
1.359 + for (var i = 0; i < skipped; i++)
1.360 + this.elms.pop();
1.361 + /* END LOOP */
1.362 +}
1.363 +
1.364 +/* --- *
1.365 + * S t r e n g t h
1.366 + * --- */
1.367 +
1.368 +/**
1.369 + * Strengths are used to measure the relative importance of constraints.
1.370 + * New strengths may be inserted in the strength hierarchy without
1.371 + * disrupting current constraints. Strengths cannot be created outside
1.372 + * this class, so pointer comparison can be used for value comparison.
1.373 + */
1.374 +function Strength(strengthValue, name) {
1.375 + this.strengthValue = strengthValue;
1.376 + this.name = name;
1.377 +}
1.378 +
1.379 +Strength.stronger = function (s1, s2) {
1.380 + return s1.strengthValue < s2.strengthValue;
1.381 +}
1.382 +
1.383 +Strength.weaker = function (s1, s2) {
1.384 + return s1.strengthValue > s2.strengthValue;
1.385 +}
1.386 +
1.387 +Strength.weakestOf = function (s1, s2) {
1.388 + return this.weaker(s1, s2) ? s1 : s2;
1.389 +}
1.390 +
1.391 +Strength.strongest = function (s1, s2) {
1.392 + return this.stronger(s1, s2) ? s1 : s2;
1.393 +}
1.394 +
1.395 +Strength.prototype.nextWeaker = function () {
1.396 + switch (this.strengthValue) {
1.397 + case 0: return Strength.WEAKEST;
1.398 + case 1: return Strength.WEAK_DEFAULT;
1.399 + case 2: return Strength.NORMAL;
1.400 + case 3: return Strength.STRONG_DEFAULT;
1.401 + case 4: return Strength.PREFERRED;
1.402 + case 5: return Strength.REQUIRED;
1.403 + }
1.404 +}
1.405 +
1.406 +// Strength constants.
1.407 +Strength.REQUIRED = new Strength(0, "required");
1.408 +Strength.STONG_PREFERRED = new Strength(1, "strongPreferred");
1.409 +Strength.PREFERRED = new Strength(2, "preferred");
1.410 +Strength.STRONG_DEFAULT = new Strength(3, "strongDefault");
1.411 +Strength.NORMAL = new Strength(4, "normal");
1.412 +Strength.WEAK_DEFAULT = new Strength(5, "weakDefault");
1.413 +Strength.WEAKEST = new Strength(6, "weakest");
1.414 +
1.415 +/* --- *
1.416 + * C o n s t r a i n t
1.417 + * --- */
1.418 +
1.419 +/**
1.420 + * An abstract class representing a system-maintainable relationship
1.421 + * (or "constraint") between a set of variables. A constraint supplies
1.422 + * a strength instance variable; concrete subclasses provide a means
1.423 + * of storing the constrained variables and other information required
1.424 + * to represent a constraint.
1.425 + */
1.426 +function Constraint(strength) {
1.427 + this.strength = strength;
1.428 +}
1.429 +
1.430 +/**
1.431 + * Activate this constraint and attempt to satisfy it.
1.432 + */
1.433 +Constraint.prototype.addConstraint = function () {
1.434 + this.addToGraph();
1.435 + planner.incrementalAdd(this);
1.436 +}
1.437 +
1.438 +/**
1.439 + * Attempt to find a way to enforce this constraint. If successful,
1.440 + * record the solution, perhaps modifying the current dataflow
1.441 + * graph. Answer the constraint that this constraint overrides, if
1.442 + * there is one, or nil, if there isn't.
1.443 + * Assume: I am not already satisfied.
1.444 + */
1.445 +Constraint.prototype.satisfy = function (mark) {
1.446 + this.chooseMethod(mark);
1.447 + if (!this.isSatisfied()) {
1.448 + if (this.strength == Strength.REQUIRED)
1.449 + alert("Could not satisfy a required constraint!");
1.450 + return null;
1.451 + }
1.452 + this.markInputs(mark);
1.453 + var out = this.output();
1.454 + var overridden = out.determinedBy;
1.455 + if (overridden != null) overridden.markUnsatisfied();
1.456 + out.determinedBy = this;
1.457 + if (!planner.addPropagate(this, mark))
1.458 + alert("Cycle encountered");
1.459 + out.mark = mark;
1.460 + return overridden;
1.461 +}
1.462 +
1.463 +Constraint.prototype.destroyConstraint = function () {
1.464 + if (this.isSatisfied()) planner.incrementalRemove(this);
1.465 + else this.removeFromGraph();
1.466 +}
1.467 +
1.468 +/**
1.469 + * Normal constraints are not input constraints. An input constraint
1.470 + * is one that depends on external state, such as the mouse, the
1.471 + * keybord, a clock, or some arbitraty piece of imperative code.
1.472 + */
1.473 +Constraint.prototype.isInput = function () {
1.474 + return false;
1.475 +}
1.476 +
1.477 +/* --- *
1.478 + * U n a r y C o n s t r a i n t
1.479 + * --- */
1.480 +
1.481 +/**
1.482 + * Abstract superclass for constraints having a single possible output
1.483 + * variable.
1.484 + */
1.485 +function UnaryConstraint(v, strength) {
1.486 + UnaryConstraint.superConstructor.call(this, strength);
1.487 + this.myOutput = v;
1.488 + this.satisfied = false;
1.489 + this.addConstraint();
1.490 +}
1.491 +
1.492 +UnaryConstraint.inherits(Constraint);
1.493 +
1.494 +/**
1.495 + * Adds this constraint to the constraint graph
1.496 + */
1.497 +UnaryConstraint.prototype.addToGraph = function () {
1.498 + this.myOutput.addConstraint(this);
1.499 + this.satisfied = false;
1.500 +}
1.501 +
1.502 +/**
1.503 + * Decides if this constraint can be satisfied and records that
1.504 + * decision.
1.505 + */
1.506 +UnaryConstraint.prototype.chooseMethod = function (mark) {
1.507 + this.satisfied = (this.myOutput.mark != mark)
1.508 + && Strength.stronger(this.strength, this.myOutput.walkStrength);
1.509 +}
1.510 +
1.511 +/**
1.512 + * Returns true if this constraint is satisfied in the current solution.
1.513 + */
1.514 +UnaryConstraint.prototype.isSatisfied = function () {
1.515 + return this.satisfied;
1.516 +}
1.517 +
1.518 +UnaryConstraint.prototype.markInputs = function (mark) {
1.519 + // has no inputs
1.520 +}
1.521 +
1.522 +/**
1.523 + * Returns the current output variable.
1.524 + */
1.525 +UnaryConstraint.prototype.output = function () {
1.526 + return this.myOutput;
1.527 +}
1.528 +
1.529 +/**
1.530 + * Calculate the walkabout strength, the stay flag, and, if it is
1.531 + * 'stay', the value for the current output of this constraint. Assume
1.532 + * this constraint is satisfied.
1.533 + */
1.534 +UnaryConstraint.prototype.recalculate = function () {
1.535 + this.myOutput.walkStrength = this.strength;
1.536 + this.myOutput.stay = !this.isInput();
1.537 + if (this.myOutput.stay) this.execute(); // Stay optimization
1.538 +}
1.539 +
1.540 +/**
1.541 + * Records that this constraint is unsatisfied
1.542 + */
1.543 +UnaryConstraint.prototype.markUnsatisfied = function () {
1.544 + this.satisfied = false;
1.545 +}
1.546 +
1.547 +UnaryConstraint.prototype.inputsKnown = function () {
1.548 + return true;
1.549 +}
1.550 +
1.551 +UnaryConstraint.prototype.removeFromGraph = function () {
1.552 + if (this.myOutput != null) this.myOutput.removeConstraint(this);
1.553 + this.satisfied = false;
1.554 +}
1.555 +
1.556 +/* --- *
1.557 + * S t a y C o n s t r a i n t
1.558 + * --- */
1.559 +
1.560 +/**
1.561 + * Variables that should, with some level of preference, stay the same.
1.562 + * Planners may exploit the fact that instances, if satisfied, will not
1.563 + * change their output during plan execution. This is called "stay
1.564 + * optimization".
1.565 + */
1.566 +function StayConstraint(v, str) {
1.567 + StayConstraint.superConstructor.call(this, v, str);
1.568 +}
1.569 +
1.570 +StayConstraint.inherits(UnaryConstraint);
1.571 +
1.572 +StayConstraint.prototype.execute = function () {
1.573 + // Stay constraints do nothing
1.574 +}
1.575 +
1.576 +/* --- *
1.577 + * E d i t C o n s t r a i n t
1.578 + * --- */
1.579 +
1.580 +/**
1.581 + * A unary input constraint used to mark a variable that the client
1.582 + * wishes to change.
1.583 + */
1.584 +function EditConstraint(v, str) {
1.585 + EditConstraint.superConstructor.call(this, v, str);
1.586 +}
1.587 +
1.588 +EditConstraint.inherits(UnaryConstraint);
1.589 +
1.590 +/**
1.591 + * Edits indicate that a variable is to be changed by imperative code.
1.592 + */
1.593 +EditConstraint.prototype.isInput = function () {
1.594 + return true;
1.595 +}
1.596 +
1.597 +EditConstraint.prototype.execute = function () {
1.598 + // Edit constraints do nothing
1.599 +}
1.600 +
1.601 +/* --- *
1.602 + * B i n a r y C o n s t r a i n t
1.603 + * --- */
1.604 +
1.605 +var Direction = new Object();
1.606 +Direction.NONE = 0;
1.607 +Direction.FORWARD = 1;
1.608 +Direction.BACKWARD = -1;
1.609 +
1.610 +/**
1.611 + * Abstract superclass for constraints having two possible output
1.612 + * variables.
1.613 + */
1.614 +function BinaryConstraint(var1, var2, strength) {
1.615 + BinaryConstraint.superConstructor.call(this, strength);
1.616 + this.v1 = var1;
1.617 + this.v2 = var2;
1.618 + this.direction = Direction.NONE;
1.619 + this.addConstraint();
1.620 +}
1.621 +
1.622 +BinaryConstraint.inherits(Constraint);
1.623 +
1.624 +/**
1.625 + * Decides if this constratint can be satisfied and which way it
1.626 + * should flow based on the relative strength of the variables related,
1.627 + * and record that decision.
1.628 + */
1.629 +BinaryConstraint.prototype.chooseMethod = function (mark) {
1.630 + if (this.v1.mark == mark) {
1.631 + this.direction = (this.v1.mark != mark && Strength.stronger(this.strength, this.v2.walkStrength))
1.632 + ? Direction.FORWARD
1.633 + : Direction.NONE;
1.634 + }
1.635 + if (this.v2.mark == mark) {
1.636 + this.direction = (this.v1.mark != mark && Strength.stronger(this.strength, this.v1.walkStrength))
1.637 + ? Direction.BACKWARD
1.638 + : Direction.NONE;
1.639 + }
1.640 + if (Strength.weaker(this.v1.walkStrength, this.v2.walkStrength)) {
1.641 + this.direction = Strength.stronger(this.strength, this.v1.walkStrength)
1.642 + ? Direction.BACKWARD
1.643 + : Direction.NONE;
1.644 + } else {
1.645 + this.direction = Strength.stronger(this.strength, this.v2.walkStrength)
1.646 + ? Direction.FORWARD
1.647 + : Direction.BACKWARD
1.648 + }
1.649 +}
1.650 +
1.651 +/**
1.652 + * Add this constraint to the constraint graph
1.653 + */
1.654 +BinaryConstraint.prototype.addToGraph = function () {
1.655 + this.v1.addConstraint(this);
1.656 + this.v2.addConstraint(this);
1.657 + this.direction = Direction.NONE;
1.658 +}
1.659 +
1.660 +/**
1.661 + * Answer true if this constraint is satisfied in the current solution.
1.662 + */
1.663 +BinaryConstraint.prototype.isSatisfied = function () {
1.664 + return this.direction != Direction.NONE;
1.665 +}
1.666 +
1.667 +/**
1.668 + * Mark the input variable with the given mark.
1.669 + */
1.670 +BinaryConstraint.prototype.markInputs = function (mark) {
1.671 + this.input().mark = mark;
1.672 +}
1.673 +
1.674 +/**
1.675 + * Returns the current input variable
1.676 + */
1.677 +BinaryConstraint.prototype.input = function () {
1.678 + return (this.direction == Direction.FORWARD) ? this.v1 : this.v2;
1.679 +}
1.680 +
1.681 +/**
1.682 + * Returns the current output variable
1.683 + */
1.684 +BinaryConstraint.prototype.output = function () {
1.685 + return (this.direction == Direction.FORWARD) ? this.v2 : this.v1;
1.686 +}
1.687 +
1.688 +/**
1.689 + * Calculate the walkabout strength, the stay flag, and, if it is
1.690 + * 'stay', the value for the current output of this
1.691 + * constraint. Assume this constraint is satisfied.
1.692 + */
1.693 +BinaryConstraint.prototype.recalculate = function () {
1.694 + var ihn = this.input(), out = this.output();
1.695 + out.walkStrength = Strength.weakestOf(this.strength, ihn.walkStrength);
1.696 + out.stay = ihn.stay;
1.697 + if (out.stay) this.execute();
1.698 +}
1.699 +
1.700 +/**
1.701 + * Record the fact that this constraint is unsatisfied.
1.702 + */
1.703 +BinaryConstraint.prototype.markUnsatisfied = function () {
1.704 + this.direction = Direction.NONE;
1.705 +}
1.706 +
1.707 +BinaryConstraint.prototype.inputsKnown = function (mark) {
1.708 + var i = this.input();
1.709 + return i.mark == mark || i.stay || i.determinedBy == null;
1.710 +}
1.711 +
1.712 +BinaryConstraint.prototype.removeFromGraph = function () {
1.713 + if (this.v1 != null) this.v1.removeConstraint(this);
1.714 + if (this.v2 != null) this.v2.removeConstraint(this);
1.715 + this.direction = Direction.NONE;
1.716 +}
1.717 +
1.718 +/* --- *
1.719 + * S c a l e C o n s t r a i n t
1.720 + * --- */
1.721 +
1.722 +/**
1.723 + * Relates two variables by the linear scaling relationship: "v2 =
1.724 + * (v1 * scale) + offset". Either v1 or v2 may be changed to maintain
1.725 + * this relationship but the scale factor and offset are considered
1.726 + * read-only.
1.727 + */
1.728 +function ScaleConstraint(src, scale, offset, dest, strength) {
1.729 + this.direction = Direction.NONE;
1.730 + this.scale = scale;
1.731 + this.offset = offset;
1.732 + ScaleConstraint.superConstructor.call(this, src, dest, strength);
1.733 +}
1.734 +
1.735 +ScaleConstraint.inherits(BinaryConstraint);
1.736 +
1.737 +/**
1.738 + * Adds this constraint to the constraint graph.
1.739 + */
1.740 +ScaleConstraint.prototype.addToGraph = function () {
1.741 + ScaleConstraint.superConstructor.prototype.addToGraph.call(this);
1.742 + this.scale.addConstraint(this);
1.743 + this.offset.addConstraint(this);
1.744 +}
1.745 +
1.746 +ScaleConstraint.prototype.removeFromGraph = function () {
1.747 + ScaleConstraint.superConstructor.prototype.removeFromGraph.call(this);
1.748 + if (this.scale != null) this.scale.removeConstraint(this);
1.749 + if (this.offset != null) this.offset.removeConstraint(this);
1.750 +}
1.751 +
1.752 +ScaleConstraint.prototype.markInputs = function (mark) {
1.753 + ScaleConstraint.superConstructor.prototype.markInputs.call(this, mark);
1.754 + this.scale.mark = this.offset.mark = mark;
1.755 +}
1.756 +
1.757 +/**
1.758 + * Enforce this constraint. Assume that it is satisfied.
1.759 + */
1.760 +ScaleConstraint.prototype.execute = function () {
1.761 + if (this.direction == Direction.FORWARD) {
1.762 + this.v2.value = this.v1.value * this.scale.value + this.offset.value;
1.763 + } else {
1.764 + this.v1.value = (this.v2.value - this.offset.value) / this.scale.value;
1.765 + }
1.766 +}
1.767 +
1.768 +/**
1.769 + * Calculate the walkabout strength, the stay flag, and, if it is
1.770 + * 'stay', the value for the current output of this constraint. Assume
1.771 + * this constraint is satisfied.
1.772 + */
1.773 +ScaleConstraint.prototype.recalculate = function () {
1.774 + var ihn = this.input(), out = this.output();
1.775 + out.walkStrength = Strength.weakestOf(this.strength, ihn.walkStrength);
1.776 + out.stay = ihn.stay && this.scale.stay && this.offset.stay;
1.777 + if (out.stay) this.execute();
1.778 +}
1.779 +
1.780 +/* --- *
1.781 + * E q u a l i t y C o n s t r a i n t
1.782 + * --- */
1.783 +
1.784 +/**
1.785 + * Constrains two variables to have the same value.
1.786 + */
1.787 +function EqualityConstraint(var1, var2, strength) {
1.788 + EqualityConstraint.superConstructor.call(this, var1, var2, strength);
1.789 +}
1.790 +
1.791 +EqualityConstraint.inherits(BinaryConstraint);
1.792 +
1.793 +/**
1.794 + * Enforce this constraint. Assume that it is satisfied.
1.795 + */
1.796 +EqualityConstraint.prototype.execute = function () {
1.797 + this.output().value = this.input().value;
1.798 +}
1.799 +
1.800 +/* --- *
1.801 + * V a r i a b l e
1.802 + * --- */
1.803 +
1.804 +/**
1.805 + * A constrained variable. In addition to its value, it maintain the
1.806 + * structure of the constraint graph, the current dataflow graph, and
1.807 + * various parameters of interest to the DeltaBlue incremental
1.808 + * constraint solver.
1.809 + **/
1.810 +function Variable(name, initialValue) {
1.811 + this.value = initialValue || 0;
1.812 + this.constraints = new OrderedCollection();
1.813 + this.determinedBy = null;
1.814 + this.mark = 0;
1.815 + this.walkStrength = Strength.WEAKEST;
1.816 + this.stay = true;
1.817 + this.name = name;
1.818 +}
1.819 +
1.820 +/**
1.821 + * Add the given constraint to the set of all constraints that refer
1.822 + * this variable.
1.823 + */
1.824 +Variable.prototype.addConstraint = function (c) {
1.825 + this.constraints.add(c);
1.826 +}
1.827 +
1.828 +/**
1.829 + * Removes all traces of c from this variable.
1.830 + */
1.831 +Variable.prototype.removeConstraint = function (c) {
1.832 + this.constraints.remove(c);
1.833 + if (this.determinedBy == c) this.determinedBy = null;
1.834 +}
1.835 +
1.836 +/* --- *
1.837 + * P l a n n e r
1.838 + * --- */
1.839 +
1.840 +/**
1.841 + * The DeltaBlue planner
1.842 + */
1.843 +function Planner() {
1.844 + this.currentMark = 0;
1.845 +}
1.846 +
1.847 +/**
1.848 + * Attempt to satisfy the given constraint and, if successful,
1.849 + * incrementally update the dataflow graph. Details: If satifying
1.850 + * the constraint is successful, it may override a weaker constraint
1.851 + * on its output. The algorithm attempts to resatisfy that
1.852 + * constraint using some other method. This process is repeated
1.853 + * until either a) it reaches a variable that was not previously
1.854 + * determined by any constraint or b) it reaches a constraint that
1.855 + * is too weak to be satisfied using any of its methods. The
1.856 + * variables of constraints that have been processed are marked with
1.857 + * a unique mark value so that we know where we've been. This allows
1.858 + * the algorithm to avoid getting into an infinite loop even if the
1.859 + * constraint graph has an inadvertent cycle.
1.860 + */
1.861 +Planner.prototype.incrementalAdd = function (c) {
1.862 + var mark = this.newMark();
1.863 + var overridden = c.satisfy(mark);
1.864 + /* BEGIN LOOP */
1.865 + while (overridden != null)
1.866 + overridden = overridden.satisfy(mark);
1.867 + /* END LOOP */
1.868 +}
1.869 +
1.870 +/**
1.871 + * Entry point for retracting a constraint. Remove the given
1.872 + * constraint and incrementally update the dataflow graph.
1.873 + * Details: Retracting the given constraint may allow some currently
1.874 + * unsatisfiable downstream constraint to be satisfied. We therefore collect
1.875 + * a list of unsatisfied downstream constraints and attempt to
1.876 + * satisfy each one in turn. This list is traversed by constraint
1.877 + * strength, strongest first, as a heuristic for avoiding
1.878 + * unnecessarily adding and then overriding weak constraints.
1.879 + * Assume: c is satisfied.
1.880 + */
1.881 +Planner.prototype.incrementalRemove = function (c) {
1.882 + var out = c.output();
1.883 + c.markUnsatisfied();
1.884 + c.removeFromGraph();
1.885 + var unsatisfied = this.removePropagateFrom(out);
1.886 + var strength = Strength.REQUIRED;
1.887 + /* BEGIN LOOP */
1.888 + do {
1.889 + /* BEGIN LOOP */
1.890 + for (var i = 0; i < unsatisfied.size(); i++) {
1.891 + var u = unsatisfied.at(i);
1.892 + if (u.strength == strength)
1.893 + this.incrementalAdd(u);
1.894 + }
1.895 + /* END LOOP */
1.896 + strength = strength.nextWeaker();
1.897 + } while (strength != Strength.WEAKEST);
1.898 + /* END LOOP */
1.899 +}
1.900 +
1.901 +/**
1.902 + * Select a previously unused mark value.
1.903 + */
1.904 +Planner.prototype.newMark = function () {
1.905 + return ++this.currentMark;
1.906 +}
1.907 +
1.908 +/**
1.909 + * Extract a plan for resatisfaction starting from the given source
1.910 + * constraints, usually a set of input constraints. This method
1.911 + * assumes that stay optimization is desired; the plan will contain
1.912 + * only constraints whose output variables are not stay. Constraints
1.913 + * that do no computation, such as stay and edit constraints, are
1.914 + * not included in the plan.
1.915 + * Details: The outputs of a constraint are marked when it is added
1.916 + * to the plan under construction. A constraint may be appended to
1.917 + * the plan when all its input variables are known. A variable is
1.918 + * known if either a) the variable is marked (indicating that has
1.919 + * been computed by a constraint appearing earlier in the plan), b)
1.920 + * the variable is 'stay' (i.e. it is a constant at plan execution
1.921 + * time), or c) the variable is not determined by any
1.922 + * constraint. The last provision is for past states of history
1.923 + * variables, which are not stay but which are also not computed by
1.924 + * any constraint.
1.925 + * Assume: sources are all satisfied.
1.926 + */
1.927 +Planner.prototype.makePlan = function (sources) {
1.928 + var mark = this.newMark();
1.929 + var plan = new Plan();
1.930 + var todo = sources;
1.931 + /* BEGIN LOOP */
1.932 + while (todo.size() > 0) {
1.933 + var c = todo.removeFirst();
1.934 + if (c.output().mark != mark && c.inputsKnown(mark)) {
1.935 + plan.addConstraint(c);
1.936 + c.output().mark = mark;
1.937 + this.addConstraintsConsumingTo(c.output(), todo);
1.938 + }
1.939 + }
1.940 + /* END LOOP */
1.941 + return plan;
1.942 +}
1.943 +
1.944 +/**
1.945 + * Extract a plan for resatisfying starting from the output of the
1.946 + * given constraints, usually a set of input constraints.
1.947 + */
1.948 +Planner.prototype.extractPlanFromConstraints = function (constraints) {
1.949 + var sources = new OrderedCollection();
1.950 + /* BEGIN LOOP */
1.951 + for (var i = 0; i < constraints.size(); i++) {
1.952 + var c = constraints.at(i);
1.953 + if (c.isInput() && c.isSatisfied())
1.954 + // not in plan already and eligible for inclusion
1.955 + sources.add(c);
1.956 + }
1.957 + /* END LOOP */
1.958 + return this.makePlan(sources);
1.959 +}
1.960 +
1.961 +/**
1.962 + * Recompute the walkabout strengths and stay flags of all variables
1.963 + * downstream of the given constraint and recompute the actual
1.964 + * values of all variables whose stay flag is true. If a cycle is
1.965 + * detected, remove the given constraint and answer
1.966 + * false. Otherwise, answer true.
1.967 + * Details: Cycles are detected when a marked variable is
1.968 + * encountered downstream of the given constraint. The sender is
1.969 + * assumed to have marked the inputs of the given constraint with
1.970 + * the given mark. Thus, encountering a marked node downstream of
1.971 + * the output constraint means that there is a path from the
1.972 + * constraint's output to one of its inputs.
1.973 + */
1.974 +Planner.prototype.addPropagate = function (c, mark) {
1.975 + var todo = new OrderedCollection();
1.976 + todo.add(c);
1.977 + /* BEGIN LOOP */
1.978 + while (todo.size() > 0) {
1.979 + var d = todo.removeFirst();
1.980 + if (d.output().mark == mark) {
1.981 + this.incrementalRemove(c);
1.982 + return false;
1.983 + }
1.984 + d.recalculate();
1.985 + this.addConstraintsConsumingTo(d.output(), todo);
1.986 + }
1.987 + /* END LOOP */
1.988 + return true;
1.989 +}
1.990 +
1.991 +
1.992 +/**
1.993 + * Update the walkabout strengths and stay flags of all variables
1.994 + * downstream of the given constraint. Answer a collection of
1.995 + * unsatisfied constraints sorted in order of decreasing strength.
1.996 + */
1.997 +Planner.prototype.removePropagateFrom = function (out) {
1.998 + out.determinedBy = null;
1.999 + out.walkStrength = Strength.WEAKEST;
1.1000 + out.stay = true;
1.1001 + var unsatisfied = new OrderedCollection();
1.1002 + var todo = new OrderedCollection();
1.1003 + todo.add(out);
1.1004 + /* BEGIN LOOP */
1.1005 + while (todo.size() > 0) {
1.1006 + var v = todo.removeFirst();
1.1007 + /* BEGIN LOOP */
1.1008 + for (var i = 0; i < v.constraints.size(); i++) {
1.1009 + var c = v.constraints.at(i);
1.1010 + if (!c.isSatisfied())
1.1011 + unsatisfied.add(c);
1.1012 + }
1.1013 + /* END LOOP */
1.1014 + var determining = v.determinedBy;
1.1015 + /* BEGIN LOOP */
1.1016 + for (var i = 0; i < v.constraints.size(); i++) {
1.1017 + var next = v.constraints.at(i);
1.1018 + if (next != determining && next.isSatisfied()) {
1.1019 + next.recalculate();
1.1020 + todo.add(next.output());
1.1021 + }
1.1022 + }
1.1023 + /* END LOOP */
1.1024 + }
1.1025 + /* END LOOP */
1.1026 + return unsatisfied;
1.1027 +}
1.1028 +
1.1029 +Planner.prototype.addConstraintsConsumingTo = function (v, coll) {
1.1030 + var determining = v.determinedBy;
1.1031 + var cc = v.constraints;
1.1032 + /* BEGIN LOOP */
1.1033 + for (var i = 0; i < cc.size(); i++) {
1.1034 + var c = cc.at(i);
1.1035 + if (c != determining && c.isSatisfied())
1.1036 + coll.add(c);
1.1037 + }
1.1038 + /* END LOOP */
1.1039 +}
1.1040 +
1.1041 +/* --- *
1.1042 + * P l a n
1.1043 + * --- */
1.1044 +
1.1045 +/**
1.1046 + * A Plan is an ordered list of constraints to be executed in sequence
1.1047 + * to resatisfy all currently satisfiable constraints in the face of
1.1048 + * one or more changing inputs.
1.1049 + */
1.1050 +function Plan() {
1.1051 + this.v = new OrderedCollection();
1.1052 +}
1.1053 +
1.1054 +Plan.prototype.addConstraint = function (c) {
1.1055 + this.v.add(c);
1.1056 +}
1.1057 +
1.1058 +Plan.prototype.size = function () {
1.1059 + return this.v.size();
1.1060 +}
1.1061 +
1.1062 +Plan.prototype.constraintAt = function (index) {
1.1063 + return this.v.at(index);
1.1064 +}
1.1065 +
1.1066 +Plan.prototype.execute = function () {
1.1067 + /* BEGIN LOOP */
1.1068 + for (var i = 0; i < this.size(); i++) {
1.1069 + var c = this.constraintAt(i);
1.1070 + c.execute();
1.1071 + }
1.1072 + /* END LOOP */
1.1073 +}
1.1074 +
1.1075 +/* --- *
1.1076 + * M a i n
1.1077 + * --- */
1.1078 +
1.1079 +/**
1.1080 + * This is the standard DeltaBlue benchmark. A long chain of equality
1.1081 + * constraints is constructed with a stay constraint on one end. An
1.1082 + * edit constraint is then added to the opposite end and the time is
1.1083 + * measured for adding and removing this constraint, and extracting
1.1084 + * and executing a constraint satisfaction plan. There are two cases.
1.1085 + * In case 1, the added constraint is stronger than the stay
1.1086 + * constraint and values must propagate down the entire length of the
1.1087 + * chain. In case 2, the added constraint is weaker than the stay
1.1088 + * constraint so it cannot be accomodated. The cost in this case is,
1.1089 + * of course, very low. Typical situations lie somewhere between these
1.1090 + * two extremes.
1.1091 + */
1.1092 +function chainTest(n) {
1.1093 + planner = new Planner();
1.1094 + var prev = null, first = null, last = null;
1.1095 +
1.1096 + // Build chain of n equality constraints
1.1097 + /* BEGIN LOOP */
1.1098 + for (var i = 0; i <= n; i++) {
1.1099 + var name = "v" + i;
1.1100 + var v = new Variable(name);
1.1101 + if (prev != null)
1.1102 + new EqualityConstraint(prev, v, Strength.REQUIRED);
1.1103 + if (i == 0) first = v;
1.1104 + if (i == n) last = v;
1.1105 + prev = v;
1.1106 + }
1.1107 + /* END LOOP */
1.1108 +
1.1109 + new StayConstraint(last, Strength.STRONG_DEFAULT);
1.1110 + var edit = new EditConstraint(first, Strength.PREFERRED);
1.1111 + var edits = new OrderedCollection();
1.1112 + edits.add(edit);
1.1113 + var plan = planner.extractPlanFromConstraints(edits);
1.1114 + /* BEGIN LOOP */
1.1115 + for (var i = 0; i < 100; i++) {
1.1116 + first.value = i;
1.1117 + plan.execute();
1.1118 + if (last.value != i)
1.1119 + alert("Chain test failed.");
1.1120 + }
1.1121 + /* END LOOP */
1.1122 +}
1.1123 +
1.1124 +/**
1.1125 + * This test constructs a two sets of variables related to each
1.1126 + * other by a simple linear transformation (scale and offset). The
1.1127 + * time is measured to change a variable on either side of the
1.1128 + * mapping and to change the scale and offset factors.
1.1129 + */
1.1130 +function projectionTest(n) {
1.1131 + planner = new Planner();
1.1132 + var scale = new Variable("scale", 10);
1.1133 + var offset = new Variable("offset", 1000);
1.1134 + var src = null, dst = null;
1.1135 +
1.1136 + var dests = new OrderedCollection();
1.1137 + /* BEGIN LOOP */
1.1138 + for (var i = 0; i < n; i++) {
1.1139 + src = new Variable("src" + i, i);
1.1140 + dst = new Variable("dst" + i, i);
1.1141 + dests.add(dst);
1.1142 + new StayConstraint(src, Strength.NORMAL);
1.1143 + new ScaleConstraint(src, scale, offset, dst, Strength.REQUIRED);
1.1144 + }
1.1145 + /* END LOOP */
1.1146 +
1.1147 + change(src, 17);
1.1148 + if (dst.value != 1170) alert("Projection 1 failed");
1.1149 + change(dst, 1050);
1.1150 + if (src.value != 5) alert("Projection 2 failed");
1.1151 + change(scale, 5);
1.1152 + /* BEGIN LOOP */
1.1153 + for (var i = 0; i < n - 1; i++) {
1.1154 + if (dests.at(i).value != i * 5 + 1000)
1.1155 + alert("Projection 3 failed");
1.1156 + }
1.1157 + /* END LOOP */
1.1158 + change(offset, 2000);
1.1159 + /* BEGIN LOOP */
1.1160 + for (var i = 0; i < n - 1; i++) {
1.1161 + if (dests.at(i).value != i * 5 + 2000)
1.1162 + alert("Projection 4 failed");
1.1163 + }
1.1164 + /* END LOOP */
1.1165 +}
1.1166 +
1.1167 +function change(v, newValue) {
1.1168 + var edit = new EditConstraint(v, Strength.PREFERRED);
1.1169 + var edits = new OrderedCollection();
1.1170 + edits.add(edit);
1.1171 + var plan = planner.extractPlanFromConstraints(edits);
1.1172 + /* BEGIN LOOP */
1.1173 + for (var i = 0; i < 10; i++) {
1.1174 + v.value = newValue;
1.1175 + plan.execute();
1.1176 + }
1.1177 + /* END LOOP */
1.1178 + edit.destroyConstraint();
1.1179 +}
1.1180 +
1.1181 +// Global variable holding the current planner.
1.1182 +var planner = null;
1.1183 +
1.1184 +function deltaBlue() {
1.1185 + chainTest(100);
1.1186 + projectionTest(100);
1.1187 +}
1.1188 +
1.1189 +function PrintResult(name, result) {
1.1190 +}
1.1191 +
1.1192 +
1.1193 +function PrintScore(score) {
1.1194 +}
1.1195 +
1.1196 +
1.1197 +BenchmarkSuite.RunSuites({ NotifyResult: PrintResult,
1.1198 + NotifyScore: PrintScore });
1.1199 +
