blob: ee0757dc39ecd2b046d1f173ed0dbd1049debd88 [file] [log] [blame]
//@skip if $memoryLimited
//@ runNoisyTestDefault
//@ runNoisyTestNoCJIT
// Copyright 2013 the V8 project authors. All rights reserved.
// Copyright (C) 2015 Apple Inc. 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.
// Performance.now is used in latency benchmarks, the fallback is Date.now.
var performance = performance || {};
performance.now = (function() {
return performance.now ||
performance.mozNow ||
performance.msNow ||
performance.oNow ||
performance.webkitNow ||
Date.now;
})();
// Simple framework for running the benchmark suites and
// computing a score based on the timing measurements.
// A benchmark has a name (string) and a function that will be run to
// do the performance measurement. The optional setup and tearDown
// arguments are functions that will be invoked before and after
// running the benchmark, but the running time of these functions will
// not be accounted for in the benchmark score.
function Benchmark(name, doWarmup, doDeterministic, run, setup, tearDown, latencyResult, minIterations) {
this.name = name;
this.doWarmup = doWarmup;
this.doDeterministic = doDeterministic;
this.run = run;
this.Setup = setup ? setup : function() { };
this.TearDown = tearDown ? tearDown : function() { };
this.latencyResult = latencyResult ? latencyResult : null;
this.minIterations = minIterations ? minIterations : 32;
}
// Benchmark results hold the benchmark and the measured time used to
// run the benchmark. The benchmark score is computed later once a
// full benchmark suite has run to completion. If latency is set to 0
// then there is no latency score for this benchmark.
function BenchmarkResult(benchmark, time, latency) {
this.benchmark = benchmark;
this.time = time;
this.latency = latency;
}
// Automatically convert results to numbers. Used by the geometric
// mean computation.
BenchmarkResult.prototype.valueOf = function() {
return this.time;
}
// Suites of benchmarks consist of a name and the set of benchmarks in
// addition to the reference timing that the final score will be based
// on. This way, all scores are relative to a reference run and higher
// scores implies better performance.
function BenchmarkSuite(name, reference, benchmarks) {
this.name = name;
this.reference = reference;
this.benchmarks = benchmarks;
BenchmarkSuite.suites.push(this);
}
// Keep track of all declared benchmark suites.
BenchmarkSuite.suites = [];
// Scores are not comparable across versions. Bump the version if
// you're making changes that will affect that scores, e.g. if you add
// a new benchmark or change an existing one.
BenchmarkSuite.version = '9';
// Override the alert function to throw an exception instead.
alert = function(s) {
throw "Alert called with argument: " + s;
};
// To make the benchmark results predictable, we replace Math.random
// with a 100% deterministic alternative.
BenchmarkSuite.ResetRNG = function() {
Math.random = (function() {
var seed = 49734321;
return function() {
// Robert Jenkins' 32 bit integer hash function.
seed = ((seed + 0x7ed55d16) + (seed << 12)) & 0xffffffff;
seed = ((seed ^ 0xc761c23c) ^ (seed >>> 19)) & 0xffffffff;
seed = ((seed + 0x165667b1) + (seed << 5)) & 0xffffffff;
seed = ((seed + 0xd3a2646c) ^ (seed << 9)) & 0xffffffff;
seed = ((seed + 0xfd7046c5) + (seed << 3)) & 0xffffffff;
seed = ((seed ^ 0xb55a4f09) ^ (seed >>> 16)) & 0xffffffff;
return (seed & 0xfffffff) / 0x10000000;
};
})();
}
// Runs all registered benchmark suites and optionally yields between
// each individual benchmark to avoid running for too long in the
// context of browsers. Once done, the final score is reported to the
// runner.
BenchmarkSuite.RunSuites = function(runner) {
var continuation = null;
var suites = BenchmarkSuite.suites;
var length = suites.length;
BenchmarkSuite.scores = [];
var index = 0;
function RunStep() {
while (continuation || index < length) {
if (continuation) {
continuation = continuation();
} else {
var suite = suites[index++];
if (runner.NotifyStart) runner.NotifyStart(suite.name);
continuation = suite.RunStep(runner);
}
if (continuation && typeof window != 'undefined' && window.setTimeout) {
window.setTimeout(RunStep, 25);
return;
}
}
// show final result
if (runner.NotifyScore) {
var score = BenchmarkSuite.GeometricMean(BenchmarkSuite.scores);
var formatted = BenchmarkSuite.FormatScore(100 * score);
runner.NotifyScore(formatted);
}
}
RunStep();
}
// Counts the total number of registered benchmarks. Useful for
// showing progress as a percentage.
BenchmarkSuite.CountBenchmarks = function() {
var result = 0;
var suites = BenchmarkSuite.suites;
for (var i = 0; i < suites.length; i++) {
result += suites[i].benchmarks.length;
}
return result;
}
// Computes the geometric mean of a set of numbers.
BenchmarkSuite.GeometricMean = function(numbers) {
var log = 0;
for (var i = 0; i < numbers.length; i++) {
log += Math.log(numbers[i]);
}
return Math.pow(Math.E, log / numbers.length);
}
// Computes the geometric mean of a set of throughput time measurements.
BenchmarkSuite.GeometricMeanTime = function(measurements) {
var log = 0;
for (var i = 0; i < measurements.length; i++) {
log += Math.log(measurements[i].time);
}
return Math.pow(Math.E, log / measurements.length);
}
// Computes the average of the worst samples. For example, if percentile is 99, this will report the
// average of the worst 1% of the samples.
BenchmarkSuite.AverageAbovePercentile = function(numbers, percentile) {
// Don't change the original array.
numbers = numbers.slice();
// Sort in ascending order.
numbers.sort(function(a, b) { return a - b; });
// Now the elements we want are at the end. Keep removing them until the array size shrinks too much.
// Examples assuming percentile = 99:
//
// - numbers.length starts at 100: we will remove just the worst entry and then not remove anymore,
// since then numbers.length / originalLength = 0.99.
//
// - numbers.length starts at 1000: we will remove the ten worst.
//
// - numbers.length starts at 10: we will remove just the worst.
var numbersWeWant = [];
var originalLength = numbers.length;
while (numbers.length / originalLength > percentile / 100)
numbersWeWant.push(numbers.pop());
var sum = 0;
for (var i = 0; i < numbersWeWant.length; ++i)
sum += numbersWeWant[i];
var result = sum / numbersWeWant.length;
// Do a sanity check.
if (numbers.length && result < numbers[numbers.length - 1]) {
throw "Sanity check fail: the worst case result is " + result +
" but we didn't take into account " + numbers;
}
return result;
}
// Computes the geometric mean of a set of latency measurements.
BenchmarkSuite.GeometricMeanLatency = function(measurements) {
var log = 0;
var hasLatencyResult = false;
for (var i = 0; i < measurements.length; i++) {
if (measurements[i].latency != 0) {
log += Math.log(measurements[i].latency);
hasLatencyResult = true;
}
}
if (hasLatencyResult) {
return Math.pow(Math.E, log / measurements.length);
} else {
return 0;
}
}
// Converts a score value to a string with at least three significant
// digits.
BenchmarkSuite.FormatScore = function(value) {
if (value > 100) {
return value.toFixed(0);
} else {
return value.toPrecision(3);
}
}
// Notifies the runner that we're done running a single benchmark in
// the benchmark suite. This can be useful to report progress.
BenchmarkSuite.prototype.NotifyStep = function(result) {
this.results.push(result);
if (this.runner.NotifyStep) this.runner.NotifyStep(result.benchmark.name);
}
// Notifies the runner that we're done with running a suite and that
// we have a result which can be reported to the user if needed.
BenchmarkSuite.prototype.NotifyResult = function() {
var mean = BenchmarkSuite.GeometricMeanTime(this.results);
var score = this.reference[0] / mean;
BenchmarkSuite.scores.push(score);
if (this.runner.NotifyResult) {
var formatted = BenchmarkSuite.FormatScore(100 * score);
this.runner.NotifyResult(this.name, formatted);
}
if (this.reference.length == 2) {
var meanLatency = BenchmarkSuite.GeometricMeanLatency(this.results);
if (meanLatency != 0) {
var scoreLatency = this.reference[1] / meanLatency;
BenchmarkSuite.scores.push(scoreLatency);
if (this.runner.NotifyResult) {
var formattedLatency = BenchmarkSuite.FormatScore(100 * scoreLatency)
this.runner.NotifyResult(this.name + "Latency", formattedLatency);
}
}
}
}
// Notifies the runner that running a benchmark resulted in an error.
BenchmarkSuite.prototype.NotifyError = function(error) {
if (this.runner.NotifyError) {
this.runner.NotifyError(this.name, error);
}
if (this.runner.NotifyStep) {
this.runner.NotifyStep(this.name);
}
}
// Runs a single benchmark for at least a second and computes the
// average time it takes to run a single iteration.
BenchmarkSuite.prototype.RunSingleBenchmark = function(benchmark, data) {
function Measure(data) {
var elapsed = 0;
var start = new Date();
// Run either for 1 second or for the number of iterations specified
// by minIterations, depending on the config flag doDeterministic.
for (var i = 0; (benchmark.doDeterministic ?
i<benchmark.minIterations : elapsed < 1000); i++) {
benchmark.run();
elapsed = new Date() - start;
}
if (data != null) {
data.runs += i;
data.elapsed += elapsed;
}
}
// Sets up data in order to skip or not the warmup phase.
if (!benchmark.doWarmup && data == null) {
data = { runs: 0, elapsed: 0 };
}
if (data == null) {
Measure(null);
return { runs: 0, elapsed: 0 };
} else {
Measure(data);
// If we've run too few iterations, we continue for another second.
if (data.runs < benchmark.minIterations) return data;
var usec = (data.elapsed * 1000) / data.runs;
var latencySamples = (benchmark.latencyResult != null) ? benchmark.latencyResult() : [0];
var percentile = 99.5;
var latency = BenchmarkSuite.AverageAbovePercentile(latencySamples, percentile) * 1000;
this.NotifyStep(new BenchmarkResult(benchmark, usec, latency));
return null;
}
}
// This function starts running a suite, but stops between each
// individual benchmark in the suite and returns a continuation
// function which can be invoked to run the next benchmark. Once the
// last benchmark has been executed, null is returned.
BenchmarkSuite.prototype.RunStep = function(runner) {
BenchmarkSuite.ResetRNG();
this.results = [];
this.runner = runner;
var length = this.benchmarks.length;
var index = 0;
var suite = this;
var data;
// Run the setup, the actual benchmark, and the tear down in three
// separate steps to allow the framework to yield between any of the
// steps.
function RunNextSetup() {
if (index < length) {
try {
suite.benchmarks[index].Setup();
} catch (e) {
suite.NotifyError(e);
return null;
}
return RunNextBenchmark;
}
suite.NotifyResult();
return null;
}
function RunNextBenchmark() {
try {
data = suite.RunSingleBenchmark(suite.benchmarks[index], data);
} catch (e) {
suite.NotifyError(e);
return null;
}
// If data is null, we're done with this benchmark.
return (data == null) ? RunNextTearDown : RunNextBenchmark();
}
function RunNextTearDown() {
try {
suite.benchmarks[index++].TearDown();
} catch (e) {
suite.NotifyError(e);
return null;
}
return RunNextSetup;
}
// Start out running the setup.
return RunNextSetup();
}
// Copyright 2009 the V8 project authors. All rights reserved.
// Copyright (C) 2015 Apple Inc. 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.
// This benchmark is based on a JavaScript log processing module used
// by the V8 profiler to generate execution time profiles for runs of
// JavaScript applications, and it effectively measures how fast the
// JavaScript engine is at allocating nodes and reclaiming the memory
// used for old nodes. Because of the way splay trees work, the engine
// also has to deal with a lot of changes to the large tree object
// graph.
var Splay = new BenchmarkSuite('Splay', [81491, 2739514], [
new Benchmark("Splay", true, false,
SplayRun, SplaySetup, SplayTearDown, SplayLatency)
]);
// Configuration.
var kSplayTreeSize = 8000;
var kSplayTreeModifications = 80;
var kSplayTreePayloadDepth = 5;
var splayTree = null;
var splaySampleTimeStart = 0.0;
function GeneratePayloadTree(depth, tag) {
if (depth == 0) {
return {
array : [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ],
string : 'String for key ' + tag + ' in leaf node'
};
} else {
return {
left: GeneratePayloadTree(depth - 1, tag),
right: GeneratePayloadTree(depth - 1, tag)
};
}
}
function GenerateKey() {
// The benchmark framework guarantees that Math.random is
// deterministic; see base.js.
return Math.random();
}
var splaySamples = [];
function SplayLatency() {
return splaySamples;
}
function SplayUpdateStats(time) {
var pause = time - splaySampleTimeStart;
splaySampleTimeStart = time;
splaySamples.push(pause);
}
function InsertNewNode() {
// Insert new node with a unique key.
var key;
do {
key = GenerateKey();
} while (splayTree.find(key) != null);
var payload = GeneratePayloadTree(kSplayTreePayloadDepth, String(key));
splayTree.insert(key, payload);
return key;
}
function SplaySetup() {
// Check if the platform has the performance.now high resolution timer.
// If not, throw exception and quit.
if (!performance.now) {
throw "PerformanceNowUnsupported";
}
splayTree = new SplayTree();
splaySampleTimeStart = performance.now()
for (var i = 0; i < kSplayTreeSize; i++) {
InsertNewNode();
if ((i+1) % 20 == 19) {
SplayUpdateStats(performance.now());
}
}
}
function SplayTearDown() {
// Allow the garbage collector to reclaim the memory
// used by the splay tree no matter how we exit the
// tear down function.
var keys = splayTree.exportKeys();
splayTree = null;
splaySamples = [];
// Verify that the splay tree has the right size.
var length = keys.length;
if (length != kSplayTreeSize) {
throw new Error("Splay tree has wrong size");
}
// Verify that the splay tree has sorted, unique keys.
for (var i = 0; i < length - 1; i++) {
if (keys[i] >= keys[i + 1]) {
throw new Error("Splay tree not sorted");
}
}
}
function SplayRun() {
// Replace a few nodes in the splay tree.
for (var i = 0; i < kSplayTreeModifications; i++) {
var key = InsertNewNode();
var greatest = splayTree.findGreatestLessThan(key);
if (greatest == null) splayTree.remove(key);
else splayTree.remove(greatest.key);
}
SplayUpdateStats(performance.now());
}
/**
* Constructs a Splay tree. A splay tree is a self-balancing binary
* search tree with the additional property that recently accessed
* elements are quick to access again. It performs basic operations
* such as insertion, look-up and removal in O(log(n)) amortized time.
*
* @constructor
*/
function SplayTree() {
};
/**
* Pointer to the root node of the tree.
*
* @type {SplayTree.Node}
* @private
*/
SplayTree.prototype.root_ = null;
/**
* @return {boolean} Whether the tree is empty.
*/
SplayTree.prototype.isEmpty = function() {
return !this.root_;
};
/**
* Inserts a node into the tree with the specified key and value if
* the tree does not already contain a node with the specified key. If
* the value is inserted, it becomes the root of the tree.
*
* @param {number} key Key to insert into the tree.
* @param {*} value Value to insert into the tree.
*/
SplayTree.prototype.insert = function(key, value) {
if (this.isEmpty()) {
this.root_ = new SplayTree.Node(key, value);
return;
}
// Splay on the key to move the last node on the search path for
// the key to the root of the tree.
this.splay_(key);
if (this.root_.key == key) {
return;
}
var node = new SplayTree.Node(key, value);
if (key > this.root_.key) {
node.left = this.root_;
node.right = this.root_.right;
this.root_.right = null;
} else {
node.right = this.root_;
node.left = this.root_.left;
this.root_.left = null;
}
this.root_ = node;
};
/**
* Removes a node with the specified key from the tree if the tree
* contains a node with this key. The removed node is returned. If the
* key is not found, an exception is thrown.
*
* @param {number} key Key to find and remove from the tree.
* @return {SplayTree.Node} The removed node.
*/
SplayTree.prototype.remove = function(key) {
if (this.isEmpty()) {
throw Error('Key not found: ' + key);
}
this.splay_(key);
if (this.root_.key != key) {
throw Error('Key not found: ' + key);
}
var removed = this.root_;
if (!this.root_.left) {
this.root_ = this.root_.right;
} else {
var right = this.root_.right;
this.root_ = this.root_.left;
// Splay to make sure that the new root has an empty right child.
this.splay_(key);
// Insert the original right child as the right child of the new
// root.
this.root_.right = right;
}
return removed;
};
/**
* Returns the node having the specified key or null if the tree doesn't contain
* a node with the specified key.
*
* @param {number} key Key to find in the tree.
* @return {SplayTree.Node} Node having the specified key.
*/
SplayTree.prototype.find = function(key) {
if (this.isEmpty()) {
return null;
}
this.splay_(key);
return this.root_.key == key ? this.root_ : null;
};
/**
* @return {SplayTree.Node} Node having the maximum key value.
*/
SplayTree.prototype.findMax = function(opt_startNode) {
if (this.isEmpty()) {
return null;
}
var current = opt_startNode || this.root_;
while (current.right) {
current = current.right;
}
return current;
};
/**
* @return {SplayTree.Node} Node having the maximum key value that
* is less than the specified key value.
*/
SplayTree.prototype.findGreatestLessThan = function(key) {
if (this.isEmpty()) {
return null;
}
// Splay on the key to move the node with the given key or the last
// node on the search path to the top of the tree.
this.splay_(key);
// Now the result is either the root node or the greatest node in
// the left subtree.
if (this.root_.key < key) {
return this.root_;
} else if (this.root_.left) {
return this.findMax(this.root_.left);
} else {
return null;
}
};
/**
* @return {Array<*>} An array containing all the keys of tree's nodes.
*/
SplayTree.prototype.exportKeys = function() {
var result = [];
if (!this.isEmpty()) {
this.root_.traverse_(function(node) { result.push(node.key); });
}
return result;
};
/**
* Perform the splay operation for the given key. Moves the node with
* the given key to the top of the tree. If no node has the given
* key, the last node on the search path is moved to the top of the
* tree. This is the simplified top-down splaying algorithm from:
* "Self-adjusting Binary Search Trees" by Sleator and Tarjan
*
* @param {number} key Key to splay the tree on.
* @private
*/
SplayTree.prototype.splay_ = function(key) {
if (this.isEmpty()) {
return;
}
// Create a dummy node. The use of the dummy node is a bit
// counter-intuitive: The right child of the dummy node will hold
// the L tree of the algorithm. The left child of the dummy node
// will hold the R tree of the algorithm. Using a dummy node, left
// and right will always be nodes and we avoid special cases.
var dummy, left, right;
dummy = left = right = new SplayTree.Node(null, null);
var current = this.root_;
while (true) {
if (key < current.key) {
if (!current.left) {
break;
}
if (key < current.left.key) {
// Rotate right.
var tmp = current.left;
current.left = tmp.right;
tmp.right = current;
current = tmp;
if (!current.left) {
break;
}
}
// Link right.
right.left = current;
right = current;
current = current.left;
} else if (key > current.key) {
if (!current.right) {
break;
}
if (key > current.right.key) {
// Rotate left.
var tmp = current.right;
current.right = tmp.left;
tmp.left = current;
current = tmp;
if (!current.right) {
break;
}
}
// Link left.
left.right = current;
left = current;
current = current.right;
} else {
break;
}
}
// Assemble.
left.right = current.left;
right.left = current.right;
current.left = dummy.right;
current.right = dummy.left;
this.root_ = current;
};
/**
* Constructs a Splay tree node.
*
* @param {number} key Key.
* @param {*} value Value.
*/
SplayTree.Node = function(key, value) {
this.key = key;
this.value = value;
};
/**
* @type {SplayTree.Node}
*/
SplayTree.Node.prototype.left = null;
/**
* @type {SplayTree.Node}
*/
SplayTree.Node.prototype.right = null;
/**
* Performs an ordered traversal of the subtree starting at
* this SplayTree.Node.
*
* @param {function(SplayTree.Node)} f Visitor function.
* @private
*/
SplayTree.Node.prototype.traverse_ = function(f) {
var current = this;
while (current) {
var left = current.left;
if (left) left.traverse_(f);
f(current);
current = current.right;
}
};
function jscSetUp() {
SplaySetup();
}
function jscTearDown() {
SplayTearDown();
}
function jscRun() {
SplayRun();
}
jscSetUp();
var __before = preciseTime();
var times = [];
for (var i = 0; i < 10000; ++i) {
//for (var i = 0; i < 1000000; ++i) {
var _before = preciseTime();
jscRun();
var _after = preciseTime();
times.push(_after - _before);
flashHeapAccess();
}
var __after = preciseTime();
jscTearDown();
function averageAbovePercentile(numbers, percentile) {
// Don't change the original array.
numbers = numbers.slice();
// Sort in ascending order.
numbers.sort(function(a, b) { return a - b; });
// Now the elements we want are at the end. Keep removing them until the array size shrinks too much.
// Examples assuming percentile = 99:
//
// - numbers.length starts at 100: we will remove just the worst entry and then not remove anymore,
// since then numbers.length / originalLength = 0.99.
//
// - numbers.length starts at 1000: we will remove the ten worst.
//
// - numbers.length starts at 10: we will remove just the worst.
var numbersWeWant = [];
var originalLength = numbers.length;
while (numbers.length / originalLength > percentile / 100)
numbersWeWant.push(numbers.pop());
var sum = 0;
for (var i = 0; i < numbersWeWant.length; ++i)
sum += numbersWeWant[i];
var result = sum / numbersWeWant.length;
// Do a sanity check.
if (numbers.length && result < numbers[numbers.length - 1]) {
throw "Sanity check fail: the worst case result is " + result +
" but we didn't take into account " + numbers;
}
return result;
}
print("That took " + (__after - __before) * 1000 + " ms.");
function printPercentile(percentile)
{
print("Above " + percentile + "%: " + averageAbovePercentile(times, percentile) * 1000 + " ms.");
}
printPercentile(99.9);
printPercentile(99.5);
printPercentile(99);
printPercentile(97.5);
printPercentile(95);
printPercentile(90);
printPercentile(75);
printPercentile(50);
printPercentile(0);
gc();