JSTests/stress/splay-flash-access.js

//@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();