Import Traceline, a Windows performance trace event logger.

tools/traceline/traceline/scripts/heap.js

Index: tools/traceline/traceline/scripts/heap.js
diff --git a/tools/traceline/traceline/scripts/heap.js b/tools/traceline/traceline/scripts/heap.js
new file mode 100755
index 0000000000000000000000000000000000000000..e8b57a781fa1c99dcac472076f2598393b0a1e49
--- /dev/null
+++ b/tools/traceline/traceline/scripts/heap.js
@@ -0,0 +1,69 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// You should run this with v8, like v8_shell_sample alloc.js datafile.json
+
+function toHex(num) {
+  var str = "";
+  var table = "0123456789abcdef";
+  while (num != 0) {
+    str = table.charAt(num & 0xf) + str;
+    num >>= 4;
+  }
+  return str;
+}
+
+function dump(obj) {
+  for (var key in obj) {
+    print('key: ' + key);
+    print('  ' + obj[key]);
+  }
+}
+
+function TopN(n) {
+  this.n = n;
+  this.min = 0;
+  this.sorted = [ ];
+}
+
+TopN.prototype.add =
+function(num, data) {
+  if (num < this.min)
+    return;
+
+  this.sorted.push([num, data]);
+  this.sorted.sort(function(a, b) { return b[0] - a[0] });
+  if (this.sorted.length > this.n)
+    this.sorted.pop();
+
+  this.min = this.sorted[this.sorted.lenth - 1];
+};
+
+TopN.prototype.datas =
+function() {
+  var datas = [ ];
+  for (var i = 0, il = this.sorted.length; i < il; ++i) {
+    datas.push(this.sorted[i][1]);
+  }
+  return datas;
+};
+
+function parseEvents(z) {
+  var topper = new TopN(1000);
+
+  // Find the largest allocation.
+  for (var i = 0, il = z.length; i < il; ++i) {
+    var e = z[i];
+
+    if (e['eventtype'] == 'EVENT_TYPE_ALLOCHEAP') {
+      var size = e['heapsize'];
+      topper.add(e['heapsize'], e);
+    }
+  }
+
+  var datas = topper.datas();
+  for (var i = 0, il = datas.length; i < il; ++i) {
+    dump(datas[i]);
+  }
+}