[polymer] Merge of master into polymer10-migration

netlog_viewer/log_grouper.js

+// Copyright (c) 2012 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.
+
+/**
+ * @fileoverview
+ * LogGroupEntry is a wrapper around log entries, which makes it easier to
+ * find the corresponding start/end of events.
+ *
+ * This is used internally by the log and timeline views to pretty print
+ * collections of log entries.
+ */
+
+// TODO(eroman): document these methods!
+
+var LogGroupEntry = (function() {
+  'use strict';
+
+  function LogGroupEntry(origEntry, index) {
+    this.orig = origEntry;
+    this.index = index;
+  }
+
+  LogGroupEntry.prototype = {
+    isBegin: function() {
+      return this.orig.phase == EventPhase.PHASE_BEGIN;
+    },
+
+    isEnd: function() {
+      return this.orig.phase == EventPhase.PHASE_END;
+    },
+
+    getDepth: function() {
+      var depth = 0;
+      var p = this.parentEntry;
+      while (p) {
+        depth += 1;
+        p = p.parentEntry;
+      }
+      return depth;
+    }
+  };
+
+  function findParentIndex(parentStack, eventType) {
+    for (var i = parentStack.length - 1; i >= 0; --i) {
+      if (parentStack[i].orig.type == eventType)
+        return i;
+    }
+    return -1;
+  }
+
+  /**
+   * Returns a list of LogGroupEntrys. This basically wraps the original log
+   * entry, but makes it easier to find the start/end of the event.
+   */
+  LogGroupEntry.createArrayFrom = function(origEntries) {
+    var groupedEntries = [];
+
+    // Stack of enclosing PHASE_BEGIN elements.
+    var parentStack = [];
+
+    for (var i = 0; i < origEntries.length; ++i) {
+      var origEntry = origEntries[i];
+
+      var groupEntry = new LogGroupEntry(origEntry, i);
+      groupedEntries.push(groupEntry);
+
+      // If this is the end of an event, match it to the start.
+      if (groupEntry.isEnd()) {
+        // Walk up the parent stack to find the corresponding BEGIN for this
+        // END.
+        var parentIndex =
+            findParentIndex(parentStack, groupEntry.orig.type);
+
+        if (parentIndex == -1) {
+          // Unmatched end.
+        } else {
+          groupEntry.begin = parentStack[parentIndex];
+
+          // Consider this as the terminator for all open BEGINs up until
+          // parentIndex.
+          while (parentIndex < parentStack.length) {
+            var p = parentStack.pop();
+            p.end = groupEntry;
+          }
+        }
+      }
+
+      // Inherit the current parent.
+      if (parentStack.length > 0)
+        groupEntry.parentEntry = parentStack[parentStack.length - 1];
+
+      if (groupEntry.isBegin())
+        parentStack.push(groupEntry);
+    }
+
+    return groupedEntries;
+  };
+
+  return LogGroupEntry;
+})();
+