Implement LoadLog, and hook up HostResolverImpl to LoadLog.

The functionality in load_log_util.h is currently unused, but since it motivates the implementation of LoadLog, figured it should be included with this review.

Note that I decided against defining the loggable event types as LoadStates, since I wanted more flexibility in adding crazy stuff, and they really seem too implementation specific to be in LoadStates.

BUG=http://crbug.com/14478
TEST=net_unittests
Review URL: http://codereview.chromium.org/165404

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@23412 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 37 insertions, 0 deletions

diff --git a/net/base/load_log.cc b/net/base/load_log.cc
new file mode 100644
index 0000000..120a58b
--- /dev/null
+++ b/net/base/load_log.cc
@@ -0,0 +1,37 @@
+// 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.
+
+#include "net/base/load_log.h"
+
+namespace net {
+
+LoadLog::LoadLog() {
+}
+
+// static
+const char* LoadLog::EventTypeToString(EventType event) {
+  switch (event) {
+#define EVENT_TYPE(label) case TYPE_ ## label: return #label;
+#include "net/base/load_log_event_type_list.h"
+#undef EVENT_TYPE
+  }
+  return NULL;
+}
+
+void LoadLog::Add(base::TimeTicks t, EventType event, EventPhase phase) {
+  // Minor optimization. TODO(eroman): use StackVector instead.
+  if (events_.empty())
+    events_.reserve(kMaxNumEntries / 2);
+
+  // Enforce a bound of kMaxNumEntries -- when we reach it, make it so the
+  // final entry in the list is |TYPE_LOG_TRUNCATED|.
+
+  if (events_.size() + 1 == kMaxNumEntries)
+    events_.push_back(Event(t, TYPE_LOG_TRUNCATED, PHASE_NONE));
+
+  if (events_.size() < kMaxNumEntries)
+    events_.push_back(Event(t, event, phase));
+}
+
+}  // namespace net