Chrome power profiler service

content/browser/devtools/devtools_power_handler.cc

+// Copyright 2014 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 "content/browser/devtools/devtools_power_handler.h"
+
+#include "base/bind.h"
+#include "base/json/json_reader.h"
+#include "base/json/json_writer.h"
+#include "base/values.h"
+#include "content/browser/devtools/devtools_protocol_constants.h"
+#include "content/browser/power_profiler/power_profiler_service.h"
+
+namespace content {
+
+DevToolsPowerHandler::DevToolsPowerHandler() {
+  RegisterCommandHandler(devtools::Power::start::kName,
+                         base::Bind(&DevToolsPowerHandler::OnStart,
+                                    base::Unretained(this)));
+  RegisterCommandHandler(devtools::Power::end::kName,
+                         base::Bind(&DevToolsPowerHandler::OnEnd,
+                                    base::Unretained(this)));
+}
+
+DevToolsPowerHandler::~DevToolsPowerHandler() {
+}
+
+void DevToolsPowerHandler::OnPowerEvent(const PowerEventVector& events) {
+  std::string json_string;
+  base::DictionaryValue message_object;
+  base::DictionaryValue* params = new base::DictionaryValue();
+  base::ListValue* event_list = new base::ListValue();
+
+  std::vector<PowerEvent>::const_iterator iter;
+  for (iter = events.begin(); iter != events.end(); ++iter) {
+    base::DictionaryValue* event_body = new base::DictionaryValue();
+
+    DCHECK(iter->type < PowerEvent::ID_COUNT);
+    event_body->SetString("type", kPowerTypeNames[iter->type]);
+    event_body->SetDouble("timestamp",
+        convertMonotonicTimeToWallTime(iter->time).ToDoubleT() * 1000.0);

[qsr, 2014/02/13 16:40:13]

Any reason for this to be in ms, instead of second? Especially when webkit
itself is using seconds?

[Pan, 2014/02/14 07:17:02]

I don't have strong preference, the reason I used ms here is to align with other
events that InspectorTimelineAgent send out(startTime and endTime is in ms).
anyway, we should described it in protocol.

+    event_body->SetDouble("value", iter->value);
+    event_list->Append(event_body);
+  }
+
+  params->Set(devtools::Power::dataAvailable::kParamValue, event_list);
+  message_object.Set("params", params);
+  message_object.SetString("method", devtools::Power::dataAvailable::kName);
+  base::JSONWriter::Write(&message_object, &json_string);
+
+  SendRawMessage(json_string);
+}
+
+base::Time DevToolsPowerHandler::convertMonotonicTimeToWallTime(
+    const base::TimeTicks& tick) {
+  return base::Time::UnixEpoch() + (tick - base::TimeTicks::UnixEpoch());
+}
+
+scoped_refptr<DevToolsProtocol::Response>
+DevToolsPowerHandler::OnStart(
+    scoped_refptr<DevToolsProtocol::Command> command) {
+  if (PowerProfilerService::GetInstance()->IsAvailable()) {
+    PowerProfilerService::GetInstance()->AddObserver(this);
+    return command->SuccessResponse(NULL);
+  }
+
+  return command->InternalErrorResponse("Power profiler service unavailable");
+}
+
+scoped_refptr<DevToolsProtocol::Response>
+DevToolsPowerHandler::OnEnd(
+    scoped_refptr<DevToolsProtocol::Command> command) {

[qsr, 2014/02/13 16:40:13]

This fits on a singe line.

[Pan, 2014/02/14 07:17:02]

Done.

+  if (PowerProfilerService::GetInstance()->IsAvailable()) {
+    PowerProfilerService::GetInstance()->RemoveObserver(this);
+    return command->SuccessResponse(NULL);
+  }
+
+  return command->InternalErrorResponse("Power profiler service unavailable");
+}
+
+}  // namespace content