extensions/browser/api/web_request/web_request_time_tracker.h

// 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.

#ifndef EXTENSIONS_BROWSER_API_WEB_REQUEST_WEB_REQUEST_TIME_TRACKER_H_
#define EXTENSIONS_BROWSER_API_WEB_REQUEST_WEB_REQUEST_TIME_TRACKER_H_

#include <stddef.h>
#include <stdint.h>

#include <map>

#include "base/gtest_prod_util.h"
#include "base/macros.h"
#include "base/time/time.h"

// This class monitors how much delay extensions add to network requests
// by using the webRequest API.
class ExtensionWebRequestTimeTracker {
 public:
  ExtensionWebRequestTimeTracker();
  ~ExtensionWebRequestTimeTracker();

  // Records the time that a request was created.
  void LogRequestStartTime(int64_t request_id, const base::Time& start_time);

  // Records the time that a request either completed or encountered an error.
  void LogRequestEndTime(int64_t request_id, const base::Time& end_time);

  // Records an additional delay for the given request caused by all extensions
  // combined.
  void IncrementTotalBlockTime(int64_t request_id,
                               const base::TimeDelta& block_time);

  // Called when an extension has canceled the given request.
  void SetRequestCanceled(int64_t request_id);

  // Called when an extension has redirected the given request to another URL.
  void SetRequestRedirected(int64_t request_id);

 private:
  FRIEND_TEST_ALL_PREFIXES(ExtensionWebRequestTimeTrackerTest, Histograms);

  // Timing information for a single request.
  struct RequestTimeLog {
    base::Time request_start_time;
    base::TimeDelta block_duration;

    RequestTimeLog();
    ~RequestTimeLog();

   private:
    DISALLOW_COPY_AND_ASSIGN(RequestTimeLog);
  };

  // Records UMA metrics for the given request and its end time.
  void AnalyzeLogRequest(const RequestTimeLog& log, const base::Time& end_time);

  // A map of current request IDs to timing info for each request.
  std::map<int64_t, RequestTimeLog> request_time_logs_;

  DISALLOW_COPY_AND_ASSIGN(ExtensionWebRequestTimeTracker);
};

#endif  // EXTENSIONS_BROWSER_API_WEB_REQUEST_WEB_REQUEST_TIME_TRACKER_H_