components/data_reduction_proxy/browser/data_reduction_proxy_usage_stats.h

// 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.

#ifndef COMPONENTS_DATA_REDUCTION_PROXY_BROWSER_DATA_REDUCTION_PROXY_USAGE_STATS_H_
#define COMPONENTS_DATA_REDUCTION_PROXY_BROWSER_DATA_REDUCTION_PROXY_USAGE_STATS_H_

#include "base/message_loop/message_loop_proxy.h"
#include "base/threading/thread_checker.h"
#include "components/data_reduction_proxy/browser/data_reduction_proxy_params.h"
#include "net/base/host_port_pair.h"
#include "net/base/network_change_notifier.h"

namespace data_reduction_proxy {

class DataReductionProxyUsageStats
    : public net::NetworkChangeNotifier::NetworkChangeObserver {
 public:
  // MessageLoopProxy instances are owned by io_thread. |params| outlives
  // this class instance.
  DataReductionProxyUsageStats(DataReductionProxyParams* params,
                               base::MessageLoopProxy* ui_thread_proxy,
                               base::MessageLoopProxy* io_thread_proxy);
  virtual ~DataReductionProxyUsageStats();

  /**
   * Callback intended to be called from |ChromeNetworkDelegate| when a
   * request completes. This method is used to gather usage stats.
   */
  void OnUrlRequestCompleted(const net::URLRequest* request, bool started);

  /**
   * Determines whether the data reduction proxy is unreachable.
   * Returns true if data reduction proxy is unreachable.
   */
  bool isDataReductionProxyUnreachable();

 private:
  DataReductionProxyParams* data_reduction_proxy_params_;
  base::MessageLoopProxy* ui_thread_proxy_;
  base::MessageLoopProxy* io_thread_proxy_;

  // The following 2 fields are used to determine if data reduction proxy is
  // unreachable. We keep a count of requests which should go through
  // data request proxy, as well as those which actually do. The proxy is
  // unreachable if no successful requests are made through it despite a
  // non-zero number of requests being eligible.

  // Count of requests which will be tried to be sent through data reduction
  // proxy. The count is only based on the config and not the bad proxy list.
  // Explicit bypasses are not part of this count. This is the desired behavior
  // since otherwise both counts would be identical.
  unsigned long eligible_num_requests_through_proxy_;
  // Count of successfull requests through data reduction proxy.
  unsigned long actual_num_requests_through_proxy_;

  // NetworkChangeNotifier::NetworkChangeObserver:
  virtual void OnNetworkChanged(
      net::NetworkChangeNotifier::ConnectionType type) OVERRIDE;

  void IncRequestCountsOnUiThread(bool actual);
  void ClearRequestCountsOnUiThread();

  base::ThreadChecker thread_checker_;

  DISALLOW_COPY_AND_ASSIGN(DataReductionProxyUsageStats);
};

}  // namespace data_reduction_proxy

#endif  // COMPONENTS_DATA_REDUCTION_PROXY_BROWSER_DATA_REDUCTION_PROXY_USAGE_STATS_H_