net/proxy/polling_proxy_config_service.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_PROXY_POLLING_PROXY_CONFIG_SERVICE_H_
   6 #define NET_PROXY_POLLING_PROXY_CONFIG_SERVICE_H_
   7
   8 #include "base/compiler_specific.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/time/time.h"
  11 #include "net/proxy/proxy_config_service.h"
  12
  13 namespace net {
  14
  15 // PollingProxyConfigService is a base class for creating ProxyConfigService
  16 // implementations that use polling to notice when settings have change.
  17 //
  18 // It runs code to get the current proxy settings on a background worker
  19 // thread, and notifies registered observers when the value changes.
  20 class NET_EXPORT_PRIVATE PollingProxyConfigService : public ProxyConfigService {
  21  public:
  22   // ProxyConfigService implementation:
  23   virtual void AddObserver(Observer* observer) OVERRIDE;
  24   virtual void RemoveObserver(Observer* observer) OVERRIDE;
  25   virtual ConfigAvailability GetLatestProxyConfig(ProxyConfig* config) OVERRIDE;
  26   virtual void OnLazyPoll() OVERRIDE;
  27
  28  protected:
  29   // Function for retrieving the current proxy configuration.
  30   // Implementors must be threadsafe as the function will be invoked from
  31   // worker threads.
  32   typedef void (*GetConfigFunction)(ProxyConfig*);
  33
  34   // Creates a polling-based ProxyConfigService which will test for new
  35   // settings at most every |poll_interval| time by calling |get_config_func|
  36   // on a worker thread.
  37   PollingProxyConfigService(
  38       base::TimeDelta poll_interval,
  39       GetConfigFunction get_config_func);
  40
  41   virtual ~PollingProxyConfigService();
  42
  43   // Polls for changes by posting a task to the worker pool.
  44   void CheckForChangesNow();
  45
  46  private:
  47   class Core;
  48   scoped_refptr<Core> core_;
  49
  50   DISALLOW_COPY_AND_ASSIGN(PollingProxyConfigService);
  51 };
  52
  53 }  // namespace net
  54
  55 #endif  // NET_PROXY_POLLING_PROXY_CONFIG_SERVICE_H_