components/update_client/request_sender.h

   1 // Copyright 2014 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 COMPONENTS_UPDATE_CLIENT_REQUEST_SENDER_H_
   6 #define COMPONENTS_UPDATE_CLIENT_REQUEST_SENDER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/callback.h"
  12 #include "base/compiler_specific.h"
  13 #include "base/macros.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/threading/thread_checker.h"
  16 #include "net/url_request/url_fetcher_delegate.h"
  17 #include "url/gurl.h"
  18
  19 namespace net {
  20 class URLFetcher;
  21 }
  22
  23 namespace update_client {
  24
  25 class Configurator;
  26
  27 // Sends a request to one of the urls provided. The class implements a chain
  28 // of responsibility design pattern, where the urls are tried in the order they
  29 // are specified, until the request to one of them succeeds or all have failed.
  30 class RequestSender : public net::URLFetcherDelegate {
  31  public:
  32   // The |source| refers to the fetcher object used to make the request. This
  33   // parameter can be NULL in some error cases.
  34   typedef base::Callback<void(const net::URLFetcher* source)>
  35       RequestSenderCallback;
  36
  37   explicit RequestSender(const Configurator& config);
  38   ~RequestSender() override;
  39
  40   void Send(const std::string& request_string,
  41             const std::vector<GURL>& urls,
  42             const RequestSenderCallback& request_sender_callback);
  43
  44  private:
  45   void SendInternal();
  46
  47   // Overrides for URLFetcherDelegate.
  48   void OnURLFetchComplete(const net::URLFetcher* source) override;
  49
  50   const Configurator& config_;
  51   std::vector<GURL> urls_;
  52   std::vector<GURL>::const_iterator cur_url_;
  53   scoped_ptr<net::URLFetcher> url_fetcher_;
  54   std::string request_string_;
  55   RequestSenderCallback request_sender_callback_;
  56
  57   base::ThreadChecker thread_checker_;
  58
  59   DISALLOW_COPY_AND_ASSIGN(RequestSender);
  60 };
  61
  62 }  // namespace update_client
  63
  64 #endif  // COMPONENTS_UPDATE_CLIENT_REQUEST_SENDER_H_