content/browser/download/download_resource_handler.h

   1 // Copyright (c) 2012 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 CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_RESOURCE_HANDLER_H_
   6 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_RESOURCE_HANDLER_H_
   7
   8 #include <string>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "content/browser/loader/resource_handler.h"
  13 #include "content/public/browser/download_interrupt_reasons.h"
  14 #include "content/public/browser/download_manager.h"
  15 #include "content/public/browser/download_save_info.h"
  16 #include "content/public/browser/download_url_parameters.h"
  17
  18 namespace net {
  19 class URLRequest;
  20 }  // namespace net
  21
  22 namespace content {
  23 class ByteStreamReader;
  24 class ByteStreamWriter;
  25 class DownloadRequestHandle;
  26 class PowerSaveBlocker;
  27 struct DownloadCreateInfo;
  28
  29 // Forwards data to the download thread.
  30 class CONTENT_EXPORT DownloadResourceHandler
  31     : public ResourceHandler,
  32       public base::SupportsWeakPtr<DownloadResourceHandler> {
  33  public:
  34   struct DownloadTabInfo;
  35
  36   // Size of the buffer used between the DownloadResourceHandler and the
  37   // downstream receiver of its output.
  38   static const int kDownloadByteStreamSize;
  39
  40   // started_cb will be called exactly once on the UI thread.
  41   // |id| should be invalid if the id should be automatically assigned.
  42   DownloadResourceHandler(
  43       uint32 id,
  44       net::URLRequest* request,
  45       const DownloadUrlParameters::OnStartedCallback& started_cb,
  46       scoped_ptr<DownloadSaveInfo> save_info);
  47
  48   bool OnRequestRedirected(const net::RedirectInfo& redirect_info,
  49                            ResourceResponse* response,
  50                            bool* defer) override;
  51
  52   // Send the download creation information to the download thread.
  53   bool OnResponseStarted(ResourceResponse* response, bool* defer) override;
  54
  55   // Pass-through implementation.
  56   bool OnWillStart(const GURL& url, bool* defer) override;
  57
  58   // Pass-through implementation.
  59   bool OnBeforeNetworkStart(const GURL& url, bool* defer) override;
  60
  61   // Create a new buffer, which will be handed to the download thread for file
  62   // writing and deletion.
  63   bool OnWillRead(scoped_refptr<net::IOBuffer>* buf,
  64                   int* buf_size,
  65                   int min_size) override;
  66
  67   bool OnReadCompleted(int bytes_read, bool* defer) override;
  68
  69   void OnResponseCompleted(const net::URLRequestStatus& status,
  70                            const std::string& security_info,
  71                            bool* defer) override;
  72
  73   // N/A to this flavor of DownloadHandler.
  74   void OnDataDownloaded(int bytes_downloaded) override;
  75
  76   void PauseRequest();
  77   void ResumeRequest();
  78
  79   // May result in this object being deleted by its owner.
  80   void CancelRequest();
  81
  82   std::string DebugString() const;
  83
  84  private:
  85   ~DownloadResourceHandler() override;
  86
  87   // Arrange for started_cb_ to be called on the UI thread with the
  88   // below values, nulling out started_cb_.  Should only be called
  89   // on the IO thread.
  90   void CallStartedCB(DownloadItem* item,
  91                      DownloadInterruptReason interrupt_reason);
  92
  93   uint32 download_id_;
  94   // This is read only on the IO thread, but may only
  95   // be called on the UI thread.
  96   DownloadUrlParameters::OnStartedCallback started_cb_;
  97   scoped_ptr<DownloadSaveInfo> save_info_;
  98
  99   // Stores information about the download that must be acquired on the UI
 100   // thread before StartOnUIThread is called.
 101   // Created on IO thread, but only accessed on UI thread. |tab_info_| holds
 102   // the pointer until we pass it off to StartOnUIThread or DeleteSoon.
 103   // Marked as a scoped_ptr<> to indicate ownership of the structure, but
 104   // deletion must occur on the IO thread.
 105   scoped_ptr<DownloadTabInfo> tab_info_;
 106
 107   // Data flow
 108   scoped_refptr<net::IOBuffer> read_buffer_;       // From URLRequest.
 109   scoped_ptr<ByteStreamWriter> stream_writer_; // To rest of system.
 110
 111   // Keeps the system from sleeping while this ResourceHandler is alive. If the
 112   // system enters power saving mode while a request is alive, it can cause the
 113   // request to fail and the associated download will be interrupted.
 114   scoped_ptr<PowerSaveBlocker> power_save_blocker_;
 115
 116   // The following are used to collect stats.
 117   base::TimeTicks download_start_time_;
 118   base::TimeTicks last_read_time_;
 119   base::TimeTicks last_stream_pause_time_;
 120   base::TimeDelta total_pause_time_;
 121   size_t last_buffer_size_;
 122   int64 bytes_read_;
 123
 124   int pause_count_;
 125   bool was_deferred_;
 126
 127   // For DCHECKing
 128   bool on_response_started_called_;
 129
 130   static const int kReadBufSize = 32768;  // bytes
 131   static const int kThrottleTimeMs = 200;  // milliseconds
 132
 133   DISALLOW_COPY_AND_ASSIGN(DownloadResourceHandler);
 134 };
 135
 136 }  // namespace content
 137
 138 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_RESOURCE_HANDLER_H_