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 "base/timer/timer.h"
  13 #include "content/browser/loader/resource_handler.h"
  14 #include "content/public/browser/download_interrupt_reasons.h"
  15 #include "content/public/browser/download_manager.h"
  16 #include "content/public/browser/download_save_info.h"
  17 #include "content/public/browser/download_url_parameters.h"
  18
  19 namespace net {
  20 class URLRequest;
  21 }  // namespace net
  22
  23 namespace content {
  24 class ByteStreamReader;
  25 class ByteStreamWriter;
  26 class DownloadRequestHandle;
  27 class PowerSaveBlocker;
  28 struct DownloadCreateInfo;
  29
  30 // Forwards data to the download thread.
  31 class CONTENT_EXPORT DownloadResourceHandler
  32     : public ResourceHandler,
  33       public base::SupportsWeakPtr<DownloadResourceHandler> {
  34  public:
  35   struct DownloadTabInfo;
  36
  37   // Size of the buffer used between the DownloadResourceHandler and the
  38   // downstream receiver of its output.
  39   static const int kDownloadByteStreamSize;
  40
  41   // started_cb will be called exactly once on the UI thread.
  42   // |id| should be invalid if the id should be automatically assigned.
  43   DownloadResourceHandler(
  44       uint32 id,
  45       net::URLRequest* request,
  46       const DownloadUrlParameters::OnStartedCallback& started_cb,
  47       scoped_ptr<DownloadSaveInfo> save_info);
  48
  49   virtual bool OnUploadProgress(uint64 position, uint64 size) OVERRIDE;
  50
  51   virtual bool OnRequestRedirected(const GURL& url,
  52                                    ResourceResponse* response,
  53                                    bool* defer) OVERRIDE;
  54
  55   // Send the download creation information to the download thread.
  56   virtual bool OnResponseStarted(ResourceResponse* response,
  57                                  bool* defer) OVERRIDE;
  58
  59   // Pass-through implementation.
  60   virtual bool OnWillStart(const GURL& url, bool* defer) OVERRIDE;
  61
  62   // Pass-through implementation.
  63   virtual bool OnBeforeNetworkStart(const GURL& url, bool* defer) OVERRIDE;
  64
  65   // Create a new buffer, which will be handed to the download thread for file
  66   // writing and deletion.
  67   virtual bool OnWillRead(scoped_refptr<net::IOBuffer>* buf,
  68                           int* buf_size,
  69                           int min_size) OVERRIDE;
  70
  71   virtual bool OnReadCompleted(int bytes_read, bool* defer) OVERRIDE;
  72
  73   virtual void OnResponseCompleted(const net::URLRequestStatus& status,
  74                                    const std::string& security_info,
  75                                    bool* defer) OVERRIDE;
  76
  77   // N/A to this flavor of DownloadHandler.
  78   virtual void OnDataDownloaded(int bytes_downloaded) OVERRIDE;
  79
  80   void PauseRequest();
  81   void ResumeRequest();
  82
  83   // May result in this object being deleted by its owner.
  84   void CancelRequest();
  85
  86   std::string DebugString() const;
  87
  88  private:
  89   virtual ~DownloadResourceHandler();
  90
  91   // Arrange for started_cb_ to be called on the UI thread with the
  92   // below values, nulling out started_cb_.  Should only be called
  93   // on the IO thread.
  94   void CallStartedCB(DownloadItem* item,
  95                      DownloadInterruptReason interrupt_reason);
  96
  97   uint32 download_id_;
  98   // This is read only on the IO thread, but may only
  99   // be called on the UI thread.
 100   DownloadUrlParameters::OnStartedCallback started_cb_;
 101   scoped_ptr<DownloadSaveInfo> save_info_;
 102
 103   // Stores information about the download that must be acquired on the UI
 104   // thread before StartOnUIThread is called.
 105   // Created on IO thread, but only accessed on UI thread. |tab_info_| holds
 106   // the pointer until we pass it off to StartOnUIThread or DeleteSoon.
 107   DownloadTabInfo* tab_info_;
 108
 109   // Data flow
 110   scoped_refptr<net::IOBuffer> read_buffer_;       // From URLRequest.
 111   scoped_ptr<ByteStreamWriter> stream_writer_; // To rest of system.
 112
 113   // Keeps the system from sleeping while this ResourceHandler is alive. If the
 114   // system enters power saving mode while a request is alive, it can cause the
 115   // request to fail and the associated download will be interrupted.
 116   scoped_ptr<PowerSaveBlocker> power_save_blocker_;
 117
 118   // The following are used to collect stats.
 119   base::TimeTicks download_start_time_;
 120   base::TimeTicks last_read_time_;
 121   base::TimeTicks last_stream_pause_time_;
 122   base::TimeDelta total_pause_time_;
 123   size_t last_buffer_size_;
 124   int64 bytes_read_;
 125
 126   int pause_count_;
 127   bool was_deferred_;
 128
 129   // For DCHECKing
 130   bool on_response_started_called_;
 131
 132   static const int kReadBufSize = 32768;  // bytes
 133   static const int kThrottleTimeMs = 200;  // milliseconds
 134
 135   DISALLOW_COPY_AND_ASSIGN(DownloadResourceHandler);
 136 };
 137
 138 }  // namespace content
 139
 140 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_RESOURCE_HANDLER_H_