content/browser/loader/buffered_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_LOADER_BUFFERED_RESOURCE_HANDLER_H_
   6 #define CONTENT_BROWSER_LOADER_BUFFERED_RESOURCE_HANDLER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/memory/weak_ptr.h"
  12 #include "content/browser/loader/layered_resource_handler.h"
  13 #include "content/public/browser/resource_controller.h"
  14
  15 namespace net {
  16 class URLRequest;
  17 }
  18
  19 namespace content {
  20 class ResourceDispatcherHostImpl;
  21 struct WebPluginInfo;
  22
  23 // Used to buffer a request until enough data has been received.
  24 class BufferedResourceHandler
  25     : public LayeredResourceHandler,
  26       public ResourceController {
  27  public:
  28   BufferedResourceHandler(scoped_ptr<ResourceHandler> next_handler,
  29                           ResourceDispatcherHostImpl* host,
  30                           net::URLRequest* request);
  31   virtual ~BufferedResourceHandler();
  32
  33  private:
  34   // ResourceHandler implementation:
  35   virtual void SetController(ResourceController* controller) OVERRIDE;
  36   virtual bool OnResponseStarted(ResourceResponse* response,
  37                                  bool* defer) OVERRIDE;
  38   virtual bool OnWillRead(scoped_refptr<net::IOBuffer>* buf,
  39                           int* buf_size,
  40                           int min_size) OVERRIDE;
  41   virtual bool OnReadCompleted(int bytes_read, bool* defer) OVERRIDE;
  42   virtual void OnResponseCompleted(const net::URLRequestStatus& status,
  43                                    const std::string& security_info,
  44                                    bool* defer) OVERRIDE;
  45
  46   // ResourceController implementation:
  47   virtual void Resume() OVERRIDE;
  48   virtual void Cancel() OVERRIDE;
  49   virtual void CancelAndIgnore() OVERRIDE;
  50   virtual void CancelWithError(int error_code) OVERRIDE;
  51
  52   bool ProcessResponse(bool* defer);
  53
  54   bool ShouldSniffContent();
  55   bool DetermineMimeType();
  56   bool SelectNextHandler(bool* defer);
  57   bool UseAlternateNextHandler(scoped_ptr<ResourceHandler> handler,
  58                                const std::string& payload_for_old_handler);
  59
  60   bool ReplayReadCompleted(bool* defer);
  61   void CallReplayReadCompleted();
  62
  63   bool MustDownload();
  64   bool HasSupportingPlugin(bool* is_stale);
  65
  66   // Copies data from |read_buffer_| to |next_handler_|.
  67   bool CopyReadBufferToNextHandler();
  68
  69   // Called on the IO thread once the list of plugins has been loaded.
  70   void OnPluginsLoaded(const std::vector<WebPluginInfo>& plugins);
  71
  72   enum State {
  73     STATE_STARTING,
  74
  75     // In this state, we are filling read_buffer_ with data for the purpose
  76     // of sniffing the mime type of the response.
  77     STATE_BUFFERING,
  78
  79     // In this state, we are select an appropriate downstream ResourceHandler
  80     // based on the mime type of the response.  We are also potentially waiting
  81     // for plugins to load so that we can determine if a plugin is available to
  82     // handle the mime type.
  83     STATE_PROCESSING,
  84
  85     // In this state, we are replaying buffered events (OnResponseStarted and
  86     // OnReadCompleted) to the downstream ResourceHandler.
  87     STATE_REPLAYING,
  88
  89     // In this state, we are just a blind pass-through ResourceHandler.
  90     STATE_STREAMING
  91   };
  92   State state_;
  93
  94   scoped_refptr<ResourceResponse> response_;
  95   ResourceDispatcherHostImpl* host_;
  96   scoped_refptr<net::IOBuffer> read_buffer_;
  97   int read_buffer_size_;
  98   int bytes_read_;
  99
 100   bool must_download_;
 101   bool must_download_is_set_;
 102
 103   base::WeakPtrFactory<BufferedResourceHandler> weak_ptr_factory_;
 104
 105   DISALLOW_COPY_AND_ASSIGN(BufferedResourceHandler);
 106 };
 107
 108 }  // namespace content
 109
 110 #endif  // CONTENT_BROWSER_LOADER_BUFFERED_RESOURCE_HANDLER_H_