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(int request_id,
  37                                  ResourceResponse* response,
  38                                  bool* defer) OVERRIDE;
  39   virtual bool OnWillRead(int request_id,
  40                           scoped_refptr<net::IOBuffer>* buf,
  41                           int* buf_size,
  42                           int min_size) OVERRIDE;
  43   virtual bool OnReadCompleted(int request_id, int bytes_read,
  44                                bool* defer) OVERRIDE;
  45   virtual void OnResponseCompleted(int request_id,
  46                                    const net::URLRequestStatus& status,
  47                                    const std::string& security_info,
  48                                    bool* defer) OVERRIDE;
  49
  50   // ResourceController implementation:
  51   virtual void Resume() OVERRIDE;
  52   virtual void Cancel() OVERRIDE;
  53   virtual void CancelAndIgnore() OVERRIDE;
  54   virtual void CancelWithError(int error_code) OVERRIDE;
  55
  56   bool ProcessResponse(bool* defer);
  57
  58   bool ShouldSniffContent();
  59   bool DetermineMimeType();
  60   bool SelectNextHandler(bool* defer);
  61   bool UseAlternateNextHandler(scoped_ptr<ResourceHandler> handler);
  62
  63   bool ReplayReadCompleted(bool* defer);
  64   void CallReplayReadCompleted();
  65
  66   bool MustDownload();
  67   bool HasSupportingPlugin(bool* is_stale);
  68
  69   // Copies data from |read_buffer_| to |next_handler_|.
  70   bool CopyReadBufferToNextHandler(int request_id);
  71
  72   // Called on the IO thread once the list of plugins has been loaded.
  73   void OnPluginsLoaded(const std::vector<WebPluginInfo>& plugins);
  74
  75   enum State {
  76     STATE_STARTING,
  77
  78     // In this state, we are filling read_buffer_ with data for the purpose
  79     // of sniffing the mime type of the response.
  80     STATE_BUFFERING,
  81
  82     // In this state, we are select an appropriate downstream ResourceHandler
  83     // based on the mime type of the response.  We are also potentially waiting
  84     // for plugins to load so that we can determine if a plugin is available to
  85     // handle the mime type.
  86     STATE_PROCESSING,
  87
  88     // In this state, we are replaying buffered events (OnResponseStarted and
  89     // OnReadCompleted) to the downstream ResourceHandler.
  90     STATE_REPLAYING,
  91
  92     // In this state, we are just a blind pass-through ResourceHandler.
  93     STATE_STREAMING
  94   };
  95   State state_;
  96
  97   scoped_refptr<ResourceResponse> response_;
  98   ResourceDispatcherHostImpl* host_;
  99   scoped_refptr<net::IOBuffer> read_buffer_;
 100   int read_buffer_size_;
 101   int bytes_read_;
 102
 103   bool must_download_;
 104   bool must_download_is_set_;
 105
 106   base::WeakPtrFactory<BufferedResourceHandler> weak_ptr_factory_;
 107
 108   DISALLOW_COPY_AND_ASSIGN(BufferedResourceHandler);
 109 };
 110
 111 }  // namespace content
 112
 113 #endif  // CONTENT_BROWSER_LOADER_BUFFERED_RESOURCE_HANDLER_H_