src/content/browser/loader/redirect_to_file_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_REDIRECT_TO_FILE_RESOURCE_HANDLER_H_
   6 #define CONTENT_BROWSER_LOADER_REDIRECT_TO_FILE_RESOURCE_HANDLER_H_
   7
   8 #include "base/files/file_path.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "base/platform_file.h"
  13 #include "content/browser/loader/layered_resource_handler.h"
  14 #include "net/url_request/url_request.h"
  15 #include "net/url_request/url_request_status.h"
  16
  17 namespace net {
  18 class FileStream;
  19 class GrowableIOBuffer;
  20 }
  21
  22 namespace webkit_blob {
  23 class ShareableFileReference;
  24 }
  25
  26 namespace content {
  27 class ResourceDispatcherHostImpl;
  28
  29 // Redirects network data to a file.  This is intended to be layered in front
  30 // of either the AsyncResourceHandler or the SyncResourceHandler.
  31 class RedirectToFileResourceHandler : public LayeredResourceHandler {
  32  public:
  33   RedirectToFileResourceHandler(
  34       scoped_ptr<ResourceHandler> next_handler,
  35       net::URLRequest* request,
  36       ResourceDispatcherHostImpl* resource_dispatcher_host);
  37   virtual ~RedirectToFileResourceHandler();
  38
  39   // ResourceHandler implementation:
  40   virtual bool OnResponseStarted(int request_id,
  41                                  ResourceResponse* response,
  42                                  bool* defer) OVERRIDE;
  43   virtual bool OnWillStart(int request_id,
  44                            const GURL& url,
  45                            bool* defer) OVERRIDE;
  46   virtual bool OnWillRead(int request_id,
  47                           scoped_refptr<net::IOBuffer>* buf,
  48                           int* buf_size,
  49                           int min_size) OVERRIDE;
  50   virtual bool OnReadCompleted(int request_id,
  51                                int bytes_read,
  52                                bool* defer) OVERRIDE;
  53   virtual bool OnResponseCompleted(int request_id,
  54                                    const net::URLRequestStatus& status,
  55                                    const std::string& security_info) OVERRIDE;
  56
  57  private:
  58   void DidCreateTemporaryFile(base::PlatformFileError error_code,
  59                               base::PassPlatformFile file_handle,
  60                               const base::FilePath& file_path);
  61   void DidWriteToFile(int result);
  62   bool WriteMore();
  63   bool BufIsFull() const;
  64   void ResumeIfDeferred();
  65
  66   base::WeakPtrFactory<RedirectToFileResourceHandler> weak_factory_;
  67
  68   ResourceDispatcherHostImpl* host_;
  69
  70   // We allocate a single, fixed-size IO buffer (buf_) used to read from the
  71   // network (buf_write_pending_ is true while the system is copying data into
  72   // buf_), and then write this buffer out to disk (write_callback_pending_ is
  73   // true while writing to disk).  Reading from the network is suspended while
  74   // the buffer is full (BufIsFull returns true).  The write_cursor_ member
  75   // tracks the offset into buf_ that we are writing to disk.
  76
  77   scoped_refptr<net::GrowableIOBuffer> buf_;
  78   bool buf_write_pending_;
  79   int write_cursor_;
  80
  81   scoped_ptr<net::FileStream> file_stream_;
  82   bool write_callback_pending_;
  83
  84   // |next_buffer_size_| is the size of the buffer to be allocated on the next
  85   // OnWillRead() call.  We exponentially grow the size of the buffer allocated
  86   // when our owner fills our buffers. On the first OnWillRead() call, we
  87   // allocate a buffer of 32k and double it in OnReadCompleted() if the buffer
  88   // was filled, up to a maximum size of 512k.
  89   int next_buffer_size_;
  90
  91   // We create a ShareableFileReference that's deletable for the temp
  92   // file created as  a result of the download.
  93   scoped_refptr<webkit_blob::ShareableFileReference> deletable_file_;
  94
  95   bool did_defer_ ;
  96
  97   bool completed_during_write_;
  98   net::URLRequestStatus completed_status_;
  99   std::string completed_security_info_;
 100
 101   DISALLOW_COPY_AND_ASSIGN(RedirectToFileResourceHandler);
 102 };
 103
 104 }  // namespace content
 105
 106 #endif  // CONTENT_BROWSER_LOADER_REDIRECT_TO_FILE_RESOURCE_HANDLER_H_