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/basictypes.h"
   9 #include "base/callback.h"
  10 #include "base/compiler_specific.h"
  11 #include "base/files/file.h"
  12 #include "base/files/file_path.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/memory/weak_ptr.h"
  16 #include "content/browser/loader/layered_resource_handler.h"
  17 #include "content/browser/loader/temporary_file_stream.h"
  18 #include "content/common/content_export.h"
  19 #include "net/url_request/url_request.h"
  20 #include "net/url_request/url_request_status.h"
  21 #include "url/gurl.h"
  22
  23 namespace net {
  24 class FileStream;
  25 class GrowableIOBuffer;
  26 }
  27
  28 namespace storage {
  29 class ShareableFileReference;
  30 }
  31
  32 namespace content {
  33
  34 // Redirects network data to a file.  This is intended to be layered in front of
  35 // either the AsyncResourceHandler or the SyncResourceHandler.  The downstream
  36 // resource handler does not see OnWillRead or OnReadCompleted calls. Instead,
  37 // the ResourceResponse contains the path to a temporary file and
  38 // OnDataDownloaded is called as the file downloads.
  39 class CONTENT_EXPORT RedirectToFileResourceHandler
  40     : public LayeredResourceHandler {
  41  public:
  42   typedef base::Callback<void(const CreateTemporaryFileStreamCallback&)>
  43       CreateTemporaryFileStreamFunction;
  44
  45   // Create a RedirectToFileResourceHandler for |request| which wraps
  46   // |next_handler|.
  47   RedirectToFileResourceHandler(scoped_ptr<ResourceHandler> next_handler,
  48                                 net::URLRequest* request);
  49   virtual ~RedirectToFileResourceHandler();
  50
  51   // Replace the CreateTemporaryFileStream implementation with a mocked one for
  52   // testing purposes. The function should create a net::FileStream and a
  53   // ShareableFileReference and then asynchronously pass them to the
  54   // CreateTemporaryFileStreamCallback.
  55   void SetCreateTemporaryFileStreamFunctionForTesting(
  56       const CreateTemporaryFileStreamFunction& create_temporary_file_stream);
  57
  58   // LayeredResourceHandler implementation:
  59   virtual bool OnResponseStarted(ResourceResponse* response,
  60                                  bool* defer) OVERRIDE;
  61   virtual bool OnWillStart(const GURL& url, bool* defer) OVERRIDE;
  62   virtual bool OnWillRead(scoped_refptr<net::IOBuffer>* buf,
  63                           int* buf_size,
  64                           int min_size) OVERRIDE;
  65   virtual bool OnReadCompleted(int bytes_read, bool* defer) OVERRIDE;
  66   virtual void OnResponseCompleted(const net::URLRequestStatus& status,
  67                                    const std::string& security_info,
  68                                    bool* defer) OVERRIDE;
  69
  70  private:
  71   void DidCreateTemporaryFile(base::File::Error error_code,
  72                               scoped_ptr<net::FileStream> file_stream,
  73                               storage::ShareableFileReference* deletable_file);
  74
  75   // Called by RedirectToFileResourceHandler::Writer.
  76   void DidWriteToFile(int result);
  77
  78   bool WriteMore();
  79   bool BufIsFull() const;
  80   void ResumeIfDeferred();
  81
  82   CreateTemporaryFileStreamFunction create_temporary_file_stream_;
  83
  84   // We allocate a single, fixed-size IO buffer (buf_) used to read from the
  85   // network (buf_write_pending_ is true while the system is copying data into
  86   // buf_), and then write this buffer out to disk (write_callback_pending_ is
  87   // true while writing to disk).  Reading from the network is suspended while
  88   // the buffer is full (BufIsFull returns true).  The write_cursor_ member
  89   // tracks the offset into buf_ that we are writing to disk.
  90
  91   scoped_refptr<net::GrowableIOBuffer> buf_;
  92   bool buf_write_pending_;
  93   int write_cursor_;
  94
  95   // Helper writer object which maintains references to the net::FileStream and
  96   // storage::ShareableFileReference. This is maintained separately so that,
  97   // on Windows, the temporary file isn't deleted until after it is closed.
  98   class Writer;
  99   Writer* writer_;
 100
 101   // |next_buffer_size_| is the size of the buffer to be allocated on the next
 102   // OnWillRead() call.  We exponentially grow the size of the buffer allocated
 103   // when our owner fills our buffers. On the first OnWillRead() call, we
 104   // allocate a buffer of 32k and double it in OnReadCompleted() if the buffer
 105   // was filled, up to a maximum size of 512k.
 106   int next_buffer_size_;
 107
 108   bool did_defer_;
 109
 110   bool completed_during_write_;
 111   GURL will_start_url_;
 112   net::URLRequestStatus completed_status_;
 113   std::string completed_security_info_;
 114
 115   base::WeakPtrFactory<RedirectToFileResourceHandler> weak_factory_;
 116
 117   DISALLOW_COPY_AND_ASSIGN(RedirectToFileResourceHandler);
 118 };
 119
 120 }  // namespace content
 121
 122 #endif  // CONTENT_BROWSER_LOADER_REDIRECT_TO_FILE_RESOURCE_HANDLER_H_