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
23namespace net {
24class FileStream;
25class GrowableIOBuffer;
26}
27
28namespace storage {
29class ShareableFileReference;
30}
31
32namespace 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.
39class 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_
123