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 STORAGE_BROWSER_BLOB_BLOB_URL_REQUEST_JOB_H_
6#define STORAGE_BROWSER_BLOB_BLOB_URL_REQUEST_JOB_H_
7
8#include <map>
9
10#include "base/memory/scoped_ptr.h"
11#include "base/memory/weak_ptr.h"
12#include "net/http/http_byte_range.h"
13#include "net/http/http_status_code.h"
14#include "net/url_request/url_request_job.h"
15#include "storage/browser/storage_browser_export.h"
16#include "storage/common/blob/blob_data.h"
17
18namespace base {
19class MessageLoopProxy;
20}
21
22namespace storage {
23class FileSystemContext;
24}
25
26namespace net {
27class DrainableIOBuffer;
28class IOBuffer;
29}
30
31namespace storage {
32
33class FileStreamReader;
34
35// A request job that handles reading blob URLs.
36class STORAGE_EXPORT BlobURLRequestJob
37    : public net::URLRequestJob {
38 public:
39  BlobURLRequestJob(net::URLRequest* request,
40                    net::NetworkDelegate* network_delegate,
41                    const scoped_refptr<BlobData>& blob_data,
42                    storage::FileSystemContext* file_system_context,
43                    base::MessageLoopProxy* resolving_message_loop_proxy);
44
45  // net::URLRequestJob methods.
46  virtual void Start() OVERRIDE;
47  virtual void Kill() OVERRIDE;
48  virtual bool ReadRawData(net::IOBuffer* buf,
49                           int buf_size,
50                           int* bytes_read) OVERRIDE;
51  virtual bool GetMimeType(std::string* mime_type) const OVERRIDE;
52  virtual void GetResponseInfo(net::HttpResponseInfo* info) OVERRIDE;
53  virtual int GetResponseCode() const OVERRIDE;
54  virtual void SetExtraRequestHeaders(
55      const net::HttpRequestHeaders& headers) OVERRIDE;
56
57 protected:
58  virtual ~BlobURLRequestJob();
59
60 private:
61  typedef std::map<size_t, FileStreamReader*> IndexToReaderMap;
62
63  // For preparing for read: get the size, apply the range and perform seek.
64  void DidStart();
65  bool AddItemLength(size_t index, int64 item_length);
66  void CountSize();
67  void DidCountSize(int error);
68  void DidGetFileItemLength(size_t index, int64 result);
69  void Seek(int64 offset);
70
71  // For reading the blob.
72  bool ReadLoop(int* bytes_read);
73  bool ReadItem();
74  void AdvanceItem();
75  void AdvanceBytesRead(int result);
76  bool ReadBytesItem(const BlobData::Item& item, int bytes_to_read);
77  bool ReadFileItem(FileStreamReader* reader, int bytes_to_read);
78
79  void DidReadFile(int result);
80  void DeleteCurrentFileReader();
81
82  int ComputeBytesToRead() const;
83  int BytesReadCompleted();
84
85  // These methods convert the result of blob data reading into response headers
86  // and pass it to URLRequestJob's NotifyDone() or NotifyHeadersComplete().
87  void NotifySuccess();
88  void NotifyFailure(int);
89  void HeadersCompleted(net::HttpStatusCode status_code);
90
91  // Returns a FileStreamReader for a blob item at |index|.
92  // If the item at |index| is not of file this returns NULL.
93  FileStreamReader* GetFileStreamReader(size_t index);
94
95  // Creates a FileStreamReader for the item at |index| with additional_offset.
96  void CreateFileStreamReader(size_t index, int64 additional_offset);
97
98  scoped_refptr<BlobData> blob_data_;
99
100  // Variables for controlling read from |blob_data_|.
101  scoped_refptr<storage::FileSystemContext> file_system_context_;
102  scoped_refptr<base::MessageLoopProxy> file_thread_proxy_;
103  std::vector<int64> item_length_list_;
104  int64 total_size_;
105  int64 remaining_bytes_;
106  int pending_get_file_info_count_;
107  IndexToReaderMap index_to_reader_;
108  size_t current_item_index_;
109  int64 current_item_offset_;
110
111  // Holds the buffer for read data with the IOBuffer interface.
112  scoped_refptr<net::DrainableIOBuffer> read_buf_;
113
114  // Is set when NotifyFailure() is called and reset when DidStart is called.
115  bool error_;
116
117  bool byte_range_set_;
118  net::HttpByteRange byte_range_;
119
120  scoped_ptr<net::HttpResponseInfo> response_info_;
121
122  base::WeakPtrFactory<BlobURLRequestJob> weak_factory_;
123
124  DISALLOW_COPY_AND_ASSIGN(BlobURLRequestJob);
125};
126
127}  // namespace storage
128
129#endif  // STORAGE_BROWSER_BLOB_BLOB_URL_REQUEST_JOB_H_
130