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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 NET_BASE_UPLOAD_DATA_STREAM_H_ | |
6 #define NET_BASE_UPLOAD_DATA_STREAM_H_ | |
7 | |
8 #include "base/basictypes.h" | |
9 #include "base/macros.h" | |
10 #include "base/memory/scoped_vector.h" | |
11 #include "net/base/completion_callback.h" | |
12 #include "net/base/net_export.h" | |
13 | |
14 namespace net { | |
15 | |
16 class DrainableIOBuffer; | |
17 class IOBuffer; | |
18 class UploadElementReader; | |
19 | |
20 // A class for retrieving all data to be sent as a request body. Supports both | |
21 // chunked and non-chunked uploads. | |
22 class NET_EXPORT UploadDataStream { | |
23 public: | |
24 // |identifier| identifies a particular upload instance, which is used by the | |
25 // cache to formulate a cache key. This value should be unique across browser | |
26 // sessions. A value of 0 is used to indicate an unspecified identifier. | |
27 UploadDataStream(bool is_chunked, int64 identifier); | |
28 | |
29 virtual ~UploadDataStream(); | |
30 | |
31 // Initializes the stream. This function must be called before calling any | |
32 // other method. It is not valid to call any method (other than the | |
33 // destructor) if Init() fails. This method can be called multiple times. | |
34 // Calling this method after an Init() success results in resetting the | |
35 // state (i.e. the stream is rewound). | |
36 // | |
37 // Does the initialization synchronously and returns the result if possible, | |
38 // otherwise returns ERR_IO_PENDING and runs the callback with the result. | |
39 // | |
40 // Returns OK on success. Returns ERR_UPLOAD_FILE_CHANGED if the expected | |
41 // file modification time is set (usually not set, but set for sliced | |
42 // files) and the target file is changed. | |
43 int Init(const CompletionCallback& callback); | |
44 | |
45 // When possible, reads up to |buf_len| bytes synchronously from the upload | |
46 // data stream to |buf| and returns the number of bytes read; otherwise, | |
47 // returns ERR_IO_PENDING and calls |callback| with the number of bytes read. | |
48 // Partial reads are allowed. Zero is returned on a call to Read when there | |
49 // are no remaining bytes in the stream, and IsEof() will return true | |
50 // hereafter. | |
51 // | |
52 // If there's less data to read than we initially observed (i.e. the actual | |
53 // upload data is smaller than size()), zeros are padded to ensure that | |
54 // size() bytes can be read, which can happen for TYPE_FILE payloads. | |
55 // | |
56 // Reads are currently not allowed to fail - they must either return | |
57 // a value >= 0 or ERR_IO_PENDING, and call OnReadCompleted with a | |
58 // value >= 0. | |
59 // TODO(mmenke): Investigate letting reads fail. | |
60 int Read(IOBuffer* buf, int buf_len, const CompletionCallback& callback); | |
61 | |
62 // Returns the total size of the data stream and the current position. | |
63 // When the data is chunked, always returns zero. Must always return the same | |
64 // value after each call to Initialize(). | |
65 uint64 size() const { return total_size_; } | |
66 uint64 position() const { return current_position_; } | |
67 | |
68 // See constructor for description. | |
69 int64 identifier() const { return identifier_; } | |
70 | |
71 bool is_chunked() const { return is_chunked_; } | |
72 | |
73 // Returns true if all data has been consumed from this upload data | |
74 // stream. For chunked uploads, returns false until the first read attempt. | |
75 // This makes some state machines a little simpler. | |
76 bool IsEOF() const; | |
77 | |
78 // Cancels all pending callbacks, and resets state. Any IOBuffer currently | |
79 // being read to is not safe for future use, as it may be in use on another | |
80 // thread. | |
81 void Reset(); | |
82 | |
83 // Returns true if the upload data in the stream is entirely in memory, and | |
84 // all read requests will succeed synchronously. Expected to return false for | |
85 // chunked requests. | |
86 virtual bool IsInMemory() const; | |
87 | |
88 // Returns a list of element readers owned by |this|, if it has any. | |
89 virtual const ScopedVector<UploadElementReader>* | |
90 GetElementReaders() const; | |
91 | |
92 protected: | |
93 // Must be called by subclasses when InitInternal and ReadInternal complete | |
94 // asynchronously. | |
95 void OnInitCompleted(int result); | |
96 void OnReadCompleted(int result); | |
97 | |
98 // Must be called before InitInternal completes, for non-chunked uploads. | |
99 // Must not be called for chunked uploads. | |
100 void SetSize(uint64 size); | |
101 | |
102 // Must be called for chunked uploads before the final ReadInternal call | |
103 // completes. Must not be called for non-chunked uploads. | |
104 void SetIsFinalChunk(); | |
105 | |
106 private: | |
107 // See Init(). If it returns ERR_IO_PENDING, OnInitCompleted must be called | |
108 // once it completes. If the upload is not chunked, SetSize must be called | |
109 // before it completes. | |
110 virtual int InitInternal() = 0; | |
111 | |
112 // See Read(). For chunked uploads, must call SetIsFinalChunk if this is the | |
113 // final chunk. For non-chunked uploads, the UploadDataStream determins which | |
114 // read is the last based on size. Must read 1 or more bytes on every call, | |
115 // though the final chunk may be 0 bytes, for chunked requests. If it returns | |
116 // ERR_IO_PENDING, OnInitCompleted must be called once it completes. Must not | |
117 // return any error, other than ERR_IO_PENDING. | |
118 virtual int ReadInternal(IOBuffer* buf, int buf_len) = 0; | |
119 | |
120 // Resets state and cancels any pending callbacks. Guaranteed to be called | |
121 // before all but the first call to InitInternal. | |
122 virtual void ResetInternal() = 0; | |
123 | |
124 uint64 total_size_; | |
125 uint64 current_position_; | |
126 | |
127 const int64 identifier_; | |
128 | |
129 const bool is_chunked_; | |
130 | |
131 // True if the initialization was successful. | |
132 bool initialized_successfully_; | |
133 | |
134 bool is_eof_; | |
135 | |
136 CompletionCallback callback_; | |
137 | |
138 DISALLOW_COPY_AND_ASSIGN(UploadDataStream); | |
139 }; | |
140 | |
141 } // namespace net | |
142 | |
143 #endif // NET_BASE_UPLOAD_DATA_STREAM_H_ | |
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