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1 // Copyright 2013 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_RENDERER_MEDIA_BUFFERED_DATA_SOURCE_H_ | |
6 #define CONTENT_RENDERER_MEDIA_BUFFERED_DATA_SOURCE_H_ | |
7 | |
8 #include <string> | |
9 | |
10 #include "base/callback.h" | |
11 #include "base/memory/scoped_ptr.h" | |
12 #include "base/synchronization/lock.h" | |
13 #include "content/common/content_export.h" | |
14 #include "content/renderer/media/buffered_resource_loader.h" | |
15 #include "media/base/data_source.h" | |
16 #include "media/base/ranges.h" | |
17 #include "url/gurl.h" | |
18 | |
19 namespace base { | |
20 class SingleThreadTaskRunner; | |
21 } | |
22 | |
23 namespace media { | |
24 class MediaLog; | |
25 } | |
26 | |
27 namespace content { | |
28 | |
29 class CONTENT_EXPORT BufferedDataSourceHost { | |
30 public: | |
31 // Notify the host of the total size of the media file. | |
32 virtual void SetTotalBytes(int64 total_bytes) = 0; | |
33 | |
34 // Notify the host that byte range [start,end] has been buffered. | |
35 // TODO(fischman): remove this method when demuxing is push-based instead of | |
36 // pull-based. http://crbug.com/131444 | |
37 virtual void AddBufferedByteRange(int64 start, int64 end) = 0; | |
38 | |
39 protected: | |
40 virtual ~BufferedDataSourceHost() {}; | |
41 }; | |
42 | |
43 // A data source capable of loading URLs and buffering the data using an | |
44 // in-memory sliding window. | |
45 // | |
46 // BufferedDataSource must be created and initialized on the render thread | |
47 // before being passed to other threads. It may be deleted on any thread. | |
48 class CONTENT_EXPORT BufferedDataSource : public media::DataSource { | |
49 public: | |
50 // Used to specify video preload states. They are "hints" to the browser about | |
51 // how aggressively the browser should load and buffer data. | |
52 // Please see the HTML5 spec for the descriptions of these values: | |
53 // http://www.w3.org/TR/html5/video.html#attr-media-preload | |
54 // | |
55 // Enum values must match the values in blink::WebMediaPlayer::Preload and | |
56 // there will be assertions at compile time if they do not match. | |
57 enum Preload { | |
58 NONE, | |
59 METADATA, | |
60 AUTO, | |
61 }; | |
62 typedef base::Callback<void(bool)> DownloadingCB; | |
63 | |
64 // |url| and |cors_mode| are passed to the object. Buffered byte range changes | |
65 // will be reported to |host|. |downloading_cb| will be called whenever the | |
66 // downloading/paused state of the source changes. | |
67 BufferedDataSource( | |
68 const GURL& url, | |
69 BufferedResourceLoader::CORSMode cors_mode, | |
70 const scoped_refptr<base::SingleThreadTaskRunner>& task_runner, | |
71 blink::WebFrame* frame, | |
72 media::MediaLog* media_log, | |
73 BufferedDataSourceHost* host, | |
74 const DownloadingCB& downloading_cb); | |
75 virtual ~BufferedDataSource(); | |
76 | |
77 // Executes |init_cb| with the result of initialization when it has completed. | |
78 // | |
79 // Method called on the render thread. | |
80 typedef base::Callback<void(bool)> InitializeCB; | |
81 void Initialize(const InitializeCB& init_cb); | |
82 | |
83 // Adjusts the buffering algorithm based on the given preload value. | |
84 void SetPreload(Preload preload); | |
85 | |
86 // Returns true if the media resource has a single origin, false otherwise. | |
87 // Only valid to call after Initialize() has completed. | |
88 // | |
89 // Method called on the render thread. | |
90 bool HasSingleOrigin(); | |
91 | |
92 // Returns true if the media resource passed a CORS access control check. | |
93 bool DidPassCORSAccessCheck() const; | |
94 | |
95 // Cancels initialization, any pending loaders, and any pending read calls | |
96 // from the demuxer. The caller is expected to release its reference to this | |
97 // object and never call it again. | |
98 // | |
99 // Method called on the render thread. | |
100 void Abort(); | |
101 | |
102 // Notifies changes in playback state for controlling media buffering | |
103 // behavior. | |
104 void MediaPlaybackRateChanged(float playback_rate); | |
105 void MediaIsPlaying(); | |
106 void MediaIsPaused(); | |
107 | |
108 // Returns true if the resource is local. | |
109 bool assume_fully_buffered() { return !url_.SchemeIsHTTPOrHTTPS(); } | |
110 | |
111 // media::DataSource implementation. | |
112 // Called from demuxer thread. | |
113 virtual void Stop() OVERRIDE; | |
114 | |
115 virtual void Read(int64 position, int size, uint8* data, | |
116 const media::DataSource::ReadCB& read_cb) OVERRIDE; | |
117 virtual bool GetSize(int64* size_out) OVERRIDE; | |
118 virtual bool IsStreaming() OVERRIDE; | |
119 virtual void SetBitrate(int bitrate) OVERRIDE; | |
120 | |
121 protected: | |
122 // A factory method to create a BufferedResourceLoader based on the read | |
123 // parameters. We can override this file to object a mock | |
124 // BufferedResourceLoader for testing. | |
125 virtual BufferedResourceLoader* CreateResourceLoader( | |
126 int64 first_byte_position, int64 last_byte_position); | |
127 | |
128 private: | |
129 friend class BufferedDataSourceTest; | |
130 | |
131 // Task posted to perform actual reading on the render thread. | |
132 void ReadTask(); | |
133 | |
134 // Cancels oustanding callbacks and sets |stop_signal_received_|. Safe to call | |
135 // from any thread. | |
136 void StopInternal_Locked(); | |
137 | |
138 // Stops |loader_| if present. Used by Abort() and Stop(). | |
139 void StopLoader(); | |
140 | |
141 // Tells |loader_| the bitrate of the media. | |
142 void SetBitrateTask(int bitrate); | |
143 | |
144 // The method that performs actual read. This method can only be executed on | |
145 // the render thread. | |
146 void ReadInternal(); | |
147 | |
148 // BufferedResourceLoader::Start() callback for initial load. | |
149 void StartCallback(BufferedResourceLoader::Status status); | |
150 | |
151 // BufferedResourceLoader::Start() callback for subsequent loads (i.e., | |
152 // when accessing ranges that are outside initial buffered region). | |
153 void PartialReadStartCallback(BufferedResourceLoader::Status status); | |
154 | |
155 // BufferedResourceLoader callbacks. | |
156 void ReadCallback(BufferedResourceLoader::Status status, int bytes_read); | |
157 void LoadingStateChangedCallback(BufferedResourceLoader::LoadingState state); | |
158 void ProgressCallback(int64 position); | |
159 | |
160 // Update |loader_|'s deferring strategy in response to a play/pause, or | |
161 // change in playback rate. | |
162 void UpdateDeferStrategy(bool paused); | |
163 | |
164 // URL of the resource requested. | |
165 GURL url_; | |
166 // crossorigin attribute on the corresponding HTML media element, if any. | |
167 BufferedResourceLoader::CORSMode cors_mode_; | |
168 | |
169 // The total size of the resource. Set during StartCallback() if the size is | |
170 // known, otherwise it will remain kPositionNotSpecified until the size is | |
171 // determined by reaching EOF. | |
172 int64 total_bytes_; | |
173 | |
174 // This value will be true if this data source can only support streaming. | |
175 // i.e. range request is not supported. | |
176 bool streaming_; | |
177 | |
178 // A webframe for loading. | |
179 blink::WebFrame* frame_; | |
180 | |
181 // A resource loader for the media resource. | |
182 scoped_ptr<BufferedResourceLoader> loader_; | |
183 | |
184 // Callback method from the pipeline for initialization. | |
185 InitializeCB init_cb_; | |
186 | |
187 // Read parameters received from the Read() method call. Must be accessed | |
188 // under |lock_|. | |
189 class ReadOperation; | |
190 scoped_ptr<ReadOperation> read_op_; | |
191 | |
192 // This buffer is intermediate, we use it for BufferedResourceLoader to write | |
193 // to. And when read in BufferedResourceLoader is done, we copy data from | |
194 // this buffer to |read_buffer_|. The reason for an additional copy is that | |
195 // we don't own |read_buffer_|. But since the read operation is asynchronous, | |
196 // |read_buffer| can be destroyed at any time, so we only copy into | |
197 // |read_buffer| in the final step when it is safe. | |
198 // Memory is allocated for this member during initialization of this object | |
199 // because we want buffer to be passed into BufferedResourceLoader to be | |
200 // always non-null. And by initializing this member with a default size we can | |
201 // avoid creating zero-sized buffered if the first read has zero size. | |
202 scoped_ptr<uint8[]> intermediate_read_buffer_; | |
203 int intermediate_read_buffer_size_; | |
204 | |
205 // The task runner of the render thread. | |
206 const scoped_refptr<base::SingleThreadTaskRunner> render_task_runner_; | |
207 | |
208 // Protects |stop_signal_received_| and |read_op_|. | |
209 base::Lock lock_; | |
210 | |
211 // Whether we've been told to stop via Abort() or Stop(). | |
212 bool stop_signal_received_; | |
213 | |
214 // This variable is true when the user has requested the video to play at | |
215 // least once. | |
216 bool media_has_played_; | |
217 | |
218 // This variable holds the value of the preload attribute for the video | |
219 // element. | |
220 Preload preload_; | |
221 | |
222 // Bitrate of the content, 0 if unknown. | |
223 int bitrate_; | |
224 | |
225 // Current playback rate. | |
226 float playback_rate_; | |
227 | |
228 scoped_refptr<media::MediaLog> media_log_; | |
229 | |
230 // Host object to report buffered byte range changes to. | |
231 BufferedDataSourceHost* host_; | |
232 | |
233 DownloadingCB downloading_cb_; | |
234 | |
235 // NOTE: Weak pointers must be invalidated before all other member variables. | |
236 base::WeakPtrFactory<BufferedDataSource> weak_factory_; | |
237 | |
238 DISALLOW_COPY_AND_ASSIGN(BufferedDataSource); | |
239 }; | |
240 | |
241 } // namespace content | |
242 | |
243 #endif // CONTENT_RENDERER_MEDIA_BUFFERED_DATA_SOURCE_H_ | |
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