| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef MEDIA_FILTERS_BLOCKING_URL_PROTOCOL_H_ |
| #define MEDIA_FILTERS_BLOCKING_URL_PROTOCOL_H_ |
| |
| #include <stdint.h> |
| |
| #include "base/callback.h" |
| #include "base/macros.h" |
| #include "base/synchronization/lock.h" |
| #include "base/synchronization/waitable_event.h" |
| #include "media/filters/ffmpeg_glue.h" |
| |
| namespace media { |
| |
| class DataSource; |
| |
| // An implementation of FFmpegURLProtocol that blocks until the underlying |
| // asynchronous DataSource::Read() operation completes. Generally constructed on |
| // the media thread and used by ffmpeg through the AVIO interface from a |
| // sequenced blocking pool. |
| class MEDIA_EXPORT BlockingUrlProtocol : public FFmpegURLProtocol { |
| public: |
| // Implements FFmpegURLProtocol using the given |data_source|. |error_cb| is |
| // fired any time DataSource::Read() returns an error. |
| BlockingUrlProtocol(DataSource* data_source, |
| const base::RepeatingClosure& error_cb); |
| virtual ~BlockingUrlProtocol(); |
| |
| // Aborts any pending reads by returning a read error. After this method |
| // returns all subsequent calls to Read() will immediately fail. May be called |
| // from any thread and upon return ensures no further use of |data_source_|. |
| void Abort(); |
| |
| // FFmpegURLProtocol implementation. |
| int Read(int size, uint8_t* data) override; |
| bool GetPosition(int64_t* position_out) override; |
| bool SetPosition(int64_t position) override; |
| bool GetSize(int64_t* size_out) override; |
| bool IsStreaming() override; |
| |
| private: |
| // Sets |last_read_bytes_| and signals the blocked thread that the read |
| // has completed. |
| void SignalReadCompleted(int size); |
| |
| // |data_source_lock_| allows Abort() to be called from any thread and stop |
| // all outstanding access to |data_source_|. Typically Abort() is called from |
| // the media thread while ffmpeg is operating on another thread. |
| base::Lock data_source_lock_; |
| DataSource* data_source_; |
| |
| base::RepeatingClosure error_cb_; |
| const bool is_streaming_; |
| |
| // Used to unblock the thread during shutdown and when reads complete. |
| base::WaitableEvent aborted_; |
| base::WaitableEvent read_complete_; |
| |
| // Cached number of bytes last read from the data source. |
| int last_read_bytes_; |
| |
| // Cached position within the data source. |
| int64_t read_position_; |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(BlockingUrlProtocol); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_FILTERS_BLOCKING_URL_PROTOCOL_H_ |