| // Copyright 2016 The Fuchsia 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 GARNET_BIN_MEDIAPLAYER_DEMUX_READER_H_ |
| #define GARNET_BIN_MEDIAPLAYER_DEMUX_READER_H_ |
| |
| #include <limits> |
| #include <memory> |
| |
| #include <lib/fit/function.h> |
| |
| #include "garnet/bin/mediaplayer/graph/result.h" |
| |
| namespace media_player { |
| |
| // Abstract base class for objects that read raw data on behalf of demuxes. |
| class Reader { |
| public: |
| using DescribeCallback = |
| fit::function<void(Result result, size_t size, bool can_seek)>; |
| using ReadAtCallback = fit::function<void(Result result, size_t bytes_read)>; |
| |
| static constexpr size_t kUnknownSize = std::numeric_limits<size_t>::max(); |
| |
| virtual ~Reader() {} |
| |
| // Returns a result, the file size and whether the reader supports seeking |
| // via a callback. The returned size is kUnknownSize if the content size isn't |
| // known. |
| virtual void Describe(DescribeCallback callback) = 0; |
| |
| // Reads the specified number of bytes into the buffer from the specified |
| // position and returns a result and the number of bytes read via the |
| // callback. |
| virtual void ReadAt(size_t position, uint8_t* buffer, size_t bytes_to_read, |
| ReadAtCallback callback) = 0; |
| }; |
| |
| } // namespace media_player |
| |
| #endif // GARNET_BIN_MEDIAPLAYER_DEMUX_READER_H_ |