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Diffstat (limited to 'src/decoder/DecoderBuffer.hxx')
-rw-r--r-- | src/decoder/DecoderBuffer.hxx | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/src/decoder/DecoderBuffer.hxx b/src/decoder/DecoderBuffer.hxx new file mode 100644 index 000000000..4a482be75 --- /dev/null +++ b/src/decoder/DecoderBuffer.hxx @@ -0,0 +1,121 @@ +/* + * Copyright (C) 2003-2014 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef MPD_DECODER_BUFFER_HXX +#define MPD_DECODER_BUFFER_HXX + +#include "Compiler.h" + +#include <stddef.h> + +/** + * This objects handles buffered reads in decoder plugins easily. You + * create a buffer object, and use its high-level methods to fill and + * read it. It will automatically handle shifting the buffer. + */ +struct DecoderBuffer; + +struct Decoder; +class InputStream; + +template<typename T> struct ConstBuffer; + +/** + * Creates a new buffer. + * + * @param decoder the decoder object, used for decoder_read(), may be nullptr + * @param is the input stream object where we should read from + * @param size the maximum size of the buffer + * @return the new decoder_buffer object + */ +DecoderBuffer * +decoder_buffer_new(Decoder *decoder, InputStream &is, + size_t size); + +/** + * Frees resources used by the decoder_buffer object. + */ +void +decoder_buffer_free(DecoderBuffer *buffer); + +gcc_pure +const InputStream & +decoder_buffer_get_stream(const DecoderBuffer *buffer); + +void +decoder_buffer_clear(DecoderBuffer *buffer); + +/** + * Read data from the input_stream and append it to the buffer. + * + * @return true if data was appended; false if there is no data + * available (yet), end of file, I/O error or a decoder command was + * received + */ +bool +decoder_buffer_fill(DecoderBuffer *buffer); + +/** + * How many bytes are stored in the buffer? + */ +gcc_pure +size_t +decoder_buffer_available(const DecoderBuffer *buffer); + +/** + * Reads data from the buffer. This data is not yet consumed, you + * have to call decoder_buffer_consume() to do that. The returned + * buffer becomes invalid after a decoder_buffer_fill() or a + * decoder_buffer_consume() call. + * + * @param buffer the decoder_buffer object + */ +gcc_pure +ConstBuffer<void> +decoder_buffer_read(const DecoderBuffer *buffer); + +/** + * Wait until this number of bytes are available. Returns nullptr on + * error. + */ +ConstBuffer<void> +decoder_buffer_need(DecoderBuffer *buffer, size_t min_size); + +/** + * Consume (delete, invalidate) a part of the buffer. The "nbytes" + * parameter must not be larger than the length returned by + * decoder_buffer_read(). + * + * @param buffer the decoder_buffer object + * @param nbytes the number of bytes to consume + */ +void +decoder_buffer_consume(DecoderBuffer *buffer, size_t nbytes); + +/** + * Skips the specified number of bytes, discarding its data. + * + * @param buffer the decoder_buffer object + * @param nbytes the number of bytes to skip + * @return true on success, false on error + */ +bool +decoder_buffer_skip(DecoderBuffer *buffer, size_t nbytes); + +#endif |