/* * Copyright (C) 2003-2009 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifndef MPD_DECODER_BUFFER_H #define MPD_DECODER_BUFFER_H #include <stdbool.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 decoder_buffer; struct decoder; struct input_stream; /** * Creates a new buffer. * * @param decoder the decoder object, used for decoder_read(), may be NULL * @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 */ struct decoder_buffer * decoder_buffer_new(struct decoder *decoder, struct input_stream *is, size_t size); /** * Frees resources used by the decoder_buffer object. */ void decoder_buffer_free(struct decoder_buffer *buffer); bool decoder_buffer_is_empty(const struct decoder_buffer *buffer); bool decoder_buffer_is_full(const struct decoder_buffer *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(struct decoder_buffer *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 * @param length_r pointer to a size_t where you will receive the * number of bytes available * @return a pointer to the read buffer, or NULL if there is no data * available */ const void * decoder_buffer_read(const struct decoder_buffer *buffer, size_t *length_r); /** * 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(struct decoder_buffer *buffer, size_t nbytes); #endif