mpd/src/decoder_buffer.c
Avuton Olrich 0aee49bdf8 all: Update copyright header.
This updates the copyright header to all be the same, which is
pretty much an update of where to mail request for a copy of the GPL
and the years of the MPD project. This also puts all committers under
'The Music Player Project' umbrella. These entries should go
individually in the AUTHORS file, for consistancy.
2009-03-13 11:51:55 -07:00

141 lines
3.2 KiB
C

/*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "decoder_buffer.h"
#include "decoder_api.h"
#include <glib.h>
#include <assert.h>
struct decoder_buffer {
struct decoder *decoder;
struct input_stream *is;
/** the allocated size of the buffer */
size_t size;
/** the current length of the buffer */
size_t length;
/** number of bytes already consumed at the beginning of the
buffer */
size_t consumed;
/** the actual buffer (dynamic size) */
unsigned char data[sizeof(size_t)];
};
struct decoder_buffer *
decoder_buffer_new(struct decoder *decoder, struct input_stream *is,
size_t size)
{
struct decoder_buffer *buffer =
g_malloc(sizeof(*buffer) - sizeof(buffer->data) + size);
assert(is != NULL);
assert(size > 0);
buffer->decoder = decoder;
buffer->is = is;
buffer->size = size;
buffer->length = 0;
buffer->consumed = 0;
return buffer;
}
void
decoder_buffer_free(struct decoder_buffer *buffer)
{
assert(buffer != NULL);
g_free(buffer);
}
bool
decoder_buffer_is_empty(const struct decoder_buffer *buffer)
{
return buffer->consumed == buffer->length;
}
bool
decoder_buffer_is_full(const struct decoder_buffer *buffer)
{
return buffer->consumed == 0 && buffer->length == buffer->size;
}
static void
decoder_buffer_shift(struct decoder_buffer *buffer)
{
assert(buffer->consumed > 0);
buffer->length -= buffer->consumed;
memmove(buffer->data, buffer->data + buffer->consumed, buffer->length);
buffer->consumed = 0;
}
bool
decoder_buffer_fill(struct decoder_buffer *buffer)
{
size_t nbytes;
if (buffer->consumed > 0)
decoder_buffer_shift(buffer);
if (buffer->length >= buffer->size)
/* buffer is full */
return false;
nbytes = decoder_read(buffer->decoder, buffer->is,
buffer->data + buffer->length,
buffer->size - buffer->length);
if (nbytes == 0)
/* end of file, I/O error or decoder command
received */
return false;
buffer->length += nbytes;
assert(buffer->length <= buffer->size);
return true;
}
const void *
decoder_buffer_read(const struct decoder_buffer *buffer, size_t *length_r)
{
if (buffer->consumed >= buffer->length)
/* buffer is empty */
return NULL;
*length_r = buffer->length - buffer->consumed;
return buffer->data + buffer->consumed;
}
void
decoder_buffer_consume(struct decoder_buffer *buffer, size_t nbytes)
{
/* just move the "consumed" pointer - decoder_buffer_shift()
will do the real work later (called by
decoder_buffer_fill()) */
buffer->consumed += nbytes;
assert(buffer->consumed <= buffer->length);
}