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/*
* A very simple circular buffer FIFO implementation
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
* Copyright (c) 2006 Roman Shaposhnik
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "common.h"
#include "fifo.h"
int av_fifo_init(AVFifoBuffer *f, int size)
{
f->wptr = f->rptr =
f->buffer = av_malloc(size);
f->end = f->buffer + size;
if (!f->buffer)
return -1;
return 0;
}
void av_fifo_free(AVFifoBuffer *f)
{
av_free(f->buffer);
}
int av_fifo_size(AVFifoBuffer *f)
{
int size = f->wptr - f->rptr;
if (size < 0)
size += f->end - f->buffer;
return size;
}
/**
* Get data from the fifo (returns -1 if not enough data).
*/
int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size)
{
return av_fifo_generic_read(f, buf_size, NULL, buf);
}
/**
* Resizes a FIFO.
*/
void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) {
unsigned int old_size= f->end - f->buffer;
if(old_size < new_size){
int len= av_fifo_size(f);
AVFifoBuffer f2;
av_fifo_init(&f2, new_size);
av_fifo_read(f, f2.buffer, len);
f2.wptr += len;
av_free(f->buffer);
*f= f2;
}
}
void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
{
do {
int len = FFMIN(f->end - f->wptr, size);
memcpy(f->wptr, buf, len);
f->wptr += len;
if (f->wptr >= f->end)
f->wptr = f->buffer;
buf += len;
size -= len;
} while (size > 0);
}
/** get data from the fifo (return -1 if not enough data) */
int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
{
int size = av_fifo_size(f);
if (size < buf_size)
return -1;
do {
int len = FFMIN(f->end - f->rptr, buf_size);
if(func) func(dest, f->rptr, len);
else{
memcpy(dest, f->rptr, len);
dest = (uint8_t*)dest + len;
}
av_fifo_drain(f, len);
buf_size -= len;
} while (buf_size > 0);
return 0;
}
/** discard data from the fifo */
void av_fifo_drain(AVFifoBuffer *f, int size)
{
f->rptr += size;
if (f->rptr >= f->end)
f->rptr -= f->end - f->buffer;
}
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