mirror of
https://github.com/libretro/RetroArch.git
synced 2024-11-25 08:59:58 +00:00
102 lines
2.6 KiB
C
102 lines
2.6 KiB
C
/* RetroArch - A frontend for libretro.
|
|
* Copyright (C) 2010-2014 - Hans-Kristian Arntzen
|
|
*
|
|
* RetroArch 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 Found-
|
|
* ation, either version 3 of the License, or (at your option) any later version.
|
|
*
|
|
* RetroArch 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 RetroArch.
|
|
* If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "fifo_buffer.h"
|
|
#include <stdint.h>
|
|
|
|
struct fifo_buffer
|
|
{
|
|
uint8_t *buffer;
|
|
size_t bufsize;
|
|
size_t first;
|
|
size_t end;
|
|
};
|
|
|
|
fifo_buffer_t *fifo_new(size_t size)
|
|
{
|
|
fifo_buffer_t *buf = (fifo_buffer_t*)calloc(1, sizeof(*buf));
|
|
if (!buf)
|
|
return NULL;
|
|
|
|
buf->buffer = (uint8_t*)calloc(1, size + 1);
|
|
if (!buf->buffer)
|
|
{
|
|
free(buf);
|
|
return NULL;
|
|
}
|
|
buf->bufsize = size + 1;
|
|
|
|
return buf;
|
|
}
|
|
|
|
void fifo_free(fifo_buffer_t *buffer)
|
|
{
|
|
free(buffer->buffer);
|
|
free(buffer);
|
|
}
|
|
|
|
size_t fifo_read_avail(fifo_buffer_t *buffer)
|
|
{
|
|
size_t first = buffer->first;
|
|
size_t end = buffer->end;
|
|
if (end < first)
|
|
end += buffer->bufsize;
|
|
return end - first;
|
|
}
|
|
|
|
size_t fifo_write_avail(fifo_buffer_t *buffer)
|
|
{
|
|
size_t first = buffer->first;
|
|
size_t end = buffer->end;
|
|
if (end < first)
|
|
end += buffer->bufsize;
|
|
|
|
return (buffer->bufsize - 1) - (end - first);
|
|
}
|
|
|
|
void fifo_write(fifo_buffer_t *buffer, const void *in_buf, size_t size)
|
|
{
|
|
size_t first_write = size;
|
|
size_t rest_write = 0;
|
|
if (buffer->end + size > buffer->bufsize)
|
|
{
|
|
first_write = buffer->bufsize - buffer->end;
|
|
rest_write = size - first_write;
|
|
}
|
|
|
|
memcpy(buffer->buffer + buffer->end, in_buf, first_write);
|
|
memcpy(buffer->buffer, (const uint8_t*)in_buf + first_write, rest_write);
|
|
|
|
buffer->end = (buffer->end + size) % buffer->bufsize;
|
|
}
|
|
|
|
|
|
void fifo_read(fifo_buffer_t *buffer, void *in_buf, size_t size)
|
|
{
|
|
size_t first_read = size;
|
|
size_t rest_read = 0;
|
|
if (buffer->first + size > buffer->bufsize)
|
|
{
|
|
first_read = buffer->bufsize - buffer->first;
|
|
rest_read = size - first_read;
|
|
}
|
|
|
|
memcpy(in_buf, (const uint8_t*)buffer->buffer + buffer->first, first_read);
|
|
memcpy((uint8_t*)in_buf + first_read, buffer->buffer, rest_read);
|
|
|
|
buffer->first = (buffer->first + size) % buffer->bufsize;
|
|
}
|
|
|