blob: 749136530a2c5410867f10caf672c155949daa2f [file] [log] [blame]
/*
* A simple FIFO implementation.
*
* Copyright (C) 2004 Stelian Pop <stelian@popies.net>
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
struct fifo {
unsigned char *buffer; /* the buffer holding the data */
unsigned int size; /* the size of the allocated buffer */
unsigned int in; /* data is added at offset (in % size) */
unsigned int out; /* data is extracted from off. (out % size) */
};
struct fifo *fifo_alloc(unsigned int);
unsigned int fifo_put(struct fifo *, void *, unsigned int);
unsigned int fifo_get(struct fifo *, void *, unsigned int);
void fifo_free(struct fifo *);
static inline unsigned int fifo_len(struct fifo *fifo)
{
return fifo->in - fifo->out;
}
static inline unsigned int fifo_room(struct fifo *fifo)
{
return fifo->size - fifo->in + fifo->out;
}
#ifndef min
#define min(x,y) ({ \
typeof(x) _x = (x); \
typeof(y) _y = (y); \
(void) (&_x == &_y); \
_x < _y ? _x : _y; })
#endif
#ifndef max
#define max(x,y) ({ \
typeof(x) _x = (x); \
typeof(y) _y = (y); \
(void) (&_x == &_y); \
_x > _y ? _x : _y; })
#endif