/*
* Copyright (c) 2010 Lenka Trochtova
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup ns8250
* @{
*/
/** @file
*/
#ifndef CYCLIC_BUFFER_H_
#define CYCLIC_BUFFER_H_
#define BUF_LEN 4096
typedef struct cyclic_buffer {
uint8_t buf[BUF_LEN];
int start;
int cnt;
} cyclic_buffer_t;
/*
* @return False if the buffer is full.
*/
static inline bool buf_push_back(cyclic_buffer_t *buf, uint8_t item)
{
if (buf->cnt >= BUF_LEN)
return false;
int pos = (buf->start + buf->cnt) % BUF_LEN;
buf->buf[pos] = item;
buf->cnt++;
return true;
}
static inline bool buf_is_empty(cyclic_buffer_t *buf)
{
return buf->cnt == 0;
}
static inline uint8_t buf_pop_front(cyclic_buffer_t *buf)
{
assert(!buf_is_empty(buf));
uint8_t res = buf->buf[buf->start];
buf->start = (buf->start + 1) % BUF_LEN;
buf->cnt--;
return res;
}
static inline void buf_clear(cyclic_buffer_t *buf)
{
buf->cnt = 0;
}
#endif
/**
* @}
*/