/* * 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 /** * @} */