84 lines
2.7 KiB
C
84 lines
2.7 KiB
C
/* SPDX-License-Identifier: BSD-3-Clause */
|
|
/* See the end of this file for copyright, licensing, and warranty information. */
|
|
|
|
/* Simple ring buffer implementation. */
|
|
|
|
#include <ardix/malloc.h>
|
|
#include <ardix/ringbuf.h>
|
|
#include <ardix/types.h>
|
|
#include <stddef.h>
|
|
|
|
struct ringbuf *ringbuf_create(size_t size)
|
|
{
|
|
struct ringbuf *buf = malloc(sizeof(*buf) + size);
|
|
if (buf == NULL)
|
|
return NULL;
|
|
|
|
buf->size = size;
|
|
buf->rpos = &buf->data[0];
|
|
buf->wpos = &buf->data[0];
|
|
|
|
return buf;
|
|
}
|
|
|
|
inline void ringbuf_destroy(struct ringbuf *buf)
|
|
{
|
|
free(buf);
|
|
}
|
|
|
|
size_t ringbuf_read(uint8_t *dest, struct ringbuf *buf, size_t len)
|
|
{
|
|
size_t n = 0;
|
|
|
|
while (len-- > 0 && buf->rpos != buf->wpos) {
|
|
*dest++ = *buf->rpos++;
|
|
n++;
|
|
|
|
/* wrap around */
|
|
if ((ptrdiff_t)(buf->rpos) - (ptrdiff_t)(&buf->data[0]) >= (ptrdiff_t)(buf->size))
|
|
buf->rpos = &buf->data[0];
|
|
}
|
|
|
|
return n;
|
|
}
|
|
|
|
size_t ringbuf_write(struct ringbuf *buf, const uint8_t *src, size_t len)
|
|
{
|
|
size_t n = 0;
|
|
|
|
while (len-- > 0 && buf->wpos != buf->rpos) {
|
|
*buf->wpos++ = *src++;
|
|
n++;
|
|
|
|
/* wrap around */
|
|
if ((ptrdiff_t)(buf->wpos) - (ptrdiff_t)(&buf->data[0]) >= (ptrdiff_t)(buf->size))
|
|
buf->wpos = &buf->data[0];
|
|
}
|
|
|
|
return n;
|
|
}
|
|
|
|
/*
|
|
* Copyright (c) 2020 Felix Kopp <sandtler@sandtler.club>
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without modification, are permitted
|
|
* provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright notice, this list of
|
|
* conditions and the following disclaimer.
|
|
* 2. 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.
|
|
* 3. Neither the name of the copyright holder nor the names of its contributors may be
|
|
* used to endorse or promote products derived from this software without specific prior
|
|
* written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER OR
|
|
* CONTRIBUTORS 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.
|
|
*/
|