ring_buf_circ.c

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/*
 * SPDX-License-Identifier: MIT
 * SPDX-FileCopyrightText: 2024, Roy Ratcliffe, Northumberland, United Kingdom
 */
#include "ring_buf_circ.h"
#include "ring_buf.h"
 
/*
 * Add a new item to the ring buffer. If the circular buffer is full, remove the
 * oldest item first.
 *
 * Fail if the new data will not fit. This should not happen if the buffer is
 * sized correctly. It will never happen if the buffer size is a multiple of the
 * data size.
 */
int ring_buf_put_circ(struct ring_buf *buf, void *data, size_t size) {
  if (ring_buf_is_full(buf))
    (void)ring_buf_get_ack(buf, ring_buf_get(buf, NULL, size));
  if (size > ring_buf_free_space(buf))
    return -EMSGSIZE;
  return ring_buf_put_ack(buf, ring_buf_put(buf, data, size));
}