size_t
ringbuf_memset(ringbuf_t dst, int c, size_t len)
{
const uint8_t *bufend = ringbuf_end(dst);
size_t nwritten = 0;
size_t count = MIN(len, ringbuf_buffer_size(dst));
int overflow = count > ringbuf_bytes_free(dst);
while (nwritten != count) {
/* don't copy beyond the end of the buffer */
assert(bufend > dst->head);
size_t n = MIN(bufend - dst->head, count - nwritten);
memset(dst->head, c, n);
dst->head += n;
nwritten += n;
/* wrap? */
if (dst->head == bufend)
dst->head = dst->buf;
}
if (overflow) {
dst->tail = ringbuf_nextp(dst, dst->head);
assert(ringbuf_is_full(dst));
}
return nwritten;
}
size_t ringbuf_memset(ringbuf_t dst, int c, size_t len)
{
const uint8_t* bufend = ringbuf_end(dst);
size_t nwritten = 0;
size_t count = LWIP_MIN(len, ringbuf_buffer_size(dst));
int overflow = count > ringbuf_bytes_free(dst);
while (nwritten != count) {
lwIP_ASSERT(bufend > dst->head);
size_t n = LWIP_MIN(bufend - dst->head, count - nwritten);
os_memset(dst->head, c, n);
dst->head += n;
nwritten += n;
if (dst->head == bufend) {
dst->head = dst->buf;
}
}
if (overflow) {
dst->tail = ringbuf_nextp(dst, dst->head);
lwIP_ASSERT(ringbuf_is_full(dst));
}
return nwritten;
}
/*
* Given a ring buffer rb and a pointer to a location within its
* contiguous buffer, return the a pointer to the next logical
* location in the ring buffer.
*/
static uint8_t *
ringbuf_nextp(ringbuf_t rb, const uint8_t *p)
{
/*
* The assert guarantees the expression (++p - rb->buf) is
* non-negative; therefore, the modulus operation is safe and
* portable.
*/
assert((p >= rb->buf) && (p < ringbuf_end(rb)));
return rb->buf + ((++p - rb->buf) % ringbuf_buffer_size(rb));
}
size_t ringbuf_findchr(const struct ringbuf_t *rb, int c, size_t offset)
{
const uint8_t *bufend = ringbuf_end(rb);
size_t bytes_used = ringbuf_bytes_used(rb);
if (offset >= bytes_used)
return bytes_used;
const uint8_t *start = rb ->buf + (((rb->tail - rb->buf) + offset) % ringbuf_buffer_size(rb));
lwIP_ASSERT0(bufend > start);
size_t n = LWIP_MIN(bufend - start, bytes_used - offset);
const uint8_t *found = (const uint8_t *)memchr(start, c, n);
if (found)
return offset + (found - start);
else
return ringbuf_findchr(rb, c, offset + n);
}
static const uint8_t* ringbuf_end(const struct ringbuf_t* rb)
{
return rb->buf + ringbuf_buffer_size(rb);
}
size_t ringbuf_capacity(const struct ringbuf_t* rb)
{
return ringbuf_buffer_size(rb) - 1;
}
static uint8_t* ringbuf_nextp(ringbuf_t rb, const uint8_t* p)
{
lwIP_ASSERT((p >= rb->buf) && (p < ringbuf_end(rb)));
return rb->buf + ((++p - rb->buf) % ringbuf_buffer_size(rb));
}
static const uint8_t* ICACHE_FLASH_ATTR
ringbuf_end(const struct ringbuf_t *rb)
{
return rb->buf + ringbuf_buffer_size(rb);
}
size_t ICACHE_FLASH_ATTR
ringbuf_capacity(const struct ringbuf_t *rb)
{
return ringbuf_buffer_size(rb) - 1;
}