fef/ardix
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Simplify ringbuf indexing

Browse source 
This whole pointer arithmetic things might be all
fancy and stuff, but the diff should make it clear
that it is just unnecessarily complicated.
This commit is contained in:
Felix Kopp 2020-10-30 18:07:29 +01:00
parent c031bf8611
commit 1fa5d159a7
No known key found for this signature in database
GPG key ID: C478BA0A85F75728
2 changed files with 17 additions and 17 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
include/ardix/ringbuf.h
View file

@ -7,8 +7,8 @@
struct ringbuf {
size_t size;
uint8_t *rpos;
uint8_t *wpos;
size_t rpos;
size_t wpos;
uint8_t data[];
};

30
kernel/ringbuf.c
View file

@ -15,8 +15,8 @@ struct ringbuf *ringbuf_create(size_t size)
return NULL;
buf->size = size;
buf->rpos = &buf->data[0];
buf->wpos = &buf->data[0];
buf->rpos = 0;
buf->wpos = 0;
return buf;
}
@ -31,12 +31,12 @@ 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++;
*dest++ = buf->data[buf->rpos++];
n++;
/* wrap around */
if ((ptrdiff_t)(buf->rpos) - (ptrdiff_t)(&buf->data[0]) >= (ptrdiff_t)(buf->size))
buf->rpos = &buf->data[0];
if (buf->rpos = buf->size)
buf->rpos = 0;
}
return n;
@ -47,12 +47,12 @@ 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++;
buf->data[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];
if (buf->wpos = buf->size)
buf->wpos = 0;
}
return n;
@ -60,14 +60,14 @@ size_t ringbuf_write(struct ringbuf *buf, const uint8_t *src, size_t len)
size_t ringbuf_size(struct ringbuf *buf)
{
ptrdiff_t size = (ptrdiff_t)(buf->wpos) - (ptrdiff_t)(buf->rpos);
if (size < 0) {
/* wpos has wrapped around already, but rpos has not */
size = (ptrdiff_t)(buf->wpos) - (ptrdiff_t)(&buf->data[0]);
size += (ptrdiff_t)(buf->size) - ((ptrdiff_t)(buf->rpos) - (ptrdiff_t)(&buf->data[0]));
}
size_t size;
return (size_t)size;
if (buf->rpos > buf->wpos)
size = buf->size - buf->rpos + buf->wpos;
else
size = buf->wpos - buf->rpos;
return size;
}
/*