@@ -145,21 +145,26 @@ static bool ustream_should_move(struct ustream_buf_list *l, struct ustream_buf *
int maxlen;
int offset;
+ /* nothing to squeeze */
if (buf->data == buf->head)
return false;
maxlen = buf->end - buf->head;
offset = buf->data - buf->head;
+ /* less than half is available */
if (offset > maxlen / 2)
return true;
+ /* less than 32 bytes data but takes more than 1/4 space */
if (buf->tail - buf->data < 32 && offset > maxlen / 4)
return true;
+ /* more buf is already in list or can be allocated */
if (buf != l->tail || ustream_can_alloc(l))
return false;
+ /* no need to move if len is available at the tail */
return (buf->end - buf->tail < len);
}
@@ -255,13 +260,14 @@ static bool ustream_prepare_buf(struct ustream *s, struct ustream_buf_list *l, i
if (l == &s->r)
ustream_fixup_string(s, buf);
}
+ /* some chunks available at the tail */
if (buf->tail != buf->end)
return true;
- }
-
- if (buf && buf->next) {
- l->data_tail = buf->next;
- return true;
+ /* next buf available */
+ if (buf->next) {
+ l->data_tail = buf->next;
+ return true;
+ }
}
if (!ustream_can_alloc(l))
No functional change. - Reuse existing NULL check on buf. - Add some comments for ease of reading the code. Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com> --- ustream.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)