address nick's comments and make evbuffer_pullup more efficient

svn:r680
This commit is contained in:
Niels Provos 2008-02-29 05:23:49 +00:00
parent 7210592777
commit 00382110b2

View File

@ -339,28 +339,37 @@ evbuffer_pullup(struct evbuffer *buf, int size)
if (size == -1)
size = buf->total_len;
/* XXX Does it make more sense, if size > buf->total_len, to
* clip it downwards? */
/* if size > buf->total_len, we cannot guarantee to the user that she
* is going to have a long enough buffer afterwards; so we return
* NULL */
if (size == 0 || size > buf->total_len)
return (NULL);
/* No need to pull up anything; the first size bytes are already here. */
/* No need to pull up anything; the first size bytes are
* already here. */
if (chain->off >= size)
return chain->buffer + chain->misalign;
/* XXX is it possible that buf->chain will already have enough space
* to hold size bytes? */
if ((tmp = evbuffer_chain_new(size)) == NULL) {
event_warn("%s: out of memory\n", __func__);
return (NULL);
if (chain->buffer_len - chain->misalign >= size) {
/* already have enough space in the first chain */
size_t old_off = chain->off;
buffer = chain->buffer + chain->misalign + chain->off;
tmp = chain;
tmp->off = size;
size -= old_off;
chain = chain->next;
} else {
if ((tmp = evbuffer_chain_new(size)) == NULL) {
event_warn("%s: out of memory\n", __func__);
return (NULL);
}
buffer = tmp->buffer;
tmp->off = size;
buf->first = tmp;
}
tmp->off = size;
buffer = tmp->buffer;
/* Copy and free every chunk that will be entirely pulled into tmp */
for (chain = buf->first;
chain != NULL && size >= chain->off; chain = next) {
for (; chain != NULL && size >= chain->off; chain = next) {
next = chain->next;
memcpy(buffer, chain->buffer + chain->misalign, chain->off);
@ -378,10 +387,9 @@ evbuffer_pullup(struct evbuffer *buf, int size)
buf->last = tmp;
}
buf->first = tmp;
tmp->next = chain;
return (tmp->buffer);
return (tmp->buffer + tmp->misalign);
}
/*