From 00382110b268891ced706f9d84ec80031213bc89 Mon Sep 17 00:00:00 2001 From: Niels Provos Date: Fri, 29 Feb 2008 05:23:49 +0000 Subject: [PATCH] address nick's comments and make evbuffer_pullup more efficient svn:r680 --- buffer.c | 38 +++++++++++++++++++++++--------------- 1 file changed, 23 insertions(+), 15 deletions(-) diff --git a/buffer.c b/buffer.c index 41d4bc27..a3574ce7 100644 --- a/buffer.c +++ b/buffer.c @@ -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); } /* -- 2.40.0