Use the native "struct iovec" as our "struct evbuffer_iovec" when available, so we do not need to copy more pointers than necessary.

svn:r1299
This commit is contained in:
Nick Mathewson 2009-05-21 20:59:00 +00:00
parent 594842970e
commit 8997f234f2
4 changed files with 29 additions and 18 deletions

View File

@ -1475,17 +1475,10 @@ _evbuffer_expand_fast(struct evbuffer *buf, size_t datlen)
#define IOV_PTR_FIELD buf
#define IOV_LEN_FIELD len
#endif
#define IOV_TYPE_FROM_EVBUFFER_IOV(i,ei) do { \
(i)->IOV_PTR_FIELD = (ei)->iov_base; \
(i)->IOV_LEN_FIELD = (ei)->iov_len; \
} while(0)
#endif
#define EVBUFFER_MAX_READ 4096
#ifdef USE_IOVEC_IMPL
/** Helper function to figure out which space to use for reading data into
an evbuffer. Internal use only.
@ -1494,7 +1487,8 @@ _evbuffer_expand_fast(struct evbuffer *buf, size_t datlen)
@param vecs An array of two iovecs or WSABUFs.
@param chainp A pointer to a variable to hold the first chain we're
reading into.
@param exact DOCDOC
@param exact Boolean: if true, we do not provide more than 'howmuch'
space in the vectors, even if more space is available.
@return The number of buffers we're using.
*/
int
@ -1546,7 +1540,6 @@ _evbuffer_read_setup_vecs(struct evbuffer *buf, ssize_t howmuch,
*chainp = chain;
return nvecs;
}
#endif
/* TODO(niels): should this function return ssize_t and take ssize_t
* as howmuch? */
@ -1605,16 +1598,23 @@ evbuffer_read(struct evbuffer *buf, evutil_socket_t fd, int howmuch)
goto done;
} else {
IOV_TYPE vecs[2];
#ifdef _EVBUFFER_IOVEC_IS_NATIVE
nvecs = _evbuffer_read_setup_vecs(buf, howmuch, vecs,
&chain, 1);
#else
/* We aren't using the native struct iovec. Therefore,
we are on win32. */
struct evbuffer_iovec ev_vecs[2];
nvecs = _evbuffer_read_setup_vecs(buf, howmuch, ev_vecs,
&chain, 1);
if (nvecs == 2) {
IOV_TYPE_FROM_EVBUFFER_IOV(&vecs[1], &ev_vecs[1]);
IOV_TYPE_FROM_EVBUFFER_IOV(&vecs[0], &ev_vecs[0]);
WSABUF_FROM_EVBUFFER_IOV(&vecs[1], &ev_vecs[1]);
WSABUF_FROM_EVBUFFER_IOV(&vecs[0], &ev_vecs[0]);
} else if (nvecs == 1) {
IOV_TYPE_FROM_EVBUFFER_IOV(&vecs[0], &ev_vecs[0]);
WSABUF_FROM_EVBUFFER_IOV(&vecs[0], &ev_vecs[0]);
}
#endif
#ifdef WIN32
{

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@ -245,11 +245,6 @@ done:
return r;
}
#define IOV_TYPE_FROM_EVBUFFER_IOV(i,ei) do { \
(i)->buf = (ei)->iov_base; \
(i)->len = (ei)->iov_len; \
} while(0)
int
evbuffer_launch_read(struct evbuffer *buf, size_t at_most)
{
@ -280,7 +275,7 @@ evbuffer_launch_read(struct evbuffer *buf, size_t at_most)
nvecs = _evbuffer_read_setup_vecs(buf, at_most,
vecs, &chain, 1);
for (i=0;i<nvecs;++i) {
IOV_TYPE_FROM_EVBUFFER_IOV(
WSABUF_FROM_EVBUFFER_IOV(
&buf_o->read_info.buffers[i],
&vecs[i]);
}

View File

@ -252,6 +252,7 @@ void _evbuffer_chain_unpin(struct evbuffer_chain *chain, unsigned flag);
/** As evbuffer_free, but requires that we hold a lock on the buffer, and
* releases the lock before freeing it and the buffer. */
void _evbuffer_decref_and_unlock(struct evbuffer *buffer);
/** As evbuffer_expand, but does not guarantee that the newly allocated memory
* is contiguous. Instead, it may be split across two chunks. */
int _evbuffer_expand_fast(struct evbuffer *, size_t);
@ -265,6 +266,12 @@ int _evbuffer_expand_fast(struct evbuffer *, size_t);
int _evbuffer_read_setup_vecs(struct evbuffer *buf, ssize_t howmuch,
struct evbuffer_iovec *vecs, struct evbuffer_chain **chainp, int exact);
/* Helper macro: copies an evbuffer_iovec in ei to a win32 WSABUF in i. */
#define WSABUF_FROM_EVBUFFER_IOV(i,ei) do { \
(i)->buf = (ei)->iov_base; \
(i)->len = (ei)->iov_len; \
} while(0)
#ifdef __cplusplus
}
#endif

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@ -70,6 +70,9 @@ extern "C" {
#ifdef _EVENT_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef _EVENT_HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
#include <event2/util.h>
struct evbuffer;
@ -94,12 +97,18 @@ struct evbuffer_ptr {
@see evbuffer_reserve_space, evbuffer_commit_space, evbuffer_peek
*/
#ifdef _EVENT_HAVE_SYS_UIO_H
#define evbuffer_iovec iovec
/* Internal use -- defined only if we are using the native struct iovec */
#define _EVBUFFER_IOVEC_IS_NATIVE
#else
struct evbuffer_iovec {
/** The start of the extent of memory. */
void *iov_base;
/** The length of the extent of memory. */
size_t iov_len;
};
#endif
/**
Allocate storage for a new evbuffer.