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Replace last_with_data with a slightly smarter version

Browse Source 
To implement evbuffer_expand() properly, you need to be able to
replace the last chunk that has data, which means that we need to keep
track of the the next pointer pointing to the last_with_data chunk,
not the last_with_data chunk itself.
This commit is contained in:
Nick Mathewson 2010-03-26 23:18:40 -04:00
parent cda56abf19
commit b7442f8e83
4 changed files with 147 additions and 95 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

178
buffer.c
View File

@ -210,29 +210,33 @@ evbuffer_chain_free(struct evbuffer_chain *chain)
} }
#endif #endif
} }
mm_free(chain); mm_free(chain);
} }
static inline void static inline void
evbuffer_chain_insert(struct evbuffer *buf, struct evbuffer_chain *chain) evbuffer_chain_insert(struct evbuffer *buf, struct evbuffer_chain *chain)
{ {
ASSERT_EVBUFFER_LOCKED(buf); ASSERT_EVBUFFER_LOCKED(buf);
if (buf->first == NULL) { if (buf->first == NULL) {
buf->first = buf->last = chain; buf->first = buf->last = chain;
buf->last_with_data = chain; buf->last_with_datap = &buf->first;
} else { } else {
/* the last chain is empty so we can just drop it */ /* the last chain is empty so we can just drop it */
if (buf->last->off == 0 && !CHAIN_PINNED(buf->last)) { if (buf->last->off == 0 && !CHAIN_PINNED(buf->last)) {
if (buf->last_with_data == buf->last) /* NOT CLOSE TO RIGHT XXXX */
buf->last_with_data = chain; if (*buf->last_with_datap == buf->last) {
*buf->last_with_datap = chain;
}
evbuffer_chain_free(buf->last); evbuffer_chain_free(buf->last);
buf->last = chain; buf->last = chain;
} else { } else {
buf->last->next = chain; buf->last->next = chain;
if (chain->off)
buf->last_with_datap = &buf->last->next;
buf->last = chain; buf->last = chain;
} }
if (chain->off)
buf->last_with_data = chain;
} }
buf->total_len += chain->off; buf->total_len += chain->off;
@ -265,6 +269,7 @@ evbuffer_new(void)
TAILQ_INIT(&buffer->callbacks); TAILQ_INIT(&buffer->callbacks);
buffer->refcnt = 1; buffer->refcnt = 1;
buffer->last_with_datap = &buffer->first;
return (buffer); return (buffer);
} }
@ -507,7 +512,7 @@ int
evbuffer_reserve_space(struct evbuffer *buf, ev_ssize_t size, evbuffer_reserve_space(struct evbuffer *buf, ev_ssize_t size,
struct evbuffer_iovec *vec, int n_vecs) struct evbuffer_iovec *vec, int n_vecs)
{ {
struct evbuffer_chain *chain; struct evbuffer_chain *chain, **chainp;
int n = -1; int n = -1;
EVBUFFER_LOCK(buf); EVBUFFER_LOCK(buf);
@ -526,7 +531,7 @@ evbuffer_reserve_space(struct evbuffer *buf, ev_ssize_t size,
} else { } else {
if (_evbuffer_expand_fast(buf, size, n_vecs)<0) if (_evbuffer_expand_fast(buf, size, n_vecs)<0)
goto done; goto done;
n = _evbuffer_read_setup_vecs(buf, size, vec, n_vecs, &chain, 0); n = _evbuffer_read_setup_vecs(buf, size, vec, n_vecs, &chainp, 0);
} }
done: done:
@ -541,11 +546,11 @@ advance_last_with_data(struct evbuffer *buf)
int n = 0; int n = 0;
ASSERT_EVBUFFER_LOCKED(buf); ASSERT_EVBUFFER_LOCKED(buf);
if (!buf->last_with_data) if (!*buf->last_with_datap)
return 0; return 0;
while (buf->last_with_data->next && buf->last_with_data->next->off) { while ((*buf->last_with_datap)->next && (*buf->last_with_datap)->next->off) {
buf->last_with_data = buf->last_with_data->next; buf->last_with_datap = &(*buf->last_with_datap)->next;
++n; ++n;
} }
return n; return n;
@ -555,7 +560,7 @@ int
evbuffer_commit_space(struct evbuffer *buf, evbuffer_commit_space(struct evbuffer *buf,
struct evbuffer_iovec *vec, int n_vecs) struct evbuffer_iovec *vec, int n_vecs)
{ {
struct evbuffer_chain *firstchain, *chain; struct evbuffer_chain *chain, **firstchainp, **chainp;
int result = -1; int result = -1;
size_t added = 0; size_t added = 0;
int i; int i;
@ -576,19 +581,19 @@ evbuffer_commit_space(struct evbuffer *buf,
buf->last->off += vec[0].iov_len; buf->last->off += vec[0].iov_len;
added = vec[0].iov_len; added = vec[0].iov_len;
if (added) if (added)
buf->last_with_data = buf->last; advance_last_with_data(buf);
goto okay; goto okay;
} }
/* Advance 'firstchain' to the first chain with space in it. */ /* Advance 'firstchain' to the first chain with space in it. */
firstchain = buf->last_with_data; firstchainp = buf->last_with_datap;
if (!firstchain) if (!*firstchainp)
goto done; goto done;
if (CHAIN_SPACE_LEN(firstchain) == 0) { if (CHAIN_SPACE_LEN(*firstchainp) == 0) {
firstchain = firstchain->next; firstchainp = &(*firstchainp)->next;
} }
chain = firstchain; chain = *firstchainp;
/* pass 1: make sure that the pointers and lengths of vecs[] are in /* pass 1: make sure that the pointers and lengths of vecs[] are in
* bounds before we try to commit anything. */ * bounds before we try to commit anything. */
for (i=0; i<n_vecs; ++i) { for (i=0; i<n_vecs; ++i) {
@ -600,13 +605,14 @@ evbuffer_commit_space(struct evbuffer *buf,
chain = chain->next; chain = chain->next;
} }
/* pass 2: actually adjust all the chains. */ /* pass 2: actually adjust all the chains. */
chain = firstchain; chainp = firstchainp;
for (i=0; i<n_vecs; ++i) { for (i=0; i<n_vecs; ++i) {
chain->off += vec[i].iov_len; (*chainp)->off += vec[i].iov_len;
added += vec[i].iov_len; added += vec[i].iov_len;
if (vec[i].iov_len) if (vec[i].iov_len) {
buf->last_with_data = chain; buf->last_with_datap = chainp;
chain = chain->next; }
chainp = &(*chainp)->next;
} }
okay: okay:
@ -624,7 +630,7 @@ done:
ASSERT_EVBUFFER_LOCKED(dst); \ ASSERT_EVBUFFER_LOCKED(dst); \
(dst)->first = NULL; \ (dst)->first = NULL; \
(dst)->last = NULL; \ (dst)->last = NULL; \
(dst)->last_with_data = NULL; \ (dst)->last_with_datap = &(dst)->first; \
(dst)->total_len = 0; \ (dst)->total_len = 0; \
} while (0) } while (0)
@ -632,7 +638,10 @@ done:
ASSERT_EVBUFFER_LOCKED(dst); \ ASSERT_EVBUFFER_LOCKED(dst); \
ASSERT_EVBUFFER_LOCKED(src); \ ASSERT_EVBUFFER_LOCKED(src); \
(dst)->first = (src)->first; \ (dst)->first = (src)->first; \
(dst)->last_with_data = (src)->last_with_data; \ if ((src)->last_with_datap == &(src)->first) \
(dst)->last_with_datap = &(dst)->first; \
else \
(dst)->last_with_datap = (src)->last_with_datap; \
(dst)->last = (src)->last; \ (dst)->last = (src)->last; \
(dst)->total_len = (src)->total_len; \ (dst)->total_len = (src)->total_len; \
} while (0) } while (0)
@ -641,20 +650,28 @@ done:
ASSERT_EVBUFFER_LOCKED(dst); \ ASSERT_EVBUFFER_LOCKED(dst); \
ASSERT_EVBUFFER_LOCKED(src); \ ASSERT_EVBUFFER_LOCKED(src); \
(dst)->last->next = (src)->first; \ (dst)->last->next = (src)->first; \
if ((src)->last_with_data) \ if ((src)->last_with_datap == &(src)->first) \
(dst)->last_with_data = (src)->last_with_data; \ (dst)->last_with_datap = &(dst)->last->next; \
else \
(dst)->last_with_datap = (src)->last_with_datap; \
(dst)->last = (src)->last; \ (dst)->last = (src)->last; \
(dst)->total_len += (src)->total_len; \ (dst)->total_len += (src)->total_len; \
} while (0) } while (0)
#define PREPEND_CHAIN(dst, src) do { \ #define PREPEND_CHAIN(dst, src) do { \
ASSERT_EVBUFFER_LOCKED(dst); \ ASSERT_EVBUFFER_LOCKED(dst); \
ASSERT_EVBUFFER_LOCKED(src); \ ASSERT_EVBUFFER_LOCKED(src); \
(src)->last->next = (dst)->first; \ (src)->last->next = (dst)->first; \
(dst)->first = (src)->first; \ (dst)->first = (src)->first; \
(dst)->total_len += (src)->total_len; \ (dst)->total_len += (src)->total_len; \
if ((dst)->last_with_data == NULL) \ if (*(dst)->last_with_datap == NULL) { \
(dst)->last_with_data = (src)->last_with_data; \ if ((src)->last_with_datap == &(src)->first) \
(dst)->last_with_datap = &(dst)->first; \
else \
(dst)->last_with_datap = (src)->last_with_datap; \
} else if ((dst)->last_with_datap == &(dst)->first) { \
(dst)->last_with_datap = &(src)->last->next; \
} \
} while (0) } while (0)
int int
@ -676,6 +693,7 @@ evbuffer_add_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf)
} }
if (out_total_len == 0) { if (out_total_len == 0) {
/* XXX need to free old outbuf chains */
COPY_CHAIN(outbuf, inbuf); COPY_CHAIN(outbuf, inbuf);
} else { } else {
APPEND_CHAIN(outbuf, inbuf); APPEND_CHAIN(outbuf, inbuf);
@ -714,6 +732,7 @@ evbuffer_prepend_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf)
} }
if (out_total_len == 0) { if (out_total_len == 0) {
/* XXX need to free old outbuf chains */
COPY_CHAIN(outbuf, inbuf); COPY_CHAIN(outbuf, inbuf);
} else { } else {
PREPEND_CHAIN(outbuf, inbuf); PREPEND_CHAIN(outbuf, inbuf);
@ -768,8 +787,12 @@ evbuffer_drain(struct evbuffer *buf, size_t len)
for (chain = buf->first; len >= chain->off; chain = next) { for (chain = buf->first; len >= chain->off; chain = next) {
next = chain->next; next = chain->next;
len -= chain->off; len -= chain->off;
if (chain == buf->last_with_data)
buf->last_with_data = next; if (chain == *buf->last_with_datap) {
buf->last_with_datap = &buf->first;
}
if (&chain->next == buf->last_with_datap)
buf->last_with_datap = &buf->first;
if (len == 0 && CHAIN_PINNED_R(chain)) if (len == 0 && CHAIN_PINNED_R(chain))
break; break;
@ -823,8 +846,9 @@ evbuffer_remove(struct evbuffer *buf, void *data_out, size_t datlen)
data += chain->off; data += chain->off;
datlen -= chain->off; datlen -= chain->off;
if (chain == buf->last_with_data) if (chain == *buf->last_with_datap) {
buf->last_with_data = chain->next; buf->last_with_datap = &buf->first;
}
tmp = chain; tmp = chain;
chain = chain->next; chain = chain->next;
@ -893,10 +917,12 @@ evbuffer_remove_buffer(struct evbuffer *src, struct evbuffer *dst,
/* We can't remove the last with data from src unless we /* We can't remove the last with data from src unless we
* remove all chains, in which case we would have done the if * remove all chains, in which case we would have done the if
* block above */ * block above */
EVUTIL_ASSERT(chain != src->last_with_data); EVUTIL_ASSERT(chain != *src->last_with_datap);
nread += chain->off; nread += chain->off;
datlen -= chain->off; datlen -= chain->off;
previous = chain; previous = chain;
if (src->last_with_datap == &chain->next)
src->last_with_datap = &src->first;
chain = chain->next; chain = chain->next;
} }
@ -908,9 +934,9 @@ evbuffer_remove_buffer(struct evbuffer *src, struct evbuffer *dst,
dst->last->next = src->first; dst->last->next = src->first;
} }
dst->last = previous; dst->last = previous;
dst->last_with_data = dst->last;
previous->next = NULL; previous->next = NULL;
src->first = chain; src->first = chain;
advance_last_with_data(dst);
dst->total_len += nread; dst->total_len += nread;
dst->n_add_for_cb += nread; dst->n_add_for_cb += nread;
@ -944,6 +970,7 @@ evbuffer_pullup(struct evbuffer *buf, ev_ssize_t size)
unsigned char *buffer, *result = NULL; unsigned char *buffer, *result = NULL;
ev_ssize_t remaining; ev_ssize_t remaining;
int removed_last_with_data = 0; int removed_last_with_data = 0;
int removed_last_with_datap = 0;
EVBUFFER_LOCK(buf); EVBUFFER_LOCK(buf);
@ -1013,8 +1040,10 @@ evbuffer_pullup(struct evbuffer *buf, ev_ssize_t size)
memcpy(buffer, chain->buffer + chain->misalign, chain->off); memcpy(buffer, chain->buffer + chain->misalign, chain->off);
size -= chain->off; size -= chain->off;
buffer += chain->off; buffer += chain->off;
if (chain == buf->last_with_data) if (chain == *buf->last_with_datap)
removed_last_with_data = 1; removed_last_with_data = 1;
if (&chain->next == buf->last_with_datap)
removed_last_with_datap = 1;
evbuffer_chain_free(chain); evbuffer_chain_free(chain);
} }
@ -1030,10 +1059,12 @@ evbuffer_pullup(struct evbuffer *buf, ev_ssize_t size)
tmp->next = chain; tmp->next = chain;
if (removed_last_with_data) { if (removed_last_with_data) {
int n; buf->last_with_datap = &buf->first;
buf->last_with_data = buf->first; } else if (removed_last_with_datap) {
n = advance_last_with_data(buf); if (buf->first->next && buf->first->next->off)
EVUTIL_ASSERT(n == 0); buf->last_with_datap = &buf->first->next;
else
buf->last_with_datap = &buf->first;
} }
result = (tmp->buffer + tmp->misalign); result = (tmp->buffer + tmp->misalign);
@ -1429,10 +1460,8 @@ evbuffer_prepend(struct evbuffer *buf, const void *data, size_t datlen)
if ((tmp = evbuffer_chain_new(datlen)) == NULL) if ((tmp = evbuffer_chain_new(datlen)) == NULL)
goto done; goto done;
buf->first = tmp; buf->first = tmp;
if (buf->last_with_data == NULL) if (buf->last_with_datap == &buf->first)
buf->last_with_data = tmp; buf->last_with_datap = &tmp->next;
else if (chain && buf->last_with_data == chain && 0==chain->off)
buf->last_with_data = tmp;
tmp->next = chain; tmp->next = chain;
@ -1515,8 +1544,6 @@ evbuffer_expand(struct evbuffer *buf, size_t datlen)
if (buf->first == chain) if (buf->first == chain)
buf->first = tmp; buf->first = tmp;
buf->last = tmp; buf->last = tmp;
if (buf->last->off || buf->last_with_data == chain)
buf->last_with_data = tmp;
evbuffer_chain_free(chain); evbuffer_chain_free(chain);
@ -1555,10 +1582,10 @@ _evbuffer_expand_fast(struct evbuffer *buf, size_t datlen, int n)
/* How many bytes can we stick at the end of buffer as it is? Iterate /* How many bytes can we stick at the end of buffer as it is? Iterate
* over the chains at the end of the buffer, tring to see how much * over the chains at the end of the buffer, tring to see how much
* space we have in the first n. */ * space we have in the first n. */
for (chain = buf->last_with_data; chain; chain = chain->next) { for (chain = *buf->last_with_datap; chain; chain = chain->next) {
if (chain->off) { if (chain->off) {
size_t space = CHAIN_SPACE_LEN(chain); size_t space = CHAIN_SPACE_LEN(chain);
EVUTIL_ASSERT(chain == buf->last_with_data); EVUTIL_ASSERT(chain == *buf->last_with_datap);
if (space) { if (space) {
avail += space; avail += space;
++used; ++used;
@ -1598,7 +1625,7 @@ _evbuffer_expand_fast(struct evbuffer *buf, size_t datlen, int n)
} else { } else {
/* Nuke _all_ the empty chains. */ /* Nuke _all_ the empty chains. */
int rmv_all = 0; /* True iff we removed last_with_data. */ int rmv_all = 0; /* True iff we removed last_with_data. */
chain = buf->last_with_data; chain = *buf->last_with_datap;
if (!chain->off) { if (!chain->off) {
EVUTIL_ASSERT(chain == buf->first); EVUTIL_ASSERT(chain == buf->first);
rmv_all = 1; rmv_all = 1;
@ -1619,16 +1646,17 @@ _evbuffer_expand_fast(struct evbuffer *buf, size_t datlen, int n)
if (rmv_all) { if (rmv_all) {
ZERO_CHAIN(buf); ZERO_CHAIN(buf);
} else { } else {
buf->last = buf->last_with_data; buf->last = *buf->last_with_datap;
buf->last_with_data->next = NULL; (*buf->last_with_datap)->next = NULL;
} }
return (-1); return (-1);
} }
if (rmv_all) { if (rmv_all) {
buf->first = buf->last = buf->last_with_data = tmp; buf->first = buf->last = tmp;
buf->last_with_datap = &buf->first;
} else { } else {
buf->last_with_data->next = tmp; (*buf->last_with_datap)->next = tmp;
buf->last = tmp; buf->last = tmp;
} }
return (0); return (0);
@ -1679,9 +1707,10 @@ _evbuffer_expand_fast(struct evbuffer *buf, size_t datlen, int n)
int int
_evbuffer_read_setup_vecs(struct evbuffer *buf, ev_ssize_t howmuch, _evbuffer_read_setup_vecs(struct evbuffer *buf, ev_ssize_t howmuch,
struct evbuffer_iovec *vecs, int n_vecs_avail, struct evbuffer_iovec *vecs, int n_vecs_avail,
struct evbuffer_chain **chainp, int exact) struct evbuffer_chain ***chainp, int exact)
{ {
struct evbuffer_chain *chain, *firstchain; struct evbuffer_chain *chain;
struct evbuffer_chain **firstchainp;
size_t so_far; size_t so_far;
int i; int i;
ASSERT_EVBUFFER_LOCKED(buf); ASSERT_EVBUFFER_LOCKED(buf);
@ -1691,11 +1720,12 @@ _evbuffer_read_setup_vecs(struct evbuffer *buf, ev_ssize_t howmuch,
so_far = 0; so_far = 0;
/* Let firstchain be the first chain with any space on it */ /* Let firstchain be the first chain with any space on it */
firstchain = buf->last_with_data; firstchainp = buf->last_with_datap;
if (CHAIN_SPACE_LEN(firstchain) == 0) if (CHAIN_SPACE_LEN(*firstchainp) == 0) {
firstchain = firstchain->next; firstchainp = &(*firstchainp)->next;
}
chain = firstchain; chain = *firstchainp;
for (i = 0; i < n_vecs_avail && so_far < howmuch; ++i) { for (i = 0; i < n_vecs_avail && so_far < howmuch; ++i) {
size_t avail = CHAIN_SPACE_LEN(chain); size_t avail = CHAIN_SPACE_LEN(chain);
if (avail > howmuch && exact) if (avail > howmuch && exact)
@ -1706,7 +1736,7 @@ _evbuffer_read_setup_vecs(struct evbuffer *buf, ev_ssize_t howmuch,
chain = chain->next; chain = chain->next;
} }
*chainp = firstchain; *chainp = firstchainp;
return i; return i;
} }
@ -1715,7 +1745,7 @@ _evbuffer_read_setup_vecs(struct evbuffer *buf, ev_ssize_t howmuch,
int int
evbuffer_read(struct evbuffer *buf, evutil_socket_t fd, int howmuch) evbuffer_read(struct evbuffer *buf, evutil_socket_t fd, int howmuch)
{ {
struct evbuffer_chain *chain; struct evbuffer_chain *chain, **chainp;
int n = EVBUFFER_MAX_READ; int n = EVBUFFER_MAX_READ;
int result; int result;
@ -1771,13 +1801,13 @@ evbuffer_read(struct evbuffer *buf, evutil_socket_t fd, int howmuch)
IOV_TYPE vecs[NUM_READ_IOVEC]; IOV_TYPE vecs[NUM_READ_IOVEC];
#ifdef _EVBUFFER_IOVEC_IS_NATIVE #ifdef _EVBUFFER_IOVEC_IS_NATIVE
nvecs = _evbuffer_read_setup_vecs(buf, howmuch, vecs, nvecs = _evbuffer_read_setup_vecs(buf, howmuch, vecs,
NUM_READ_IOVEC, &chain, 1); NUM_READ_IOVEC, &chainp, 1);
#else #else
/* We aren't using the native struct iovec. Therefore, /* We aren't using the native struct iovec. Therefore,
we are on win32. */ we are on win32. */
struct evbuffer_iovec ev_vecs[NUM_READ_IOVEC]; struct evbuffer_iovec ev_vecs[NUM_READ_IOVEC];
nvecs = _evbuffer_read_setup_vecs(buf, howmuch, ev_vecs, 2, nvecs = _evbuffer_read_setup_vecs(buf, howmuch, ev_vecs, 2,
&chain, 1); &chainp, 1);
for (i=0; i < nvecs; ++i) for (i=0; i < nvecs; ++i)
WSABUF_FROM_EVBUFFER_IOV(&vecs[i], &ev_vecs[i]); WSABUF_FROM_EVBUFFER_IOV(&vecs[i], &ev_vecs[i]);
@ -1835,20 +1865,20 @@ evbuffer_read(struct evbuffer *buf, evutil_socket_t fd, int howmuch)
#ifdef USE_IOVEC_IMPL #ifdef USE_IOVEC_IMPL
remaining = n; remaining = n;
for (i=0; i < nvecs; ++i) { for (i=0; i < nvecs; ++i) {
ev_ssize_t space = CHAIN_SPACE_LEN(chain); ev_ssize_t space = CHAIN_SPACE_LEN(*chainp);
if (space < remaining) { if (space < remaining) {
chain->off += space; (*chainp)->off += space;
remaining -= space; remaining -= space;
} else { } else {
chain->off += remaining; (*chainp)->off += remaining;
buf->last_with_data = chain; buf->last_with_datap = chainp;
break; break;
} }
chain = chain->next; chainp = &(*chainp)->next;
} }
#else #else
chain->off += n; chain->off += n;
buf->last_with_data = chain; advance_last_with_data(buf);
#endif #endif
buf->total_len += n; buf->total_len += n;
buf->n_add_for_cb += n; buf->n_add_for_cb += n;

6
buffer_iocp.c
View File

@ -233,7 +233,7 @@ evbuffer_launch_read(struct evbuffer *buf, size_t at_most,
int r = -1, i; int r = -1, i;
int nvecs; int nvecs;
int npin=0; int npin=0;
struct evbuffer_chain *chain=NULL; struct evbuffer_chain *chain=NULL, **chainp;
DWORD bytesRead; DWORD bytesRead;
DWORD flags = 0; DWORD flags = 0;
struct evbuffer_iovec vecs[MAX_WSABUFS]; struct evbuffer_iovec vecs[MAX_WSABUFS];
@ -257,7 +257,7 @@ evbuffer_launch_read(struct evbuffer *buf, size_t at_most,
* not "2". But commit_read() above can't handle more than two * not "2". But commit_read() above can't handle more than two
* buffers yet. */ * buffers yet. */
nvecs = _evbuffer_read_setup_vecs(buf, at_most, nvecs = _evbuffer_read_setup_vecs(buf, at_most,
vecs, 2, &chain, 1); vecs, 2, &chainp, 1);
for (i=0;i<nvecs;++i) { for (i=0;i<nvecs;++i) {
WSABUF_FROM_EVBUFFER_IOV( WSABUF_FROM_EVBUFFER_IOV(
&buf_o->buffers[i], &buf_o->buffers[i],
@ -265,7 +265,7 @@ evbuffer_launch_read(struct evbuffer *buf, size_t at_most,
} }
buf_o->n_buffers = nvecs; buf_o->n_buffers = nvecs;
buf_o->first_pinned = chain; buf_o->first_pinned = chain= *chainp;
npin=0; npin=0;
for ( ; chain; chain = chain->next) { for ( ; chain; chain = chain->next) {
_evbuffer_chain_pin(chain, EVBUFFER_MEM_PINNED_R); _evbuffer_chain_pin(chain, EVBUFFER_MEM_PINNED_R);

20
evbuffer-internal.h
View File

@ -81,10 +81,20 @@ struct evbuffer {
/** The last chain in this buffer's linked list of chains. */ /** The last chain in this buffer's linked list of chains. */
struct evbuffer_chain *last; struct evbuffer_chain *last;
/** The last chain that has any data in it. If all chains in the /** Pointer to the next pointer pointing at the 'last_with_data' chain.
* buffer are empty, points to the first chain. If the buffer has no *
* chains, this is NULL. */ * To unpack:
struct evbuffer_chain *last_with_data; *
* The last_with_data chain is the last chain that has any data in it.
* If all chains in the buffer are empty, it is the first chain.
* If the buffer has no chains, it is NULL.
*
* The last_with_datap pointer points at _whatever 'next' pointer_
* points at the last_with_datap chain. If the last_with_data chain
* is the first chain, or it is NULL, then the last_with_datap pointer
* is &buf->first.
*/
struct evbuffer_chain **last_with_datap;
/** Total amount of bytes stored in all chains.*/ /** Total amount of bytes stored in all chains.*/
size_t total_len; size_t total_len;
@ -246,7 +256,7 @@ int _evbuffer_expand_fast(struct evbuffer *, size_t, int);
* Returns the number of vecs used. * Returns the number of vecs used.
*/ */
int _evbuffer_read_setup_vecs(struct evbuffer *buf, ev_ssize_t howmuch, int _evbuffer_read_setup_vecs(struct evbuffer *buf, ev_ssize_t howmuch,
struct evbuffer_iovec *vecs, int n_vecs, struct evbuffer_chain **chainp, int exact); struct evbuffer_iovec *vecs, int n_vecs, struct evbuffer_chain ***chainp, int exact);
/* Helper macro: copies an evbuffer_iovec in ei to a win32 WSABUF in i. */ /* Helper macro: copies an evbuffer_iovec in ei to a win32 WSABUF in i. */
#define WSABUF_FROM_EVBUFFER_IOV(i,ei) do { \ #define WSABUF_FROM_EVBUFFER_IOV(i,ei) do { \

38
test/regress_buffer.c
View File

@ -68,7 +68,7 @@ _evbuffer_validate(struct evbuffer *buf)
{ {
struct evbuffer_chain *chain; struct evbuffer_chain *chain;
size_t sum = 0; size_t sum = 0;
int found_last_with_data = 0; int found_last_with_datap = 0;
if (buf->first == NULL) { if (buf->first == NULL) {
tt_assert(buf->last == NULL); tt_assert(buf->last == NULL);
@ -76,9 +76,14 @@ _evbuffer_validate(struct evbuffer *buf)
} }
chain = buf->first; chain = buf->first;
tt_assert(buf->last_with_datap);
if (buf->last_with_datap == &buf->first)
found_last_with_datap = 1;
while (chain != NULL) { while (chain != NULL) {
if (chain == buf->last_with_data) if (&chain->next == buf->last_with_datap)
found_last_with_data = 1; found_last_with_datap = 1;
sum += chain->off; sum += chain->off;
if (chain->next == NULL) { if (chain->next == NULL) {
tt_assert(buf->last == chain); tt_assert(buf->last == chain);
@ -88,10 +93,10 @@ _evbuffer_validate(struct evbuffer *buf)
} }
if (buf->first) if (buf->first)
tt_assert(buf->last_with_data); tt_assert(*buf->last_with_datap);
if (buf->last_with_data) {
tt_assert(found_last_with_data); if (*buf->last_with_datap) {
chain = buf->last_with_data; chain = *buf->last_with_datap;
if (chain->off == 0 || buf->total_len == 0) { if (chain->off == 0 || buf->total_len == 0) {
tt_assert(chain->off == 0) tt_assert(chain->off == 0)
tt_assert(chain == buf->first); tt_assert(chain == buf->first);
@ -102,7 +107,10 @@ _evbuffer_validate(struct evbuffer *buf)
tt_assert(chain->off == 0); tt_assert(chain->off == 0);
chain = chain->next; chain = chain->next;
} }
} else {
tt_assert(buf->last_with_datap == &buf->first);
} }
tt_assert(found_last_with_datap);
tt_assert(sum == buf->total_len); tt_assert(sum == buf->total_len);
return 1; return 1;
@ -111,7 +119,7 @@ _evbuffer_validate(struct evbuffer *buf)
} }
#define evbuffer_validate(buf) \ #define evbuffer_validate(buf) \
TT_STMT_BEGIN if (!_evbuffer_validate(buf)) goto end; TT_STMT_END TT_STMT_BEGIN if (!_evbuffer_validate(buf)) TT_DIE(("Buffer format invalid")); TT_STMT_END
static void static void
test_evbuffer(void *ptr) test_evbuffer(void *ptr)
@ -481,7 +489,9 @@ test_evbuffer_add_file(void *ptr)
evbuffer_validate(src); evbuffer_validate(src);
} }
evbuffer_validate(src);
tt_assert(evbuffer_read(src, pair[1], strlen(data)) == strlen(data)); tt_assert(evbuffer_read(src, pair[1], strlen(data)) == strlen(data));
evbuffer_validate(src);
compare = (char *)evbuffer_pullup(src, strlen(data)); compare = (char *)evbuffer_pullup(src, strlen(data));
tt_assert(compare != NULL); tt_assert(compare != NULL);
if (memcmp(compare, data, strlen(data))) if (memcmp(compare, data, strlen(data)))
@ -933,16 +943,20 @@ test_evbuffer_callbacks(void *ptr)
* adds a summary of length changes to buf_out1/buf_out2 when called. */ * adds a summary of length changes to buf_out1/buf_out2 when called. */
/* size: 0-> 36. */ /* size: 0-> 36. */
evbuffer_add_printf(buf, "The %d magic words are spotty pudding", 2); evbuffer_add_printf(buf, "The %d magic words are spotty pudding", 2);
evbuffer_validate(buf);
evbuffer_cb_clear_flags(buf, cb2, EVBUFFER_CB_ENABLED); evbuffer_cb_clear_flags(buf, cb2, EVBUFFER_CB_ENABLED);
evbuffer_drain(buf, 10); /*36->26*/ evbuffer_drain(buf, 10); /*36->26*/
evbuffer_validate(buf);
evbuffer_prepend(buf, "Hello", 5);/*26->31*/ evbuffer_prepend(buf, "Hello", 5);/*26->31*/
evbuffer_cb_set_flags(buf, cb2, EVBUFFER_CB_ENABLED); evbuffer_cb_set_flags(buf, cb2, EVBUFFER_CB_ENABLED);
evbuffer_add_reference(buf, "Goodbye", 7, NULL, NULL); /*31->38*/ evbuffer_add_reference(buf, "Goodbye", 7, NULL, NULL); /*31->38*/
evbuffer_remove_cb_entry(buf, cb1); evbuffer_remove_cb_entry(buf, cb1);
evbuffer_validate(buf);
evbuffer_drain(buf, evbuffer_get_length(buf)); /*38->0*/; evbuffer_drain(buf, evbuffer_get_length(buf)); /*38->0*/;
tt_assert(-1 == evbuffer_remove_cb(buf, log_change_callback, NULL)); tt_assert(-1 == evbuffer_remove_cb(buf, log_change_callback, NULL));
evbuffer_add(buf, "X", 1); /* 0->1 */ evbuffer_add(buf, "X", 1); /* 0->1 */
tt_assert(!evbuffer_remove_cb(buf, log_change_callback, buf_out2)); tt_assert(!evbuffer_remove_cb(buf, log_change_callback, buf_out2));
evbuffer_validate(buf);
tt_str_op(evbuffer_pullup(buf_out1, -1), ==, tt_str_op(evbuffer_pullup(buf_out1, -1), ==,
"0->36; 36->26; 26->31; 31->38; "); "0->36; 36->26; 26->31; 31->38; ");
@ -950,7 +964,6 @@ test_evbuffer_callbacks(void *ptr)
"0->36; 31->38; 38->0; 0->1; "); "0->36; 31->38; 38->0; 0->1; ");
evbuffer_drain(buf_out1, evbuffer_get_length(buf_out1)); evbuffer_drain(buf_out1, evbuffer_get_length(buf_out1));
evbuffer_drain(buf_out2, evbuffer_get_length(buf_out2)); evbuffer_drain(buf_out2, evbuffer_get_length(buf_out2));
/* Let's test the obsolete buffer_setcb function too. */ /* Let's test the obsolete buffer_setcb function too. */
cb1 = evbuffer_add_cb(buf, log_change_callback, buf_out1); cb1 = evbuffer_add_cb(buf, log_change_callback, buf_out1);
cb2 = evbuffer_add_cb(buf, log_change_callback, buf_out2); cb2 = evbuffer_add_cb(buf, log_change_callback, buf_out2);
@ -962,11 +975,9 @@ test_evbuffer_callbacks(void *ptr)
evbuffer_setcb(buf, NULL, NULL); evbuffer_setcb(buf, NULL, NULL);
evbuffer_add_printf(buf, "This will not."); evbuffer_add_printf(buf, "This will not.");
tt_str_op(evbuffer_pullup(buf, -1), ==, "This will not."); tt_str_op(evbuffer_pullup(buf, -1), ==, "This will not.");
evbuffer_validate(buf); evbuffer_validate(buf);
evbuffer_drain(buf, evbuffer_get_length(buf)); evbuffer_drain(buf, evbuffer_get_length(buf));
evbuffer_validate(buf); evbuffer_validate(buf);
#if 0 #if 0
/* Now let's try a suspended callback. */ /* Now let's try a suspended callback. */
cb1 = evbuffer_add_cb(buf, log_change_callback, buf_out1); cb1 = evbuffer_add_cb(buf, log_change_callback, buf_out1);
@ -1128,6 +1139,7 @@ test_evbuffer_prepend(void *ptr)
evbuffer_add_printf(buf1, "Here is string %d. ", n++); evbuffer_add_printf(buf1, "Here is string %d. ", n++);
evbuffer_prepend_buffer(buf2, buf1); evbuffer_prepend_buffer(buf2, buf1);
evbuffer_validate(buf2); evbuffer_validate(buf2);
evbuffer_validate(buf1);
n = evbuffer_remove(buf2, tmp, sizeof(tmp)-1); n = evbuffer_remove(buf2, tmp, sizeof(tmp)-1);
tmp[n]='\0'; tmp[n]='\0';
tt_str_op(tmp,==,"Here is string 1000. Here is string 999. "); tt_str_op(tmp,==,"Here is string 1000. Here is string 999. ");
@ -1362,13 +1374,13 @@ struct testcase_t evbuffer_testcases[] = {
{ "search", test_evbuffer_search, 0, NULL, NULL }, { "search", test_evbuffer_search, 0, NULL, NULL },
{ "callbacks", test_evbuffer_callbacks, 0, NULL, NULL }, { "callbacks", test_evbuffer_callbacks, 0, NULL, NULL },
{ "add_reference", test_evbuffer_add_reference, 0, NULL, NULL }, { "add_reference", test_evbuffer_add_reference, 0, NULL, NULL },
{ "prepend", test_evbuffer_prepend, 0, NULL, NULL }, { "prepend", test_evbuffer_prepend, TT_FORK, NULL, NULL },
{ "peek", test_evbuffer_peek, 0, NULL, NULL }, { "peek", test_evbuffer_peek, 0, NULL, NULL },
{ "freeze_start", test_evbuffer_freeze, 0, &nil_setup, (void*)"start" }, { "freeze_start", test_evbuffer_freeze, 0, &nil_setup, (void*)"start" },
{ "freeze_end", test_evbuffer_freeze, 0, &nil_setup, (void*)"end" }, { "freeze_end", test_evbuffer_freeze, 0, &nil_setup, (void*)"end" },
#ifndef WIN32 #ifndef WIN32
/* TODO: need a temp file implementation for Windows */ /* TODO: need a temp file implementation for Windows */
{ "add_file", test_evbuffer_add_file, 0, NULL, NULL }, { "add_file", test_evbuffer_add_file, TT_FORK, NULL, NULL },
#endif #endif
END_OF_TESTCASES END_OF_TESTCASES