+++ /dev/null
-/*
- * Copyright (c) 2009-2010 Niels Provos, Nick Mathewson
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <sys/types.h>
-
-#ifdef WIN32
-#include <winsock2.h>
-#endif
-
-#include "event2/event-config.h"
-
-#include "event2/util.h"
-#include "event2/buffer.h"
-#include "event2/bufferevent.h"
-#include "event2/bufferevent_struct.h"
-#include "event2/event.h"
-#include "defer-internal.h"
-#include "bufferevent-internal.h"
-#include "mm-internal.h"
-#include "util-internal.h"
-
-struct bufferevent_pair {
- struct bufferevent_private bev;
- struct bufferevent_pair *partner;
-};
-
-
-/* Given a bufferevent that's really a bev part of a bufferevent_pair,
- * return that bufferevent_filtered. Returns NULL otherwise.*/
-static inline struct bufferevent_pair *
-upcast(struct bufferevent *bev)
-{
- struct bufferevent_pair *bev_p;
- if (bev->be_ops != &bufferevent_ops_pair)
- return NULL;
- bev_p = EVUTIL_UPCAST(bev, struct bufferevent_pair, bev.bev);
- EVUTIL_ASSERT(bev_p->bev.bev.be_ops == &bufferevent_ops_pair);
- return bev_p;
-}
-
-#define downcast(bev_pair) (&(bev_pair)->bev.bev)
-
-static inline void
-incref_and_lock(struct bufferevent *b)
-{
- struct bufferevent_pair *bevp;
- _bufferevent_incref_and_lock(b);
- bevp = upcast(b);
- if (bevp->partner)
- _bufferevent_incref_and_lock(downcast(bevp->partner));
-}
-
-static inline void
-decref_and_unlock(struct bufferevent *b)
-{
- struct bufferevent_pair *bevp = upcast(b);
- if (bevp->partner)
- _bufferevent_decref_and_unlock(downcast(bevp->partner));
- _bufferevent_decref_and_unlock(b);
-}
-
-/* XXX Handle close */
-
-static void be_pair_outbuf_cb(struct evbuffer *,
- const struct evbuffer_cb_info *, void *);
-
-static struct bufferevent_pair *
-bufferevent_pair_elt_new(struct event_base *base,
- int options)
-{
- struct bufferevent_pair *bufev;
- if (! (bufev = mm_calloc(1, sizeof(struct bufferevent_pair))))
- return NULL;
- if (bufferevent_init_common(&bufev->bev, base, &bufferevent_ops_pair,
- options)) {
- mm_free(bufev);
- return NULL;
- }
- if (!evbuffer_add_cb(bufev->bev.bev.output, be_pair_outbuf_cb, bufev)) {
- bufferevent_free(downcast(bufev));
- return NULL;
- }
-
- _bufferevent_init_generic_timeout_cbs(&bufev->bev.bev);
-
- return bufev;
-}
-
-int
-bufferevent_pair_new(struct event_base *base, int options,
- struct bufferevent *pair[2])
-{
- struct bufferevent_pair *bufev1 = NULL, *bufev2 = NULL;
- int tmp_options;
-
- options |= BEV_OPT_DEFER_CALLBACKS;
- tmp_options = options & ~BEV_OPT_THREADSAFE;
-
- bufev1 = bufferevent_pair_elt_new(base, options);
- if (!bufev1)
- return -1;
- bufev2 = bufferevent_pair_elt_new(base, tmp_options);
- if (!bufev2) {
- bufferevent_free(downcast(bufev1));
- return -1;
- }
-
- if (options & BEV_OPT_THREADSAFE) {
- /*XXXX check return */
- bufferevent_enable_locking(downcast(bufev2), bufev1->bev.lock);
- }
-
- bufev1->partner = bufev2;
- bufev2->partner = bufev1;
-
- evbuffer_freeze(downcast(bufev1)->input, 0);
- evbuffer_freeze(downcast(bufev1)->output, 1);
- evbuffer_freeze(downcast(bufev2)->input, 0);
- evbuffer_freeze(downcast(bufev2)->output, 1);
-
- pair[0] = downcast(bufev1);
- pair[1] = downcast(bufev2);
-
- return 0;
-}
-
-static void
-be_pair_transfer(struct bufferevent *src, struct bufferevent *dst,
- int ignore_wm)
-{
- size_t src_size, dst_size;
- size_t n;
-
- evbuffer_unfreeze(src->output, 1);
- evbuffer_unfreeze(dst->input, 0);
-
- if (dst->wm_read.high) {
- size_t dst_size = evbuffer_get_length(dst->input);
- if (dst_size < dst->wm_read.high) {
- n = dst->wm_read.high - dst_size;
- evbuffer_remove_buffer(src->output, dst->input, n);
- } else {
- if (!ignore_wm)
- goto done;
- n = evbuffer_get_length(src->output);
- evbuffer_add_buffer(dst->input, src->output);
- }
- } else {
- n = evbuffer_get_length(src->output);
- evbuffer_add_buffer(dst->input, src->output);
- }
-
- if (n) {
- BEV_RESET_GENERIC_READ_TIMEOUT(dst);
-
- if (evbuffer_get_length(dst->output))
- BEV_RESET_GENERIC_WRITE_TIMEOUT(dst);
- else
- BEV_DEL_GENERIC_WRITE_TIMEOUT(dst);
- }
-
- src_size = evbuffer_get_length(src->output);
- dst_size = evbuffer_get_length(dst->input);
-
- if (dst_size >= dst->wm_read.low) {
- _bufferevent_run_readcb(dst);
- }
- if (src_size <= src->wm_write.low) {
- _bufferevent_run_writecb(src);
- }
-done:
- evbuffer_freeze(src->output, 1);
- evbuffer_freeze(dst->input, 0);
-}
-
-static inline int
-be_pair_wants_to_talk(struct bufferevent_pair *src,
- struct bufferevent_pair *dst)
-{
- return (downcast(src)->enabled & EV_WRITE) &&
- (downcast(dst)->enabled & EV_READ) &&
- !dst->bev.read_suspended &&
- evbuffer_get_length(downcast(src)->output);
-}
-
-static void
-be_pair_outbuf_cb(struct evbuffer *outbuf,
- const struct evbuffer_cb_info *info, void *arg)
-{
- struct bufferevent_pair *bev_pair = arg;
- struct bufferevent_pair *partner = bev_pair->partner;
-
- incref_and_lock(downcast(bev_pair));
-
- if (info->n_added > info->n_deleted && partner) {
- /* We got more data. If the other side's reading, then
- hand it over. */
- if (be_pair_wants_to_talk(bev_pair, partner)) {
- be_pair_transfer(downcast(bev_pair), downcast(partner), 0);
- }
- }
-
- decref_and_unlock(downcast(bev_pair));
-}
-
-static int
-be_pair_enable(struct bufferevent *bufev, short events)
-{
- struct bufferevent_pair *bev_p = upcast(bufev);
- struct bufferevent_pair *partner = bev_p->partner;
-
- incref_and_lock(bufev);
-
- if (events & EV_READ) {
- BEV_RESET_GENERIC_READ_TIMEOUT(bufev);
- }
- if ((events & EV_WRITE) && evbuffer_get_length(bufev->output))
- BEV_RESET_GENERIC_WRITE_TIMEOUT(bufev);
-
- /* We're starting to read! Does the other side have anything to write?*/
- if ((events & EV_READ) && partner &&
- be_pair_wants_to_talk(partner, bev_p)) {
- be_pair_transfer(downcast(partner), bufev, 0);
- }
- /* We're starting to write! Does the other side want to read? */
- if ((events & EV_WRITE) && partner &&
- be_pair_wants_to_talk(bev_p, partner)) {
- be_pair_transfer(bufev, downcast(partner), 0);
- }
- decref_and_unlock(bufev);
- return 0;
-}
-
-static int
-be_pair_disable(struct bufferevent *bev, short events)
-{
- if (events & EV_READ) {
- BEV_DEL_GENERIC_READ_TIMEOUT(bev);
- }
- if (events & EV_WRITE)
- BEV_DEL_GENERIC_WRITE_TIMEOUT(bev);
- return 0;
-}
-
-static void
-be_pair_destruct(struct bufferevent *bev)
-{
- struct bufferevent_pair *bev_p = upcast(bev);
-
- if (bev_p->partner) {
- bev_p->partner->partner = NULL;
- bev_p->partner = NULL;
- }
-
- _bufferevent_del_generic_timeout_cbs(bev);
-}
-
-static int
-be_pair_flush(struct bufferevent *bev, short iotype,
- enum bufferevent_flush_mode mode)
-{
- struct bufferevent_pair *bev_p = upcast(bev);
- struct bufferevent *partner;
- incref_and_lock(bev);
- if (!bev_p->partner)
- return -1;
-
- partner = downcast(bev_p->partner);
-
- if (mode == BEV_NORMAL)
- return 0;
-
- if ((iotype & EV_READ) != 0)
- be_pair_transfer(partner, bev, 1);
-
- if ((iotype & EV_WRITE) != 0)
- be_pair_transfer(bev, partner, 1);
-
- if (mode == BEV_FINISHED) {
- _bufferevent_run_eventcb(partner, iotype|BEV_EVENT_EOF);
- }
- decref_and_unlock(bev);
- return 0;
-}
-
-struct bufferevent *
-bufferevent_pair_get_partner(struct bufferevent *bev)
-{
- struct bufferevent_pair *bev_p;
- struct bufferevent *partner;
- bev_p = upcast(bev);
- if (! bev_p)
- return NULL;
-
- incref_and_lock(bev);
- partner = downcast(bev_p->partner);
- decref_and_unlock(bev);
- return partner;
-}
-
-const struct bufferevent_ops bufferevent_ops_pair = {
- "pair_elt",
- evutil_offsetof(struct bufferevent_pair, bev.bev),
- be_pair_enable,
- be_pair_disable,
- be_pair_destruct,
- _bufferevent_generic_adj_timeouts,
- be_pair_flush,
- NULL, /* ctrl */
-};
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