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+/*
+ Copyright (c) 2010-2011 250bpm s.r.o.
+ Copyright (c) 2011 VMware, Inc.
+ Copyright (c) 2010-2011 Other contributors as noted in the AUTHORS file
+
+ This file is part of 0MQ.
+
+ 0MQ is free software; you can redistribute it and/or modify it under
+ the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ 0MQ is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <string.h>
+
+#include "xsub.hpp"
+#include "err.hpp"
+
+zmq::xsub_t::xsub_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
+ socket_base_t (parent_, tid_, sid_),
+ has_message (false),
+ more (false)
+{
+ options.type = ZMQ_XSUB;
+
+ // When socket is being closed down we don't want to wait till pending
+ // subscription commands are sent to the wire.
+ options.linger = 0;
+
+ int rc = message.init ();
+ errno_assert (rc == 0);
+}
+
+zmq::xsub_t::~xsub_t ()
+{
+ int rc = message.close ();
+ errno_assert (rc == 0);
+}
+
+void zmq::xsub_t::xattach_pipe (pipe_t *pipe_, bool icanhasall_)
+{
+ // icanhasall_ is unused
+ (void)icanhasall_;
+
+ zmq_assert (pipe_);
+ fq.attach (pipe_);
+ dist.attach (pipe_);
+
+ // Send all the cached subscriptions to the new upstream peer.
+ subscriptions.apply (send_subscription, pipe_);
+ pipe_->flush ();
+}
+
+void zmq::xsub_t::xread_activated (pipe_t *pipe_)
+{
+ fq.activated (pipe_);
+}
+
+void zmq::xsub_t::xwrite_activated (pipe_t *pipe_)
+{
+ dist.activated (pipe_);
+}
+
+void zmq::xsub_t::xterminated (pipe_t *pipe_)
+{
+ fq.terminated (pipe_);
+ dist.terminated (pipe_);
+}
+
+void zmq::xsub_t::xhiccuped (pipe_t *pipe_)
+{
+ // Send all the cached subscriptions to the hiccuped pipe.
+ subscriptions.apply (send_subscription, pipe_);
+ pipe_->flush ();
+}
+
+int zmq::xsub_t::xsend (msg_t *msg_, int flags_)
+{
+ size_t size = msg_->size ();
+ unsigned char *data = (unsigned char*) msg_->data ();
+
+ // Malformed subscriptions.
+ if (size < 1 || (*data != 0 && *data != 1)) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ // Process the subscription.
+ if (*data == 1) {
+ if (subscriptions.add (data + 1, size - 1))
+ return dist.send_to_all (msg_, flags_);
+ }
+ else {
+ if (subscriptions.rm (data + 1, size - 1))
+ return dist.send_to_all (msg_, flags_);
+ }
+
+ int rc = msg_->close ();
+ errno_assert (rc == 0);
+ rc = msg_->init ();
+ errno_assert (rc == 0);
+
+ return 0;
+}
+
+bool zmq::xsub_t::xhas_out ()
+{
+ // Subscription can be added/removed anytime.
+ return true;
+}
+
+int zmq::xsub_t::xrecv (msg_t *msg_, int flags_)
+{
+ // flags_ is unused
+ (void)flags_;
+
+ // If there's already a message prepared by a previous call to zmq_poll,
+ // return it straight ahead.
+ if (has_message) {
+ int rc = msg_->move (message);
+ errno_assert (rc == 0);
+ has_message = false;
+ more = msg_->flags () & msg_t::more ? true : false;
+ return 0;
+ }
+
+ // TODO: This can result in infinite loop in the case of continuous
+ // stream of non-matching messages which breaks the non-blocking recv
+ // semantics.
+ while (true) {
+
+ // Get a message using fair queueing algorithm.
+ int rc = fq.recv (msg_);
+
+ // If there's no message available, return immediately.
+ // The same when error occurs.
+ if (rc != 0)
+ return -1;
+
+ // Check whether the message matches at least one subscription.
+ // Non-initial parts of the message are passed
+ if (more || !options.filter || match (msg_)) {
+ more = msg_->flags () & msg_t::more ? true : false;
+ return 0;
+ }
+
+ // Message doesn't match. Pop any remaining parts of the message
+ // from the pipe.
+ while (msg_->flags () & msg_t::more) {
+ rc = fq.recv (msg_);
+ errno_assert (rc == 0);
+ }
+ }
+}
+
+bool zmq::xsub_t::xhas_in ()
+{
+ // There are subsequent parts of the partly-read message available.
+ if (more)
+ return true;
+
+ // If there's already a message prepared by a previous call to zmq_poll,
+ // return straight ahead.
+ if (has_message)
+ return true;
+
+ // TODO: This can result in infinite loop in the case of continuous
+ // stream of non-matching messages.
+ while (true) {
+
+ // Get a message using fair queueing algorithm.
+ int rc = fq.recv (&message);
+
+ // If there's no message available, return immediately.
+ // The same when error occurs.
+ if (rc != 0) {
+ errno_assert (errno == EAGAIN);
+ return false;
+ }
+
+ // Check whether the message matches at least one subscription.
+ if (!options.filter || match (&message)) {
+ has_message = true;
+ return true;
+ }
+
+ // Message doesn't match. Pop any remaining parts of the message
+ // from the pipe.
+ while (message.flags () & msg_t::more) {
+ rc = fq.recv (&message);
+ errno_assert (rc == 0);
+ }
+ }
+}
+
+bool zmq::xsub_t::match (msg_t *msg_)
+{
+ return subscriptions.check ((unsigned char*) msg_->data (), msg_->size ());
+}
+
+void zmq::xsub_t::send_subscription (unsigned char *data_, size_t size_,
+ void *arg_)
+{
+ pipe_t *pipe = (pipe_t*) arg_;
+
+ // Create the subsctription message.
+ msg_t msg;
+ int rc = msg.init_size (size_ + 1);
+ errno_assert (rc == 0);
+ unsigned char *data = (unsigned char*) msg.data ();
+ data [0] = 1;
+ memcpy (data + 1, data_, size_);
+
+ // Send it to the pipe.
+ bool sent = pipe->write (&msg);
+ // If we reached the SNDHWM, and thus cannot send the subscription, drop
+ // the subscription message instead. This matches the behaviour of
+ // zmq_setsockopt(ZMQ_SUBSCRIBE, ...), which also drops subscriptions
+ // when the SNDHWM is reached.
+ if (!sent)
+ msg.close ();
+}
+
+zmq::xsub_session_t::xsub_session_t (io_thread_t *io_thread_, bool connect_,
+ socket_base_t *socket_, const options_t &options_,
+ const address_t *addr_) :
+ session_base_t (io_thread_, connect_, socket_, options_, addr_)
+{
+}
+
+zmq::xsub_session_t::~xsub_session_t ()
+{
+}
+