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/*
Copyright (c) 2007-2011 iMatix Corporation
Copyright (c) 2007-2011 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_) :
socket_base_t (parent_, tid_),
has_message (false),
more (false)
{
options.type = ZMQ_XSUB;
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_, const blob_t &peer_identity_)
{
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
return 0;
}
else if (*data == 0) {
if (subscriptions.rm (data + 1, size - 1))
return dist.send_to_all (msg_, flags_);
else
return 0;
}
zmq_assert (false);
return -1;
}
bool zmq::xsub_t::xhas_out ()
{
// Subscription can be added/removed anytime.
return true;
}
int zmq::xsub_t::xrecv (msg_t *msg_, int 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 | msg_t::label);
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_, flags_);
// 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 | msg_t::label);
return 0;
}
// Message doesn't match. Pop any remaining parts of the message
// from the pipe.
while (msg_->flags () & (msg_t::more | msg_t::label)) {
rc = fq.recv (msg_, ZMQ_DONTWAIT);
zmq_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, ZMQ_DONTWAIT);
// If there's no message available, return immediately.
// The same when error occurs.
if (rc != 0) {
zmq_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 | msg_t::label)) {
rc = fq.recv (&message, ZMQ_DONTWAIT);
zmq_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);
zmq_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);
zmq_assert (sent);
msg.close ();
}
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