diff options
Diffstat (limited to 'src/sub.cpp')
-rw-r--r-- | src/sub.cpp | 111 |
1 files changed, 109 insertions, 2 deletions
diff --git a/src/sub.cpp b/src/sub.cpp index 2d6ade6..11c4532 100644 --- a/src/sub.cpp +++ b/src/sub.cpp @@ -22,19 +22,39 @@ #include "msg.hpp" zmq::sub_t::sub_t (class ctx_t *parent_, uint32_t tid_) : - xsub_t (parent_, tid_) + xsub_t (parent_, tid_), + has_message (false), + more (false) { options.type = ZMQ_SUB; + int rc = message.init (); + errno_assert (rc == 0); } zmq::sub_t::~sub_t () { + int rc = message.close (); + errno_assert (rc == 0); } int zmq::sub_t::xsetsockopt (int option_, const void *optval_, size_t optvallen_) { - if (option_ != ZMQ_SUBSCRIBE && option_ != ZMQ_UNSUBSCRIBE) { + // Process a subscription. + if (option_ == ZMQ_SUBSCRIBE) + subscriptions.add ((unsigned char*) optval_, optvallen_); + + // Process an unsubscription. Return error if there is no corresponding + // subscription. + else if (option_ == ZMQ_UNSUBSCRIBE) { + if (!subscriptions.rm ((unsigned char*) optval_, optvallen_)) { + errno = EINVAL; + return -1; + } + } + + // Unknow option. + else { errno = EINVAL; return -1; } @@ -74,3 +94,90 @@ bool zmq::sub_t::xhas_out () // Overload the XSUB's send. return false; } + +int zmq::sub_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; + 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 = xsub_t::xrecv (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 || match (msg_)) { + more = msg_->flags () & msg_t::more; + return 0; + } + + // Message doesn't match. Pop any remaining parts of the message + // from the pipe. + while (msg_->flags () & msg_t::more) { + rc = xsub_t::xrecv (msg_, ZMQ_DONTWAIT); + zmq_assert (rc == 0); + } + } +} + +bool zmq::sub_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 = xsub_t::xrecv (&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 (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 = xsub_t::xrecv (&message, ZMQ_DONTWAIT); + zmq_assert (rc == 0); + } + } +} + +bool zmq::sub_t::match (msg_t *msg_) +{ + return subscriptions.check ((unsigned char*) msg_->data (), msg_->size ()); +} + |