diff options
Diffstat (limited to 'src/stream.cpp')
| -rw-r--r-- | src/stream.cpp | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/src/stream.cpp b/src/stream.cpp new file mode 100644 index 0000000..0b495a5 --- /dev/null +++ b/src/stream.cpp @@ -0,0 +1,257 @@ +/* + Copyright (c) 2007-2013 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 "stream.hpp" +#include "pipe.hpp" +#include "wire.hpp" +#include "random.hpp" +#include "likely.hpp" +#include "err.hpp" + +zmq::stream_t::stream_t (class ctx_t *parent_, uint32_t tid_, int sid_) : + socket_base_t (parent_, tid_, sid_), + prefetched (false), + identity_sent (false), + current_out (NULL), + more_out (false), + next_peer_id (generate_random ()) +{ + options.type = ZMQ_STREAM; + options.raw_sock = true; + + prefetched_id.init (); + prefetched_msg.init (); +} + +zmq::stream_t::~stream_t () +{ + zmq_assert (outpipes.empty ()); + prefetched_id.close (); + prefetched_msg.close (); +} + +void zmq::stream_t::xattach_pipe (pipe_t *pipe_, bool subscribe_to_all_) +{ + // subscribe_to_all_ is unused + (void)subscribe_to_all_; + + zmq_assert (pipe_); + + identify_peer (pipe_); + fq.attach (pipe_); +} + +void zmq::stream_t::xpipe_terminated (pipe_t *pipe_) +{ + outpipes_t::iterator it = outpipes.find (pipe_->get_identity ()); + zmq_assert (it != outpipes.end ()); + outpipes.erase (it); + fq.pipe_terminated (pipe_); + if (pipe_ == current_out) + current_out = NULL; +} + +void zmq::stream_t::xread_activated (pipe_t *pipe_) +{ + fq.activated (pipe_); +} + +void zmq::stream_t::xwrite_activated (pipe_t *pipe_) +{ + outpipes_t::iterator it; + for (it = outpipes.begin (); it != outpipes.end (); ++it) + if (it->second.pipe == pipe_) + break; + + zmq_assert (it != outpipes.end ()); + zmq_assert (!it->second.active); + it->second.active = true; +} + +int zmq::stream_t::xsend (msg_t *msg_) +{ + // If this is the first part of the message it's the ID of the + // peer to send the message to. + if (!more_out) { + zmq_assert (!current_out); + + // If we have malformed message (prefix with no subsequent message) + // then just silently ignore it. + // TODO: The connections should be killed instead. + if (msg_->flags () & msg_t::more) { + + // Find the pipe associated with the identity stored in the prefix. + // If there's no such pipe return an error + blob_t identity ((unsigned char*) msg_->data (), msg_->size ()); + outpipes_t::iterator it = outpipes.find (identity); + + if (it != outpipes.end ()) { + current_out = it->second.pipe; + if (!current_out->check_write ()) { + it->second.active = false; + current_out = NULL; + errno = EAGAIN; + return -1; + } + } + else { + errno = EHOSTUNREACH; + return -1; + } + } + + // Expect one more message frame. + more_out = true; + + int rc = msg_->close (); + errno_assert (rc == 0); + rc = msg_->init (); + errno_assert (rc == 0); + return 0; + } + + // Ignore the MORE flag + msg_->reset_flags (msg_t::more); + + // This is the last part of the message. + more_out = false; + + // Push the message into the pipe. If there's no out pipe, just drop it. + if (current_out) { + + // Close the remote connection if user has asked to do so + // by sending zero length message. + // Pending messages in the pipe will be dropped (on receiving term- ack) + if (msg_->size () == 0) { + current_out->terminate (false); + int rc = msg_->close (); + errno_assert (rc == 0); + current_out = NULL; + return 0; + } + bool ok = current_out->write (msg_); + if (likely (ok)) + current_out->flush (); + current_out = NULL; + } + else { + int rc = msg_->close (); + errno_assert (rc == 0); + } + + // Detach the message from the data buffer. + int rc = msg_->init (); + errno_assert (rc == 0); + + return 0; +} + +int zmq::stream_t::xrecv (msg_t *msg_) +{ + if (prefetched) { + if (!identity_sent) { + int rc = msg_->move (prefetched_id); + errno_assert (rc == 0); + identity_sent = true; + } + else { + int rc = msg_->move (prefetched_msg); + errno_assert (rc == 0); + prefetched = false; + } + return 0; + } + + pipe_t *pipe = NULL; + int rc = fq.recvpipe (&prefetched_msg, &pipe); + if (rc != 0) + return -1; + + zmq_assert (pipe != NULL); + zmq_assert ((prefetched_msg.flags () & msg_t::more) == 0); + + // We have received a frame with TCP data. + // Rather than sendig this frame, we keep it in prefetched + // buffer and send a frame with peer's ID. + blob_t identity = pipe->get_identity (); + rc = msg_->init_size (identity.size ()); + errno_assert (rc == 0); + memcpy (msg_->data (), identity.data (), identity.size ()); + msg_->set_flags (msg_t::more); + + prefetched = true; + identity_sent = true; + + return 0; +} + +bool zmq::stream_t::xhas_in () +{ + // We may already have a message pre-fetched. + if (prefetched) + return true; + + // Try to read the next message. + // The message, if read, is kept in the pre-fetch buffer. + pipe_t *pipe = NULL; + int rc = fq.recvpipe (&prefetched_msg, &pipe); + if (rc != 0) + return false; + + zmq_assert (pipe != NULL); + zmq_assert ((prefetched_msg.flags () & msg_t::more) == 0); + + blob_t identity = pipe->get_identity (); + rc = prefetched_id.init_size (identity.size ()); + errno_assert (rc == 0); + memcpy (prefetched_id.data (), identity.data (), identity.size ()); + prefetched_id.set_flags (msg_t::more); + + prefetched = true; + identity_sent = false; + + return true; +} + +bool zmq::stream_t::xhas_out () +{ + // In theory, STREAM socket is always ready for writing. Whether actual + // attempt to write succeeds depends on which pipe the message is going + // to be routed to. + return true; +} + +void zmq::stream_t::identify_peer (pipe_t *pipe_) +{ + // Always assign identity for raw-socket + unsigned char buffer [5]; + buffer [0] = 0; + put_uint32 (buffer + 1, next_peer_id++); + blob_t identity = blob_t (buffer, sizeof buffer); + + memcpy (options.identity, identity.data (), identity.size ()); + options.identity_size = identity.size (); + + pipe_->set_identity (identity); + // Add the record into output pipes lookup table + outpipe_t outpipe = {pipe_, true}; + const bool ok = outpipes.insert ( + outpipes_t::value_type (identity, outpipe)).second; + zmq_assert (ok); +} |