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Diffstat (limited to 'src/rep.cpp')
| -rw-r--r-- | src/rep.cpp | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/src/rep.cpp b/src/rep.cpp new file mode 100644 index 0000000..34b77c4 --- /dev/null +++ b/src/rep.cpp @@ -0,0 +1,280 @@ +/* + Copyright (c) 2007-2010 iMatix Corporation + + This file is part of 0MQ. + + 0MQ is free software; you can redistribute it and/or modify it under + the terms of the Lesser GNU 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 + Lesser GNU General Public License for more details. + + You should have received a copy of the Lesser GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "../include/zmq.h" + +#include "rep.hpp" +#include "err.hpp" +#include "pipe.hpp" + +zmq::rep_t::rep_t (class app_thread_t *parent_) : + socket_base_t (parent_), + active (0), + current (0), + sending_reply (false), + more (false), + reply_pipe (NULL) +{ + options.requires_in = true; + options.requires_out = true; + + // We don't need immediate connect. We'll be able to send messages + // (replies) only when connection is established and thus requests + // can arrive anyway. + options.immediate_connect = false; +} + +zmq::rep_t::~rep_t () +{ +} + +void zmq::rep_t::xattach_pipes (class reader_t *inpipe_, + class writer_t *outpipe_, const blob_t &peer_identity_) +{ + zmq_assert (inpipe_ && outpipe_); + zmq_assert (in_pipes.size () == out_pipes.size ()); + + in_pipes.push_back (inpipe_); + in_pipes.swap (active, in_pipes.size () - 1); + out_pipes.push_back (outpipe_); + out_pipes.swap (active, out_pipes.size () - 1); + active++; +} + +void zmq::rep_t::xdetach_inpipe (class reader_t *pipe_) +{ + zmq_assert (sending_reply || !more || in_pipes [current] != pipe_); + + zmq_assert (pipe_); + zmq_assert (in_pipes.size () == out_pipes.size ()); + + in_pipes_t::size_type index = in_pipes.index (pipe_); + + if (index < active) { + active--; + if (current == active) + current = 0; + } + + if (out_pipes [index]) + out_pipes [index]->term (); + in_pipes.erase (index); + out_pipes.erase (index); +} + +void zmq::rep_t::xdetach_outpipe (class writer_t *pipe_) +{ + zmq_assert (pipe_); + zmq_assert (in_pipes.size () == out_pipes.size ()); + + out_pipes_t::size_type index = out_pipes.index (pipe_); + + // If the connection we've got the request from disconnects, + // there's nowhere to send the reply. Forget about the reply pipe. + // Once the reply is sent it will be dropped. + if (sending_reply && pipe_ == reply_pipe) + reply_pipe = NULL; + + if (out_pipes.index (pipe_) < active) { + active--; + if (current == active) + current = 0; + } + + if (in_pipes [index]) + in_pipes [index]->term (); + in_pipes.erase (index); + out_pipes.erase (index); +} + +void zmq::rep_t::xkill (class reader_t *pipe_) +{ + // Move the pipe to the list of inactive pipes. + in_pipes_t::size_type index = in_pipes.index (pipe_); + active--; + in_pipes.swap (index, active); + out_pipes.swap (index, active); +} + +void zmq::rep_t::xrevive (class reader_t *pipe_) +{ + // Move the pipe to the list of active pipes. + in_pipes_t::size_type index = in_pipes.index (pipe_); + in_pipes.swap (index, active); + out_pipes.swap (index, active); + active++; +} + +void zmq::rep_t::xrevive (class writer_t *pipe_) +{ +} + +int zmq::rep_t::xsetsockopt (int option_, const void *optval_, + size_t optvallen_) +{ + errno = EINVAL; + return -1; +} + +int zmq::rep_t::xsend (zmq_msg_t *msg_, int flags_) +{ + if (!sending_reply) { + errno = EFSM; + return -1; + } + + if (reply_pipe) { + + // Push message to the reply pipe. + bool written = reply_pipe->write (msg_); + zmq_assert (!more || written); + + // The pipe is full... + // When this happens, we simply return an error. + // This makes REP sockets vulnerable to DoS attack when + // misbehaving requesters stop collecting replies. + // TODO: Tear down the underlying connection (?) + if (!written) { + errno = EAGAIN; + return -1; + } + + more = msg_->flags & ZMQ_MSG_MORE; + } + else { + + // If the requester have disconnected in the meantime, drop the reply. + more = msg_->flags & ZMQ_MSG_MORE; + zmq_msg_close (msg_); + } + + // Flush the reply to the requester. + if (!more) { + if (reply_pipe) + reply_pipe->flush (); + sending_reply = false; + reply_pipe = NULL; + } + + // Detach the message from the data buffer. + int rc = zmq_msg_init (msg_); + zmq_assert (rc == 0); + + return 0; +} + +int zmq::rep_t::xrecv (zmq_msg_t *msg_, int flags_) +{ + // If we are in middle of sending a reply, we cannot receive next request. + if (sending_reply) { + errno = EFSM; + return -1; + } + + // Deallocate old content of the message. + zmq_msg_close (msg_); + + // We haven't started reading a request yet... + if (!more) { + + // Round-robin over the pipes to get next message. + int count; + for (count = active; count != 0; count--) { + if (in_pipes [current]->read (msg_)) + break; + current++; + if (current >= active) + current = 0; + } + + // No message is available. Initialise the output parameter + // to be a 0-byte message. + if (count == 0) { + zmq_msg_init (msg_); + errno = EAGAIN; + return -1; + } + + // We are aware of a new message now. Setup the reply pipe. + reply_pipe = out_pipes [current]; + + // Copy the routing info to the reply pipe. + while (true) { + + // Push message to the reply pipe. + // TODO: What if the pipe is full? + // Tear down the underlying connection? + bool written = reply_pipe->write (msg_); + zmq_assert (written); + + // Message part of zero size delimits the traceback stack. + if (zmq_msg_size (msg_) == 0) + break; + + // Get next part of the message. + bool fetched = in_pipes [current]->read (msg_); + zmq_assert (fetched); + } + } + + // Now the routing info is processed. Get the first part + // of the message payload and exit. + bool fetched = in_pipes [current]->read (msg_); + zmq_assert (fetched); + more = msg_->flags & ZMQ_MSG_MORE; + if (!more) { + current++; + if (current >= active) + current = 0; + sending_reply = true; + } + return 0; +} + +bool zmq::rep_t::xhas_in () +{ + if (sending_reply) + return false; + + if (more) + return true; + + for (int count = active; count != 0; count--) { + if (in_pipes [current]->check_read ()) + return !sending_reply; + current++; + if (current >= active) + current = 0; + } + + return false; +} + +bool zmq::rep_t::xhas_out () +{ + if (!sending_reply) + return false; + + if (more) + return true; + + // TODO: No check for write here... + return sending_reply; +} + |