From ed291b02516ac5c9fe01f328d505305d36fe6319 Mon Sep 17 00:00:00 2001 From: Martin Sustrik Date: Sat, 27 Mar 2010 09:24:38 +0100 Subject: multi-part messages work with PUB/SUB --- src/fq.cpp | 31 +++++++++++++++++++++++++------ src/fq.hpp | 4 ++++ src/pipe.cpp | 10 ++++++++-- src/pub.cpp | 3 ++- src/sub.cpp | 27 +++++++++++++++++++++++++-- src/sub.hpp | 4 ++++ src/ypipe.hpp | 2 +- 7 files changed, 69 insertions(+), 12 deletions(-) diff --git a/src/fq.cpp b/src/fq.cpp index a7e93ce..3ab1d32 100644 --- a/src/fq.cpp +++ b/src/fq.cpp @@ -25,7 +25,8 @@ zmq::fq_t::fq_t () : active (0), - current (0) + current (0), + tbc (false) { } @@ -44,6 +45,8 @@ void zmq::fq_t::attach (reader_t *pipe_) void zmq::fq_t::detach (reader_t *pipe_) { + zmq_assert (!tbc || pipes [current] != pipe_); + // Remove the pipe from the list; adjust number of active pipes // accordingly. if (pipes.index (pipe_) < active) { @@ -75,14 +78,26 @@ int zmq::fq_t::recv (zmq_msg_t *msg_, int flags_) // Deallocate old content of the message. zmq_msg_close (msg_); - // Round-robin over the pipes to get next message. + // Round-robin over the pipes to get the next message. for (int count = active; count != 0; count--) { + + // Try to fetch new message. If we've already read part of the message + // subsequent part should be immediately available. bool fetched = pipes [current]->read (msg_); - current++; - if (current >= active) - current = 0; - if (fetched) + zmq_assert (!(tbc && !fetched)); + + // Note that when message is not fetched, current pipe is killed and + // replaced by another active pipe. Thus we don't have to increase + // the 'current' pointer. + if (fetched) { + tbc = msg_->flags & ZMQ_MSG_TBC; + if (!tbc) { + current++; + if (current >= active) + current = 0; + } return 0; + } } // No message is available. Initialise the output parameter @@ -94,6 +109,10 @@ int zmq::fq_t::recv (zmq_msg_t *msg_, int flags_) bool zmq::fq_t::has_in () { + // There are subsequent parts of the partly-read message available. + if (tbc) + return true; + // Note that messing with current doesn't break the fairness of fair // queueing algorithm. If there are no messages available current will // get back to its original value. Otherwise it'll point to the first diff --git a/src/fq.hpp b/src/fq.hpp index 6b6561e..28217ec 100644 --- a/src/fq.hpp +++ b/src/fq.hpp @@ -55,6 +55,10 @@ namespace zmq // Index of the next bound pipe to read a message from. pipes_t::size_type current; + // If true, part of a multipart message was already received, but + // there are following parts still waiting in the current pipe. + bool tbc; + fq_t (const fq_t&); void operator = (const fq_t&); }; diff --git a/src/pipe.cpp b/src/pipe.cpp index 14a6ef4..e844865 100644 --- a/src/pipe.cpp +++ b/src/pipe.cpp @@ -77,7 +77,9 @@ bool zmq::reader_t::read (zmq_msg_t *msg_) return false; } - msgs_read++; + if (!(msg_->flags & ZMQ_MSG_TBC)) + msgs_read++; + if (lwm > 0 && msgs_read % lwm == 0) send_reader_info (peer, msgs_read); @@ -161,7 +163,8 @@ bool zmq::writer_t::write (zmq_msg_t *msg_) } pipe->write (*msg_); - msgs_written++; + if (!(msg_->flags & ZMQ_MSG_TBC)) + msgs_written++; return true; } @@ -194,6 +197,9 @@ void zmq::writer_t::term () { endpoint = NULL; + // Rollback any unfinished messages. + rollback (); + // Push delimiter into the pipe. // Trick the compiler to belive that the tag is a valid pointer. zmq_msg_t msg; diff --git a/src/pub.cpp b/src/pub.cpp index 6f92cd2..1e86b28 100644 --- a/src/pub.cpp +++ b/src/pub.cpp @@ -170,7 +170,8 @@ bool zmq::pub_t::write (class writer_t *pipe_, zmq_msg_t *msg_) pipes.swap (pipes.index (pipe_), active); return false; } - pipe_->flush (); + if (!(msg_->flags & ZMQ_MSG_TBC)) + pipe_->flush (); return true; } diff --git a/src/sub.cpp b/src/sub.cpp index e32e198..fd3176f 100644 --- a/src/sub.cpp +++ b/src/sub.cpp @@ -26,7 +26,8 @@ zmq::sub_t::sub_t (class app_thread_t *parent_) : socket_base_t (parent_), - has_message (false) + has_message (false), + tbc (false) { options.requires_in = true; options.requires_out = false; @@ -105,6 +106,7 @@ int zmq::sub_t::xrecv (zmq_msg_t *msg_, int flags_) if (has_message) { zmq_msg_move (msg_, &message); has_message = false; + tbc = msg_->flags & ZMQ_MSG_TBC; return 0; } @@ -122,13 +124,27 @@ int zmq::sub_t::xrecv (zmq_msg_t *msg_, int flags_) return -1; // Check whether the message matches at least one subscription. - if (match (msg_)) + // Non-initial parts of the message are passed + if (tbc || match (msg_)) { + tbc = msg_->flags & ZMQ_MSG_TBC; return 0; + } + + // Message doesn't match. Pop any remaining parts of the message + // from the pipe. + while (msg_->flags & ZMQ_MSG_TBC) { + rc = fq.recv (msg_, ZMQ_NOBLOCK); + zmq_assert (rc == 0); + } } } bool zmq::sub_t::xhas_in () { + // There are subsequent parts of the partly-read message available. + if (tbc) + return true; + // If there's already a message prepared by a previous call to zmq_poll, // return straight ahead. if (has_message) @@ -153,6 +169,13 @@ bool zmq::sub_t::xhas_in () has_message = true; return true; } + + // Message doesn't match. Pop any remaining parts of the message + // from the pipe. + while (message.flags & ZMQ_MSG_TBC) { + rc = fq.recv (&message, ZMQ_NOBLOCK); + zmq_assert (rc == 0); + } } } diff --git a/src/sub.hpp b/src/sub.hpp index 84fab5e..d630731 100644 --- a/src/sub.hpp +++ b/src/sub.hpp @@ -68,6 +68,10 @@ namespace zmq bool has_message; zmq_msg_t message; + // If true, part of a multipart message was already received, but + // there are following parts still waiting. + bool tbc; + sub_t (const sub_t&); void operator = (const sub_t&); }; diff --git a/src/ypipe.hpp b/src/ypipe.hpp index 225b6a7..83ae6a7 100644 --- a/src/ypipe.hpp +++ b/src/ypipe.hpp @@ -84,8 +84,8 @@ namespace zmq { if (w == &queue.back ()) return false; - *value_ = queue.back (); queue.unpush (); + *value_ = queue.back (); return true; } -- cgit v1.2.3