NAME

       ZeroMQ - A ZeroMQ2 wrapper for Perl (DEPRECATED)

SYNOPSIS ( HIGH-LEVEL API )

           # echo server
           use ZeroMQ qw/:all/;

           my $cxt = ZeroMQ::Context->new;
           my $sock = $cxt->socket(ZMQ_REP);
           $sock->bind($addr);

           my $msg;
           foreach (1..$roundtrip_count) {
               $msg = $sock->recv();
               $sock->send($msg);
           }

           # json (if JSON.pm is available)
           $sock->send_as( json => { foo => "bar" } );
           my $thing = $sock->recv_as( "json" );

           # custom serialization
           ZeroMQ::register_read_type(myformat => sub { ... });
           ZeroMQ::register_write_type(myformat => sub { .. });

           $sock->send_as( myformat => $data ); # serialize using above callback
           my $thing = $sock->recv_as( "myformat" );

SYNOPSIS ( LOW-LEVEL API )

           use ZeroMQ::Raw;

           my $ctxt = zmq_init($threads);
           my $rv   = zmq_term($ctxt);

           my $msg  = zmq_msg_init();
           my $msg  = zmq_msg_init_size( $size );
           my $msg  = zmq_msg_init_data( $data );
           my $rv   = zmq_msg_close( $msg );
           my $rv   = zmq_msg_move( $dest, $src );
           my $rv   = zmq_msg_copy( $dest, $src );
           my $data = zmq_msg_data( $msg );
           my $size = zmq_msg_size( $msg);

           my $sock = zmq_socket( $ctxt, $type );
           my $rv   = zmq_close( $sock );
           my $rv   = zmq_setsockopt( $socket, $option, $value );
           my $val  = zmq_getsockopt( $socket, $option );
           my $rv   = zmq_bind( $sock, $addr );
           my $rv   = zmq_send( $sock, $msg, $flags );
           my $msg  = zmq_recv( $sock, $flags );

INSTALLATION

       If you have libzmq registered with pkg-config:

           perl Makefile.PL
           make
           make test
           make install

       If you don't have pkg-config, and libzmq is installed under /usr/local/libzmq:

           ZMQ_HOME=/usr/local/libzmq \
               perl Makefile.PL
           make
           make test
           make install

       If you want to customize include directories and such:

           ZMQ_INCLUDES=/path/to/libzmq/include \
           ZMQ_LIBS=/path/to/libzmq/lib \
           ZMQ_H=/path/to/libzmq/include/zmq.h \
               perl Makefile.PL
           make
           make test
           make install

       If you want to compile with debugging on:

           perl Makefile.PL -g

DESCRIPTION

       Please note that this module has been DEPRECATED in favor of ZMQ::LibZMQ2, ZMQ::LibZMQ3,
       and ZMQ. see https://github.com/lestrrat/p5-ZMQ and other CPAN pages.

       The "ZeroMQ" module is a wrapper of the 0MQ message passing library for Perl.  It's a thin
       wrapper around the C API. Please read <http://zeromq.org> for more details on ZeroMQ.

CLASS WALKTHROUGH

       ZeroMQ::Raw
           Use ZeroMQ::Raw to get access to the C API such as "zmq_init", "zmq_socket", et al.
           Functions provided in this low level API should follow the C API exactly.

       ZeroMQ::Constants
           ZeroMQ::Constants contains all of the constants that are known to be extractable from
           zmq.h. Do note that sometimes the list changes due to additions/deprecations in the
           underlying zeromq2 library. We try to do our best to make things available (at least
           to warn you that some symbols are deprecated), but it may not always be possible.

       ZeroMQ::Context
       ZeroMQ::Socket
       ZeroMQ::Message
           ZeroMQ::Context, ZeroMQ::Socket, ZeroMQ::Message contain the high-level, more perl-ish
           interface to the zeromq functionalities.

       ZeroMQ
           Loading "ZeroMQ" will make the ZeroMQ::Context, ZeroMQ::Socket, and ZeroMQ::Message
           classes available as well.

BASIC USAGE

       To start using ZeroMQ, you need to create a context object, then as many ZeroMQ::Socket as
       you need:

           my $ctxt = ZeroMQ::Context->new;
           my $socket = $ctxt->socket( ... options );

       You need to call "bind()" or "connect()" on the socket, depending on your usage. For
       example on a typical server-client model you would write on the server side:

           $socket->bind( "tcp://127.0.0.1:9999" );

       and on the client side:

           $socket->connect( "tcp://127.0.0.1:9999" );

       The underlying zeromq library offers TCP, multicast, in-process, and ipc connection
       patterns. Read the zeromq manual for more details on other ways to setup the socket.

       When sending data, you can either pass a ZeroMQ::Message object or a Perl string.

           # the following two send() calls are equivalent
           my $msg = ZeroMQ::Message->new( "a simple message" );
           $socket->send( $msg );
           $socket->send( "a simple message" );

       In most cases using ZeroMQ::Message is redundunt, so you will most likely use the string
       version.

       To receive, simply call "recv()" on the socket

           my $msg = $socket->recv;

       The received message is an instance of ZeroMQ::Message object, and you can access the
       content held in the message via the "data()" method:

           my $data = $msg->data;

SERIALIZATION

       ZeroMQ.pm comes with a simple serialization/deserialization mechanism.

       To serialize, use "register_write_type()" to register a name and an associated callback to
       serialize the data. For example, for JSON we do the following (this is already done for
       you in ZeroMQ.pm if you have JSON.pm installed):

           use JSON ();
           ZeroMQ::register_write_type('json' => \&JSON::encode_json);
           ZeroMQ::register_read_type('json' => \&JSON::decode_json);

       Then you can use "send_as()" and "recv_as()" to specify the serialization type as the
       first argument:

           my $ctxt = ZeroMQ::Context->new();
           my $sock = $ctxt->socket( ZMQ_REQ );

           $sock->send_as( json => $complex_perl_data_structure );

       The otherside will receive a JSON encoded data. The receivind side can be written as:

           my $ctxt = ZeroMQ::Context->new();
           my $sock = $ctxt->socket( ZMQ_REP );

           my $complex_perl_data_structure = $sock->recv_as( 'json' );

       If you have JSON.pm (must be 2.00 or above), then the JSON serializer / deserializer is
       automatically enabled. If you want to tweak the serializer option, do something like this:

           my $coder = JSON->new->utf8->pretty; # pretty print
           ZeroMQ::register_write_type( json => sub { $coder->encode($_[0]) } );
           ZeroMQ::register_read_type( json => sub { $coder->decode($_[0]) } );

       Note that this will have a GLOBAL effect. If you want to change only your application, use
       a name that's different from 'json'.

ASYNCHRONOUS I/O WITH ZEROMQ

       By default ZeroMQ comes with its own zmq_poll() mechanism that can handle non-blocking
       sockets. You can use this by calling zmq_poll with a list of hashrefs:

           zmq_poll([
               {
                   fd => fileno(STDOUT),
                   events => ZMQ_POLLOUT,
                   callback => \&callback,
               },
               {
                   socket => $zmq_socket,
                   events => ZMQ_POLLIN,
                   callback => \&callback
               },
           ], $timeout );

       Unfortunately this custom polling scheme doesn't play too well with AnyEvent.

       As of zeromq2-2.1.0, you can use getsockopt to retrieve the underlying file descriptor, so
       use that to integrate ZeroMQ and AnyEvent:

           my $socket = zmq_socket( $ctxt, ZMQ_REP );
           my $fh = zmq_getsockopt( $socket, ZMQ_FD );
           my $w; $w = AE::io $fh, 0, sub {
               while ( my $msg = zmq_recv( $socket, ZMQ_RCVMORE ) ) {
                   # do something with $msg;
               }
               undef $w;
           };

NOTES ON MULTI-PROCESS and MULTI-THREADED USAGE

       ZeroMQ works on both multi-process and multi-threaded use cases, but you need to be
       careful bout sharing ZeroMQ objects.

       For multi-process environments, you should not be sharing the context object.  Create
       separate contexts for each process, and therefore you shouldn't be sharing the socket
       objects either.

       For multi-thread environemnts, you can share the same context object. However you cannot
       share sockets.

FUNCTIONS

   version()
       Returns the version of the underlying zeromq library that is being linked.  In scalar
       context, returns a dotted version string. In list context, returns a 3-element list of the
       version numbers:

           my $version_string = ZeroMQ::version();
           my ($major, $minor, $patch) = ZeroMQ::version();

   device($type, $sock1, $sock2)
   register_read_type($name, \&callback)
       Register a read callback for a given $name. This is used in "recv_as()".  The callback
       receives the data received from the socket.

   register_write_type($name, \&callback)
       Register a write callback for a given $name. This is used in "send_as()" The callback
       receives the Perl structure given to "send_as()"

DEBUGGING XS

       If you see segmentation faults, and such, you need to figure out where the error is
       occuring in order for the maintainers to figure out what happened. Here's a very very
       brief explanation of steps involved.

       First, make sure to compile ZeroMQ.pm with debugging on by specifying -g:

           perl Makefile.PL -g
           make

       Then fire gdb:

           gdb perl
           (gdb) R -Mblib /path/to/your/script.pl

       When you see the crash, get a backtrace:

           (gdb) bt

CAVEATS

       This is an early release. Proceed with caution, please report (or better yet: fix) bugs
       you encounter.

       This module has been tested againt zeromq 2.1.4. Semantics of this module rely heavily on
       the underlying zeromq version. Make sure you know which version of zeromq you're working
       with.

SEE ALSO

       ZeroMQ::Raw, ZeroMQ::Context, ZeroMQ::Socket, ZeroMQ::Message

       <http://zeromq.org>

       <http://github.com/lestrrat/ZeroMQ-Perl>

AUTHOR

       Daisuke Maki "<daisuke@endeworks.jp>"

       Steffen Mueller, "<smueller@cpan.org>"

COPYRIGHT AND LICENSE

       The ZeroMQ module is

       Copyright (C) 2010 by Daisuke Maki

       This library is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself, either Perl version 5.8.0 or, at your option, any later version of
       Perl 5 you may have available.