Ruby Zyre

home : https://gitlab.com/ravngroup/open-source/ruby-zyre

code : https://gitlab.com/ravngroup/open-source/ruby-zyre/-/tree/master

github : https://github.com/ged/ruby-zyre

docs : https://deveiate.org/code/zyre

Description

A ZRE library for Ruby. This is a Ruby (MRI) binding for the Zyre library for reliable group messaging over local area networks, an implementation of the ZeroMQ Realtime Exchange protocol.

Examples

Zyre is a P2P library which has two modes: pub/sub and direct messaging. To use it, you create a node, optionally join some groups (subscribing), and start it. Then you can send broadcast messages to all other nodes in a group, or direct messages to a particular node.

This example joins the Zyre network and dumps messages it sees in the 'global' group to stderr:

node = Zyre::Node.new
node.join( 'global' )
node.start

node.each_event do |event|
  event.print
end

To send a direct message to a different node you need to know its UUID. There are number of ways to discover this:

# The UUIDs of all connected peers
node.peers
# The UUIDs of all the peers which have joined the `general` group
node.peers_by_group( 'general' )
# The UUID of the peer that sent the event
received_event.peer_uuid

You read events from the network with the Zyre::Node#recv method, but it blocks until an event arrives:

event = node.recv

You can also iterate over arriving events:

node.each do |event|
    ...
end

or use Zyre::Node#each as an Enumerator:

five_events = node.each_event.take( 5 )

You can also wait for a certain type of event:

event = node.wait_for( :SHOUT )

and time out if it doesn't arrive within a certain length of time:

event = node.wait_for( :ENTER, timeout: 2.0 ) or
    raise "No one else on the network!"

You can join a group with Zyre::Node#join:

node.join( 'alerts' )

and you can detect other nodes joining one of your groups by looking for JOIN events (Zyre::Event::Join objects):

node.wait_for( :JOIN )

You can publish a message to all nodes in a group with Zyre::Node#shout:

node.shout( "group1", "This is a message." )

and read it:

event = other_node.recv
event.is_multipart?  # => false
event.msg            # => "This is a message."
event.multipart_msg  # => ["This is a message."]

Or publish a message with multiple parts:

node.shout( "group1", 'message.type', "This is a message." )

and read it:

event = other_node.recv
event.is_multipart?  # => true
event.msg            # => "message.type"
event.multipart_msg  # => ["message.type", "This is a message."]

To-Do

• Implement the draft API methods on Zyre::Node
• Hook up logging via zsys_set_logsender
• Add richer matching to Zyre::Event#match.

Prerequisites

• Ruby 2.7+
• Zyre (https://github.com/zeromq/zyre)

Installation

$ gem install zyre

Contributing

You can check out the current development source with Mercurial via its project page.

After checking out the source, run:

$ gem install -Ng
$ rake setup

This will install dependencies, and do any other necessary setup for development.

Authors

• Michael Granger ged@faeriemud.org

License

Copyright (c) 2020, Ravn Group All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

• Neither the name of the author/s, nor the names of the project's contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.