Roughed out a pub/sub example with ZMQMachine

003_ZMQMachine/002_a_pub_sub_example.rb

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+# NOTE: This example isn't quite ready for students,
+# It's not styled right, and is just here for me to 
+# rough out an idea for this lesson.
+# Annotations and explanations will come in good time
+
+require 'rubygems'
+require 'zmqmachine'
+Thread.abort_on_exception = true
+
+ADDR = ZM::Address.new('127.0.0.1', 2200, :tcp)
+
+class PubHandler
+  def initialize(ctx,name)
+    @ctx  = ctx
+    @name = name
+    @sent_messages = 0
+  end
+
+  def on_attach(socket)
+    socket.bind(ADDR)
+  end
+
+  def on_writable(socket)
+    @sent_messages += 1
+    msg = "#{@name} | #{@sent_messages}"
+    puts "P: #{msg}"
+    socket.send_message_string(msg)
+    sleep 1
+  end
+end
+
+class SubHandler
+  def initialize(ctx,name)
+    @ctx  = ctx
+    @name = name
+  end
+
+  def on_attach(socket)
+    socket.connect(ADDR)
+    socket.subscribe('')
+  end
+
+  def on_readable(socket,messages)
+    message = messages.first.copy_out_string
+    puts "#{@name}: #{message}"
+  end
+end
+
+reactor = ZM::Reactor.new(:my_reactor).run do |ctx|
+  ctx.pub_socket(PubHandler.new(ctx, 'pub1'))
+
+  ctx.sub_socket(SubHandler.new(ctx, 'sub1'))
+  ctx.sub_socket(SubHandler.new(ctx, 'sub2'))
+end
+
+reactor.join