Tutorial 6 ported to Bunny

Author: Michael Klishin

ruby/rpc_client.rb

@@ -0,0 +1,62 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+require "bunny"
+
+conn = Bunny.new
+conn.start
+
+ch   = conn.create_channel
+
+class FibonacciClient
+  attr_reader :reply_queue
+
+  def initialize(ch, server_queue)
+    @ch             = ch
+    @x              = ch.default_exchange
+
+    @server_queue   = server_queue
+    @reply_queue    = ch.queue("", :exclusive => true)
+  end
+
+  def call(n)
+    correlation_id = self.generate_uuid
+
+    @x.publish(n.to_s,
+      :routing_key    => @server_queue,
+      :correlation_id => correlation_id,
+      :reply_to       => @reply_queue.name)
+
+    response = nil
+    @reply_queue.subscribe(:block => true) do |delivery_info, properties, payload|
+      if properties[:correlation_id] == correlation_id
+        response = payload.to_i
+
+        delivery_info.consumer.cancel
+      end
+    end
+
+    response
+  end
+
+  protected
+
+  def generate_uuid
+    # very naive but good enough for code
+    # examples
+    "#{rand}#{rand}#{rand}"
+  end
+end
+
+
+begin
+  client   = FibonacciClient.new(ch, "rpc_queue")
+  puts " [x] Requesting fib(30). Collecting replies from #{client.reply_queue.name}"
+  response = client.call(30)
+  puts " [.] Got #{response}"
+rescue Interrupt => _
+  puts " [*] Shutting down..."
+
+  ch.close
+  conn.close
+end

ruby/rpc_server.rb

@@ -0,0 +1,51 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+require "bunny"
+
+conn = Bunny.new
+conn.start
+
+ch   = conn.create_channel
+
+class FibonacciServer
+
+  def initialize(ch)
+    @ch = ch
+  end
+
+  def start(queue_name)
+    @q = @ch.queue(queue_name)
+    @x = @ch.default_exchange
+
+    @q.subscribe(:block => true) do |delivery_info, properties, payload|
+      n = payload.to_i
+      r = self.class.fib(n)
+
+      puts " [*] Serving a request: #{n} => #{r}. Replying to #{properties.reply_to}"
+
+      @x.publish(r.to_s, :routing_key => properties.reply_to, :correlation_id => properties.correlation_id)
+    end
+  end
+
+
+  def self.fib(n)
+    case n
+    when 0 then 0
+    when 1 then 1
+    else
+      fib(n - 1) + fib(n - 2)
+    end
+  end
+end
+
+begin
+  server = FibonacciServer.new(ch)
+  puts " [*] Waiting for requests..."
+  server.start("rpc_queue")
+rescue Interrupt => _
+  puts " [*] Shutting down..."
+
+  ch.close
+  conn.close
+end