refactored rpc_server.js

javascript-nodejs/src/rpc_server.js

@@ -1,42 +1,32 @@
 #!/usr/bin/env node
 
-var amqp = require('amqplib');
+var amqp = require('amqplib/callback_api');
 
-var conn = amqp.connect('amqp://localhost');
-conn.then(createChannel).then(null, console.warn);
+amqp.connect('amqp://localhost', function(err, conn) {
+  conn.createChannel(function(err, ch) {
+    var q = 'rpc_queue';
 
-function createChannel(conn) {
-  process.once('SIGINT', function() { conn.close(); });
-  return conn.createChannel().then(consume);
-}
-
-function consume(ch) {
-  var ok = ch.assertQueue('rpc_queue', {durable: false});
-  ok = ok.then(function() {
+    ch.assertQueue(q, {durable: false});
     ch.prefetch(1);
-    return ch.consume('rpc_queue', reply);
-  });
-
-  return ok.then(function(_ignore) {
     console.log(' [x] Awaiting RPC requests');
-  });
+    ch.consume(q, function reply(msg) {
+      var n = parseInt(msg.content.toString());
+      var r = fibonacci(n);
 
-  function reply(msg) {
-    var n = parseInt(msg.content.toString());
-    console.log(' [.] fib(%d)', n);
-    var response = fib(n);
-    ch.sendToQueue( msg.properties.replyTo,
-        new Buffer(response.toString()),
+      console.log(" [.] fib(%d)", n);
+
+      ch.sendToQueue(msg.properties.replyTo,
+        new Buffer(r.toString()),
         {correlationId: msg.properties.correlationId});
-    ch.ack(msg);
-  }
-}
 
-function fib(n) {
-  if(n == 0)
-    return 0;
-  else if(n == 1)
-    return 1;
+      ch.ack(msg);
+    });
+  });
+});
+
+function fibonacci(n) {
+  if (n == 0 || n == 1)
+    return n;
   else
-    return fib(n-1) + fib(n-2);
+    return fibonacci(n - 1) + fibonacci(n - 2);
 }