events: add check for listeners length

Ability to return just the length of listeners for a given type, using
EventEmitter.listenerCount(emitter, event). This will be a lot cheaper
than creating a copy of the listeners array just to check its length.

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/stream.js b/lib/stream.js
index 481d7644e5..098ff613d2 100644
--- a/lib/stream.js
+++ b/lib/stream.js
@@ -21,10 +21,10 @@
 
 module.exports = Stream;
 
-var events = require('events');
+var EE = require('events').EventEmitter;
 var util = require('util');
 
-util.inherits(Stream, events.EventEmitter);
+util.inherits(Stream, EE);
 Stream.Readable = require('_stream_readable');
 Stream.Writable = require('_stream_writable');
 Stream.Duplex = require('_stream_duplex');
@@ -40,7 +40,7 @@ Stream.Stream = Stream;
 // part of this class) is overridden in the Readable class.
 
 function Stream() {
-  events.EventEmitter.call(this);
+  EE.call(this);
 }
 
 Stream.prototype.pipe = function(dest, options) {
@@ -90,7 +90,7 @@ Stream.prototype.pipe = function(dest, options) {
   // don't leave dangling pipes when there are errors.
   function onerror(er) {
     cleanup();
-    if (this.listeners('error').length === 0) {
+    if (EE.listenerCount(this, 'error') === 0) {
       throw er; // Unhandled stream error in pipe.
     }
   }