Merge pull request #8 from drob/handler-leak

Fixes an event handler leak.

copy-to.js

@@ -8,18 +8,23 @@ var util = require('util')
 var CopyStreamQuery = function(text) {
   Transform.call(this)
   this.text = text
-  this._listeners = null
+  this._listeners = {}
   this._copyOutResponse = null
   this.rowCount = 0
 }
 
 util.inherits(CopyStreamQuery, Transform)
 
+var eventTypes = ['close', 'data', 'end']
+
 CopyStreamQuery.prototype.submit = function(connection) {
   connection.query(this.text)
   this.connection = connection
-  this._listeners = connection.stream.listeners('data')
-  connection.stream.removeAllListeners('data')
+  var self = this
+  eventTypes.forEach(function(type) {
+    self._listeners[type] = connection.stream.listeners(type)
+    connection.stream.removeAllListeners(type)
+  })
   connection.stream.pipe(this)
 }
 
@@ -32,10 +37,12 @@ var code = {
 
 CopyStreamQuery.prototype._detach = function() {
   this.connection.stream.unpipe()
-  this.connection.stream.removeAllListeners('data')
   var self = this
-  this._listeners.forEach(function(listener) {
-    self.connection.stream.on('data', listener)
+  eventTypes.forEach(function(type) {
+    self.connection.stream.removeAllListeners(type)
+    self._listeners[type].forEach(function(listener) {
+      self.connection.stream.on(type, listener)
+    })
   })
 }
 

package.json

@@ -27,6 +27,7 @@
     "concat-stream": "~1.1.0",
     "gonna": "0.0.0",
     "lodash": "~2.2.1",
-    "heroku-env": "~0.1.1"
+    "heroku-env": "~0.1.1",
+    "async": "~0.2.10"
   }
 }

test/copy-to.js

@@ -1,20 +1,21 @@
 var assert = require('assert')
 var gonna = require('gonna')
 
-var concat = require('concat-stream')
 var _ = require('lodash')
+var async = require('async')
+var concat = require('concat-stream')
 var pg = require('pg.js')
 
+var copy = require('../').to
+
+var client = function() {
+  var client = new pg.Client()
+  client.connect()
+  return client
+}
+
 var testRange = function(top) {
-  var client = function() {
-    var client = new pg.Client()
-    client.connect()
-    return client
-  }
-
   var fromClient = client()
-  var copy = require('../').to
-
   var txt = 'COPY (SELECT * from generate_series(0, ' + (top - 1) + ')) TO STDOUT'
 
   var stream = fromClient.query(copy(txt))
@@ -32,3 +33,27 @@ var testRange = function(top) {
 }
 
 testRange(10000)
+
+var testLeak = function(rounds) {
+  var fromClient = client()
+  var txt = 'COPY (SELECT 10) TO STDOUT'
+
+  var runStream = function(num, callback) {
+    var stream = fromClient.query(copy(txt))
+    stream.on('data', function(data) {
+      // Just throw away the data.
+    })
+    stream.on('end', callback)
+    stream.on('error', callback)
+  }
+
+  async.timesSeries(rounds, runStream, function(err) {
+    assert.equal(err, null)
+    assert.equal(fromClient.connection.stream.listeners('data').length, 1)
+    assert.equal(fromClient.connection.stream.listeners('end').length, 2)
+    assert.equal(fromClient.connection.stream.listeners('close').length, 0)
+    fromClient.end()
+  })
+}
+
+testLeak(5)