Fix issue #473 (Make Pool emit a "connection" event)

lib/Pool.js

@@ -1,9 +1,13 @@
 
 var Mysql        = require('../');
 var Connection   = require('./Connection');
+var EventEmitter = require('events').EventEmitter;
+var Util         = require('util');
 
 module.exports = Pool;
+Util.inherits(Pool, EventEmitter);
 function Pool(options) {
+  EventEmitter.call(this);
   this.config = options.config;
   this.config.connectionConfig.pool = this;
 
@@ -34,11 +38,16 @@ Pool.prototype.getConnection = function(cb) {
       else if (err) {
         cb(err);
       } else {
+        self.emit('connection', null, connection);
         cb(null, connection);
       }
     });
   } else if (this.config.waitForConnections) {
-    this._connectionQueue.push(cb);
+    if (this.config.queueLimit && this._connectionQueue.length >= this.config.queueLimit) {
+      cb(new Error('Queue limit reached.'))
+    } else {
+      this._connectionQueue.push(cb);
+    }
   } else {
     cb(new Error('No connections available.'));
   }

lib/PoolConfig.js

@@ -11,4 +11,7 @@ function PoolConfig(options) {
   this.connectionLimit    = (options.connectionLimit === undefined)
     ? 10
     : Number(options.connectionLimit);
+  this.queueLimit         = (options.queueLimit === undefined)
+    ? 0
+    : Number(options.queueLimit);
 }

test/common.js

@@ -31,7 +31,9 @@ common.createConnection = function(config) {
 
 common.createPool = function(config) {
   config = mergeTestConfig(config);
-  config.createConnection = common.createConnection;
+  if (!config.createConnection) {
+    config.createConnection = common.createConnection;
+  }
   return Mysql.createPool(config);
 };
 

test/integration/pool/test-create-connection.js

@@ -0,0 +1,15 @@
+var common     = require('../../common');
+var assert     = require('assert');
+var Connection = require(common.lib + '/Connection');
+var pool       = common.createPool({
+  createConnection: function() {
+    var connection = common.createConnection()
+    connection.query('SET SESSION sql_mode="STRICT_ALL_TABLES"')
+    return connection
+  }
+});
+
+pool.getConnection(function(err, connection) {
+  if (err) throw err;
+  pool.end()
+});

test/integration/pool/test-queue-limit.js

@@ -0,0 +1,28 @@
+var common = require('../../common');
+var assert = require('assert');
+var pool   = common.createPool({
+  connectionLimit    : 1,
+  queueLimit         : 1,
+  waitForConnections : true
+});
+
+// First connection we get right away
+pool.getConnection(function(err, connection) {
+	connection.end()
+})
+
+// Second connection request goes into the queue
+pool.getConnection(function(err, connection) {
+	connection.end()
+	pool.end()
+})
+
+// Third connection request gets refused, since the queue is full
+var thirdGetErr
+pool.getConnection(function(err, connection) {
+	thirdGetErr = err
+})
+
+process.on('exit', function() {
+	assert.equal(thirdGetErr.message, 'Queue limit reached.')	
+})

test/integration/pool/test-set-session-vars.js

@@ -0,0 +1,16 @@
+var common     = require('../../common');
+var assert     = require('assert');
+var Connection = require(common.lib + '/Connection');
+var pool       = common.createPool();
+
+var wasSet = false;
+pool.on('connection', function(err, connection) {
+  connection.query('SET SESSION sql_mode="STRICT_ALL_TABLES"');
+  wasSet = true;
+})
+
+pool.getConnection(function(err, connection) {
+  if (err) throw err;
+  assert.equal(wasSet, true);
+  pool.end();
+});