add Warning Full Connection Pool (event)

lib/Pool.js

@@ -3,6 +3,7 @@ var Connection     = require('./Connection');
 var EventEmitter   = require('events').EventEmitter;
 var Util           = require('util');
 var PoolConnection = require('./PoolConnection');
+var WarningFullConnectionPoolEvent = require('./WarningFullConnectionPoolEvent');
 
 module.exports = Pool;
 
@@ -30,14 +31,19 @@ Pool.prototype.getConnection = function (cb) {
 
   if (this._freeConnections.length > 0) {
     connection = this._freeConnections.shift();
-
+    if(this.config.warningFullConnectionPool) {
+        connection._stack = new Error().stack;
+    }
     return process.nextTick(function(){
       cb(null, connection);
     });
   }
 
   if (this.config.connectionLimit === 0 || this._allConnections.length < this.config.connectionLimit) {
     connection = new PoolConnection(this, { config: this.config.connectionConfig });
+    if(this.config.warningFullConnectionPool) {
+        connection._stack = new Error().stack;
+    }
 
     this._allConnections.push(connection);
 
@@ -64,6 +70,10 @@ Pool.prototype.getConnection = function (cb) {
     return cb(new Error('Queue limit reached.'));
   }
 
+  if(this.config.warningFullConnectionPool) {
+    this.emit('warningFullConnectionPool', new WarningFullConnectionPoolEvent(this));
+  }
+
   if (cb && process.domain)
     cb = process.domain.bind(cb);
   this._connectionQueue.push(cb);

lib/PoolConfig.js

@@ -13,4 +13,7 @@ function PoolConfig(options) {
   this.queueLimit         = (options.queueLimit === undefined)
     ? 0
     : Number(options.queueLimit);
+  this.warningFullConnectionPool = (options.warningFullConnectionPool === undefined)
+    ? false
+    : Boolean(options.warningFullConnectionPool);
 }

lib/PoolConnection.js

@@ -50,3 +50,12 @@ PoolConnection.prototype._removeFromPool = function(connection) {
 
   pool._removeConnection(this);
 };
+
+PoolConnection.prototype.query = function(sql, values, cb) {
+  if(this._pool.config.warningFullConnectionPool) {
+    this._lastQuery = sql;
+    this._lastQueryStack = new Error().stack;
+  }
+  return PoolConnection.super_.prototype.query.apply(this, [sql, values, cb]);
+};
+

lib/WarningFullConnectionPoolEvent.js

@@ -0,0 +1,42 @@
+module.exports = WarningFullConnectionPoolEvent;
+
+function WarningFullConnectionPoolEvent(pool) {
+  this._pool = pool;
+  this._data = [];
+
+  for(var i=0; i<pool._allConnections.length; i++) {
+    this._data.push(new ConnectionData(pool._allConnections[i]));
+  }
+}
+
+WarningFullConnectionPoolEvent.prototype.getData = function () {
+  return this._data;
+}
+
+function ConnectionData(conn) {
+  this._conn = conn;
+  this._stack = conn._stack;
+  this._lastQuery = conn._lastQuery;
+  this._lastQueryStack = conn._lastQueryStack;
+}
+
+ConnectionData.prototype.getStack = function () {
+  return this._stack;
+}
+
+ConnectionData.prototype.getLastQuery = function () {
+  return this._lastQuery;
+}
+
+ConnectionData.prototype.getLastQueryStack = function () {
+  return this._lastQueryStack;
+}
+
+ConnectionData.prototype.toString = function () {
+  var str = "";
+  str += "Full Mysql Connection Pool - lastConnectionData\n";
+  str += "stack : " + this.getStack() + "\n";
+  str += "query : " + this.getLastQuery() + "\n";
+  str += "query stack : " + this.getLastQueryStack() + "\n";
+  return str;
+}