Add support for pool exhaustion, and eventually processing queued con…

…nection requests.
calvium · Oct 7, 2012 · 592e42f · 592e42f
1 parent f468f02
commit 592e42f
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Showing 2 changed files with 66 additions and 13 deletions.
diff --git a/index.js b/index.js
@@ -1,6 +1,18 @@
 var Connection = require('tedious').Connection;
 var util = require('util');
 
+var connectionEventNames = [
+  'connect',
+  'end',
+  'debug',
+  'infoMessage',
+  'errorMessage',
+  'databaseChange',
+  'languageChange',
+  'charsetChange',
+  'secure'
+];
+
 function PooledConnection(pool, config) {
     Connection.call(this, config);
     this.pool = pool;
@@ -10,7 +22,7 @@ util.inherits(PooledConnection, Connection);
 
 PooledConnection.prototype.close = function() {
     this.emit('end');
-    this.pool.connectionAvailable(this);
+    this.pool.returnConnectionToPool(this);
 }
 
 PooledConnection.prototype._close = function() {
@@ -21,35 +33,54 @@ function ConnectionPool(poolConfig, connectionConfig) {
   var pool = this;
 
   pool.config = poolConfig;
+  pool.requestNumber = 0;
+  pool.stats = {
+    maxSize: poolConfig.maxSize,
+    connections: 0
+  };
   pool.inUseConnections = [];
   pool.availableConnections = [];
   pool.pendingConnectionRequests = [];
 
-  pool.connectionAvailable = function(connection) {
-    this.inUseConnections.splice(this.inUseConnections.indexOf(connection), 1);
+  pool.returnConnectionToPool = function(connection) {
+    connectionEventNames.forEach(function removeAllListeners(eventName) {
+      connection.removeAllListeners(eventName);
+    });
+
+    pool.inUseConnections.splice(pool.inUseConnections.indexOf(connection), 1);
+
+    if (pool.pendingConnectionRequests.length > 0) {
+      var pendingConnectionRequest = pool.pendingConnectionRequests.shift();
+
+      pendingConnectionRequest(connection);
+    }
   };
 
   pool.requestConnection = function(callback) {
+    var requestNumber = ++pool.requestNumber;
     var connection;
 
-    if (pool.availableConnections.length > 1) {
+    if (pool.availableConnections.length > 0) {
       connection = availableConnections.shift();
+      connection.emit('connect');
     } else if (pool.inUseConnections.length < pool.config.maxSize) {
       connection = new PooledConnection(pool, connectionConfig);
+      connection.number = ++pool.stats.connections;
     }
 
     if (connection) {
       useConnection(connection);
     } else {
-      pool.pendingConnectionRequests.push(useConnection);
+      pool.pendingConnectionRequests.push(function (connection) {
+        useConnection(connection);
+        connection.emit('connect');
+      });
     }
 
     function useConnection(connection) {
       pool.inUseConnections.push(connection);
 
-      process.nextTick(function() {
-        callback(connection);
-      });
+      callback(connection);
     }
   };
 

diff --git a/test/connection-pool.test.js b/test/connection-pool.test.js
@@ -7,6 +7,14 @@ var connectionConfig = {
   userName: 'test',
   password: 'test',
   server: '192.168.1.212',
+  // options: {
+  //   debug: {
+  //     packet: true,
+  //     data: true,
+  //     payload: true,
+  //     token: true
+  //   }
+  // }
 };
 
 describe('ConnectionPool', function() {
@@ -24,22 +32,36 @@ describe('ConnectionPool', function() {
 
   describe('multiple connections within pool maxSize', function() {
     var poolConfig = {maxSize: 5};
+    var numberOfConnectionsToUse = poolConfig.maxSize;
 
     it('should connect, and end', function(done) {
-      testPool(poolConfig, poolConfig.maxSize, requestConnectionAndClose, done);
+      testPool(poolConfig, numberOfConnectionsToUse, requestConnectionAndClose, done);
     });
 
     it('should connect, select, and end', function(done) {
-      testPool(poolConfig, poolConfig.maxSize, requestConnectionSelectAndClose, done);
+      testPool(poolConfig, numberOfConnectionsToUse, requestConnectionSelectAndClose, done);
+    });
+  });
+
+  describe('connections exceed pool maxSize', function() {
+    var poolConfig = {maxSize: 5};
+    var numberOfConnectionsToUse = 20;
+
+    it('should connect, and end', function(done) {
+      testPool(poolConfig, numberOfConnectionsToUse, requestConnectionAndClose, done);
+    });
+
+    it('should connect, select, and end', function(done) {
+      testPool(poolConfig, numberOfConnectionsToUse, requestConnectionSelectAndClose, done);
     });
   });
 });
 
-function testPool(poolConfig, numberOfConnectionsToUse, useConnectionfunction, done) {
+function testPool(poolConfig, numberOfConnectionsToUse, useConnectionFunction, done) {
   var pool = new ConnectionPool(poolConfig, connectionConfig);
 
   function doIt(done) {
-    useConnectionfunction(pool, function() {
+    useConnectionFunction(pool, function() {
       done();
     });
   }
@@ -61,7 +83,7 @@ function requestConnectionAndClose(pool, done) {
     connection.on('end', function(err) {
       done();
     });
-  });
+  } );
 }
 
 function requestConnectionSelectAndClose(pool, done) {