Add connection.threadId to get MySQL connection ID

fixes #602

Author: dougwilson

Changes.md

@@ -17,6 +17,7 @@ you spot any mistakes.
 * Fix `pool.end` to handle queued connections #797
 * Fix `pool.releaseConnection` to keep connection queue flowing #797
 * Fix SSL handshake error to  be catchable #800
+* Add `connection.threadId` to get MySQL connection ID #602
 
 ## v2.1.1 (2014-03-13)
 

Readme.md

@@ -105,7 +105,12 @@ var connection = mysql.createConnection({
 });
 
 connection.connect(function(err) {
-  // connected! (unless `err` is set)
+  if (err) {
+    console.error('error connecting: ' + err.stack);
+    return;
+  }
+
+  console.log('connected as id ' + connection.threadId);
 });
 ```
 
@@ -592,6 +597,18 @@ connection.query('UPDATE posts SET ...', function (err, response) {
 })
 ```
 
+## Getting the connection ID
+
+You can get the MySQL connection ID ("thread ID") of a given connection using the `threadId`
+property.
+
+```js
+connection.connect(function(err) {
+  if (err) throw err;
+  console.log('connected as id ' + connection.threadId);
+});
+```
+
 ## Executing queries in parallel
 
 The MySQL protocol is sequential, this means that you need multiple connections

lib/Connection.js

@@ -17,6 +17,7 @@ function Connection(options) {
   this._protocol      = new Protocol({config: this.config, connection: this});
   this._connectCalled = false;
   this.state          = "disconnected";
+  this.threadId       = null;
 }
 
 function bindToCurrentDomain(cb) {
@@ -282,8 +283,9 @@ Connection.prototype._handleProtocolConnect = function() {
   this.state = "connected";
 };
 
-Connection.prototype._handleProtocolHandshake = function() {
-  this.state = "authenticated";
+Connection.prototype._handleProtocolHandshake = function _handleProtocolHandshake(packet) {
+  this.state    = "authenticated";
+  this.threadId = packet.threadId;
 };
 
 Connection.prototype._handleProtocolEnd = function(err) {

lib/protocol/Protocol.js

@@ -229,7 +229,7 @@ Protocol.prototype._determinePacket = function(sequence) {
     case 0x00:
       if (!this._handshaked) {
         this._handshaked = true;
-        this.emit('handshake');
+        this.emit('handshake', this._handshakeInitializationPacket);
       }
       return Packets.OkPacket;
     case 0xfe: return Packets.EofPacket;

test/FakeServer.js

@@ -1,6 +1,7 @@
 // An experimental fake MySQL server for tricky integration tests. Expanded
 // as needed.
 
+var _            = require('underscore');
 var Net          = require('net');
 var Packets      = require('../lib/protocol/packets');
 var PacketWriter = require('../lib/protocol/PacketWriter');
@@ -54,12 +55,14 @@ function FakeConnection(socket) {
 FakeConnection.prototype.handshake = function(options) {
   this._handshakeOptions = options || {};
 
-  this._handshakeInitializationPacket = new Packets.HandshakeInitializationPacket({
+  var packetOpiotns = _.extend({
     scrambleBuff1       : new Buffer('1020304050607080', 'hex'),
     scrambleBuff2       : new Buffer('0102030405060708090A0B0C', 'hex'),
     serverCapabilities1 : 512, // only 1 flag, PROTOCOL_41
     protocol41          : true
-  });
+  }, this._handshakeOptions);
+
+  this._handshakeInitializationPacket = new Packets.HandshakeInitializationPacket(packetOpiotns);
 
   this._sendPacket(this._handshakeInitializationPacket);
 };

test/integration/connection/test-connection-thread-id.js

@@ -0,0 +1,17 @@
+var assert     = require('assert');
+var common     = require('../../common');
+var connection = common.createConnection();
+
+assert.strictEqual(connection.threadId, null);
+
+connection.connect(function(err) {
+  assert.ifError(err);
+  assert.notStrictEqual(connection.threadId, null);
+  assert.notStrictEqual(connection.threadId, 0);
+
+  connection.end(function(err) {
+    assert.ifError(err);
+    assert.notStrictEqual(connection.threadId, null);
+    assert.notStrictEqual(connection.threadId, 0);
+  });
+});

test/unit/connection/test-connection-thread-id.js

@@ -0,0 +1,27 @@
+var assert     = require('assert');
+var common     = require('../../common');
+var connection = common.createConnection({port: common.fakeServerPort});
+
+var server = common.createFakeServer();
+
+server.listen(common.fakeServerPort, function(err) {
+  assert.ifError(err);
+  assert.strictEqual(connection.threadId, null);
+
+  connection.connect(function(err) {
+    assert.ifError(err);
+    assert.strictEqual(connection.threadId, 42);
+
+    connection.end(function(err) {
+      assert.ifError(err);
+      assert.strictEqual(connection.threadId, 42);
+      server.destroy();
+    });
+  });
+});
+
+server.on('connection', function(incomingConnection) {
+  incomingConnection.handshake({
+    threadId : 42
+  });
+});