Lookup an instance name using SQL Server Browser.

Not yet used, other than by integration test.

Issue #20

lib/instance-lookup.coffee

@@ -0,0 +1,71 @@
+dgram = require('dgram')
+
+SQL_SERVER_BROWSER_PORT = 1434
+TIMEOUT = 2 * 1000
+RETRIES = 3
+
+module.exports = (server, instanceName, callback) ->
+  retriesLeft = RETRIES
+  timer = undefined
+  socket = undefined
+
+  message = (message, rinfo) ->
+    if timer
+      clearTimeout(timer)
+      timer = undefined
+
+    message = message.toString('ascii', 3)
+    parts = message.split(';')
+
+    for p in [0..parts.length - 1] by 2
+      name = parts[p]
+      value = parts[p + 1]
+
+      if (name == 'tcp' && getPort)
+        port = parseInt(value, 10)
+
+      if name == 'InstanceName'
+        if value.toUpperCase() == instanceName.toUpperCase()
+          getPort = true
+        else
+          getPort = false
+
+    socket.close()
+
+    if port
+      callback(undefined, port)
+    else
+      callback("Port for #{instanceName} not found in #{message}")
+
+  error = (err) ->
+    if timer
+      clearTimeout(timer)
+      timer = undefined
+
+    socket.close()
+
+    callback("Failed to lookup instance on #{server} : #{err}")
+
+  timeout = () ->
+    timer = undefined
+    socket.close()
+    makeAttempt()
+
+  makeAttempt = () ->
+    if retriesLeft > 0
+      retriesLeft--
+
+      request = new Buffer([0x02])
+
+      socket = dgram.createSocket('udp4')
+      socket.on('error', error)
+      socket.on('message', message)
+
+      socket.send(request, 0, request.length, SQL_SERVER_BROWSER_PORT, server)
+
+      timer = setTimeout(timeout, TIMEOUT)
+    else
+      callback("Failed to get response from SQL Server Browser on #{server}")
+
+  makeAttempt()
+

test/integration/connection-test.coffee

@@ -377,57 +377,3 @@ exports.execProcAsSql = (test) ->
   connection.on('debug', (text) ->
     #console.log(text)
   )
-
-###
-exports.requestInfoErrorMessages = (test) ->
-  test.expect(9)
-
-  config = getConfig()
-  done = 0
-
-  request = new Request("use #{config.options.database}; select 1; select s;", (err) ->
-      test.ok(err)
-
-      connection.close()
-  )
-
-  request.on('done', (rowCount, more) ->
-      switch ++done
-        when 1
-          console.log 1
-          test.ok(more)
-        when 2
-          console.log 2
-          test.ok(more)
-        when 2
-          console.log 3
-          test.ok(!more)
-  )
-
-  connection = new Connection(config)
-
-  connection.on('connect', (err) ->
-      connection.execSql(request)
-  )
-
-  connection.on('end', (info) ->
-      test.done()
-  )
-
-  request.on('row', (columns) ->
-      console.log columns
-  )
-
-  connection.on('infoMessage', (info) ->
-    console.log("#{info.number} : #{info.message}")
-  )
-
-  connection.on('errorMessage', (error) ->
-    console.log("#{error.number} : #{error.message}")
-  )
-
-  connection.on('debug', (text) ->
-    #console.log(text)
-  )
-
-###

test/integration/instance-lookup-test.coffee

@@ -0,0 +1,39 @@
+fs = require('fs')
+instanceLookup = require('../../lib/instance-lookup')
+
+getConfig = ->
+  server: JSON.parse(fs.readFileSync(process.env.HOME + '/.tedious/test-connection.json', 'utf8')).config.server
+  instanceName: JSON.parse(fs.readFileSync(process.env.HOME + '/.tedious/test-connection.json', 'utf8')).instanceName
+
+exports.goodInstance = (test) ->
+  config = getConfig()
+
+  callback = (err, port) ->
+    test.ok(!err)
+    test.ok(port)
+
+    test.done()
+
+  instanceLookup(config.server, config.instanceName, callback)
+
+exports.badInstance = (test) ->
+  config = getConfig()
+
+  callback = (err, port) ->
+    test.ok(err)
+    test.ok(!port)
+
+    test.done()
+
+  instanceLookup(config.server, 'badInstanceName', callback)
+
+exports.badServer = (test) ->
+  config = getConfig()
+
+  callback = (err, port) ->
+    test.ok(err)
+    test.ok(!port)
+
+    test.done()
+
+  instanceLookup('badServer', config.instanceName, callback)