add experimental server scheduler

src/local.coffee

@@ -34,6 +34,7 @@ inetAton = (ipStr) ->
     buf
 
 fs = require("fs")
+scheduler = require('./scheduler')
 configContent = fs.readFileSync("config.json")
 config = JSON.parse(configContent)
 SERVER = config.server
@@ -42,11 +43,9 @@ PORT = config.local_port
 KEY = config.password
 timeout = Math.floor(config.timeout * 1000)
 
+myScheduler = new scheduler.Scheduler SERVER
 getServer = ->
-  if SERVER instanceof Array
-    SERVER[Math.floor(Math.random() * SERVER.length)]
-  else
-    SERVER
+  myScheduler.getServer()
 
 net = require("net")
 encrypt = require("./encrypt")
@@ -56,7 +55,7 @@ encryptTable = tables[0]
 decryptTable = tables[1]
 
 server = net.createServer((connection) ->
-  console.log "server connected"
+  console.log "local connected"
   console.log "concurrent connections: " + server.connections
   stage = 0
   headerLength = 0
@@ -66,6 +65,7 @@ server = net.createServer((connection) ->
   remoteAddr = null
   remotePort = null
   addrToSend = ""
+  serverUsing = getServer()
   connection.on "data", (data) ->
     if stage is 5
       # pipe sockets
@@ -118,9 +118,8 @@ server = net.createServer((connection) ->
         buf.writeInt16BE remotePort, 8
         connection.write buf
         # connect remote server
-        aServer = getServer()
-        remote = net.connect(REMOTE_PORT, aServer, ->
-          console.log "connecting #{remoteAddr} via #{aServer}"
+        remote = net.connect(REMOTE_PORT, serverUsing, ->
+          console.log "connecting #{remoteAddr} via #{serverUsing}"
           addrToSendBuf = new Buffer(addrToSend, "binary")
           encrypt.encrypt encryptTable, addrToSendBuf
           remote.write addrToSendBuf
@@ -144,12 +143,13 @@ server = net.createServer((connection) ->
           console.log "concurrent connections: " + server.connections
 
         remote.on "error", ->
+          myScheduler.serverFailed(serverUsing)
           if stage is 4
             console.warn "remote connection refused"
             connection.destroy()
-            return
-          console.warn "remote error"
-          connection.end()
+          else
+            console.warn "remote error"
+            connection.end()
           console.log "concurrent connections: " + server.connections
 
         remote.on "drain", ->
@@ -176,12 +176,13 @@ server = net.createServer((connection) ->
       # make sure no data is lost
 
   connection.on "end", ->
-    console.log "server disconnected"
-    remote.destroy()  if remote
+    myScheduler.serverSucceeded(serverUsing)
+    console.log "local disconnected"
+    remote.end()  if remote
     console.log "concurrent connections: " + server.connections
 
   connection.on "error", ->
-    console.warn "server error"
+    console.warn "local error"
     remote.destroy()  if remote
     console.log "concurrent connections: " + server.connections
 

src/scheduler.coffee

@@ -0,0 +1,40 @@
+
+class Scheduler
+  constructor: (servers) ->
+    if servers instanceof Array
+      this._servers = servers
+    else
+      this._servers = [servers]
+
+  _servers: []
+  _failureCount: {}
+  _successCount: {}
+  _ping: {}
+
+  toString: ->
+    "[" + this._servers.join(',') + "]"
+
+  _increaseCounter: (counter, key) ->
+    if key of counter
+      counter[key]++
+    else
+      counter[key] = 1
+
+  serverFailed: (server) ->
+    console.log "#{server} failed"
+    this._increaseCounter(this._failureCount, server)
+
+  serverSucceeded: (server) ->
+    console.log "#{server} succeeded"
+    this._increaseCounter(this._successCount, server)
+
+  updatePing: (server, ping)->
+    if server of _ping
+      _ping[server] = ping
+    else
+      _ping[server] = (_ping[server] * 0.8 + ping * 0.2)
+
+  getServer: ->
+    this._servers[Math.floor(Math.random() * this._servers.length)]
+
+exports.Scheduler = Scheduler

src/server.coffee

@@ -136,7 +136,7 @@ server = net.createServer((connection) ->
 
   connection.on "end", ->
     console.log "server disconnected"
-    remote.destroy()  if remote
+    remote.end()  if remote
     console.log "concurrent connections: " + server.connections
 
   connection.on "error", ->