// NewClient creates, initiates, and returns a new client. This function
// should return after a connection with the server has been established
// (i.e., the client has received an Ack message from the server in response
// to its connection request), and should return a non-nil error if a
// connection could not be made (i.e., if after K epochs, the client still
// hasn't received an Ack message from the server in response to its K
// connection requests).
//
// hostport is a colon-separated string identifying the server's host address
// and port number (i.e., "localhost:9999").
func NewClient(hostport string, params *Params) (Client, error) {
if params == nil {
params = &Params{5, 2000, 1}
}
addr, err := lspnet.ResolveUDPAddr("udp", hostport)
if err != nil {
return nil, err
}
conn, err := lspnet.DialUDP("udp", nil, addr)
if err != nil {
return nil, err
}
c := &client{
comm: NewCommon(addr, params),
connUDP: conn,
readBufToAppChan: make(chan *Message),
netToReadWinChan: make(chan *Message),
epochToReadWinChan: make(chan *Message),
appToWriteBufChan: make(chan *Message),
netToWriteBufChan: make(chan *Message),
epochToWriteBufChan: make(chan *Message),
connChan: make(chan *Message),
appCloseSynChan: make(chan bool, 1),
netLostCloseSynChan: make(chan bool, 1),
}
// go c.manageReceivedMsg()
go c.handleEpoch()
go c.readFromServer()
go c.handleReadSlideWindow()
go c.handleWriteSlideWindow()
//init lock
// c.connIDSynChan <- 0
c.appCloseSynChan <- false
c.netLostCloseSynChan <- false
//start connect
c.writeToServer(c.generateMsg(MsgConnect, 0, nil))
connMsg := <-c.connChan
if connMsg.Type == MsgAck && connMsg.SeqNum == 0 {
SetValueToIntChan(c.comm.connIDSynChan, connMsg.ConnID)
SetValueToBoolChan(c.comm.isConnectedSynChan, true)
c.comm.connID = connMsg.ConnID
fmt.Println("Client:", c.comm.connID, "Start")
return c, nil
}
return nil, errors.New("Connection failed")
}
// listen to incoming UDP data using the given hostport, used on server side
func (h *networkUtility) listen(hostport string) error {
serverAddr, err := lspnet.ResolveUDPAddr("udp", hostport)
if err != nil {
return nil
}
conn, err := lspnet.ListenUDP("udp", serverAddr)
if err != nil {
return err
}
h.conn = conn
return nil
}
func (now *Connect) listen(hostport string) error {
serverAddr, err := lspnet.ResolveUDPAddr("udp", hostport)
if err != nil {
return nil
}
conn, err := lspnet.ListenUDP("udp", serverAddr)
if err != nil {
return err
}
now.conn = conn
now.addr = serverAddr
return nil
}
func (now *Connect) dial(hostport string) error {
serverAddr, err := lspnet.ResolveUDPAddr("udp", hostport)
if err != nil {
return err
}
conn, err := lspnet.DialUDP("udp", nil, serverAddr)
if err != nil {
return err
}
now.addr = serverAddr
now.conn = conn
return nil
}
func (s *server) StartListen(port string) error {
uAddr, err := lspnet.ResolveUDPAddr("udp", ":"+port)
if err != nil {
fmt.Println("Unable to resolve UDP addr ", port)
return err
}
s.sConn, err = lspnet.ListenUDP("udp", uAddr)
if err != nil {
fmt.Println("Unable to listen on port ", port)
return err
}
go s.handleMessages()
go s.ticking()
for {
select {
case <-s.quitAllChan:
fmt.Println("server quit listener")
return nil
default:
// read a msg from UDP and check its type
buf := make([]byte, 2000)
n, addr, err := s.sConn.ReadFromUDP(buf)
if err != nil {
return err
}
msg := Message{}
json.Unmarshal(buf[0:n], &msg)
switch msg.Type {
case MsgConnect:
// receive a conn msg from client
s.addChan <- addr
case MsgData:
// add to data channel if hash match, drop otherwise
if hex.EncodeToString(calMD5Hash(msg)) == hex.EncodeToString(msg.Hash) {
s.dataChan <- &msg
} else {
fmt.Println("Hash does not match")
}
case MsgAck:
s.ackChan <- &msg
}
}
}
return err
}
func NewFixedSizeUDPServer(maxMsgSize int, port int) (UDPServer, error) {
addr, err := net.ResolveUDPAddr("udp4", fmt.Sprintf(":%v", port))
if err != nil {
return nil, err
}
conn, err := net.ListenUDP("udp", addr) // non-blocking. no need to wait for any client to establish a connection like TCP does
if err != nil {
return nil, err
}
return &FixedSizeUDPServer{
maxMsgSize: maxMsgSize,
addr: addr,
conn: conn,
closed: false,
}, nil
}
func (c *client) StartDial(hostport string) error {
var err error
c.sAddr, err = lspnet.ResolveUDPAddr("udp", hostport)
if err != nil {
fmt.Println("Unable to resolve server UDP addr ", hostport)
return err
}
go c.handleMessages()
go c.ticking()
c.conn, err = lspnet.DialUDP("udp", nil, c.sAddr)
if err != nil {
fmt.Println("cannot dial to port ", hostport)
return err
}
fmt.Println("dial to ", hostport)
// send connect message
c.writeChan <- clientWriteData{MsgConnect, 0, nil}
// waiting for connect ack
buf := make([]byte, 2000)
msg := Message{}
n, err := c.conn.Read(buf)
if err != nil {
fmt.Println("unable read from connection")
msg = <-c.connSucChan
} else {
json.Unmarshal(buf[0:n], &msg)
}
switch msg.Type {
case MsgAck:
c.setidChan <- msg.ConnID
default:
return errors.New("unable to connect")
}
// start listen on data/ack
go c.StartListen()
return nil
}
func NewFixedSizeUDPClient(maxMsgSize int, serverHostPort string) (UDPClient, error) {
serverAddr, err := net.ResolveUDPAddr("udp4", serverHostPort)
if err != nil {
return nil, err
}
// non-blocking. it won't wait for server to build connection as TCP does
// it returns non-nil error even though the server is not running. (no connection)
conn, err := net.DialUDP("udp", nil, serverAddr)
if err != nil {
return nil, err
}
return &FixedSizeUDPClient{
maxMsgSize: maxMsgSize,
serverAddr: serverAddr,
conn: conn,
closed: false,
}, nil
}
// NewServer creates, initiates, and returns a new server. This function should
// NOT block. Instead, it should spawn one or more goroutines (to handle things
// like accepting incoming client connections, triggering epoch events at
// fixed intervals, synchronizing events using a for-select loop like you saw in
// project 0, etc.) and immediately return. It should return a non-nil error if
// there was an error resolving or listening on the specified port number.
func NewServer(port int, params *Params) (Server, error) {
s := &server{
nextConnectId: 1,
clients: make(map[int]*abstractClient),
readFromClientChan: make(chan *msgPackage),
writeToClientChan: make(chan *Message),
readRequest: &requestRead{
ask: make(chan int),
response: make(chan *Message),
},
writeRequest: &requestWrite{
ask: make(chan []byte),
connId: make(chan int),
response: make(chan error),
},
readList: list.New(),
writeList: list.New(),
flag: false,
// variables for window size
windowSize: params.WindowSize,
mapNeedSend: list.New(),
// variables for epoch
epochChan: make(chan int),
epochMillis: params.EpochMillis,
epochLimit: params.EpochLimit,
// close
deleteClient: make(chan int),
closeConnRequest: &requestCloseConn{
ask: make(chan int),
getError: make(chan error),
},
waitToWriteFinish: false,
writeFinished: make(chan int),
waitToAckFinish: false,
ackFinished: make(chan int),
closeRead: make(chan int, 1),
closeEpoch: make(chan int, 1),
closeEvent: make(chan int, 1),
// close conn
closeConn: make(chan int, 1),
}
// start server
addr, err := lspnet.ResolveUDPAddr("udp", "localhost:"+strconv.Itoa(port))
if err != nil {
return nil, err
}
conn, err := lspnet.ListenUDP("udp", addr)
if err != nil {
return nil, err
}
s.conn = conn
go s.readMessage()
go s.handleMessage()
go s.epochFire()
fmt.Println("new server")
return s, nil
}
// NewClient creates, initiates, and returns a new client. This function
// should return after a connection with the server has been established
// (i.e., the client has received an Ack message from the server in response
// to its connection request), and should return a non-nil error if a
// connection could not be made (i.e., if after K epochs, the client still
// hasn't received an Ack message from the server in response to its K
// connection requests).
//
// hostport is a colon-separated string identifying the server's host address
// and port number (i.e., "localhost:9999").
func NewClient(hostport string, params *Params) (Client, error) {
c := &client{
nextSN: 1,
writeToServerChan: make(chan *Message),
readFromServerChan: make(chan *Message),
readRequest: &requestRead{
ask: make(chan int),
response: make(chan *Message),
},
writeRequest: &requestWrite{
ask: make(chan []byte),
response: make(chan error),
},
readMap: make(map[int]*Message),
// write list has order
writeMap: make(map[int]*Message),
connected: make(chan int),
flag: false,
connect: false,
// variables for window size
windowSize: params.WindowSize,
// send to client data
nextSmallestAck: 1,
mapAck: make(map[int]bool),
mapNeedAck: make(map[int]*Message),
// receive from client data
nextSmallestData: 1,
// TODO: didn't need this
mapAcked: make(map[int]bool),
mapReceived: make(map[int]*Message),
nextDataRead: 1,
// epoch variables
epochChan: make(chan int),
epochMillis: params.EpochMillis,
epochLimit: params.EpochLimit,
epochNum: 0,
lostConn: false,
// clsoe
closeRequest: &requestClose{
ask: make(chan int),
//response: make(chan int),
getError: make(chan error),
},
waitToWriteFinish: false,
writeFinished: make(chan int),
waitToAckFinish: false,
ackFinished: make(chan int),
closeRead: make(chan int, 1),
closeEpoch: make(chan int, 1),
closeEvent: make(chan int, 1),
}
// connect to server
addr, err := lspnet.ResolveUDPAddr("udp", hostport)
if err != nil {
return nil, err
}
conn, err := lspnet.DialUDP("udp", nil, addr)
if err != nil {
return nil, err
}
fmt.Println("new client")
c.conn = conn
c.addr = addr
fmt.Println("70")
////fmt.Println("74")
go c.readMessage()
go c.handleMessage()
go c.epochFire()
msg := NewConnect()
c.writeToServerChan <- msg
<-c.connected
//fmt.Println("Client 156: connect success")
return c, nil
}
// NewClient creates, initiates, and returns a new client. This function
// should return after a connection with the server has been established
// (i.e., the client has received an Ack message from the server in response
// to its connection request), and should return a non-nil error if a
// connection could not be made (i.e., if after K epochs, the client still
// hasn't received an Ack message from the server in response to its K
// connection requests).
//
// hostport is a colon-separated string identifying the server's host address
// and port number (i.e., "localhost:9999").
func NewClient(hostport string, params *Params) (Client, error) {
c := &client{
hostport: hostport,
params: params,
connID: -1,
seqNum: 0,
conn: nil,
connected: false,
connOpen: make(chan struct{}),
connClose: make(chan struct{}),
connMsg: NewConnect(),
dataMsgTo: make(chan *Message),
dataMsgFr: make(chan *Message),
dataMsgTokens: make(chan struct{}, params.WindowSize),
seqNumToActChan: make(chan map[int]*Activity),
seqNumToAckMsgChan: make(chan map[int]*Message),
dataWrWindow: make(chan *SlideWindow, 1),
dataRdWindow: make(chan *SlideWindow, 1),
}
raddr, err := lspnet.ResolveUDPAddr("udp", hostport)
if err != nil {
return nil, err
}
conn, err := lspnet.DialUDP("udp", nil, raddr)
if err != nil {
return nil, err
}
c.conn = conn
c.dataWrWindow <- &SlideWindow{
seqNumLower: 1,
seqNumUpper: 1 + c.params.WindowSize,
}
c.dataRdWindow <- &SlideWindow{
seqNumLower: 1,
seqNumUpper: 1 + c.params.WindowSize,
}
go c.onWrite()
go c.onRead()
go c.epoch()
go c.connect()
for {
select {
case <-c.connOpen:
c.connected = true
return c, nil
case <-c.connClose:
c.connected = false
return nil, errors.New("connection not yet established")
}
}
return nil, errors.New("not yet implemented")
}