tcp.go

package nsqlookupd

import (

    "io"

    "net"

    "github.com/nsqio/nsq/internal/protocol"

)

type tcpServer struct {

    ctx *Context

}

func (p *tcpServer) Handle(clientConn net.Conn) {

    p.ctx.nsqlookupd.logf("TCP: new client(%s)", clientConn.RemoteAddr())

    // The client should initialize itself by sending a 4 byte sequence indicating

    // the version of the protocol that it intends to communicate, this will allow us

    // to gracefully upgrade the protocol away from text/line oriented to whatever...

    buf := make([]byte, 4)

    _, err := io.ReadFull(clientConn, buf)

    if err != nil {

        p.ctx.nsqlookupd.logf("ERROR: failed to read protocol version - %s", err)

        return

    }

    protocolMagic := string(buf)

    p.ctx.nsqlookupd.logf("CLIENT(%s): desired protocol magic '%s'",

        clientConn.RemoteAddr(), protocolMagic)

    var prot protocol.Protocol

    switch protocolMagic {

    case "  V1":

        prot = &LookupProtocolV1{ctx: p.ctx}

    default:

        protocol.SendResponse(clientConn, []byte("E_BAD_PROTOCOL"))

        clientConn.Close()

        p.ctx.nsqlookupd.logf("ERROR: client(%s) bad protocol magic '%s'",

            clientConn.RemoteAddr(), protocolMagic)

        return

    }

    err = prot.IOLoop(clientConn)

    if err != nil {

        p.ctx.nsqlookupd.logf("ERROR: client(%s) - %s", clientConn.RemoteAddr(), err)

        return

    }

}