A TCP Server Framework with graceful shutdown,custom protocol.
Before create server and client, you need define the protocol format first.
// Packet is the unit of data.typePacketinterface{fmt.Stringer } // Protocol use to pack/unpack Packet.typeProtocolinterface{// return the size need for pack the Packet.PackSize(pPacket) int// PackTo pack the Packet to w.// The return value n is the number of bytes written;// Any error encountered during the write is also returned.PackTo(pPacket, w io.Writer) (int, error) // Pack pack the Packet to new created buf.Pack(pPacket) ([]byte, error) // try to unpack the buf to Packet. If return len > 0, then buf[:len] will be discard.// The following return conditions must be implement:// (nil, 0, nil) : buf size not enough for unpack one Packet.// (nil, len, err) : buf size enough but error encountered.// (p, len, nil) : unpack succeed.Unpack(buf []byte) (Packet, int, error) }funcSetLogger(lLogger)Note: xtcp will not output any log by default unless you implement your own logger.
In xtcp, there are some events to notify the state of net conn, you can handle them according your need:
const ( // EventAccept mean server accept a new connect.EventAcceptEventType=iota// EventConnected mean client connected to a server.EventConnected// EventRecv mean conn recv a packet.EventRecv// EventClosed mean conn is closed.EventClosed )To handle the event, just implement the OnEvent interface.
// Handler is the event callback.// p will be nil when event is EventAccept/EventConnected/EventClosedtypeHandlerinterface{OnEvent(etEventType, c*Conn, pPacket) }// 1. create protocol and handler.// ...// 2. create opts.opts:=xtcp.NewOpts(handler, protocol) // 3. create server.server:=xtcp.NewServer(opts) // 4. start.goserver.ListenAndServe("addr")// 1. create protocol and handler.// ...// 2. create opts.opts:=xtcp.NewOpts(handler, protocol) // 3. create client.client:=NewConn(opts) // 4. startgoclient.DialAndServe("addr")To send data, just call the 'Send' function of Conn. You can safe call it in any goroutines.
func (c*Conn) Send(buf []byte) errorTo recv a packet, implement your handler function:
func (h*myhandler) OnEvent(etEventType, c*Conn, pPacket){switchet{caseEventRecv: ... } }xtcp have three stop modes, stop gracefully mean conn will stop until all cached data sended.
// StopMode define the stop mode of server and conn.typeStopModeuint8const ( // StopImmediately mean stop directly, the cached data maybe will not send.StopImmediatelyStopMode=iota// StopGracefullyButNotWait stop and flush cached data.StopGracefullyButNotWait// StopGracefullyAndWait stop and block until cached data sended.StopGracefullyAndWait )The example define a protocol format which use protobuf inner. You can see how to define the protocol and how to create server and client.
