separate package for com port wrappers

comwrapper/comport.go

@@ -0,0 +1,61 @@
+// Examples of using RS-232/Virtual-Serial over USB
+// as the transport layer for the protocol.
+
+package comwrapper
+
+import (
+ "github.com/RoanBrand/SerialToTCPBridgeProtocol/protocol"
+ "github.com/tarm/serial"
+ "log"
+ "net"
+ "time"
+)
+
+// Connect to a address on a tcp network, using a protocol Client.
+// We connect to a Gateway over a serial connection first.
+func Dial(portName string, baudRate int, address string) (net.Conn, error) {
+ p, err := serial.OpenPort(&serial.Config{Name: portName, Baud: baudRate})
+ if err != nil {
+ return nil, err
+ }
+ return protocol.Dial(p, address)
+}
+
+// A Protocol Gateway listening on a COM port.
+type comGateway struct {
+ protocol.Gateway
+ ComConfig *serial.Config
+}
+
+func NewComPortGateway(portName string, baudRate int) *comGateway {
+ return &comGateway{
+ ComConfig: &serial.Config{Name: portName, Baud: baudRate},
+ }
+}
+
+// Start Gateway on a COM port interface to service single protocol Client.
+func (com *comGateway) ListenAndServe() {
+ for {
+ var port *serial.Port
+ firstTryDone := false
+ // Attempt to open the COM port on the system.
+ for {
+ p, err := serial.OpenPort(com.ComConfig)
+ if err == nil {
+ port = p
+ break
+ }
+ if !firstTryDone {
+ log.Printf("Gateway @ '%s': Error opening COM port -> %v\nRetrying every 5s..\n", com.ComConfig.Name, err)
+ firstTryDone = true
+ }
+ time.Sleep(time.Second * 5)
+ }
+
+ // Open success.
+ log.Printf("Gateway @ '%s': Started service.\n", com.ComConfig.Name)
+ com.Listen(port)
+ log.Printf("Gateway @ '%s': Fatal error. Closing COM port\n", com.ComConfig.Name)
+ time.Sleep(time.Second * 2)
+ }
+}

example.go

@@ -2,7 +2,7 @@ package main
 
 import (
  "encoding/json"
- "github.com/RoanBrand/SerialToTCPBridgeProtocol/protocol"
+ "github.com/RoanBrand/SerialToTCPBridgeProtocol/comwrapper"
  "log"
  "os"
  "sync"
@@ -21,14 +21,15 @@ func main() {
  for _, v := range c.Gateways {
  w.Add(1)
  go func(v gatewayConfig) {
- com := protocol.NewComGateway(v.COMPortName, v.COMBaudRate)
- com.ServeCOM()
+ com := comwrapper.NewComPortGateway(v.COMPortName, v.COMBaudRate)
+ com.ListenAndServe()
  w.Done()
  }(v)
  }
  w.Wait()
 }
 
+// Configuration by json file.
 type gatewayConfig struct {
  GatewayName string `json:"gateway name"`
  COMPortName string `json:"comport name"`

protocol/protocolGateway.go → protocol/gateway.go

@@ -8,13 +8,13 @@ import (
 )
 
 // Implementation of the Protocol Gateway.
-type gateway struct {
+type Gateway struct {
  protocolTransport // Connection between Protocol Gateway & Client.
  uStream net.Conn // Upstream connection to tcp Server.
 }
 
 // Initialize downstream RX and listen for a protocol Client.
-func (g *gateway) Listen(ds serialInterface) {
+func (g *Gateway) Listen(ds serialInterface) {
  g.com = ds
  g.rxBuff = make(chan byte, 512)
  g.acknowledgeEvent = make(chan bool)
@@ -27,7 +27,7 @@ func (g *gateway) Listen(ds serialInterface) {
 }
 
 // Packet RX done. Handle it.
-func (g *gateway) handleRxPacket(packet *Packet) {
+func (g *Gateway) handleRxPacket(packet *Packet) {
  switch packet.command & 0x0F {
  case publish:
  // Payload from serial client
@@ -100,7 +100,7 @@ func (g *gateway) handleRxPacket(packet *Packet) {
 }
 
 // End link session between upstream server and downstream client.
-func (g *gateway) dropLink() {
+func (g *Gateway) dropLink() {
  if g.uStream != nil {
  g.uStream.Close()
  }
@@ -112,7 +112,7 @@ func (g *gateway) dropLink() {
 }
 
 // Stop activity and release downstream interface.
-func (g *gateway) dropGateway() {
+func (g *Gateway) dropGateway() {
  g.dropLink()
  g.com.Close()
  close(g.rxBuff)

protocol/protocol_internal_test.go → protocol/protocol_test.go

@@ -1,7 +1,8 @@
-package protocol
+package protocol_test
 
 import (
  "bytes"
+ "github.com/RoanBrand/SerialToTCPBridgeProtocol/protocol"
  "github.com/RoanBrand/goBuffers"
  "io"
  "net"
@@ -23,12 +24,12 @@ func TestEcho(t *testing.T) {
 
  // start protocol gateway server
  serialTransport := NewFakeTransport()
- gateway := gateway{}
+ gateway := protocol.Gateway{}
  go gateway.Listen(&fakeTransportServerInterface{serialTransport})
  t.Log("Protocol Gateway started")
 
  // start protocol client
- endClient, err := Dial(&fakeTransportClientInterface{serialTransport}, "127.0.0.1:"+strconv.Itoa(PORT))
+ endClient, err := protocol.Dial(&fakeTransportClientInterface{serialTransport}, "127.0.0.1:"+strconv.Itoa(PORT))
  if err != nil {
  t.Fatalf("Protocol client unable to connect to gateway: %v", err)
  }