// Reads a device ID change or message delivery request from the service. If
// an error occurs or the socket is closed, the connection will be removed
// from the router.
func readServiceRequest(c *serviceConn) (serviceState, error) {
for ok := true; ok; {
var request Request
headerBytes, err := c.readWriter.Peek(2)
if err != nil {
return nil, err
}
switch common.Header(binary.BigEndian.Uint16(headerBytes)) {
// Message delivery request from service.
case HeaderServiceDeliver:
request = <-c.recycleChan
// Device ID change request from service.
case HeaderServiceDeviceChange:
request = new(DeviceChangeRequest)
// Invalid request packet sent by service.
default:
ok = false
continue
}
// Read and forward the request to the router.
if _, err := request.ReadServiceRequest(c.readWriter); err != nil {
return nil, err
}
c.Requests() <- request
}
return nil, nil
}
// Reads a message delivery or device change ACK from the service socket.
// This is a terminal state. If an error occurs or the socket is closed
// (unblocking `Read()` and `Peek()` with an `io.EOF`), the connection
// will be removed from the router.
func readServiceReply(conn *serviceConn) (next serviceState, err error) {
defer conn.Router.RemoveServiceConn(conn, conn.service)
for ok := true; ok; {
var reply Reply
headerBytes, err := conn.readWriter.Peek(2)
if err != nil {
return nil, err
}
switch common.Header(binary.BigEndian.Uint16(headerBytes)) {
// Message delivery ACK from service.
case HeaderServiceDeliver:
reply = new(DeliverReply)
// Device ID change ACK from service.
case HeaderServiceDeviceChange:
reply = new(DeviceChangeReply)
// Invalid command sent by service.
default:
ok = false
continue
}
// Read the reply and forward to the router. The router will
// forward the ACK to the CN.
if _, err = reply.ReadServiceReply(conn.readWriter); err != nil {
return nil, err
}
conn.Replies() <- reply
}
return nil, nil
}
// Reads a device connection status change, device ID change ACK, or message
// delivery ACK from the CN. If an error occurs or the socket is closed, the
// connection will be removed from the router.
func readNodeUpdate(c *nodeConn) (nodeState, error) {
defer c.Router.RemoveNodeConn(c)
for ok := true; ok; {
var reply Reply
headerBytes, err := c.readWriter.Peek(2)
if err != nil {
return nil, err
}
switch common.Header(binary.BigEndian.Uint16(headerBytes)) {
// Device connection status change from CN.
case HeaderNodeConnChange:
request := new(ConnChange)
if _, err := request.ReadNodeRequest(c.readWriter); err != nil {
return nil, err
}
c.Router.SetConnStatus(request)
continue
// Device ID change ACK from CN.
case HeaderNodeDeviceChange:
reply = new(DeviceChangeReply)
// Message delivery ACK from CN.
case HeaderNodeDeliver:
reply = new(DeliverReply)
// Invalid packet sent by CN.
default:
ok = false
continue
}
// Read and forward the ACK to the router.
if _, err := reply.ReadNodeReply(c.readWriter); err != nil {
return nil, err
}
c.Replies() <- reply
}
return nil, nil
}
func readNodeRequest(conn *nodeConn) (next nodeState, err error) {
defer conn.Router.RemoveNodeConn(conn)
for ok := true; ok; {
var request Request
headerBytes, err := conn.readWriter.Peek(2)
if err != nil {
return nil, err
}
switch common.Header(binary.BigEndian.Uint16(headerBytes)) {
// Message delivery request from CN.
case HeaderNodeDeliver:
request = <-conn.recycleChan
// Device ID change request from CN.
case HeaderNodeDeviceChange:
request = &DeviceChangeRequest{
ConnId: conn.Id(),
}
// Invalid packet sent by CN.
default:
ok = false
continue
}
// Read the request and forward to the router. The router will forward
// the message to the correct service.
if _, err = request.ReadNodeRequest(conn.readWriter); err != nil {
request.Recycle()
return nil, err
}
conn.Requests() <- request
}
return nil, nil
}