/
server.go
221 lines (190 loc) · 6.54 KB
/
server.go
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package server
import (
"context"
"net/http"
"strings"
"time"
webSocket "github.com/Dharitri-org/drtg-communication/websocket"
"github.com/Dharitri-org/drtg-communication/websocket/connection"
"github.com/Dharitri-org/drtg-communication/websocket/data"
"github.com/Dharitri-org/drtg-communication/websocket/transceiver"
"github.com/Dharitri-org/drtg-core/core"
"github.com/Dharitri-org/drtg-core/core/check"
"github.com/gorilla/mux"
"github.com/gorilla/websocket"
)
// ArgsWebSocketServer holds all the components needed to create a server
type ArgsWebSocketServer struct {
RetryDurationInSeconds int
AckTimeoutInSeconds int
BlockingAckOnError bool
WithAcknowledge bool
DropMessagesIfNoConnection bool
URL string
PayloadConverter webSocket.PayloadConverter
Log core.Logger
PayloadVersion uint32
}
type server struct {
blockingAckOnError bool
withAcknowledge bool
dropMessagesIfNoConnection bool
ackTimeoutInSec int
payloadConverter webSocket.PayloadConverter
retryDuration time.Duration
log core.Logger
httpServer webSocket.HttpServerHandler
transceiversAndConn transceiversAndConnHandler
payloadHandler webSocket.PayloadHandler
payloadVersion uint32
}
// NewWebSocketServer will create a new instance of server
func NewWebSocketServer(args ArgsWebSocketServer) (*server, error) {
if err := checkArgs(args); err != nil {
return nil, err
}
wsServer := &server{
transceiversAndConn: newTransceiversAndConnHolder(),
blockingAckOnError: args.BlockingAckOnError,
log: args.Log,
retryDuration: time.Duration(args.RetryDurationInSeconds) * time.Second,
payloadConverter: args.PayloadConverter,
payloadHandler: webSocket.NewNilPayloadHandler(),
withAcknowledge: args.WithAcknowledge,
dropMessagesIfNoConnection: args.DropMessagesIfNoConnection,
ackTimeoutInSec: args.AckTimeoutInSeconds,
payloadVersion: args.PayloadVersion,
}
wsServer.initializeServer(args.URL, data.WSRoute)
return wsServer, nil
}
func checkArgs(args ArgsWebSocketServer) error {
if check.IfNil(args.Log) {
return core.ErrNilLogger
}
if check.IfNil(args.PayloadConverter) {
return data.ErrNilPayloadConverter
}
if args.URL == "" {
return data.ErrEmptyUrl
}
if args.RetryDurationInSeconds == 0 {
return data.ErrZeroValueRetryDuration
}
return nil
}
func (s *server) connectionHandler(connection webSocket.WSConClient) {
webSocketTransceiver, err := transceiver.NewTransceiver(transceiver.ArgsTransceiver{
PayloadConverter: s.payloadConverter,
Log: s.log,
RetryDurationInSec: int(s.retryDuration.Seconds()),
AckTimeoutInSec: s.ackTimeoutInSec,
BlockingAckOnError: s.blockingAckOnError,
WithAcknowledge: s.withAcknowledge,
PayloadVersion: s.payloadVersion,
})
if err != nil {
s.log.Warn("s.connectionHandler cannot create transceiver", "error", err)
return
}
err = webSocketTransceiver.SetPayloadHandler(s.payloadHandler)
if err != nil {
s.log.Warn("s.SetPayloadHandler cannot set payload handler", "error", err)
}
go func() {
s.transceiversAndConn.addTransceiverAndConn(webSocketTransceiver, connection)
// this method is blocking
_ = webSocketTransceiver.Listen(connection)
s.log.Info("connection closed", "client id", connection.GetID())
// if method listen will end, the client was disconnected, and we should remove the listener from the list
s.transceiversAndConn.remove(connection.GetID())
}()
}
func (s *server) initializeServer(wsURL string, wsPath string) {
router := mux.NewRouter()
httpServer := &http.Server{
Addr: wsURL,
Handler: router,
}
upgrader := websocket.Upgrader{
ReadBufferSize: 1024,
WriteBufferSize: 1024,
}
s.log.Info("wsServer.initializeServer(): initializing WebSocket server", "url", wsURL, "path", wsPath)
addClientFunc := func(writer http.ResponseWriter, r *http.Request) {
s.log.Info("new connection", "route", wsPath, "remote address", r.RemoteAddr)
upgrader.CheckOrigin = func(r *http.Request) bool { return true }
ws, errUpgrade := upgrader.Upgrade(writer, r, nil)
if errUpgrade != nil {
s.log.Warn("could not update websocket connection", "remote address", r.RemoteAddr, "error", errUpgrade)
return
}
client := connection.NewWSConnClientWithConn(ws)
s.connectionHandler(client)
}
routeSendData := router.HandleFunc(wsPath, addClientFunc)
if routeSendData.GetError() != nil {
s.log.Error("sender router failed to handle send data",
"route", routeSendData.GetName(),
"error", routeSendData.GetError())
}
s.httpServer = httpServer
s.start()
}
// Send will send the provided payload from args
func (s *server) Send(payload []byte, topic string) error {
transceiversAndCon := s.transceiversAndConn.getAll()
noClients := len(transceiversAndCon) == 0
if noClients && !s.dropMessagesIfNoConnection {
return data.ErrNoClientsConnected
}
for _, tuple := range transceiversAndCon {
err := tuple.transceiver.Send(payload, topic, tuple.conn)
if err != nil {
s.log.Debug("s.Send() cannot send message", "id", tuple.conn.GetID(), "error", err.Error())
}
}
return nil
}
func (s *server) start() {
go func() {
err := s.httpServer.ListenAndServe()
shouldLogError := err != nil && !strings.Contains(err.Error(), data.ErrServerIsClosed.Error())
if shouldLogError {
s.log.Error("could not initialize webserver", "error", err)
return
}
s.log.Info("server was closed")
}()
}
// SetPayloadHandler will set the provided payload handler
func (s *server) SetPayloadHandler(handler webSocket.PayloadHandler) error {
s.payloadHandler = handler
return nil
}
// Close will close the server
func (s *server) Close() error {
var lastError error
err := s.httpServer.Shutdown(context.Background())
if err != nil {
s.log.Debug("server.Close() cannot close http server", "error", err)
lastError = err
}
for _, tuple := range s.transceiversAndConn.getAll() {
err = tuple.transceiver.Close()
if err != nil {
s.log.Debug("server.Close() cannot close transceiver", "error", err)
lastError = err
}
err = tuple.conn.Close()
if err != nil {
s.log.Debug("server.Close() cannot close connection", "id", tuple.conn.GetID(), "error", err.Error())
lastError = err
}
}
return lastError
}
// IsInterfaceNil returns true if there is no value under the interface
func (s *server) IsInterfaceNil() bool {
return s == nil
}