Add API client lib

api/client/websocket.go

@@ -0,0 +1,121 @@
+package client
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/Safing/portbase/log"
+	"github.com/tevino/abool"
+
+	"github.com/gorilla/websocket"
+)
+
+type wsState struct {
+	wsConn     *websocket.Conn
+	wg         sync.WaitGroup
+	failing    *abool.AtomicBool
+	failSignal chan struct{}
+}
+
+func (c *Client) wsConnect() error {
+	state := &wsState{
+		failing:    abool.NewBool(false),
+		failSignal: make(chan struct{}),
+	}
+
+	var err error
+	state.wsConn, _, err = websocket.DefaultDialer.Dial(fmt.Sprintf("ws://%s/api/database/v1", c.server), nil)
+	if err != nil {
+		return err
+	}
+
+	c.signalOnline()
+
+	state.wg.Add(2)
+	go c.wsReader(state)
+	go c.wsWriter(state)
+
+	// wait for end of connection
+	select {
+	case <-state.failSignal:
+	case <-c.shutdownSignal:
+		state.Error("")
+	}
+	state.wsConn.Close()
+	state.wg.Wait()
+
+	return nil
+}
+
+func (c *Client) wsReader(state *wsState) {
+	defer state.wg.Done()
+	for {
+		_, data, err := state.wsConn.ReadMessage()
+		log.Tracef("client: read message")
+		if err != nil {
+			if !websocket.IsCloseError(err, websocket.CloseNormalClosure, websocket.CloseGoingAway) {
+				state.Error(fmt.Sprintf("client: read error: %s", err))
+			} else {
+				state.Error("client: connection closed by server")
+			}
+			return
+		}
+		log.Tracef("client: received message: %s", string(data))
+		m, err := ParseMessage(data)
+		if err != nil {
+			log.Warningf("client: failed to parse message: %s", err)
+		} else {
+			select {
+			case c.recv <- m:
+			case <-state.failSignal:
+				return
+			}
+		}
+	}
+}
+
+func (c *Client) wsWriter(state *wsState) {
+	defer state.wg.Done()
+	for {
+		select {
+		case <-state.failSignal:
+			return
+		case m := <-c.resend:
+			data, err := m.Pack()
+			if err == nil {
+				err = state.wsConn.WriteMessage(websocket.BinaryMessage, data)
+			}
+			if err != nil {
+				state.Error(fmt.Sprintf("client: write error: %s", err))
+				return
+			}
+			log.Tracef("client: sent message: %s", string(data))
+			if m.sent != nil {
+				m.sent.Set()
+			}
+		case m := <-c.send:
+			data, err := m.Pack()
+			if err == nil {
+				err = state.wsConn.WriteMessage(websocket.BinaryMessage, data)
+			}
+			if err != nil {
+				c.resend <- m
+				state.Error(fmt.Sprintf("client: write error: %s", err))
+				return
+			}
+			log.Tracef("client: sent message: %s", string(data))
+			if m.sent != nil {
+				m.sent.Set()
+			}
+		}
+	}
+}
+
+func (state *wsState) Error(message string) {
+	if state.failing.SetToIf(false, true) {
+		close(state.failSignal)
+		if message != "" {
+			log.Warning(message)
+		}
+	}
+}