lib/relay/client: Stricter typing and remove unused code (#7819)

lib/relay/client/client.go

@@ -11,58 +11,43 @@ import (
 
 	"github.com/syncthing/syncthing/lib/relay/protocol"
 	"github.com/syncthing/syncthing/lib/svcutil"
-	"github.com/syncthing/syncthing/lib/sync"
 
 	"github.com/thejerf/suture/v4"
 )
 
-type relayClientFactory func(uri *url.URL, certs []tls.Certificate, invitations chan protocol.SessionInvitation, timeout time.Duration) RelayClient
-
-var (
-	supportedSchemes = map[string]relayClientFactory{
-		"relay":         newStaticClient,
-		"dynamic+http":  newDynamicClient,
-		"dynamic+https": newDynamicClient,
-	}
-)
-
 type RelayClient interface {
 	suture.Service
 	Error() error
-	Latency() time.Duration
 	String() string
-	Invitations() chan protocol.SessionInvitation
+	Invitations() <-chan protocol.SessionInvitation
 	URI() *url.URL
 }
 
 func NewClient(uri *url.URL, certs []tls.Certificate, timeout time.Duration) (RelayClient, error) {
-	factory, ok := supportedSchemes[uri.Scheme]
-	if !ok {
+	invitations := make(chan protocol.SessionInvitation)
+
+	switch uri.Scheme {
+	case "relay":
+		return newStaticClient(uri, certs, invitations, timeout), nil
+	case "dynamic+http", "dynamic+https":
+		return newDynamicClient(uri, certs, invitations, timeout), nil
+	default:
 		return nil, fmt.Errorf("unsupported scheme: %s", uri.Scheme)
 	}
-
-	invitations := make(chan protocol.SessionInvitation)
-	return factory(uri, certs, invitations, timeout), nil
 }
 
 type commonClient struct {
 	svcutil.ServiceWithError
-
 	invitations chan protocol.SessionInvitation
-	mut         sync.RWMutex
 }
 
 func newCommonClient(invitations chan protocol.SessionInvitation, serve func(context.Context) error, creator string) commonClient {
-	c := commonClient{
-		invitations: invitations,
-		mut:         sync.NewRWMutex(),
+	return commonClient{
+		ServiceWithError: svcutil.AsService(serve, creator),
+		invitations:      invitations,
 	}
-	c.ServiceWithError = svcutil.AsService(serve, creator)
-	return c
 }
 
-func (c *commonClient) Invitations() chan protocol.SessionInvitation {
-	c.mut.RLock()
-	defer c.mut.RUnlock()
+func (c *commonClient) Invitations() <-chan protocol.SessionInvitation {
 	return c.invitations
 }

lib/relay/client/dynamic.go

@@ -11,6 +11,7 @@ import (
 	"net/http"
 	"net/url"
 	"sort"
+	"sync"
 	"time"
 
 	"github.com/syncthing/syncthing/lib/osutil"
@@ -25,10 +26,11 @@ type dynamicClient struct {
 	certs    []tls.Certificate
 	timeout  time.Duration
 
-	client RelayClient
+	mut    sync.RWMutex // Protects client.
+	client *staticClient
 }
 
-func newDynamicClient(uri *url.URL, certs []tls.Certificate, invitations chan protocol.SessionInvitation, timeout time.Duration) RelayClient {
+func newDynamicClient(uri *url.URL, certs []tls.Certificate, invitations chan protocol.SessionInvitation, timeout time.Duration) *dynamicClient {
 	c := &dynamicClient{
 		pooladdr: uri,
 		certs:    certs,
@@ -114,15 +116,6 @@ func (c *dynamicClient) Error() error {
 	return c.client.Error()
 }
 
-func (c *dynamicClient) Latency() time.Duration {
-	c.mut.RLock()
-	defer c.mut.RUnlock()
-	if c.client == nil {
-		return time.Hour
-	}
-	return c.client.Latency()
-}
-
 func (c *dynamicClient) String() string {
 	return fmt.Sprintf("DynamicClient:%p:%s@%s", c, c.URI(), c.pooladdr)
 }

lib/relay/client/static.go

@@ -28,12 +28,9 @@ type staticClient struct {
 	connectTimeout time.Duration
 
 	conn *tls.Conn
-
-	connected bool
-	latency   time.Duration
 }
 
-func newStaticClient(uri *url.URL, certs []tls.Certificate, invitations chan protocol.SessionInvitation, timeout time.Duration) RelayClient {
+func newStaticClient(uri *url.URL, certs []tls.Certificate, invitations chan protocol.SessionInvitation, timeout time.Duration) *staticClient {
 	c := &staticClient{
 		uri: uri,
 
@@ -67,10 +64,6 @@ func (c *staticClient) serve(ctx context.Context) error {
 
 	l.Infof("Joined relay %s://%s", c.uri.Scheme, c.uri.Host)
 
-	c.mut.Lock()
-	c.connected = true
-	c.mut.Unlock()
-
 	messages := make(chan interface{})
 	errorsc := make(chan error, 1)
 
@@ -128,20 +121,6 @@ func (c *staticClient) serve(ctx context.Context) error {
 	}
 }
 
-func (c *staticClient) StatusOK() bool {
-	c.mut.RLock()
-	con := c.connected
-	c.mut.RUnlock()
-	return con
-}
-
-func (c *staticClient) Latency() time.Duration {
-	c.mut.RLock()
-	lat := c.latency
-	c.mut.RUnlock()
-	return lat
-}
-
 func (c *staticClient) String() string {
 	return fmt.Sprintf("StaticClient:%p@%s", c, c.URI())
 }
@@ -155,7 +134,6 @@ func (c *staticClient) connect(ctx context.Context) error {
 		return fmt.Errorf("unsupported relay scheme: %v", c.uri.Scheme)
 	}
 
-	t0 := time.Now()
 	timeoutCtx, cancel := context.WithTimeout(ctx, c.connectTimeout)
 	defer cancel()
 	tcpConn, err := dialer.DialContext(timeoutCtx, "tcp", c.uri.Host)
@@ -163,10 +141,6 @@ func (c *staticClient) connect(ctx context.Context) error {
 		return err
 	}
 
-	c.mut.Lock()
-	c.latency = time.Since(t0)
-	c.mut.Unlock()
-
 	conn := tls.Client(tcpConn, c.config)
 
 	if err := conn.SetDeadline(time.Now().Add(c.connectTimeout)); err != nil {
@@ -185,10 +159,6 @@ func (c *staticClient) connect(ctx context.Context) error {
 
 func (c *staticClient) disconnect() {
 	l.Debugln(c, "disconnecting")
-	c.mut.Lock()
-	c.connected = false
-	c.mut.Unlock()
-
 	c.conn.Close()
 }