cmd/syncthing, lib/events, lib/sync: Add timeout to REST event API, remove Ping (fixes #3933)

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3941

cmd/syncthing/auditservice_test.go

@@ -20,13 +20,13 @@ func TestAuditService(t *testing.T) {
 	service := newAuditService(buf)
 
 	// Event sent before start, will not be logged
-	events.Default.Log(events.Ping, "the first event")
+	events.Default.Log(events.ConfigSaved, "the first event")
 
 	go service.Serve()
 	service.WaitForStart()
 
 	// Event that should end up in the audit log
-	events.Default.Log(events.Ping, "the second event")
+	events.Default.Log(events.ConfigSaved, "the second event")
 
 	// We need to give the events time to arrive, since the channels are buffered etc.
 	time.Sleep(10 * time.Millisecond)
@@ -35,7 +35,7 @@ func TestAuditService(t *testing.T) {
 	service.WaitForStop()
 
 	// This event should not be logged, since we have stopped.
-	events.Default.Log(events.Ping, "the third event")
+	events.Default.Log(events.ConfigSaved, "the third event")
 
 	result := string(buf.Bytes())
 	t.Log(result)

cmd/syncthing/gui.go

@@ -233,8 +233,8 @@ func (s *apiService) Serve() {
 	getRestMux.HandleFunc("/rest/db/need", s.getDBNeed)                          // folder [perpage] [page]
 	getRestMux.HandleFunc("/rest/db/status", s.getDBStatus)                      // folder
 	getRestMux.HandleFunc("/rest/db/browse", s.getDBBrowse)                      // folder [prefix] [dirsonly] [levels]
-	getRestMux.HandleFunc("/rest/events", s.getIndexEvents)                      // since [limit]
-	getRestMux.HandleFunc("/rest/events/disk", s.getDiskEvents)                  // since [limit]
+	getRestMux.HandleFunc("/rest/events", s.getIndexEvents)                      // since [limit] [timeout]
+	getRestMux.HandleFunc("/rest/events/disk", s.getDiskEvents)                  // since [limit] [timeout]
 	getRestMux.HandleFunc("/rest/stats/device", s.getDeviceStats)                // -
 	getRestMux.HandleFunc("/rest/stats/folder", s.getFolderStats)                // -
 	getRestMux.HandleFunc("/rest/svc/deviceid", s.getDeviceID)                   // id
@@ -1019,9 +1019,15 @@ func (s *apiService) getEvents(w http.ResponseWriter, r *http.Request, eventSub
 	qs := r.URL.Query()
 	sinceStr := qs.Get("since")
 	limitStr := qs.Get("limit")
+	timeoutStr := qs.Get("timeout")
 	since, _ := strconv.Atoi(sinceStr)
 	limit, _ := strconv.Atoi(limitStr)
 
+	timeout := defaultEventTimeout
+	if timeoutSec, timeoutErr := strconv.Atoi(timeoutStr); timeoutErr == nil && timeoutSec >= 0 { // 0 is a valid timeout
+		timeout = time.Duration(timeoutSec) * time.Second
+	}
+
 	// Flush before blocking, to indicate that we've received the request and
 	// that it should not be retried. Must set Content-Type header before
 	// flushing.
@@ -1029,7 +1035,8 @@ func (s *apiService) getEvents(w http.ResponseWriter, r *http.Request, eventSub
 	f := w.(http.Flusher)
 	f.Flush()
 
-	evs := eventSub.Since(since, nil)
+	// If there are no events available return an empty slice, as this gets serialized as `[]`
+	evs := eventSub.Since(since, []events.Event{}, timeout)
 	if 0 < limit && limit < len(evs) {
 		evs = evs[len(evs)-limit:]
 	}

cmd/syncthing/main.go

@@ -79,7 +79,7 @@ const (
 	tlsDefaultCommonName = "syncthing"
 	httpsRSABits         = 2048
 	bepRSABits           = 0 // 384 bit ECDSA used instead
-	pingEventInterval    = time.Minute
+	defaultEventTimeout  = time.Minute
 	maxSystemErrors      = 5
 	initialSystemLog     = 10
 	maxSystemLog         = 250
@@ -594,7 +594,7 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 	// events. The LocalChangeDetected event might overwhelm the event
 	// receiver in some situations so we will not subscribe to it here.
 	apiSub := events.NewBufferedSubscription(events.Default.Subscribe(events.AllEvents&^events.LocalChangeDetected&^events.RemoteChangeDetected), 1000)
-	diskSub := events.NewBufferedSubscription(events.Default.Subscribe(events.LocalChangeDetected|events.RemoteChangeDetected|events.Ping), 1000)
+	diskSub := events.NewBufferedSubscription(events.Default.Subscribe(events.LocalChangeDetected|events.RemoteChangeDetected), 1000)
 
 	if len(os.Getenv("GOMAXPROCS")) == 0 {
 		runtime.GOMAXPROCS(runtime.NumCPU())
@@ -877,7 +877,6 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 	events.Default.Log(events.StartupComplete, map[string]string{
 		"myID": myID.String(),
 	})
-	go generatePingEvents()
 
 	cleanConfigDirectory()
 
@@ -1091,13 +1090,6 @@ func defaultConfig(myName string) config.Configuration {
 	return newCfg
 }
 
-func generatePingEvents() {
-	for {
-		time.Sleep(pingEventInterval)
-		events.Default.Log(events.Ping, nil)
-	}
-}
-
 func resetDB() error {
 	return os.RemoveAll(locations[locDatabase])
 }

cmd/syncthing/mocked_events_test.go

@@ -6,10 +6,14 @@
 
 package main
 
-import "github.com/syncthing/syncthing/lib/events"
+import (
+	"time"
+
+	"github.com/syncthing/syncthing/lib/events"
+)
 
 type mockedEventSub struct{}
 
-func (s *mockedEventSub) Since(id int, into []events.Event) []events.Event {
+func (s *mockedEventSub) Since(id int, into []events.Event, timeout time.Duration) []events.Event {
 	select {}
 }

cmd/syncthing/summaryservice.go

@@ -169,7 +169,7 @@ func (c *folderSummaryService) foldersToHandle() []string {
 	c.lastEventReqMut.Lock()
 	last := c.lastEventReq
 	c.lastEventReqMut.Unlock()
-	if time.Since(last) > pingEventInterval {
+	if time.Since(last) > defaultEventTimeout {
 		return nil
 	}
 

cmd/syncthing/verboseservice.go

@@ -66,7 +66,7 @@ func (s *verboseService) WaitForStart() {
 
 func (s *verboseService) formatEvent(ev events.Event) string {
 	switch ev.Type {
-	case events.Ping, events.DownloadProgress, events.LocalIndexUpdated:
+	case events.DownloadProgress, events.LocalIndexUpdated:
 		// Skip
 		return ""