feature: Refresh dashboards when entity files change. (#319)

* feature: Refresh dashboards when entities change

* feature: Refresh dashboards when entities change

* bugfix: Concurrency, lock around websocket write

OliveTin.proto

@@ -184,6 +184,7 @@ message GetReadyzResponse {
 	string status = 1;
 }
 
+message EventEntityChanged {}
 message EventConfigChanged {}
 message EventExecutionFinished {
 	LogEntry log_entry = 1;

cmd/OliveTin/main.go

@@ -144,6 +144,7 @@ func main() {
 	go onfileindir.WatchFilesInDirectory(cfg, executor)
 	go oncalendarfile.Schedule(cfg, executor)
 
+	entityfiles.AddListener(websocket.OnEntityChanged)
 	go entityfiles.SetupEntityFileWatchers(cfg)
 
 	go updatecheck.StartUpdateChecker(version, commit, cfg, cfg.GetDir())

internal/entityfiles/entityfiles.go

@@ -14,6 +14,15 @@ import (
 	"strings"
 )
 
+var (
+	EntityChangedSender chan bool
+	listeners           []func()
+)
+
+func AddListener(l func()) {
+	listeners = append(listeners, l)
+}
+
 func SetupEntityFileWatchers(cfg *config.Config) {
 	configDir := cfg.GetDir()
 
@@ -121,4 +130,8 @@ func updateEvmFromFile(entityname string, data []map[string]string) {
 			sv.Set(prefix+"."+k, v)
 		}
 	}
+
+	for _, l := range listeners {
+		l()
+	}
 }

internal/filehelper/file_change_notify.go

@@ -4,6 +4,19 @@ import (
 	"github.com/fsnotify/fsnotify"
 	log "github.com/sirupsen/logrus"
 	"path/filepath"
+	"time"
+)
+
+var (
+	debounceWriteLog map[string]time.Time
+)
+
+func init() {
+	debounceWriteLog = make(map[string]time.Time)
+}
+
+const (
+	debounceDelay = 300
 )
 
 type watchContext struct {
@@ -11,6 +24,7 @@ type watchContext struct {
 	filedir         string
 	callback        func(filename string)
 	interestedEvent fsnotify.Op
+	event           *fsnotify.Event
 }
 
 func WatchDirectoryCreate(fullpath string, callback func(filename string)) {
@@ -73,7 +87,9 @@ func watchPath(ctx *watchContext) {
 func processEvent(ctx *watchContext, watcher *fsnotify.Watcher) {
 	select {
 	case event, ok := <-watcher.Events:
-		if !consumeEvent(ok, ctx, &event) {
+		ctx.event = &event
+
+		if !consumeEvent(ok, ctx) {
 			return
 		}
 
@@ -84,26 +100,39 @@ func processEvent(ctx *watchContext, watcher *fsnotify.Watcher) {
 	}
 }
 
-func consumeEvent(ok bool, ctx *watchContext, event *fsnotify.Event) bool {
+func consumeEvent(ok bool, ctx *watchContext) bool {
 	if !ok {
 		return false
 	}
 
-	if ctx.filename != "" && filepath.Base(event.Name) != ctx.filename {
+	if ctx.filename != "" && filepath.Base(ctx.event.Name) != ctx.filename {
-		log.Tracef("fsnotify irreleventa event different file %+v", event)
+		log.Tracef("fsnotify irreleventa event different file %+v", ctx.event)
 		return true
 	}
 
-	consumeRelevantEvents(ctx, event)
+	consumeRelevantEvents(ctx)
 
 	return true
 }
 
-func consumeRelevantEvents(ctx *watchContext, event *fsnotify.Event) {
+func consumeRelevantEvents(ctx *watchContext) {
-	if event.Has(ctx.interestedEvent) {
+	if ctx.event.Has(ctx.interestedEvent) {
-		log.Debugf("fsnotify write event: %v", event)
+		log.Debugf("fsnotify write event: %v", ctx.event)
-		ctx.callback(event.Name)
+
+		processDebounce(ctx)
 	} else {
-		log.Debugf("fsnotify irrelevant event on file %v", event)
+		log.Debugf("fsnotify irrelevant event on file %v", ctx.event)
+	}
+}
+
+func processDebounce(ctx *watchContext) {
+	entry, found := debounceWriteLog[ctx.filename]
+
+	if !found || time.Since(entry) < debounceDelay {
+		debounceWriteLog[ctx.filename] = time.Now()
+
+		ctx.callback(ctx.event.Name)
+	} else {
+		log.Debugf("Supressing write event because it's within the debounce delay: %v", ctx.filename)
 	}
 }

internal/websocket/websocket.go

@@ -8,12 +8,17 @@ import (
 	"google.golang.org/protobuf/encoding/protojson"
 	"google.golang.org/protobuf/reflect/protoreflect"
 	"net/http"
+	"sync"
 )
 
 var upgrader = ws.Upgrader{
 	CheckOrigin: checkOriginPermissive,
 }
 
+var (
+	sendmutex = sync.Mutex{}
+)
+
 type WebsocketClient struct {
 	conn *ws.Conn
 }
@@ -44,6 +49,10 @@ func (WebsocketExecutionListener) OnExecutionStarted(title string) {
 	*/
 }
 
+func OnEntityChanged() {
+	broadcast(&pb.EventEntityChanged{})
+}
+
 /*
 The default checkOrigin function checks that the origin (browser) matches the
 request origin. However in OliveTin we expect many users to deliberately proxy
@@ -113,9 +122,11 @@ func broadcast(pbmsg protoreflect.ProtoMessage) {
 	hackyMessage = append(hackyMessage, []byte("}")...)
 	// </EVIL>
 
+	sendmutex.Lock()
 	for _, client := range clients {
 		client.conn.WriteMessage(ws.TextMessage, hackyMessage)
 	}
+	sendmutex.Unlock()
 }
 
 func (c *WebsocketClient) messageLoop() {

webui.dev/js/marshaller.js

@@ -14,6 +14,8 @@ export function initMarshaller () {
 
   window.initialHash = window.location.hash
 
+  window.currentSection = ''
+
   window.addEventListener('EventExecutionFinished', onExecutionFinished)
 }
 
@@ -99,6 +101,8 @@ function onExecutionFinished (evt) {
 function showSection (title) {
   title = title.replaceAll(' ', '')
 
+  window.currentSection = title
+
   for (const section of document.querySelectorAll('section')) {
     if (section.title === title) {
       section.style.display = 'block'
@@ -213,7 +217,9 @@ function marshalDashboardStructureToHtml (json) {
     }
   }
 
-  if (window.initialHash !== '' && document.body.getAttribute('initial-marshal-complete') === null) {
+  if (window.currentSection !== '') {
+    showSection(window.currentSection)
+  } else if (window.initialHash !== '' && document.body.getAttribute('initial-marshal-complete') === null) {
     showSection(window.initialHash.replace('#', ''))
   } else {
     if (rootGroup.querySelectorAll('action-button').length === 0 && json.dashboards.length > 0) {

webui.dev/js/websocket.js

@@ -42,10 +42,11 @@ function websocketOnMessage (msg) {
   switch (j.type) {
     case 'EventConfigChanged':
     case 'EventExecutionFinished':
+    case 'EventEntityChanged':
       window.dispatchEvent(e)
       break
     default:
-      window.showBigError('Unknown message type from server: ' + j.type)
+      window.showBigError('ws-unhandled-message', 'handling websocket message', 'Unhandled websocket message type from server: ' + j.type, true)
   }
 }