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

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() {