fix(sync): prevent duplicate pushes

Document changes trigger awareness updates.
Wait before sending them in a push request so they can be combined.

Also make use of prosemirrors transactions to detect own changes
instead of listening to yjs updates.

Signed-off-by: Max <max@nextcloud.com>

src/components/Editor.vue

@@ -321,7 +321,6 @@ export default {
 	},
 	created() {
 		this.$ydoc = new Doc()
-		this.$ydoc.on('update', this.onYjsUpdate)
 		this.$providers = []
 		this.$editor = null
 		this.$syncService = null
@@ -508,7 +507,6 @@ export default {
 											: (session?.guestName || t('text', 'Guest')),
 										color: session?.color,
 										clientId: this.$ydoc.clientID,
-										lastUpdate: Date.now(),
 									},
 								}),
 								Keymap.configure({
@@ -644,13 +642,6 @@ export default {
 			this.emit('delete-image-node', imageUrl)
 		},
 
-		onYjsUpdate(_update, origin) {
-			if (origin.key === 'y-sync$') {
-				// Update timestamp of own cursor
-				this.$editor.commands.updateSelf()
-			}
-		},
-
 		async close() {
 			if (this.currentSession && this.$syncService) {
 				try {

src/extensions/CollaborationCursor.js

@@ -20,6 +20,13 @@ function showCursorLabel(clientId) {
 	}, 50)
 }
 
+/**
+ * Unix timestamp in seconds.
+ */
+function getTimestamp() {
+	return Math.floor(Date.now() / 1000)
+}
+
 const CollaborationCursor = TiptapCollaborationCursor.extend({
 	addOptions() {
 		return {
@@ -28,7 +35,7 @@ const CollaborationCursor = TiptapCollaborationCursor.extend({
 				name: null,
 				clientId: null,
 				color: null,
-				lastUpdate: null,
+				lastUpdate: getTimestamp(),
 			},
 			render: user => {
 				const cursor = document.createElement('span')
@@ -61,13 +68,12 @@ const CollaborationCursor = TiptapCollaborationCursor.extend({
 		})
 	},
 
-	addCommands() {
-		return {
-			...this.parent(),
-			updateSelf: () => ({ editor }) => {
-				const attributes = { ...this.options.user, lastUpdate: Date.now() }
-				return editor.commands.updateUser(attributes)
-			},
+	// Flag own cursor as active on undoable changes to the document state
+	onTransaction({ transaction }) {
+		const { updated, meta } = transaction
+		if (updated && (meta.addToHistory ?? true) && !meta.pointer) {
+			this.options.user.lastUpdate = getTimestamp()
+			this.options.provider.awareness.setLocalStateField('user', this.options.user)
 		}
 	},
 })

src/services/SyncService.js

@@ -150,14 +150,10 @@ class SyncService {
 	}
 
 	sendSteps(getSendable) {
-		// If already retrying, do nothing.
+		// If already waiting to send, do nothing.
 		if (this.#sendIntervalId) {
 			return
 		}
-		if (this.connection && !this.sending) {
-			return this._sendSteps(getSendable)
-		}
-		// If already sending, retry every 200ms.
 		return new Promise((resolve, reject) => {
 			this.#sendIntervalId = setInterval(() => {
 				if (this.connection && !this.sending) {