perf(editor): Improve canvas rendering performance (#8022)

## Summary
- Refactor usage of `setSuspendDrawing`, removing it from loops and only
calling it after batch operations are done
- Batch adding of nodes to improve copy/paste and workflow load
performance
- Cache i18n calls
- Debounce connections dragging handler if there are more than 20 nodes


## Related tickets and issues
> Include links to **Linear ticket** or Github issue or Community forum
post. Important in order to close *automatically* and provide context to
reviewers.
- https://community.n8n.io/t/slow-ui-in-big-scenarios/33830/8

---------

Signed-off-by: Oleg Ivaniv <me@olegivaniv.com>

packages/editor-ui/src/components/Node.vue

@@ -637,8 +637,7 @@ export default defineComponent({
 			// so we only update it when necessary (when node is mounted and when it's opened and closed (isActive))
 			try {
 				const nodeSubtitle =
-					this.nodeHelpers.getNodeSubtitle(this.data, this.nodeType, this.getCurrentWorkflow()) ||
+					this.nodeHelpers.getNodeSubtitle(this.data, this.nodeType, this.workflow) || '';
-					'';
 
 				this.nodeSubtitle = nodeSubtitle.includes(CUSTOM_API_CALL_KEY) ? '' : nodeSubtitle;
 			} catch (e) {

packages/editor-ui/src/plugins/i18n/index.ts

@@ -23,6 +23,8 @@ export const i18nInstance = createI18n({
 });
 
 export class I18nClass {
+	private baseTextCache = new Map<string, string>();
+
 	private get i18n() {
 		return i18nInstance.global;
 	}
@@ -50,11 +52,25 @@ export class I18nClass {
 		key: BaseTextKey,
 		options?: { adjustToNumber?: number; interpolate?: { [key: string]: string } },
 	): string {
-		if (options?.adjustToNumber !== undefined) {
+		// Create a unique cache key
-			return this.i18n.tc(key, options.adjustToNumber, options?.interpolate).toString();
+		const cacheKey = `${key}-${JSON.stringify(options)}`;
+
+		// Check if the result is already cached
+		if (this.baseTextCache.has(cacheKey)) {
+			return this.baseTextCache.get(cacheKey) ?? key;
 		}
 
-		return this.i18n.t(key, options?.interpolate).toString();
+		let result: string;
+		if (options?.adjustToNumber !== undefined) {
+			result = this.i18n.tc(key, options.adjustToNumber, options?.interpolate ?? {}).toString();
+		} else {
+			result = this.i18n.t(key, options?.interpolate ?? {}).toString();
+		}
+
+		// Store the result in the cache
+		this.baseTextCache.set(cacheKey, result);
+
+		return result;
 	}
 
 	/**

packages/editor-ui/src/plugins/jsplumb/N8nAddInputEndpointRenderer.ts

@@ -70,7 +70,6 @@ export const register = () => {
 			container.appendChild(unconnectedGroup);
 			container.appendChild(defaultGroup);
 
-			endpointInstance.setupOverlays();
 			endpointInstance.setVisible(false);
 
 			return container;

packages/editor-ui/src/plugins/jsplumb/N8nAddInputEndpointType.ts

@@ -33,11 +33,6 @@ export class N8nAddInputEndpoint extends EndpointRepresentation<ComputedN8nAddIn
 
 	type = N8nAddInputEndpoint.type;
 
-	setupOverlays() {
-		this.endpoint.instance.setSuspendDrawing(true);
-		this.endpoint.instance.setSuspendDrawing(false);
-	}
-
 	bindEvents() {
 		this.instance.bind(EVENT_ENDPOINT_CLICK, this.fireClickEvent);
 	}

packages/editor-ui/src/plugins/jsplumb/N8nPlusEndpointType.ts

@@ -49,7 +49,6 @@ export class N8nPlusEndpoint extends EndpointRepresentation<ComputedN8nPlusEndpo
 
 	setupOverlays() {
 		this.clearOverlays();
-		this.endpoint.instance.setSuspendDrawing(true);
 		this.stalkOverlay = this.endpoint.addOverlay({
 			type: 'Custom',
 			options: {
@@ -78,7 +77,6 @@ export class N8nPlusEndpoint extends EndpointRepresentation<ComputedN8nPlusEndpo
 				},
 			},
 		});
-		this.endpoint.instance.setSuspendDrawing(false);
 	}
 
 	bindEvents() {
@@ -151,18 +149,14 @@ export class N8nPlusEndpoint extends EndpointRepresentation<ComputedN8nPlusEndpo
 	}
 
 	setIsVisible(visible: boolean) {
-		this.instance.setSuspendDrawing(true);
 		Object.keys(this.endpoint.getOverlays()).forEach((overlay) => {
 			this.endpoint.getOverlays()[overlay].setVisible(visible);
 		});
-
 		this.setVisible(visible);
-
 		// Re-trigger the success state if label is set
 		if (visible && this.label) {
 			this.setSuccessOutput(this.label);
 		}
-		this.instance.setSuspendDrawing(false);
 	}
 
 	setSuccessOutput(label: string) {

packages/editor-ui/src/stores/workflows.store.ts

@@ -894,8 +894,6 @@ export const useWorkflowsStore = defineStore(STORES.WORKFLOWS, {
 					},
 				};
 			}
-
-			this.workflowExecutionPairedItemMappings = getPairedItemsMapping(this.workflowExecutionData);
 		},
 
 		resetAllNodesIssues(): boolean {
@@ -1130,7 +1128,6 @@ export const useWorkflowsStore = defineStore(STORES.WORKFLOWS, {
 				};
 			}
 			this.workflowExecutionData.data!.resultData.runData[pushData.nodeName].push(pushData.data);
-			this.workflowExecutionPairedItemMappings = getPairedItemsMapping(this.workflowExecutionData);
 		},
 		clearNodeExecutionData(nodeName: string): void {
 			if (!this.workflowExecutionData?.data) {

packages/editor-ui/src/views/NodeView.vue

@@ -75,6 +75,7 @@
 						@removeNode="(name) => removeNode(name, true)"
 						:key="`${stickyData.id}_sticky`"
 						:name="stickyData.name"
+						:workflow="currentWorkflowObject"
 						:isReadOnly="isReadOnlyRoute || readOnlyEnv"
 						:instance="instance"
 						:isActive="!!activeNode && activeNode.name === stickyData.name"
@@ -732,6 +733,7 @@ export default defineComponent({
 			showTriggerMissingTooltip: false,
 			workflowData: null as INewWorkflowData | null,
 			activeConnection: null as null | Connection,
+			isInsertingNodes: false,
 			isProductionExecutionPreview: false,
 			enterTimer: undefined as undefined | ReturnType<typeof setTimeout>,
 			exitTimer: undefined as undefined | ReturnType<typeof setTimeout>,
@@ -2735,15 +2737,6 @@ export default defineComponent({
 							});
 						},
 					);
-					setTimeout(() => {
-						NodeViewUtils.addConnectionTestData(
-							info.source,
-							info.target,
-							info.connection?.connector?.hasOwnProperty('canvas')
-								? (info.connection.connector.canvas as HTMLElement)
-								: undefined,
-						);
-					}, 0);
 
 					const endpointArrow = NodeViewUtils.getOverlay(
 						info.connection,
@@ -2763,14 +2756,44 @@ export default defineComponent({
 					if (!this.suspendRecordingDetachedConnections) {
 						this.historyStore.pushCommandToUndo(new AddConnectionCommand(connectionData));
 					}
-					this.nodeHelpers.updateNodesInputIssues();
+					// When we add multiple nodes, this event could be fired hundreds of times for large workflows.
-					this.resetEndpointsErrors();
+					// And because the updateNodesInputIssues() method is quite expensive, we only call it if not in insert mode
+					if (!this.isInsertingNodes) {
+						this.nodeHelpers.updateNodesInputIssues();
+						this.resetEndpointsErrors();
+						setTimeout(() => {
+							NodeViewUtils.addConnectionTestData(
+								info.source,
+								info.target,
+								info.connection?.connector?.hasOwnProperty('canvas')
+									? (info.connection.connector.canvas as HTMLElement)
+									: undefined,
+							);
+						}, 0);
+					}
 				}
 			} catch (e) {
 				console.error(e);
 			}
 		},
+		addConectionsTestData() {
+			this.instance.connections.forEach((connection) => {
+				NodeViewUtils.addConnectionTestData(
+					connection.source,
+					connection.target,
+					connection?.connector?.hasOwnProperty('canvas')
+						? (connection?.connector.canvas as HTMLElement)
+						: undefined,
+				);
+			});
+		},
 		onDragMove() {
+			const totalNodes = this.nodes.length;
+			void this.callDebounced('updateConnectionsOverlays', {
+				debounceTime: totalNodes > 20 ? 200 : 0,
+			});
+		},
+		updateConnectionsOverlays() {
 			this.instance?.connections.forEach((connection) => {
 				NodeViewUtils.showOrHideItemsLabel(connection);
 				NodeViewUtils.showOrHideMidpointArrow(connection);
@@ -3899,7 +3922,7 @@ export default defineComponent({
 			if (!nodes?.length) {
 				return;
 			}
-
+			this.isInsertingNodes = true;
 			// Before proceeding we must check if all nodes contain the `properties` attribute.
 			// Nodes are loaded without this information so we must make sure that all nodes
 			// being added have this information.
@@ -3957,60 +3980,64 @@ export default defineComponent({
 
 				// check and match credentials, apply new format if old is used
 				this.matchCredentials(node);
-
 				this.workflowsStore.addNode(node);
 				if (trackHistory) {
 					this.historyStore.pushCommandToUndo(new AddNodeCommand(node));
 				}
 			});
 
-			// Wait for the node to be rendered
+			// Wait for the nodes to be rendered
 			await this.$nextTick();
 
-			// Suspend drawing
 			this.instance?.setSuspendDrawing(true);
 
-			// Load the connections
+			if (connections) {
-			if (connections !== undefined) {
+				await this.addConnections(connections);
-				let connectionData;
-				for (const sourceNode of Object.keys(connections)) {
-					for (const type of Object.keys(connections[sourceNode])) {
-						for (
-							let sourceIndex = 0;
-							sourceIndex < connections[sourceNode][type].length;
-							sourceIndex++
-						) {
-							const outwardConnections = connections[sourceNode][type][sourceIndex];
-							if (!outwardConnections) {
-								continue;
-							}
-							outwardConnections.forEach((targetData) => {
-								connectionData = [
-									{
-										node: sourceNode,
-										type,
-										index: sourceIndex,
-									},
-									{
-										node: targetData.node,
-										type: targetData.type,
-										index: targetData.index,
-									},
-								] as [IConnection, IConnection];
-
-								this.__addConnection(connectionData);
-							});
-						}
-					}
-				}
 			}
-
 			// Add the node issues at the end as the node-connections are required
-			void this.nodeHelpers.refreshNodeIssues();
+			this.nodeHelpers.refreshNodeIssues();
+			this.nodeHelpers.updateNodesInputIssues();
+			this.resetEndpointsErrors();
+			this.isInsertingNodes = false;
 
 			// Now it can draw again
 			this.instance?.setSuspendDrawing(false, true);
 		},
+		async addConnections(connections: IConnections) {
+			const batchedConnectionData: Array<[IConnection, IConnection]> = [];
+
+			for (const sourceNode in connections) {
+				for (const type in connections[sourceNode]) {
+					connections[sourceNode][type].forEach((outwardConnections, sourceIndex) => {
+						if (outwardConnections) {
+							outwardConnections.forEach((targetData) => {
+								batchedConnectionData.push([
+									{ node: sourceNode, type, index: sourceIndex },
+									{ node: targetData.node, type: targetData.type, index: targetData.index },
+								]);
+							});
+						}
+					});
+				}
+			}
+
+			// Process the connections in batches
+			await this.processConnectionBatch(batchedConnectionData);
+			setTimeout(this.addConectionsTestData, 0);
+		},
+
+		async processConnectionBatch(batchedConnectionData: Array<[IConnection, IConnection]>) {
+			const batchSize = 100;
+
+			for (let i = 0; i < batchedConnectionData.length; i += batchSize) {
+				const batch = batchedConnectionData.slice(i, i + batchSize);
+
+				batch.forEach((connectionData) => {
+					this.__addConnection(connectionData);
+				});
+			}
+		},
+
 		async addNodesToWorkflow(data: IWorkflowDataUpdate): Promise<IWorkflowDataUpdate> {
 			// Because nodes with the same name maybe already exist, it could
 			// be needed that they have to be renamed. Also could it be possible