Improve request log tree performance

Author: Sibidharan

src/extension/log/vscode-node/requestLogTree.ts

@@ -559,6 +559,10 @@ type TreeItem = ChatPromptItem | ChatRequestItem | ChatElementItem | ToolCallIte
 
 class ChatRequestProvider extends Disposable implements vscode.TreeDataProvider<TreeItem> {
 	private readonly filters: LogTreeFilters;
+	private rootItems: (ChatPromptItem | TreeChildItem)[] = [];
+	private seenChatRequests = new WeakSet<ChatRequest>();
+	private processedCount = 0;
+	private currentPrompt: ChatPromptItem | undefined;
 
 	constructor(
 		@IRequestLogger private readonly requestLogger: IRequestLogger,
@@ -567,8 +571,9 @@ class ChatRequestProvider extends Disposable implements vscode.TreeDataProvider<
 		super();
 		this.filters = this._register(instantiationService.createInstance(LogTreeFilters));
 		this._register(new LogTreeFilterCommands(this.filters));
-		this._register(this.requestLogger.onDidChangeRequests(() => this._onDidChangeTreeData.fire()));
+		this._register(this.requestLogger.onDidChangeRequests(() => this.handleRequestChange()));
 		this._register(this.filters.onDidChangeFilters(() => this._onDidChangeTreeData.fire()));
+		this.rebuildFromScratch();
 	}
 
 	private readonly _onDidChangeTreeData = new vscode.EventEmitter<TreeItem | undefined | void>();
@@ -580,48 +585,80 @@ class ChatRequestProvider extends Disposable implements vscode.TreeDataProvider<
 
 	getChildren(element?: TreeItem | undefined): vscode.ProviderResult<TreeItem[]> {
 		if (element instanceof ChatPromptItem) {
-			return element.children;
-		} else if (element) {
+			return element.children.filter(child => this.filters.itemIncluded(child));
+		}
+
+		if (element) {
 			return [];
-		} else {
-			let lastPrompt: ChatPromptItem | undefined;
-			const result: (ChatPromptItem | TreeChildItem)[] = [];
-			const seen = new Set<ChatRequest | undefined>();
-
-			for (const r of this.requestLogger.getRequests()) {
-				const item = this.logToTreeItem(r);
-				if (r.chatRequest !== lastPrompt?.request) {
-					if (lastPrompt) {
-						result.push(lastPrompt);
-					}
-					lastPrompt = r.chatRequest ? ChatPromptItem.create(r, r.chatRequest, seen.has(r.chatRequest)) : undefined;
-					seen.add(r.chatRequest);
+		}
+
+		return this.rootItems.filter(item => this.filters.itemIncluded(item));
+	}
+
+	private rebuildFromScratch(): void {
+		this.rootItems = [];
+		this.seenChatRequests = new WeakSet<ChatRequest>();
+		this.processedCount = 0;
+		this.currentPrompt = undefined;
+		this.appendNewEntries();
+	}
+
+	private handleRequestChange(): void {
+		this.appendNewEntries();
+	}
+
+	private appendNewEntries(): void {
+		const requests = this.requestLogger.getRequests();
+		let rootChanged = false;
+		const promptsToRefresh = new Set<ChatPromptItem>();
+		const newPrompts = new Set<ChatPromptItem>();
+
+		if (requests.length < this.processedCount) {
+			this.rootItems = [];
+			this.seenChatRequests = new WeakSet<ChatRequest>();
+			this.processedCount = 0;
+			this.currentPrompt = undefined;
+			rootChanged = true;
+		}
+
+		for (let i = this.processedCount; i < requests.length; i++) {
+			const info = requests[i];
+			const child = this.logToTreeItem(info);
+			const request = info.chatRequest;
+
+			if (request) {
+				const hasSeen = this.seenChatRequests.has(request);
+				if (!this.currentPrompt || this.currentPrompt.request !== request) {
+					this.currentPrompt = ChatPromptItem.create(info, request, hasSeen);
+					this.currentPrompt.children = [];
+					this.rootItems.push(this.currentPrompt);
+					this.seenChatRequests.add(request);
+					rootChanged = true;
+					newPrompts.add(this.currentPrompt);
 				}
 
-				if (lastPrompt) {
-					if (!lastPrompt.children.find(c => c.id === item.id)) {
-						lastPrompt.children.push(item);
-					}
-					if (!lastPrompt.children.find(c => c.id === item.id)) {
-						lastPrompt.children.push(item);
-					}
-				} else {
-					result.push(item);
+				if (!this.currentPrompt.children.some(c => c.id === child.id)) {
+					this.currentPrompt.children.push(child);
+					promptsToRefresh.add(this.currentPrompt);
 				}
+			} else {
+				this.currentPrompt = undefined;
+				this.rootItems.push(child);
+				rootChanged = true;
 			}
+		}
 
-			if (lastPrompt) {
-				result.push(lastPrompt);
-			}
+		this.processedCount = requests.length;
 
-			return result.map(r => {
-				if (r instanceof ChatPromptItem) {
-					return r.withFilteredChildren(child => this.filters.itemIncluded(child));
-				}
+		if (rootChanged) {
+			this._onDidChangeTreeData.fire(undefined);
+		}
 
-				return r;
-			})
-				.filter(r => this.filters.itemIncluded(r));
+		for (const prompt of promptsToRefresh) {
+			if (rootChanged && newPrompts.has(prompt)) {
+				continue;
+			}
+			this._onDidChangeTreeData.fire(prompt);
 		}
 	}
 
@@ -824,4 +861,4 @@ class LogTreeFilterCommands extends Disposable {
 		this._register(vscode.commands.registerCommand('github.copilot.chat.debug.showNesRequests', () => filters.setNesRequestsShown(true)));
 		this._register(vscode.commands.registerCommand('github.copilot.chat.debug.hideNesRequests', () => filters.setNesRequestsShown(false)));
 	}
-}
+}