fix: reduce CPU load from file watchers and improve performance

- Increased debounce delays to reduce frequency of file system events
- Fixed MCP Hub file watcher cleanup to prevent duplicate watchers
- Optimized ripgrep process handling with early termination
- Improved timeout handling in list-files scanning
- Updated tests to match new debounce timings

Fixes #7595

src/integrations/workspace/WorkspaceTracker.ts

@@ -106,7 +106,7 @@ class WorkspaceTracker {
 				this.prevWorkSpacePath = this.cwd
 				this.initializeFilePaths()
 			}
-		}, 300) // Debounce for 300ms
+		}, 500) // Increased debounce to 500ms to reduce CPU load
 	}
 
 	private workspaceDidUpdate() {
@@ -125,7 +125,7 @@ class WorkspaceTracker {
 				openedTabs: this.getOpenedTabsInfo(),
 			})
 			this.updateTimer = null
-		}, 300) // Debounce for 300ms
+		}, 500) // Increased debounce to 500ms to reduce CPU load
 	}
 
 	private normalizeFilePath(filePath: string): string {

src/integrations/workspace/__tests__/WorkspaceTracker.spec.ts

@@ -225,8 +225,8 @@ describe("WorkspaceTracker", () => {
 		// Simulate tab change event
 		await registeredTabChangeCallback!()
 
-		// Run the debounce timer for workspaceDidReset
-		vitest.advanceTimersByTime(300)
+		// Run the debounce timer for workspaceDidReset (now 500ms)
+		vitest.advanceTimersByTime(500)
 
 		// Should clear file paths and reset workspace
 		expect(mockProvider.postMessageToWebview).toHaveBeenCalledWith({
@@ -314,8 +314,8 @@ describe("WorkspaceTracker", () => {
 		// Call again before timer completes
 		await registeredTabChangeCallback!()
 
-		// Advance timer
-		vitest.advanceTimersByTime(300)
+		// Advance timer (now 500ms)
+		vitest.advanceTimersByTime(500)
 
 		// Should only have one call to postMessageToWebview
 		expect(mockProvider.postMessageToWebview).toHaveBeenCalledWith({
@@ -338,8 +338,8 @@ describe("WorkspaceTracker", () => {
 		// Dispose before timer completes
 		workspaceTracker.dispose()
 
-		// Advance timer
-		vitest.advanceTimersByTime(300)
+		// Advance timer (now 500ms)
+		vitest.advanceTimersByTime(500)
 
 		// Should have called dispose on all disposables
 		expect(mockDispose).toHaveBeenCalled()

src/services/code-index/processors/file-watcher.ts

@@ -37,7 +37,7 @@ export class FileWatcher implements IFileWatcher {
 	private ignoreController: RooIgnoreController
 	private accumulatedEvents: Map<string, { uri: vscode.Uri; type: "create" | "change" | "delete" }> = new Map()
 	private batchProcessDebounceTimer?: NodeJS.Timeout
-	private readonly BATCH_DEBOUNCE_DELAY_MS = 500
+	private readonly BATCH_DEBOUNCE_DELAY_MS = 1000 // Increased from 500ms to reduce CPU load
 	private readonly FILE_PROCESSING_CONCURRENCY_LIMIT = 10
 	private readonly batchSegmentThreshold: number
 

src/services/glob/list-files.ts

@@ -626,29 +626,42 @@ async function execRipgrep(rgPath: string, args: string[], limit: number): Promi
 		const rgProcess = childProcess.spawn(rgPath, args)
 		let output = ""
 		let results: string[] = []
+		let processKilled = false
 
-		// Set timeout to avoid hanging
+		// Set timeout to avoid hanging - increased timeout for slower systems
 		const timeoutId = setTimeout(() => {
-			rgProcess.kill()
-			console.warn("ripgrep timed out, returning partial results")
-			resolve(results.slice(0, limit))
-		}, 10_000)
+			if (!processKilled) {
+				processKilled = true
+				rgProcess.kill("SIGTERM")
+				console.warn("ripgrep timed out, returning partial results")
+				resolve(results.slice(0, limit))
+			}
+		}, 15_000) // Increased timeout to 15 seconds
 
 		// Process stdout data as it comes in
 		rgProcess.stdout.on("data", (data) => {
+			// Early exit if we've already killed the process
+			if (processKilled) return
+
 			output += data.toString()
 			processRipgrepOutput()
 
 			// Kill the process if we've reached the limit
-			if (results.length >= limit) {
-				rgProcess.kill()
-				clearTimeout(timeoutId) // Clear the timeout when we kill the process due to reaching the limit
+			if (results.length >= limit && !processKilled) {
+				processKilled = true
+				clearTimeout(timeoutId)
+				rgProcess.kill("SIGTERM")
+				// Resolve immediately when limit is reached
+				resolve(results.slice(0, limit))
 			}
 		})
 
 		// Process stderr but don't fail on non-zero exit codes
 		rgProcess.stderr.on("data", (data) => {
-			console.error(`ripgrep stderr: ${data}`)
+			// Only log errors if not killed intentionally
+			if (!processKilled) {
+				console.error(`ripgrep stderr: ${data}`)
+			}
 		})
 
 		// Handle process completion
@@ -656,22 +669,27 @@ async function execRipgrep(rgPath: string, args: string[], limit: number): Promi
 			// Clear the timeout to avoid memory leaks
 			clearTimeout(timeoutId)
 
-			// Process any remaining output
-			processRipgrepOutput(true)
+			// Only process if not already resolved
+			if (!processKilled) {
+				// Process any remaining output
+				processRipgrepOutput(true)
 
-			// Log non-zero exit codes but don't fail
-			if (code !== 0 && code !== null && code !== 143 /* SIGTERM */) {
-				console.warn(`ripgrep process exited with code ${code}, returning partial results`)
+				// Log non-zero exit codes but don't fail
+				if (code !== 0 && code !== null && code !== 143 /* SIGTERM */) {
+					console.warn(`ripgrep process exited with code ${code}, returning partial results`)
+				}
+
+				resolve(results.slice(0, limit))
 			}
-
-			resolve(results.slice(0, limit))
 		})
 
 		// Handle process errors
 		rgProcess.on("error", (error) => {
 			// Clear the timeout to avoid memory leaks
 			clearTimeout(timeoutId)
-			reject(new Error(`ripgrep process error: ${error.message}`))
+			if (!processKilled) {
+				reject(new Error(`ripgrep process error: ${error.message}`))
+			}
 		})
 
 		// Helper function to process output buffer

src/services/mcp/McpHub.ts

@@ -286,11 +286,11 @@ export class McpHub {
 			clearTimeout(existingTimer)
 		}
 
-		// Set new timer
+		// Set new timer with longer debounce to reduce CPU usage
 		const timer = setTimeout(async () => {
 			this.configChangeDebounceTimers.delete(key)
 			await this.handleConfigFileChange(filePath, source)
-		}, 500) // 500ms debounce
+		}, 1000) // Increased to 1000ms debounce to reduce CPU load
 
 		this.configChangeDebounceTimers.set(key, timer)
 	}
@@ -1033,7 +1033,6 @@ export class McpHub {
 		if (manageConnectingState) {
 			this.isConnecting = true
 		}
-		this.removeAllFileWatchers()
 		// Filter connections by source
 		const currentConnections = this.connections.filter(
 			(conn) => conn.server.source === source || (!conn.server.source && source === "global"),
@@ -1041,7 +1040,7 @@ export class McpHub {
 		const currentNames = new Set(currentConnections.map((conn) => conn.server.name))
 		const newNames = new Set(Object.keys(newServers))
 
-		// Delete removed servers
+		// Delete removed servers (this will also clean up their file watchers)
 		for (const name of currentNames) {
 			if (!newNames.has(name)) {
 				await this.deleteConnection(name, source)
@@ -1065,10 +1064,7 @@ export class McpHub {
 			if (!currentConnection) {
 				// New server
 				try {
-					// Only setup file watcher for enabled servers
-					if (!validatedConfig.disabled) {
-						this.setupFileWatcher(name, validatedConfig, source)
-					}
+					// connectToServer will handle file watcher setup for enabled servers
 					await this.connectToServer(name, validatedConfig, source)
 				} catch (error) {
 					this.showErrorMessage(`Failed to connect to new MCP server ${name}`, error)
@@ -1076,11 +1072,9 @@ export class McpHub {
 			} else if (!deepEqual(JSON.parse(currentConnection.server.config), config)) {
 				// Existing server with changed config
 				try {
-					// Only setup file watcher for enabled servers
-					if (!validatedConfig.disabled) {
-						this.setupFileWatcher(name, validatedConfig, source)
-					}
+					// Delete connection first (this cleans up old file watchers)
 					await this.deleteConnection(name, source)
+					// connectToServer will handle file watcher setup for enabled servers
 					await this.connectToServer(name, validatedConfig, source)
 				} catch (error) {
 					this.showErrorMessage(`Failed to reconnect MCP server ${name}`, error)