perf(webview): sample memory usage telemetry (#2194)

Author: hassoncs

webview-ui/src/services/MemoryService.ts

@@ -1,6 +1,7 @@
 // kilocode_change - new file
 import { telemetryClient } from "../utils/TelemetryClient"
 import { TelemetryEventName } from "@roo-code/types"
+import { createSampledFunction } from "../utils/sampling"
 
 interface PerformanceMemory {
 	usedJSHeapSize?: number
@@ -9,7 +10,11 @@ interface PerformanceMemory {
 
 export class MemoryService {
 	private intervalId: number | null = null
-	private readonly intervalMs: number = 60 * 1000 // 1 min
+	private readonly intervalMs: number = 10 * 60 * 1000 // 10 min(s)
+	private readonly sampledTelemetryCapture = createSampledFunction(
+		telemetryClient.capture.bind(telemetryClient),
+		0.01, // 1% sampling rate
+	)
 
 	public start(): void {
 		if (this.intervalId) {
@@ -35,7 +40,7 @@ export class MemoryService {
 			heapUsedMb: this.bytesToMegabytes(memory?.usedJSHeapSize || 0),
 			heapTotalMb: this.bytesToMegabytes(memory?.totalJSHeapSize || 0),
 		}
-		telemetryClient.capture(TelemetryEventName.WEBVIEW_MEMORY_USAGE, memoryInfo)
+		this.sampledTelemetryCapture(TelemetryEventName.WEBVIEW_MEMORY_USAGE, memoryInfo)
 	}
 
 	private bytesToMegabytes(bytes: number): number {

webview-ui/src/utils/__tests__/sampling.spec.ts

@@ -0,0 +1,28 @@
+import { createSampledFunction } from "../sampling"
+import { vi } from "vitest"
+
+describe("createSampledFunction", () => {
+	beforeEach(() => {
+		vi.restoreAllMocks()
+	})
+
+	it("should call the wrapped function when random value is less than sample rate", () => {
+		vi.spyOn(Math, "random").mockReturnValue(0.005) // 0.5%
+		const mockFn = vi.fn()
+		const sampledFn = createSampledFunction(mockFn, 0.01) // 1%
+
+		sampledFn("test", 123)
+
+		expect(mockFn).toHaveBeenCalledWith("test", 123)
+	})
+
+	it("should not call the wrapped function when random value is greater than sample rate", () => {
+		vi.spyOn(Math, "random").mockReturnValue(0.015) // 1.5%
+		const mockFn = vi.fn()
+		const sampledFn = createSampledFunction(mockFn, 0.01) // 1%
+
+		sampledFn("test", 123)
+
+		expect(mockFn).not.toHaveBeenCalled()
+	})
+})

webview-ui/src/utils/sampling.ts

@@ -0,0 +1,16 @@
+/**
+ * Creates a sampled version of a function that only executes based on the provided sample rate.
+ *
+ * @param fn - The function to wrap with sampling
+ * @param sampleRate - The sampling rate as a decimal (e.g., 0.01 for 1%, 0.1 for 10%)
+ * @returns A new function that only executes the original function based on the sample rate
+ */
+export function createSampledFunction<T extends (...args: any[]) => any>(fn: T, sampleRate: number): T {
+	const clampedRate = Math.max(0, Math.min(1, sampleRate))
+
+	return ((...args: Parameters<T>) => {
+		if (Math.random() < clampedRate) {
+			return fn(...args)
+		}
+	}) as T
+}