writing telemetry into a file when running the app for perf tests (#802)

src/sql/platform/telemetry/fileTelemetryService.ts

@@ -0,0 +1,43 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+'use strict';
+
+import { TPromise } from 'vs/base/common/winjs.base';
+import { ITelemetryService, ITelemetryInfo, ITelemetryData } from 'vs/platform/telemetry/common/telemetry';
+const fs = require('fs');
+
+/**
+ * Write telemetry into a file for test purposes
+ */
+export class FileTelemetryService implements ITelemetryService {
+	_serviceBrand: undefined;
+	private _isFirst = true;
+
+	constructor(private _outputFile: string) {
+	}
+
+	publicLog(eventName: string, data?: ITelemetryData) {
+		let telemetryData = JSON.stringify(Object.assign({eventName: eventName, data: data}));
+		if (this._outputFile) {
+			if (this._isFirst) {
+				fs.open(this._outputFile,  fs.O_WRONLY | fs.O_CREAT, (err, fr) => {
+					fs.writeFileSync(this._outputFile, telemetryData + '\n');
+					this._isFirst = false;
+				});
+			} else {
+				fs.appendFileSync(this._outputFile, telemetryData + '\n');
+			}
+		}
+		return TPromise.wrap<void>(null);
+	}
+	isOptedIn: true;
+	getTelemetryInfo(): TPromise<ITelemetryInfo> {
+		return TPromise.wrap({
+			instanceId: 'someValue.instanceId',
+			sessionId: 'someValue.sessionId',
+			machineId: 'someValue.machineId'
+		});
+	}
+};