Squashed 'lib/vscode/' content from commit e5a624b788

git-subtree-dir: lib/vscode
git-subtree-split: e5a624b788d92b8d34d1392e4c4d9789406efe8f

src/vs/base/common/stopwatch.ts

@@ -0,0 +1,40 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { globals } from 'vs/base/common/platform';
+
+const hasPerformanceNow = (globals.performance && typeof globals.performance.now === 'function');
+
+export class StopWatch {
+
+	private _highResolution: boolean;
+	private _startTime: number;
+	private _stopTime: number;
+
+	public static create(highResolution: boolean = true): StopWatch {
+		return new StopWatch(highResolution);
+	}
+
+	constructor(highResolution: boolean) {
+		this._highResolution = hasPerformanceNow && highResolution;
+		this._startTime = this._now();
+		this._stopTime = -1;
+	}
+
+	public stop(): void {
+		this._stopTime = this._now();
+	}
+
+	public elapsed(): number {
+		if (this._stopTime !== -1) {
+			return this._stopTime - this._startTime;
+		}
+		return this._now() - this._startTime;
+	}
+
+	private _now(): number {
+		return this._highResolution ? globals.performance.now() : new Date().getTime();
+	}
+}