vscode中调用链的方案

[Wscats]

vscode/src/vs/platform/instantiation/common/instantiationService.ts

class Trace {

	private static readonly _None = new class extends Trace {
		constructor() { super(-1, null); }
		stop() { }
		branch() { return this; }
	};

	static traceInvocation(ctor: any): Trace {
		return !_enableTracing ? Trace._None : new Trace(TraceType.Invocation, ctor.name || (ctor.toString() as string).substring(0, 42).replace(/\n/g, ''));
	}

	static traceCreation(ctor: any): Trace {
		return !_enableTracing ? Trace._None : new Trace(TraceType.Creation, ctor.name);
	}

	private static _totals: number = 0;
	private readonly _start: number = Date.now();
	private readonly _dep: [ServiceIdentifier<any>, boolean, Trace?][] = [];

	private constructor(
		readonly type: TraceType,
		readonly name: string | null
	) { }

	branch(id: ServiceIdentifier<any>, first: boolean): Trace {
		let child = new Trace(TraceType.Branch, id.toString());
		this._dep.push([id, first, child]);
		return child;
	}

	stop() {
		let dur = Date.now() - this._start;
		Trace._totals += dur;

		let causedCreation = false;

		function printChild(n: number, trace: Trace) {
			let res: string[] = [];
			let prefix = new Array(n + 1).join('\t');
			for (const [id, first, child] of trace._dep) {
				if (first && child) {
					causedCreation = true;
					res.push(`${prefix}CREATES -> ${id}`);
					let nested = printChild(n + 1, child);
					if (nested) {
						res.push(nested);
					}
				} else {
					res.push(`${prefix}uses -> ${id}`);
				}
			}
			return res.join('\n');
		}

		let lines = [
			`${this.type === TraceType.Creation ? 'CREATE' : 'CALL'} ${this.name}`,
			`${printChild(1, this)}`,
			`DONE, took ${dur.toFixed(2)}ms (grand total ${Trace._totals.toFixed(2)}ms)`
		];

		if (dur > 2 || causedCreation) {
			console.log(lines.join('\n'));
		}
	}
}