2 * Copyright (c) 2019 The xterm.js authors. All rights reserved.
5 * This was heavily inspired from microsoft/vscode's dependency injection system (MIT).
7 /*---------------------------------------------------------------------------------------------
8 * Copyright (c) Microsoft Corporation. All rights reserved.
9 * Licensed under the MIT License. See License.txt in the project root for license information.
10 *--------------------------------------------------------------------------------------------*/
12 import { IInstantiationService, IServiceIdentifier } from 'common/services/Services';
13 import { getServiceDependencies } from 'common/services/ServiceRegistry';
15 export class ServiceCollection {
17 private _entries = new Map<IServiceIdentifier<any>, any>();
19 constructor(...entries: [IServiceIdentifier<any>, any][]) {
20 for (const [id, service] of entries) {
21 this.set(id, service);
25 set<T>(id: IServiceIdentifier<T>, instance: T): T {
26 const result = this._entries.get(id);
27 this._entries.set(id, instance);
31 forEach(callback: (id: IServiceIdentifier<any>, instance: any) => any): void {
32 this._entries.forEach((value, key) => callback(key, value));
35 has(id: IServiceIdentifier<any>): boolean {
36 return this._entries.has(id);
39 get<T>(id: IServiceIdentifier<T>): T {
40 return this._entries.get(id);
44 export class InstantiationService implements IInstantiationService {
45 private readonly _services: ServiceCollection = new ServiceCollection();
48 this._services.set(IInstantiationService, this);
51 public setService<T>(id: IServiceIdentifier<T>, instance: T): void {
52 this._services.set(id, instance);
55 public createInstance<T>(ctor: any, ...args: any[]): any {
56 const serviceDependencies = getServiceDependencies(ctor).sort((a, b) => a.index - b.index);
58 const serviceArgs: any[] = [];
59 for (const dependency of serviceDependencies) {
60 const service = this._services.get(dependency.id);
62 throw new Error(`[createInstance] ${ctor.name} depends on UNKNOWN service ${dependency.id}.`);
64 serviceArgs.push(service);
67 const firstServiceArgPos = serviceDependencies.length > 0 ? serviceDependencies[0].index : args.length;
69 // check for argument mismatches, adjust static args if needed
70 if (args.length !== firstServiceArgPos) {
71 throw new Error(`[createInstance] First service dependency of ${ctor.name} at position ${firstServiceArgPos + 1} conflicts with ${args.length} static arguments`);
74 // now create the instance
75 return <T>new ctor(...[...args, ...serviceArgs]);