1// Copyright (C) 2018 The Android Open Source Project
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15export interface HasKind { kind: string; }
16
17export class Registry<T extends HasKind> {
18  private registry: Map<string, T>;
19
20  constructor() {
21    this.registry = new Map<string, T>();
22  }
23
24  register(registrant: T) {
25    const kind = registrant.kind;
26    if (this.registry.has(kind)) {
27      throw new Error(`Registrant ${kind} already exists in the registry`);
28    }
29    this.registry.set(kind, registrant);
30  }
31
32  has(kind: string): boolean {
33    return this.registry.has(kind);
34  }
35
36  get(kind: string): T {
37    const registrant = this.registry.get(kind);
38    if (registrant === undefined) {
39      throw new Error(`${kind} has not been registered.`);
40    }
41    return registrant;
42  }
43
44  unregisterAllForTesting(): void {
45    this.registry.clear();
46  }
47}
48