1 /*
2  * Copyright (C) 2024 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.server.deviceconfig;
18 
19 import android.annotation.Nullable;
20 import android.content.Context;
21 import android.content.pm.PackageInfo;
22 import android.content.pm.PackageManager;
23 import android.util.Log;
24 
25 import com.android.internal.annotations.VisibleForTesting;
26 
27 import java.util.List;
28 import java.util.Optional;
29 
30 /**
31  * Helper class for the service resources package.
32  *
33  * @hide
34  */
35 public class ServiceResourcesHelper {
36     private static final String TAG = "ServiceResourcesHelper";
37 
38     @VisibleForTesting
39     static final String RESOURCES_PACKAGE_SUFFIX =
40             ".android.server.deviceconfig.resources";
41 
42     @Nullable private static ServiceResourcesHelper sHelper; // singleton.
43 
44     /** Provides an instance of the helper. */
get(Context context)45     public static ServiceResourcesHelper get(Context context) {
46         if (sHelper == null) {
47             sHelper = new ServiceResourcesHelper(context);
48         }
49         return sHelper;
50     }
51 
52     /** Sets the helper instance for testing purposes. */
53     @VisibleForTesting
setInstanceForTest(ServiceResourcesHelper helper)54     public static void setInstanceForTest(ServiceResourcesHelper helper) {
55         sHelper = helper;
56     }
57 
58     private final Optional<String> mServiceResourcesPackageName;
59 
60     @VisibleForTesting
ServiceResourcesHelper(Context context)61     public ServiceResourcesHelper(Context context) {
62         mServiceResourcesPackageName =
63                 getSystemPackageNameBySuffix(context, RESOURCES_PACKAGE_SUFFIX);
64     }
65 
66     /**
67      * Returns an {@link Optional} containing the service resources package name, or an empty
68      * {@link Optional} if the package cannot be found.
69      */
getResourcesPackageName()70     public Optional<String> getResourcesPackageName() {
71         return mServiceResourcesPackageName;
72     }
73 
getSystemPackageNameBySuffix(Context context, String suffix)74     private Optional<String> getSystemPackageNameBySuffix(Context context, String suffix) {
75         PackageManager packageManager = context.getPackageManager();
76         List<PackageInfo> installedSystemPackages =
77                 packageManager.getInstalledPackages(PackageManager.MATCH_SYSTEM_ONLY);
78 
79         String serviceResourcesPackageName = null;
80         for (PackageInfo packageInfo : installedSystemPackages) {
81             final String packageName = packageInfo.packageName;
82             if (packageInfo.packageName.endsWith(RESOURCES_PACKAGE_SUFFIX)) {
83                 Log.i(TAG, "Found service resource package: " + packageName);
84                 if (serviceResourcesPackageName != null) {
85                     Log.w(TAG, "Multiple service resource packages found");
86                 } else {
87                     serviceResourcesPackageName = packageName;
88                 }
89             }
90         }
91 
92         return Optional.ofNullable(serviceResourcesPackageName);
93     }
94 }