ApiLoader.java revision 6bd3ab6dc6ad4001c387d7f4a4a2ce954be6ca16 
1/*
2 * Copyright (C) 2017 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
17package android.media.update;
18
19import android.app.ActivityManager;
20import android.app.AppGlobals;
21import android.content.Context;
22import android.content.pm.ApplicationInfo;
23import android.content.pm.PackageManager;
24import android.content.pm.PackageManager.NameNotFoundException;
25import android.os.Build;
26import android.os.RemoteException;
27import android.os.UserHandle;
28
29import com.android.internal.annotations.GuardedBy;
30
31import dalvik.system.PathClassLoader;
32
33import java.io.File;
34
35/**
36 * @hide
37 */
38public final class ApiLoader {
39    @GuardedBy("this")
40    private static StaticProvider sMediaUpdatable;
41
42    private static final String UPDATE_PACKAGE = "com.android.media.update";
43    private static final String UPDATE_CLASS = "com.android.media.update.ApiFactory";
44    private static final String UPDATE_METHOD = "initialize";
45    private static final boolean REGISTER_UPDATE_DEPENDENCY = true;
46
47    private ApiLoader() { }
48
49    public static StaticProvider getProvider() {
50        if (sMediaUpdatable != null) return sMediaUpdatable;
51
52        try {
53            return getMediaUpdatable();
54        } catch (RemoteException e) {
55            throw e.rethrowFromSystemServer();
56        } catch (NameNotFoundException | ReflectiveOperationException e) {
57            throw new RuntimeException(e);
58        }
59    }
60
61    // TODO This method may do I/O; Ensure it does not violate (emit warnings in) strict mode.
62    private static synchronized StaticProvider getMediaUpdatable()
63            throws NameNotFoundException, ReflectiveOperationException, RemoteException {
64        if (sMediaUpdatable != null) return sMediaUpdatable;
65
66        // TODO Figure out when to use which package (query media update service)
67        int flags = Build.IS_DEBUGGABLE ? 0 : PackageManager.MATCH_FACTORY_ONLY;
68        flags |= PackageManager.GET_SHARED_LIBRARY_FILES;
69        ApplicationInfo ai = AppGlobals.getPackageManager().getApplicationInfo(
70                UPDATE_PACKAGE, flags, UserHandle.myUserId());
71
72        if (REGISTER_UPDATE_DEPENDENCY) {
73            // Register a dependency to the updatable in order to be killed during updates
74            ActivityManager.getService().addPackageDependency(ai.packageName);
75        }
76
77        ClassLoader classLoader = new PathClassLoader(ai.sourceDir,
78                ai.nativeLibraryDir + File.pathSeparator + System.getProperty("java.library.path"),
79                ClassLoader.getSystemClassLoader().getParent());
80        return sMediaUpdatable = (StaticProvider) classLoader.loadClass(UPDATE_CLASS)
81                .getMethod(UPDATE_METHOD, ApplicationInfo.class).invoke(null, ai);
82    }
83}
84