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 
17 package com.android.server.wm;
18 
19 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME;
20 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
21 
22 import android.app.ActivityManager.TaskSnapshot;
23 import android.content.ComponentName;
24 import android.graphics.Bitmap;
25 import android.graphics.Bitmap.Config;
26 import android.graphics.BitmapFactory;
27 import android.graphics.BitmapFactory.Options;
28 import android.graphics.GraphicBuffer;
29 import android.graphics.Rect;
30 import android.util.Slog;
31 
32 import com.android.server.wm.nano.WindowManagerProtos.TaskSnapshotProto;
33 
34 import java.io.File;
35 import java.io.IOException;
36 import java.nio.file.Files;
37 
38 /**
39  * Loads a persisted {@link TaskSnapshot} from disk.
40  * <p>
41  * Do not hold the window manager lock when accessing this class.
42  * <p>
43  * Test class: {@link TaskSnapshotPersisterLoaderTest}
44  */
45 class TaskSnapshotLoader {
46 
47     private static final String TAG = TAG_WITH_CLASS_NAME ? "TaskSnapshotLoader" : TAG_WM;
48 
49     private final TaskSnapshotPersister mPersister;
50 
TaskSnapshotLoader(TaskSnapshotPersister persister)51     TaskSnapshotLoader(TaskSnapshotPersister persister) {
52         mPersister = persister;
53     }
54 
55     /**
56      * Loads a task from the disk.
57      * <p>
58      * Do not hold the window manager lock when calling this method, as we directly read data from
59      * disk here, which might be slow.
60      *
61      * @param taskId The id of the task to load.
62      * @param userId The id of the user the task belonged to.
63      * @param reducedResolution Whether to load a reduced resolution version of the snapshot.
64      * @return The loaded {@link TaskSnapshot} or {@code null} if it couldn't be loaded.
65      */
loadTask(int taskId, int userId, boolean reducedResolution)66     TaskSnapshot loadTask(int taskId, int userId, boolean reducedResolution) {
67         final File protoFile = mPersister.getProtoFile(taskId, userId);
68         final File bitmapFile = reducedResolution
69                 ? mPersister.getReducedResolutionBitmapFile(taskId, userId)
70                 : mPersister.getBitmapFile(taskId, userId);
71         if (bitmapFile == null || !protoFile.exists() || !bitmapFile.exists()) {
72             return null;
73         }
74         try {
75             final byte[] bytes = Files.readAllBytes(protoFile.toPath());
76             final TaskSnapshotProto proto = TaskSnapshotProto.parseFrom(bytes);
77             final Options options = new Options();
78             options.inPreferredConfig = Config.HARDWARE;
79             final Bitmap bitmap = BitmapFactory.decodeFile(bitmapFile.getPath(), options);
80             if (bitmap == null) {
81                 Slog.w(TAG, "Failed to load bitmap: " + bitmapFile.getPath());
82                 return null;
83             }
84             final GraphicBuffer buffer = bitmap.createGraphicBufferHandle();
85             if (buffer == null) {
86                 Slog.w(TAG, "Failed to retrieve gralloc buffer for bitmap: "
87                         + bitmapFile.getPath());
88                 return null;
89             }
90             final ComponentName topActivityComponent = ComponentName.unflattenFromString(
91                     proto.topActivityComponent);
92             // For legacy snapshots, restore the scale based on the reduced resolution state
93             final float legacyScale = reducedResolution ? mPersister.getReducedScale() : 1f;
94             final float scale = Float.compare(proto.scale, 0f) != 0 ? proto.scale : legacyScale;
95             return new TaskSnapshot(topActivityComponent, buffer, bitmap.getColorSpace(),
96                     proto.orientation,
97                     new Rect(proto.insetLeft, proto.insetTop, proto.insetRight, proto.insetBottom),
98                     reducedResolution, scale, proto.isRealSnapshot, proto.windowingMode,
99                     proto.systemUiVisibility, proto.isTranslucent);
100         } catch (IOException e) {
101             Slog.w(TAG, "Unable to load task snapshot data for taskId=" + taskId);
102             return null;
103         }
104     }
105 }
106