content: /*
   * Copyright (C) 2017 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License
   */
  
  package com.android.server.wm;
  
  import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME;
  import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
  
  import android.app.ActivityManager.TaskSnapshot;
  import android.content.ComponentName;
  import android.graphics.Bitmap;
  import android.graphics.Bitmap.Config;
  import android.graphics.BitmapFactory;
  import android.graphics.BitmapFactory.Options;
  import android.graphics.GraphicBuffer;
  import android.graphics.Rect;
  import android.util.Slog;
  
  import com.android.server.wm.nano.WindowManagerProtos.TaskSnapshotProto;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.Files;
  
  /**
   * Loads a persisted {@link TaskSnapshot} from disk.
   * <p>
   * Do not hold the window manager lock when accessing this class.
   * <p>
   * Test class: {@link TaskSnapshotPersisterLoaderTest}
   */
  class TaskSnapshotLoader {
  
      private static final String TAG = TAG_WITH_CLASS_NAME ? "TaskSnapshotLoader" : TAG_WM;
  
      private final TaskSnapshotPersister mPersister;
  
      TaskSnapshotLoader(TaskSnapshotPersister persister) {
          mPersister = persister;
      }
  
      /**
       * Loads a task from the disk.
       * <p>
       * Do not hold the window manager lock when calling this method, as we directly read data from
       * disk here, which might be slow.
       *
       * @param taskId The id of the task to load.
       * @param userId The id of the user the task belonged to.
       * @param reducedResolution Whether to load a reduced resolution version of the snapshot.
       * @return The loaded {@link TaskSnapshot} or {@code null} if it couldn't be loaded.
       */
      TaskSnapshot loadTask(int taskId, int userId, boolean reducedResolution) {
          final File protoFile = mPersister.getProtoFile(taskId, userId);
          final File bitmapFile = reducedResolution
                  ? mPersister.getReducedResolutionBitmapFile(taskId, userId)
                  : mPersister.getBitmapFile(taskId, userId);
          if (bitmapFile == null || !protoFile.exists() || !bitmapFile.exists()) {
              return null;
          }
          try {
              final byte[] bytes = Files.readAllBytes(protoFile.toPath());
              final TaskSnapshotProto proto = TaskSnapshotProto.parseFrom(bytes);
              final Options options = new Options();
              options.inPreferredConfig = Config.HARDWARE;
              final Bitmap bitmap = BitmapFactory.decodeFile(bitmapFile.getPath(), options);
              if (bitmap == null) {
                  Slog.w(TAG, "Failed to load bitmap: " + bitmapFile.getPath());
                  return null;
              }
              final GraphicBuffer buffer = bitmap.createGraphicBufferHandle();
              if (buffer == null) {
                  Slog.w(TAG, "Failed to retrieve gralloc buffer for bitmap: "
                          + bitmapFile.getPath());
                  return null;
              }
              final ComponentName topActivityComponent = ComponentName.unflattenFromString(
                      proto.topActivityComponent);
              // For legacy snapshots, restore the scale based on the reduced resolution state
              final float legacyScale = reducedResolution ? mPersister.getReducedScale() : 1f;
              final float scale = Float.compare(proto.scale, 0f) != 0 ? proto.scale : legacyScale;
              return new TaskSnapshot(topActivityComponent, buffer, bitmap.getColorSpace(),
                      proto.orientation,
                      new Rect(proto.insetLeft, proto.insetTop, proto.insetRight, proto.insetBottom),
                      reducedResolution, scale, proto.isRealSnapshot, proto.windowingMode,
                      proto.systemUiVisibility, proto.isTranslucent);
          } catch (IOException e) {
              Slog.w(TAG, "Unable to load task snapshot data for taskId=" + taskId);
              return null;
          }
      }
  }
  