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 android.app.usage;
  
  import android.annotation.SystemApi;
  import android.app.Service;
  import android.app.usage.ICacheQuotaService;
  import android.content.Intent;
  import android.os.Bundle;
  import android.os.Handler;
  import android.os.IBinder;
  import android.os.Looper;
  import android.os.Message;
  import android.os.RemoteCallback;
  import android.util.Log;
  import android.util.Pair;
  
  import java.util.List;
  
  /**
   * CacheQuoteService defines a service which accepts cache quota requests and processes them,
   * thereby filling out how much quota each request deserves.
   * {@hide}
   */
  @SystemApi
  public abstract class CacheQuotaService extends Service {
      private static final String TAG = "CacheQuotaService";
  
      /**
       * The {@link Intent} action that must be declared as handled by a service
       * in its manifest for the system to recognize it as a quota providing service.
       */
      public static final String SERVICE_INTERFACE = "android.app.usage.CacheQuotaService";
  
      /** {@hide} **/
      public static final String REQUEST_LIST_KEY = "requests";
  
      private CacheQuotaServiceWrapper mWrapper;
      private Handler mHandler;
  
      @Override
      public void onCreate() {
          super.onCreate();
          mWrapper = new CacheQuotaServiceWrapper();
          mHandler = new ServiceHandler(getMainLooper());
      }
  
      @Override
      public IBinder onBind(Intent intent) {
          return mWrapper;
      }
  
      /**
       * Processes the cache quota list upon receiving a list of requests.
       * @param requests A list of cache quotas to fulfill.
       * @return A completed list of cache quota requests.
       */
      public abstract List<CacheQuotaHint> onComputeCacheQuotaHints(
              List<CacheQuotaHint> requests);
  
      private final class CacheQuotaServiceWrapper extends ICacheQuotaService.Stub {
          @Override
          public void computeCacheQuotaHints(
                  RemoteCallback callback, List<CacheQuotaHint> requests) {
              final Pair<RemoteCallback, List<CacheQuotaHint>> pair =
                      Pair.create(callback, requests);
              Message msg = mHandler.obtainMessage(ServiceHandler.MSG_SEND_LIST, pair);
              mHandler.sendMessage(msg);
          }
      }
  
      private final class ServiceHandler extends Handler {
          public static final int MSG_SEND_LIST = 1;
  
          public ServiceHandler(Looper looper) {
              super(looper, null, true);
          }
  
          @Override
          public void handleMessage(Message msg) {
              final int action = msg.what;
              switch (action) {
                  case MSG_SEND_LIST:
                      final Pair<RemoteCallback, List<CacheQuotaHint>> pair =
                              (Pair<RemoteCallback, List<CacheQuotaHint>>) msg.obj;
                      List<CacheQuotaHint> processed = onComputeCacheQuotaHints(pair.second);
                      final Bundle data = new Bundle();
                      data.putParcelableList(REQUEST_LIST_KEY, processed);
  
                      final RemoteCallback callback = pair.first;
                      callback.sendResult(data);
                      break;
                  default:
                      Log.w(TAG, "Handling unknown message: " + action);
              }
          }
      }
  }
  