content: /*
   * Copyright (C) 2016 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.os.health;
  
  import android.annotation.SystemService;
  import android.annotation.UnsupportedAppUsage;
  import android.content.Context;
  import android.os.BatteryStats;
  import android.os.Build;
  import android.os.Process;
  import android.os.RemoteException;
  import android.os.ServiceManager;
  import android.os.ServiceManager.ServiceNotFoundException;
  
  import com.android.internal.app.IBatteryStats;
  
  /**
   * Provides access to data about how various system resources are used by applications.
   * @more
   * <p>
   * If you are going to be using this class to log your application's resource usage,
   * please consider the amount of resources (battery, network, etc) that will be used
   * by the logging itself.  It can be substantial.
   * <p>
   * <b>Battery Usage</b><br>
   * Since Android version {@link android.os.Build.VERSION_CODES#Q}, the statistics related to power
   * (battery) usage are recorded since the device was last considered fully charged (for previous
   * versions, it is instead since the device was last unplugged).
   * It is expected that applications schedule more work to do while the device is
   * plugged in (e.g. using {@link android.app.job.JobScheduler JobScheduler}), and
   * while that can affect charging rates, it is still preferable to actually draining
   * the battery.
   */
  @SystemService(Context.SYSTEM_HEALTH_SERVICE)
  public class SystemHealthManager {
      private final IBatteryStats mBatteryStats;
  
      /**
       * Construct a new SystemHealthManager object.
       * @hide
       */
      @UnsupportedAppUsage
      public SystemHealthManager() {
          this(IBatteryStats.Stub.asInterface(ServiceManager.getService(BatteryStats.SERVICE_NAME)));
      }
  
      /** {@hide} */
      public SystemHealthManager(IBatteryStats batteryStats) {
          mBatteryStats = batteryStats;
      }
  
      /**
       * Obtain a SystemHealthManager object for the supplied context.
       *
       * @hide
       */
      @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
      public static SystemHealthManager from(Context context) {
          return (SystemHealthManager)context.getSystemService(Context.SYSTEM_HEALTH_SERVICE);
      }
  
      /**
       * Return a {@link HealthStats} object containing a snapshot of system health
       * metrics for the given uid (user-id, which in usually corresponds to application).
       * @more
       *
       * An application must hold the {@link android.Manifest.permission#BATTERY_STATS
       * android.permission.BATTERY_STATS} permission in order to retrieve any HealthStats
       * other than its own.
       *
       * @param uid User ID for a given application.
       * @return A {@link HealthStats} object containing the metrics for the requested
       * application. The keys for this HealthStats object will be from the {@link UidHealthStats}
       * class.
       * @see Process#myUid() Process.myUid()
       */
      public HealthStats takeUidSnapshot(int uid) {
          try {
              final HealthStatsParceler parceler = mBatteryStats.takeUidSnapshot(uid);
              return parceler.getHealthStats();
          } catch (RemoteException ex) {
              throw new RuntimeException(ex);
          }
      }
  
      /**
       * Return a {@link HealthStats} object containing a snapshot of system health
       * metrics for the application calling this API. This method is the same as calling
       * {@code takeUidSnapshot(Process.myUid())}.
       *
       * @return A {@link HealthStats} object containing the metrics for this application. The keys
       * for this HealthStats object will be from the {@link UidHealthStats} class.
       */
      public HealthStats takeMyUidSnapshot() {
          return takeUidSnapshot(Process.myUid());
      }
  
      /**
       * Return a {@link HealthStats} object containing a snapshot of system health
       * metrics for the given uids (user-id, which in usually corresponds to application).
       * @more
       *
       * An application must hold the {@link android.Manifest.permission#BATTERY_STATS
       * android.permission.BATTERY_STATS} permission in order to retrieve any HealthStats
       * other than its own.
       *
       * @param uids An array of User IDs to retrieve.
       * @return An array of {@link HealthStats} objects containing the metrics for each of
       * the requested uids. The keys for this HealthStats object will be from the
       * {@link UidHealthStats} class.
       */
      public HealthStats[] takeUidSnapshots(int[] uids) {
          try {
              final HealthStatsParceler[] parcelers = mBatteryStats.takeUidSnapshots(uids);
              final HealthStats[] results = new HealthStats[uids.length];
              final int N = uids.length;
              for (int i=0; i<N; i++) {
                  results[i] = parcelers[i].getHealthStats();
              }
              return results;
          } catch (RemoteException ex) {
              throw new RuntimeException(ex);
          }
      }
  
  }
  
  