content: /*
   * Copyright (C) 2015 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.backup;
  
  import static com.android.server.backup.BackupManagerService.DEBUG_SCHEDULING;
  
  import android.app.AlarmManager;
  import android.app.job.JobInfo;
  import android.app.job.JobParameters;
  import android.app.job.JobScheduler;
  import android.app.job.JobService;
  import android.content.ComponentName;
  import android.content.Context;
  import android.os.Bundle;
  import android.os.RemoteException;
  import android.util.Slog;
  import android.util.SparseBooleanArray;
  import android.util.SparseLongArray;
  
  import com.android.internal.annotations.GuardedBy;
  import com.android.internal.annotations.VisibleForTesting;
  
  import java.util.Random;
  
  /**
   * Job for scheduling key/value backup work.  This module encapsulates all
   * of the policy around when those backup passes are executed.
   */
  public class KeyValueBackupJob extends JobService {
      private static final String TAG = "KeyValueBackupJob";
      private static ComponentName sKeyValueJobService =
              new ComponentName("android", KeyValueBackupJob.class.getName());
  
      private static final String USER_ID_EXTRA_KEY = "userId";
  
      // Once someone asks for a backup, this is how long we hold off until we find
      // an on-charging opportunity.  If we hit this max latency we will run the operation
      // regardless.  Privileged callers can always trigger an immediate pass via
      // BackupManager.backupNow().
      private static final long MAX_DEFERRAL = AlarmManager.INTERVAL_DAY;
  
      @GuardedBy("KeyValueBackupJob.class")
      private static final SparseBooleanArray sScheduledForUserId = new SparseBooleanArray();
      @GuardedBy("KeyValueBackupJob.class")
      private static final SparseLongArray sNextScheduledForUserId = new SparseLongArray();
  
      @VisibleForTesting
      public static final int MIN_JOB_ID = 52417896;
      @VisibleForTesting
      public static final int MAX_JOB_ID = 52418896;
  
      public static void schedule(int userId, Context ctx, BackupManagerConstants constants) {
          schedule(userId, ctx, 0, constants);
      }
  
      public static void schedule(int userId, Context ctx, long delay,
              BackupManagerConstants constants) {
          synchronized (KeyValueBackupJob.class) {
              if (sScheduledForUserId.get(userId)) {
                  return;
              }
  
              final long interval;
              final long fuzz;
              final int networkType;
              final boolean needsCharging;
  
              synchronized (constants) {
                  interval = constants.getKeyValueBackupIntervalMilliseconds();
                  fuzz = constants.getKeyValueBackupFuzzMilliseconds();
                  networkType = constants.getKeyValueBackupRequiredNetworkType();
                  needsCharging = constants.getKeyValueBackupRequireCharging();
              }
              if (delay <= 0) {
                  delay = interval + new Random().nextInt((int) fuzz);
              }
              if (DEBUG_SCHEDULING) {
                  Slog.v(TAG, "Scheduling k/v pass in " + (delay / 1000 / 60) + " minutes");
              }
  
              JobInfo.Builder builder = new JobInfo.Builder(getJobIdForUserId(userId),
                      sKeyValueJobService)
                      .setMinimumLatency(delay)
                      .setRequiredNetworkType(networkType)
                      .setRequiresCharging(needsCharging)
                      .setOverrideDeadline(MAX_DEFERRAL);
  
              Bundle extraInfo = new Bundle();
              extraInfo.putInt(USER_ID_EXTRA_KEY, userId);
              builder.setTransientExtras(extraInfo);
  
              JobScheduler js = (JobScheduler) ctx.getSystemService(Context.JOB_SCHEDULER_SERVICE);
              js.schedule(builder.build());
  
              sScheduledForUserId.put(userId, true);
              sNextScheduledForUserId.put(userId, System.currentTimeMillis() + delay);
          }
      }
  
      public static void cancel(int userId, Context ctx) {
          synchronized (KeyValueBackupJob.class) {
              JobScheduler js = (JobScheduler) ctx.getSystemService(
                      Context.JOB_SCHEDULER_SERVICE);
              js.cancel(getJobIdForUserId(userId));
  
              clearScheduledForUserId(userId);
          }
      }
  
      public static long nextScheduled(int userId) {
          synchronized (KeyValueBackupJob.class) {
              return sNextScheduledForUserId.get(userId);
          }
      }
  
      @VisibleForTesting
      public static boolean isScheduled(int userId) {
          synchronized (KeyValueBackupJob.class) {
              return sScheduledForUserId.get(userId);
          }
      }
  
      @Override
      public boolean onStartJob(JobParameters params) {
          int userId = params.getTransientExtras().getInt(USER_ID_EXTRA_KEY);
  
          synchronized (KeyValueBackupJob.class) {
              clearScheduledForUserId(userId);
          }
  
          // Time to run a key/value backup!
          Trampoline service = BackupManagerService.getInstance();
          try {
              service.backupNowForUser(userId);
          } catch (RemoteException e) {}
  
          // This was just a trigger; ongoing wakelock management is done by the
          // rest of the backup system.
          return false;
      }
  
      @Override
      public boolean onStopJob(JobParameters params) {
          // Intentionally empty; the job starting was just a trigger
          return false;
      }
  
      @GuardedBy("KeyValueBackupJob.class")
      private static void clearScheduledForUserId(int userId) {
          sScheduledForUserId.delete(userId);
          sNextScheduledForUserId.delete(userId);
      }
  
      private static int getJobIdForUserId(int userId) {
          return JobIdManager.getJobIdForUserId(MIN_JOB_ID, MAX_JOB_ID, userId);
      }
  }
  