1 /* 2 * Copyright (C) 2016 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 android.os.health; 18 19 import android.annotation.SystemService; 20 import android.annotation.UnsupportedAppUsage; 21 import android.content.Context; 22 import android.os.BatteryStats; 23 import android.os.Build; 24 import android.os.Process; 25 import android.os.RemoteException; 26 import android.os.ServiceManager; 27 import android.os.ServiceManager.ServiceNotFoundException; 28 29 import com.android.internal.app.IBatteryStats; 30 31 /** 32 * Provides access to data about how various system resources are used by applications. 33 * @more 34 * <p> 35 * If you are going to be using this class to log your application's resource usage, 36 * please consider the amount of resources (battery, network, etc) that will be used 37 * by the logging itself. It can be substantial. 38 * <p> 39 * <b>Battery Usage</b><br> 40 * Since Android version {@link android.os.Build.VERSION_CODES#Q}, the statistics related to power 41 * (battery) usage are recorded since the device was last considered fully charged (for previous 42 * versions, it is instead since the device was last unplugged). 43 * It is expected that applications schedule more work to do while the device is 44 * plugged in (e.g. using {@link android.app.job.JobScheduler JobScheduler}), and 45 * while that can affect charging rates, it is still preferable to actually draining 46 * the battery. 47 */ 48 @SystemService(Context.SYSTEM_HEALTH_SERVICE) 49 public class SystemHealthManager { 50 private final IBatteryStats mBatteryStats; 51 52 /** 53 * Construct a new SystemHealthManager object. 54 * @hide 55 */ 56 @UnsupportedAppUsage SystemHealthManager()57 public SystemHealthManager() { 58 this(IBatteryStats.Stub.asInterface(ServiceManager.getService(BatteryStats.SERVICE_NAME))); 59 } 60 61 /** {@hide} */ SystemHealthManager(IBatteryStats batteryStats)62 public SystemHealthManager(IBatteryStats batteryStats) { 63 mBatteryStats = batteryStats; 64 } 65 66 /** 67 * Obtain a SystemHealthManager object for the supplied context. 68 * 69 * @hide 70 */ 71 @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023) from(Context context)72 public static SystemHealthManager from(Context context) { 73 return (SystemHealthManager)context.getSystemService(Context.SYSTEM_HEALTH_SERVICE); 74 } 75 76 /** 77 * Return a {@link HealthStats} object containing a snapshot of system health 78 * metrics for the given uid (user-id, which in usually corresponds to application). 79 * @more 80 * 81 * An application must hold the {@link android.Manifest.permission#BATTERY_STATS 82 * android.permission.BATTERY_STATS} permission in order to retrieve any HealthStats 83 * other than its own. 84 * 85 * @param uid User ID for a given application. 86 * @return A {@link HealthStats} object containing the metrics for the requested 87 * application. The keys for this HealthStats object will be from the {@link UidHealthStats} 88 * class. 89 * @see Process#myUid() Process.myUid() 90 */ takeUidSnapshot(int uid)91 public HealthStats takeUidSnapshot(int uid) { 92 try { 93 final HealthStatsParceler parceler = mBatteryStats.takeUidSnapshot(uid); 94 return parceler.getHealthStats(); 95 } catch (RemoteException ex) { 96 throw new RuntimeException(ex); 97 } 98 } 99 100 /** 101 * Return a {@link HealthStats} object containing a snapshot of system health 102 * metrics for the application calling this API. This method is the same as calling 103 * {@code takeUidSnapshot(Process.myUid())}. 104 * 105 * @return A {@link HealthStats} object containing the metrics for this application. The keys 106 * for this HealthStats object will be from the {@link UidHealthStats} class. 107 */ takeMyUidSnapshot()108 public HealthStats takeMyUidSnapshot() { 109 return takeUidSnapshot(Process.myUid()); 110 } 111 112 /** 113 * Return a {@link HealthStats} object containing a snapshot of system health 114 * metrics for the given uids (user-id, which in usually corresponds to application). 115 * @more 116 * 117 * An application must hold the {@link android.Manifest.permission#BATTERY_STATS 118 * android.permission.BATTERY_STATS} permission in order to retrieve any HealthStats 119 * other than its own. 120 * 121 * @param uids An array of User IDs to retrieve. 122 * @return An array of {@link HealthStats} objects containing the metrics for each of 123 * the requested uids. The keys for this HealthStats object will be from the 124 * {@link UidHealthStats} class. 125 */ takeUidSnapshots(int[] uids)126 public HealthStats[] takeUidSnapshots(int[] uids) { 127 try { 128 final HealthStatsParceler[] parcelers = mBatteryStats.takeUidSnapshots(uids); 129 final HealthStats[] results = new HealthStats[uids.length]; 130 final int N = uids.length; 131 for (int i=0; i<N; i++) { 132 results[i] = parcelers[i].getHealthStats(); 133 } 134 return results; 135 } catch (RemoteException ex) { 136 throw new RuntimeException(ex); 137 } 138 } 139 140 } 141 142