ａｎｄｒｏｉｄ功耗相关资料
2016-12-14 14:48
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引用其他优秀资料，如有侵权，请联系我，删除
android电量计算（软硬件）： http://gityuan.com/2016/01/10/power_rank/
android耗电统计算法 ：
http://gityuan.com/2016/01/10/power_rank/
基于Android 6.0的源码剖析
一、 概述
Android系统中的耗电统计分为软件排行榜和硬件排行榜，软件排序榜是统计每个App的耗电总量的排行榜，硬件排行榜则是统计主要硬件的耗电总量的排行榜。
涉及耗电统计相关的核心类：
/framework/base/core/res/res/xml/power_profile.xml
/framework/base/core/java/com/andorid/internal/os/PowerProfile.java
/framework/base/core/java/com/andorid/internal/os/BatteryStatsHelper.java
/framework/base/core/java/com/andorid/internal/os/BatterySipper.java
• PowerProfile.java用于获取各个组件的电流数值；power_profile.xml是一个可配置的功耗数据文件。
• 软件排行榜的计算算法：BatteryStatsHelper类中的processAppUsage()方法
• 硬件排行榜的计算算法：BatteryStatsHelper类中的processMiscUsage()方法
下面直接切入主题，分别讲述软件和硬件的耗电统计
二、软件排行榜
processAppUsage统计每个App的耗电情况
private void processAppUsage(SparseArray<UserHandle> asUsers) {
//判断是否统计所有用户的App耗电使用情况，目前该参数为true
final boolean forAllUsers = (asUsers.get(UserHandle.USER_ALL) != null);
mStatsPeriod = mTypeBatteryRealtime; //耗电的统计时长
BatterySipper osSipper = null;
//获取每个uid的统计信息
final SparseArray<? extends Uid> uidStats = mStats.getUidStats();
final int NU = uidStats.size();
// 开始遍历每个uid的耗电情况
for (int iu = 0; iu < NU; iu++) {
final Uid u = uidStats.valueAt(iu);
final BatterySipper app = new BatterySipper(BatterySipper.DrainType.APP, u, 0);
mCpuPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mWakelockPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mMobileRadioPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mWifiPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mBluetoothPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mSensorPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mCameraPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mFlashlightPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
final double totalPower = app.sumPower(); //对App的8项耗电再进行累加。
//将app添加到 app list, WiFi, Bluetooth等，或其他用户列表
if (totalPower != 0 || u.getUid() == 0) {
final int uid = app.getUid();
final int userId = UserHandle.getUserId(uid);
if (uid == Process.WIFI_UID) { //uid为wifi的情况
mWifiSippers.add(app);
} else if (uid == Process.BLUETOOTH_UID) {//uid为蓝牙的情况
mBluetoothSippers.add(app);
} else if (!forAllUsers && asUsers.get(userId) == null
&& UserHandle.getAppId(uid) >= Process.FIRST_APPLICATION_UID) {
//就目前来说 forAllUsers=true，不会进入此分支。
List<BatterySipper> list = mUserSippers.get(userId);
if (list == null) {
list = new ArrayList<>();
mUserSippers.put(userId, list);
}
list.add(app);
} else {
mUsageList.add(app); //把app耗电加入到mUsageList
}
if (uid == 0) {
osSipper = app; // root用户，代表操作系统的耗电量
}
}
}
//app之外的耗电量
if (osSipper != null) {
mWakelockPowerCalculator.calculateRemaining(osSipper, mStats, mRawRealtime, mRawUptime, mStatsType);
osSipper.sumPower();
}
}
流程分析：
mTypeBatteryRealtime
mTypeBatteryRealtime = mStats.computeBatteryRealtime(rawRealtimeUs, mStatsType);
private int mStatsType = BatteryStats.STATS_SINCE_CHARGED;
BatteryStats.STATS_SINCE_CHARGED，计算规则是从上次充满电后数据；另外STATS_SINCE_UNPLUGGED是拔掉USB线后的数据。说明充电时间的计算是从上一次拔掉设备到现在的耗电量统计。
耗电计算项
8大模块的耗电计算器，都继承与PowerCalculator抽象类
计算值添加到列表
• mWifiSippers.add(app)： uid为wifi的情况
• mBluetoothSippers.add(app)： uid为蓝牙的情况
• mUsageList.add(app)： app耗电加入到mUsageList
• osSipper： root用户，代表操作系统的耗电量，app之外的wakelock耗电也计算该项
公式
processAppUsage统计的是Uid。一般地来说每个App都对应一个Uid，但存在以下特殊情况，如果两个或多个App签名和 sharedUserId相同，则在运行时，他们拥有相同Uid。对于系统应用uid为system，则统一算入system应用的耗电量。
Uid_Power = process_1_Power + … + process_N_Power，其中所有进程都是属于同一个uid。 当同一的uid下，只有一个进程时，Uid_Power = process_Power;
其中process_Power = CPU功耗 + Wakelock功耗 + 无线电功耗 + WIFI功耗 + 蓝牙功耗 + Sensor功耗 + 相机功耗 + 闪光灯功耗。
接下来开始分配说明每一项的功耗计算公式。
2.1 CPU
CPU功耗项的计算是通过CpuPowerCalculator类
初始化
public CpuPowerCalculator(PowerProfile profile) {
final int speedSteps = profile.getNumSpeedSteps(); //获取cpu的主频等级的级数
mPowerCpuNormal = new double[speedSteps]; //用于记录不同频率下的功耗值
mSpeedStepTimes = new long[speedSteps];
for (int p = 0; p < speedSteps; p++) {
mPowerCpuNormal[p] = profile.getAveragePower(PowerProfile.POWER_CPU_ACTIVE, p);
}
}
从对象的构造方法，可以看出PowerProfile类提供相应所需的基础功耗值，而真正的功耗值数据来源于power_profile.xml文件，故可以通过配置合理的基础功耗值，来达到较为精准的功耗统计结果。后续所有的PowerCalculator子类在构造方法中都有会相应所需的功耗配置项。
CPU功耗可配置项：
• POWER_CPU_SPEEDS = “cpu.speeds” 所对应的数组，配置CPU的频点，频点个数取决于CPU硬件特性
• POWER_CPU_ACTIVE = “cpu.active” 所对应的数组，配置CPU频点所对应的单位功耗(mAh)
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
final int speedSteps = mSpeedStepTimes.length;
long totalTimeAtSpeeds = 0;
for (int step = 0; step < speedSteps; step++) {
//获取Cpu不同频点下的运行时间
mSpeedStepTimes[step] = u.getTimeAtCpuSpeed(step, statsType);
totalTimeAtSpeeds += mSpeedStepTimes[step];
}
totalTimeAtSpeeds = Math.max(totalTimeAtSpeeds, 1); //获取Cpu总共的运行时间
app.cpuTimeMs = (u.getUserCpuTimeUs(statsType) + u.getSystemCpuTimeUs(statsType)) / 1000; //获取cpu在用户态和内核态的执行时长
double cpuPowerMaMs = 0;
// 计算Cpu的耗电量
for (int step = 0; step < speedSteps; step++) {
final double ratio = (double) mSpeedStepTimes[step] / totalTimeAtSpeeds;
final double cpuSpeedStepPower = ratio * app.cpuTimeMs * mPowerCpuNormal[step];
cpuPowerMaMs += cpuSpeedStepPower;
}
//追踪不同进程的耗电情况
double highestDrain = 0;
app.cpuFgTimeMs = 0;
final ArrayMap<String, ? extends BatteryStats.Uid.Proc> processStats = u.getProcessStats();
final int processStatsCount = processStats.size();
//统计同一个uid的不同进程的耗电情况
for (int i = 0; i < processStatsCount; i++) {
final BatteryStats.Uid.Proc ps = processStats.valueAt(i);
final String processName = processStats.keyAt(i);
app.cpuFgTimeMs += ps.getForegroundTime(statsType);
final long costValue = ps.getUserTime(statsType) + ps.getSystemTime(statsType) + ps.getForegroundTime(statsType);
//App可以有多个packages和多个不同的进程，跟踪耗电最大的进程
if (app.packageWithHighestDrain == null ||
app.packageWithHighestDrain.startsWith("*")) {
highestDrain = costValue;
app.packageWithHighestDrain = processName;
} else if (highestDrain < costValue && !processName.startsWith("*")) {
highestDrain = costValue;
app.packageWithHighestDrain = processName;
}
}
//当Cpu前台时间 大于Cpu时间，将cpuFgTimeMs赋值为cpuTimeMs
if (app.cpuFgTimeMs > app.cpuTimeMs) {
app.cpuTimeMs = app.cpuFgTimeMs;
}
app.cpuPowerMah = cpuPowerMaMs / (60 * 60 * 1000); //转换为mAh
}
}
子公式
cpuPower = ratio_1 * cpu_time * cpu_ratio_1_power + … +ratio_n * cpu_time * cpu_ratio_n_power
其中： ratio_i = cpu_speed_time/ cpu_speeds_total_time，（i=1,2,…,N，N为CPU频点个数）
2.2 Wakelock
Wakelock功耗项的计算是通过WakelockPowerCalculator类
初始化
public WakelockPowerCalculator(PowerProfile profile) {
mPowerWakelock = profile.getAveragePower(PowerProfile.POWER_CPU_AWAKE);
}
Wakelock功耗可配置项：
power_profile.xml文件：
• POWER_CPU_AWAKE = “cpu.awake” 所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
long wakeLockTimeUs = 0;
final ArrayMap<String, ? extends BatteryStats.Uid.Wakelock> wakelockStats =
u.getWakelockStats();
final int wakelockStatsCount = wakelockStats.size();
for (int i = 0; i < wakelockStatsCount; i++) {
final BatteryStats.Uid.Wakelock wakelock = wakelockStats.valueAt(i);
//只统计partial wake locks，由于 full wake locks在灭屏后会自动取消
BatteryStats.Timer timer = wakelock.getWakeTime(BatteryStats.WAKE_TYPE_PARTIAL);
if (timer != null) {
wakeLockTimeUs += timer.getTotalTimeLocked(rawRealtimeUs, statsType);
}
}
app.wakeLockTimeMs = wakeLockTimeUs / 1000; //转换单位为秒
mTotalAppWakelockTimeMs += app.wakeLockTimeMs;
//计算唤醒功耗
app.wakeLockPowerMah = (app.wakeLockTimeMs * mPowerWakelock) / (1000*60*60);
}
子公式
wakeLockPowerMah = (app.wakeLockTimeMs * mPowerWakelock) / (10006060);
2.3 Wifi
WifiPowerCalculator
Wifi功耗项的计算是通过WifiPowerCalculator类
初始化
public WifiPowerCalculator(PowerProfile profile) {
mIdleCurrentMa = profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_IDLE);
mTxCurrentMa = profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_TX);
mRxCurrentMa = profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_RX);
}
Wifi功耗可配置项：
• POWER_WIFI_CONTROLLER_IDLE = “wifi.controller.idle” 项所对应的值
• POWER_WIFI_CONTROLLER_RX = “wifi.controller.rx” 项所对应的值
• POWER_WIFI_CONTROLLER_TX = “wifi.controller.tx” 项所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
final long idleTime = u.getWifiControllerActivity(BatteryStats.CONTROLLER_IDLE_TIME, statsType);
final long txTime = u.getWifiControllerActivity(BatteryStats.CONTROLLER_TX_TIME, statsType);
final long rxTime = u.getWifiControllerActivity(BatteryStats.CONTROLLER_RX_TIME, statsType);
app.wifiRunningTimeMs = idleTime + rxTime + txTime; //计算wifi的时间
app.wifiPowerMah = ((idleTime * mIdleCurrentMa) + (txTime * mTxCurrentMa) + (rxTime * mRxCurrentMa)) / (1000*60*60);
mTotalAppPowerDrain += app.wifiPowerMah;
app.wifiRxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_WIFI_RX_DATA,
statsType);
app.wifiTxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_WIFI_TX_DATA,
statsType);
app.wifiRxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_WIFI_RX_DATA,
statsType);
app.wifiTxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_WIFI_TX_DATA,
statsType);
}
子公式
wifiPowerMah = ((idleTime * mIdleCurrentMa) + (txTime * mTxCurrentMa) + (rxTime * mRxCurrentMa)) / (1000* 60* 60);
WifiPowerEstimator
可配置项
• POWER_WIFI_ACTIVE = “wifi.active”（用于计算mWifiPowerPerPacket）
• POWER_WIFI_ON=”wifi.on”
• POWER_WIFI_SCAN = “wifi.scan”
• POWER_WIFI_BATCHED_SCAN = “wifi.batchedscan”;
功耗计算-
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
app.wifiRxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_WIFI_RX_DATA,
statsType);
app.wifiTxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_WIFI_TX_DATA,
statsType);
app.wifiRxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_WIFI_RX_DATA,
statsType);
app.wifiTxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_WIFI_TX_DATA,
statsType);
final double wifiPacketPower = (app.wifiRxPackets + app.wifiTxPackets)
* mWifiPowerPerPacket;
app.wifiRunningTimeMs = u.getWifiRunningTime(rawRealtimeUs, statsType) / 1000;
mTotalAppWifiRunningTimeMs += app.wifiRunningTimeMs;
final double wifiLockPower = (app.wifiRunningTimeMs * mWifiPowerOn) / (1000*60*60);
final long wifiScanTimeMs = u.getWifiScanTime(rawRealtimeUs, statsType) / 1000;
final double wifiScanPower = (wifiScanTimeMs * mWifiPowerScan) / (1000*60*60);
double wifiBatchScanPower = 0;
for (int bin = 0; bin < BatteryStats.Uid.NUM_WIFI_BATCHED_SCAN_BINS; bin++) {
final long batchScanTimeMs =
u.getWifiBatchedScanTime(bin, rawRealtimeUs, statsType) / 1000;
final double batchScanPower = (batchScanTimeMs * mWifiPowerBatchScan) / (1000*60*60);
wifiBatchScanPower += batchScanPower;
}
app.wifiPowerMah = wifiPacketPower + wifiLockPower + wifiScanPower + wifiBatchScanPower;
}
其中 BatteryStats.Uid.NUM_WIFI_BATCHED_SCAN_BINS=5
另外
private static double getWifiPowerPerPacket(PowerProfile profile) {
final long WIFI_BPS = 1000000; //初略估算每秒的收发1000000bit
final double WIFI_POWER = profile.getAveragePower(PowerProfile.POWER_WIFI_ACTIVE)
/ 3600;
return (WIFI_POWER / (((double)WIFI_BPS) / 8 / 2048)) / (60*60);
}
子公式
wifiPowerMah = wifiPacketPower + wifiLockPower + wifiScanPower + wifiBatchScanPower;
wifiPacketPower = (wifiRxPackets + wifiTxPackets) * mWifiPowerPerPacket; wifiLockPower = (wifiRunningTimeMs * mWifiPowerOn) / (1000* 60* 60); wifiScanPower = (wifiScanTimeMs * mWifiPowerScan) / (1000* 60* 60);
wifiBatchScanPower = ∑ (batchScanTimeMs * mWifiPowerBatchScan) / (1000* 60* 60) ，5次相加。
2.4 Bluetooth
Bluetooth功耗项的计算是通过BluetoothPowerCalculator类
初始化
public BluetoothPowerCalculator(PowerProfile profile) {
mIdleMa = profile.getAveragePower(PowerProfile.POWER_BLUETOOTH_CONTROLLER_IDLE);
mRxMa = profile.getAveragePower(PowerProfile.POWER_BLUETOOTH_CONTROLLER_RX);
mTxMa = profile.getAveragePower(PowerProfile.POWER_BLUETOOTH_CONTROLLER_TX);
}
Bluetooth功耗可配置项(目前蓝牙功耗计算的方法为空，此配置暂可忽略)：
• POWER_BLUETOOTH_CONTROLLER_IDLE = “bluetooth.controller.idle” 所对应的值
• POWER_BLUETOOTH_CONTROLLER_RX = “bluetooth.controller.rx” 所对应的值
• POWER_BLUETOOTH_CONTROLLER_TX = “bluetooth.controller.tx” 所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
// No per-app distribution yet.
}
子公式
bluePower = 0;
还没有给每个App统计蓝牙的算法。
2.5 Camera
Camera功耗项的计算是通过CameraPowerCalculator类
初始化
public CameraPowerCalculator(PowerProfile profile) {
mCameraPowerOnAvg = profile.getAveragePower(PowerProfile.POWER_CAMERA);
}
Camera功耗可配置项：
• POWER_CAMERA = “camera.avg” 所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
//对于camera功耗的评估比较粗，camera打开认定功耗一致
final BatteryStats.Timer timer = u.getCameraTurnedOnTimer();
if (timer != null) {
final long totalTime = timer.getTotalTimeLocked(rawRealtimeUs, statsType) / 1000;
app.cameraTimeMs = totalTime;
app.cameraPowerMah = (totalTime * mCameraPowerOnAvg) / (1000*60*60);
} else {
app.cameraTimeMs = 0;
app.cameraPowerMah = 0;
}
}
子公式
cameraPowerMah = (totalTime * mCameraPowerOnAvg) / (10006060);
2.6 Flashlight
Flashlight功耗项的计算是通过FlashlightPowerCalculator类
初始化
public FlashlightPowerCalculator(PowerProfile profile) {
mFlashlightPowerOnAvg = profile.getAveragePower(PowerProfile.POWER_FLASHLIGHT);
}
Flashlight功耗可配置项：
• POWER_FLASHLIGHT = “camera.flashlight” 所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
final BatteryStats.Timer timer = u.getFlashlightTurnedOnTimer();
if (timer != null) {
final long totalTime = timer.getTotalTimeLocked(rawRealtimeUs, statsType) / 1000;
app.flashlightTimeMs = totalTime;
app.flashlightPowerMah = (totalTime * mFlashlightPowerOnAvg) / (1000*60*60);
} else {
app.flashlightTimeMs = 0;
app.flashlightPowerMah = 0;
}
}
子公式
flashlightPowerMah = (totalTime * mFlashlightPowerOnAvg) / (10006060);
flashlight计算方式与Camera功耗计算思路一样。
2.7 MobileRadio
无线电功耗项的计算是通过MobileRadioPowerCalculator类
初始化
public MobileRadioPowerCalculator(PowerProfile profile, BatteryStats stats) {
mPowerRadioOn = profile.getAveragePower(PowerProfile.POWER_RADIO_ACTIVE);
for (int i = 0; i < mPowerBins.length; i++) {
mPowerBins[i] = profile.getAveragePower(PowerProfile.POWER_RADIO_ON, i);
}
mPowerScan = profile.getAveragePower(PowerProfile.POWER_RADIO_SCANNING);
mStats = stats;
}
无线电功耗可配置项：
• POWER_RADIO_ACTIVE = “radio.active” 所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
app.mobileRxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_MOBILE_RX_DATA, statsType);
app.mobileTxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_MOBILE_TX_DATA, statsType);
app.mobileActive = u.getMobileRadioActiveTime(statsType) / 1000;
app.mobileActiveCount = u.getMobileRadioActiveCount(statsType);
app.mobileRxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_MOBILE_RX_DATA,
statsType);
app.mobileTxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_MOBILE_TX_DATA,
statsType);
if (app.mobileActive > 0) {
// 当追踪信号的开头，则采用mobileActive时间乘以相应功耗
mTotalAppMobileActiveMs += app.mobileActive;
app.mobileRadioPowerMah = (app.mobileActive * mPowerRadioOn) / (1000*60*60);
} else {
//当没有追踪信号开关，则采用收发数据包来评估功耗
app.mobileRadioPowerMah = (app.mobileRxPackets + app.mobileTxPackets) * getMobilePowerPerPacket(rawRealtimeUs, statsType);
}
}
计算出每收/发一个数据包的功耗值
private double getMobilePowerPerPacket(long rawRealtimeUs, int statsType) {
final long MOBILE_BPS = 200000; //Extract average bit rates from system
final double MOBILE_POWER = mPowerRadioOn / 3600;
final long mobileRx = mStats.getNetworkActivityPackets(BatteryStats.NETWORK_MOBILE_RX_DATA,
statsType);
final long mobileTx = mStats.getNetworkActivityPackets(BatteryStats.NETWORK_MOBILE_TX_DATA,
statsType);
final long mobileData = mobileRx + mobileTx;
final long radioDataUptimeMs =
mStats.getMobileRadioActiveTime(rawRealtimeUs, statsType) / 1000;
final double mobilePps = (mobileData != 0 && radioDataUptimeMs != 0)
? (mobileData / (double)radioDataUptimeMs)
: (((double)MOBILE_BPS) / 8 / 2048);
return (MOBILE_POWER / mobilePps) / (60*60);
}
子公式
情况一：当追踪信号活动时间，即mobileActive > 0，采用：
mobileRadioPowerMah = (app.mobileActive * mPowerRadioOn) / (1000* 60* 60);
情况二：当没有追踪信号活动时间，则采用：
mobileRadioPowerMah = (app.mobileRxPackets + app.mobileTxPackets) * MobilePowerPerPacket
其中MobilePowerPerPacket = (（mPowerRadioOn / 3600） / mobilePps) / (60*60)， mobilePps= （mobileRx + mobileTx）/radioDataUptimeMs
2.8 Sensor
Sensor功耗项的计算是通过SensorPowerCalculator类
初始化
public SensorPowerCalculator(PowerProfile profile, SensorManager sensorManager) {
mSensors = sensorManager.getSensorList(Sensor.TYPE_ALL);
mGpsPowerOn = profile.getAveragePower(PowerProfile.POWER_GPS_ON);
}
Sensor功耗可配置项：
• POWER_GPS_ON = “gps.on” 所对应的值
功耗计算
d calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs, long rawUptimeUs, int statsType) {
// 计算没有个Uid
final SparseArray<? extends BatteryStats.Uid.Sensor> sensorStats = u.getSensorStats();
final int NSE = sensorStats.size();
for (int ise = 0; ise < NSE; ise++) {
final BatteryStats.Uid.Sensor sensor = sensorStats.valueAt(ise);
final int sensorHandle = sensorStats.keyAt(ise);
final BatteryStats.Timer timer = sensor.getSensorTime();
final long sensorTime = timer.getTotalTimeLocked(rawRealtimeUs, statsType) / 1000;
switch (sensorHandle) {
case BatteryStats.Uid.Sensor.GPS: //对于uid为GPS的情况
app.gpsTimeMs = sensorTime;
app.gpsPowerMah = (app.gpsTimeMs * mGpsPowerOn) / (1000*60*60);
break;
default:
final int sensorsCount = mSensors.size();
for (int i = 0; i < sensorsCount; i++) { //统计所有的sensor情况
final Sensor s = mSensors.get(i);
if (s.getHandle() == sensorHandle) {
app.sensorPowerMah += (sensorTime * s.getPower()) / (1000*60*60);
break;
}
}
break;
}
}
}
GPS的功耗计算与sensor的计算方法放在一块
子公式
gpsPowerMah = (app.gpsTimeMs * mGpsPowerOn) / (1000* 60* 60);
软件功耗总公式
BatterySipper中，功耗计算方法：
public double sumPower() {
return totalPowerMah = usagePowerMah + wifiPowerMah + gpsPowerMah + cpuPowerMah +
sensorPowerMah + mobileRadioPowerMah + wakeLockPowerMah + cameraPowerMah +
flashlightPowerMah;
}
软件功耗的子项共分为9项：
目前没有统计蓝牙的耗电，源码中统计蓝牙耗电的方法是空方法。gps耗电的计算在sensor模块一起计算的。
软件功耗总公式
三、 硬件排行榜
processMiscUsage()
private void processMiscUsage() {
addUserUsage();
addPhoneUsage();
addScreenUsage();
addWiFiUsage();
addBluetoothUsage();
addIdleUsage();
if (!mWifiOnly) { //对于只有wifi上网功能的设备，将不算计此项
addRadioUsage();
}
}
硬件功耗的子项共分为7项：
3.1 User
用户功耗的类型DrainType.USER
功耗计算
private void addUserUsage() {
for (int i = 0; i < mUserSippers.size(); i++) {
final int userId = mUserSippers.keyAt(i);
BatterySipper bs = new BatterySipper(DrainType.USER, null, 0);
bs.userId = userId;
aggregateSippers(bs, mUserSippers.valueAt(i), "User"); //将UserSippers中的功耗都合入bs.
mUsageList.add(bs);
}
}
合计
private void aggregateSippers(BatterySipper bs, List<BatterySipper> from, String tag) {
for (int i=0; i<from.size(); i++) {
BatterySipper wbs = from.get(i);
bs.add(wbs); //将from中的功耗数据合入bs
}
bs.computeMobilemspp();
bs.sumPower(); //计算总功耗
}
子公式
user_power = user_1_power + user_2_power + … + user_n_power; (n为所有的user的总数)
3.2 Phone
通话功耗的类型为DrainType.PHONE
通话功耗可配置项：
• POWER_RADIO_ACTIVE = “radio.active” 所对应的值
功耗计算
private void addPhoneUsage() {
long phoneOnTimeMs = mStats.getPhoneOnTime(mRawRealtime, mStatsType) / 1000;
double phoneOnPower = mPowerProfile.getAveragePower(PowerProfile.POWER_RADIO_ACTIVE) * phoneOnTimeMs / (60*60*1000);
if (phoneOnPower != 0) {
addEntry(BatterySipper.DrainType.PHONE, phoneOnTimeMs, phoneOnPower);
}
}
子公式
phone_powers = (phoneOnTimeMs * phoneOnPower) / (60* 60* 1000)
3.3 CPU Idle
CPU Idle功耗的类型为DrainType.IDLE
CPU Idle功耗可配置项：
• PowerProfile.POWER_CPU_IDLE = “cpu.idle” 所对应的值
功耗计算
private void addIdleUsage() {
long idleTimeMs = (mTypeBatteryRealtime - mStats.getScreenOnTime(mRawRealtime, mStatsType)) / 1000;
double idlePower = (idleTimeMs * mPowerProfile.getAveragePower(PowerProfile.POWER_CPU_IDLE)) / (60*60*1000);
if (idlePower != 0) {
addEntry(BatterySipper.DrainType.IDLE, idleTimeMs, idlePower);
}
}
子公式
idlePower = (idleTimeMs * cpuIdlePower) / (60* 60* 1000)
3.4 Screen
屏幕功耗的类型为DrainType.SCREEN
屏幕功耗可配置项
• POWER_SCREEN_ON = “screen.on” 所对应的值
• POWER_SCREEN_FULL = “screen.full” 所对应的值
功耗计算
private void addScreenUsage() {
double power = 0;
long screenOnTimeMs = mStats.getScreenOnTime(mRawRealtime, mStatsType) / 1000;
power += screenOnTimeMs * mPowerProfile.getAveragePower(PowerProfile.POWER_SCREEN_ON);
final double screenFullPower =
mPowerProfile.getAveragePower(PowerProfile.POWER_SCREEN_FULL);
for (int i = 0; i < BatteryStats.NUM_SCREEN_BRIGHTNESS_BINS; i++) {
double screenBinPower = screenFullPower * (i + 0.5f)
/ BatteryStats.NUM_SCREEN_BRIGHTNESS_BINS;
long brightnessTime = mStats.getScreenBrightnessTime(i, mRawRealtime, mStatsType) / 1000;
double p = screenBinPower*brightnessTime;
power += p;
}
power /= (60*60*1000); // To hours
if (power != 0) {
addEntry(BatterySipper.DrainType.SCREEN, screenOnTimeMs, power);
}
}
其中参数：
BatteryStats.NUM_SCREEN_BRIGHTNESS_BINS = 5；
static final String[] SCREEN_BRIGHTNESS_NAMES = {
"dark", "dim", "medium", "light", "bright"
};
static final String[] SCREEN_BRIGHTNESS_SHORT_NAMES = {
"0", "1", "2", "3", "4"
};
子公式
公式：screen_power = screenOnTimeMs * screenOnPower + backlight_power
其中：backlight_power = 0.1 * dark_brightness_time * screenFullPower + 0.3 * dim_brightness_time * screenFullPower + 0.5 * medium_brightness_time * screenFullPower + 0.7 * light_brightness_time + 0.9 * bright_brightness_time * screenFullPower;
3.5 Wifi
WifiPowerCalculater
Wifi的硬件功耗的类型DrainType.WIFI。
Wifi功耗可配置项
power_profile.xml文件：
• POWER_WIFI_CONTROLLER_IDLE = “wifi.controller.idle” 所对应的值
• POWER_WIFI_CONTROLLER_RX = “wifi.controller.rx” 所对应的值
• POWER_WIFI_CONTROLLER_TX = “wifi.controller.tx” 所对应的值
功耗计算
wifi的硬件功耗是指除去App消耗之外的剩余wifi功耗
private void addWiFiUsage() {
BatterySipper bs = new BatterySipper(DrainType.WIFI, null, 0);
mWifiPowerCalculator.calculateRemaining(bs, mStats, mRawRealtime, mRawUptime, mStatsType); //计算wifi硬件功耗
aggregateSippers(bs, mWifiSippers, "WIFI"); //将Wifi硬件合计入总功耗
if (bs.totalPowerMah > 0) {
mUsageList.add(bs);
}
}
计算
@Override
public void calculateRemaining(BatterySipper app, BatteryStats stats, long rawRealtimeUs, long rawUptimeUs, int statsType) {
final long idleTimeMs = stats.getWifiControllerActivity(BatteryStats.CONTROLLER_IDLE_TIME, statsType);
final long rxTimeMs = stats.getWifiControllerActivity(BatteryStats.CONTROLLER_RX_TIME, statsType);
final long txTimeMs = stats.getWifiControllerActivity(BatteryStats.CONTROLLER_TX_TIME, statsType);
app.wifiRunningTimeMs = idleTimeMs + rxTimeMs + txTimeMs;
double powerDrainMah = stats.getWifiControllerActivity(BatteryStats.CONTROLLER_POWER_DRAIN, statsType) / (double)(1000*60*60);
if (powerDrainMah == 0) {
//对于不直接报告功耗的组件，可通过直接计算的方式来获取
powerDrainMah = ((idleTimeMs * mIdleCurrentMa) + (txTimeMs * mTxCurrentMa) + (rxTimeMs * mRxCurrentMa)) / (1000*60*60);
}
app.wifiPowerMah = Math.max(0, powerDrainMah - mTotalAppPowerDrain);
}
子公式 公式：wifiPowerMah = powerDrainMah - mTotalAppPowerDrain；
powerDrainMah = ((idleTimeMs * mIdleCurrentMa) + (txTimeMs * mTxCurrentMa) +(rxTimeMs * mRxCurrentMa)；
mTotalAppPowerDrain是通过calculateApp计算过程中获取，记录所有App的wifi功耗值之和。
WifiPowerEstimator
可配置项
POWER_WIFI_ON=”wifi.on”
功耗计算
public void calculateRemaining(BatterySipper app, BatteryStats stats, long rawRealtimeUs, long rawUptimeUs, int statsType) {
final long totalRunningTimeMs = stats.getGlobalWifiRunningTime(rawRealtimeUs, statsType) / 1000;
final double powerDrain = ((totalRunningTimeMs - mTotalAppWifiRunningTimeMs) * mWifiPowerOn) / (1000*60*60);
app.wifiRunningTimeMs = totalRunningTimeMs;
app.wifiPowerMah = Math.max(0, powerDrain);
}
子公式
wifiPowerMah = ((totalRunningTimeMs - mTotalAppWifiRunningTimeMs) * mWifiPowerOn) / (1000* 60* 60)；
3.6 Bluetooth
蓝牙功耗的类型DrainType.BLUETOOTH
蓝牙功耗可配置项
• POWER_BLUETOOTH_CONTROLLER_IDLE = “bluetooth.controller.idle” 所对应的值
• POWER_BLUETOOTH_CONTROLLER_RX = “bluetooth.controller.rx” 所对应的值
• POWER_BLUETOOTH_CONTROLLER_TX = “bluetooth.controller.tx” 所对应的值
功耗计算
private void addBluetoothUsage() {
BatterySipper bs = new BatterySipper(BatterySipper.DrainType.BLUETOOTH, null, 0);
mBluetoothPowerCalculator.calculateRemaining(bs, mStats, mRawRealtime, mRawUptime, mStatsType);
aggregateSippers(bs, mBluetoothSippers, "Bluetooth"); //将蓝牙功耗合计入总功耗
if (bs.totalPowerMah > 0) {
mUsageList.add(bs);
}
}
计算：
public void calculateRemaining(BatterySipper app, BatteryStats stats, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
final long idleTimeMs = stats.getBluetoothControllerActivity(
BatteryStats.CONTROLLER_IDLE_TIME, statsType);
final long txTimeMs = stats.getBluetoothControllerActivity(
BatteryStats.CONTROLLER_TX_TIME, statsType);
final long rxTimeMs = stats.getBluetoothControllerActivity(
BatteryStats.CONTROLLER_RX_TIME, statsType);
final long totalTimeMs = idleTimeMs + txTimeMs + rxTimeMs;
double powerMah = stats.getBluetoothControllerActivity(
BatteryStats.CONTROLLER_POWER_DRAIN, statsType) / (double)(1000*60*60);
if (powerMah == 0) {
//对于不直接报告功耗的组件，可通过直接计算的方式来获取
powerMah = ((idleTimeMs * mIdleMa) + (rxTimeMs * mRxMa) + (txTimeMs * mTxMa)) / (1000*60*60);
}
app.usagePowerMah = powerMah;
app.usageTimeMs = totalTimeMs;
}
子公式
公式：usagePowerMah = ((idleTimeMs * mIdleMa) + (rxTimeMs * mRxMa) + (txTimeMs * mTxMa)) / (1000 * 60 * 60);
蓝牙的计算与3.5 wifi计算方式相仿。
3.7 MobileRadio
无线电功耗的类型为DrainType.CELL
无线电功耗可配置项
power_profile.xml文件：
• POWER_RADIO_ON = “radio.on” 所对应的数组，该数组大小为NUM_SIGNAL_STRENGTH_BINS = 5
• POWER_RADIO_SCANNING = “radio.scanning” 所对应的值
功耗计算
对于只支持wifi的设备则不需要计算该项
private void addRadioUsage() {
BatterySipper radio = new BatterySipper(BatterySipper.DrainType.CELL, null, 0);
mMobileRadioPowerCalculator.calculateRemaining(radio, mStats, mRawRealtime, mRawUptime, mStatsType);
radio.sumPower();
if (radio.totalPowerMah > 0) {
mUsageList.add(radio);
}
}
计算
@Override
public void calculateRemaining(BatterySipper app, BatteryStats stats, long rawRealtimeUs, long rawUptimeUs, int statsType) {
double power = 0;
long signalTimeMs = 0;
long noCoverageTimeMs = 0;
for (int i = 0; i < mPowerBins.length; i++) {
long strengthTimeMs = stats.getPhoneSignalStrengthTime(i, rawRealtimeUs, statsType)
/ 1000;
final double p = (strengthTimeMs * mPowerBins[i]) / (60*60*1000);
power += p;
signalTimeMs += strengthTimeMs;
if (i == 0) {
noCoverageTimeMs = strengthTimeMs;
}
}
final long scanningTimeMs = stats.getPhoneSignalScanningTime(rawRealtimeUs, statsType)
/ 1000;
final double p = (scanningTimeMs * mPowerScan) / (60*60*1000);
power += p;
long radioActiveTimeMs = mStats.getMobileRadioActiveTime(rawRealtimeUs, statsType) / 1000;
long remainingActiveTimeMs = radioActiveTimeMs - mTotalAppMobileActiveMs;
if (remainingActiveTimeMs > 0) {
power += (mPowerRadioOn * remainingActiveTimeMs) / (1000*60*60);
}
if (power != 0) {
if (signalTimeMs != 0) {
app.noCoveragePercent = noCoverageTimeMs * 100.0 / signalTimeMs;
}
app.mobileActive = remainingActiveTimeMs;
app.mobileActiveCount = stats.getMobileRadioActiveUnknownCount(statsType);
app.mobileRadioPowerMah = power;
}
}
常量：
public static final int NUM_SIGNAL_STRENGTH_BINS = 5;
public static final String[] SIGNAL_STRENGTH_NAMES = {
"none", "poor", "moderate", "good", "great"
};
子公式
mobileRadioPowerMah = strengthOnPower + scanningPower + remainingActivePower
其中： strengthOnPower = none_strength_Ms * none_strength_Power + poor_strength_Ms * poor_strength_Power + moderate_strength_Ms * moderate_strength_Power + good_strength_Ms * good_strength_Power + great_strength_Ms * great_strength_Power；
scanningPower = scanningTimeMs * mPowerScan；
remainingActivePower = （radioActiveTimeMs - mTotalAppMobileActiveMs）* mPowerRadioOn；
硬件耗电总公式
四、总结
(1) 关于WifiPowerCalculator && WifiPowerEstimator的选择问题
在 BatteryStatsHelper.java中：
final boolean hasWifiPowerReporting = checkHasWifiPowerReporting(mStats, mPowerProfile);
if (mWifiPowerCalculator == null || hasWifiPowerReporting != mHasWifiPowerReporting) {
mWifiPowerCalculator = hasWifiPowerReporting ?
new WifiPowerCalculator(mPowerProfile) :
new WifiPowerEstimator(mPowerProfile);
mHasWifiPowerReporting = hasWifiPowerReporting;
}
• 当hasWifiPowerReporting = true时，采用WifiPowerCalculator算法；
• 当hasWifiPowerReporting = false时，采用WifiPowerEstimator算法；
其中
public static boolean checkHasWifiPowerReporting(BatteryStats stats, PowerProfile profile) {
return stats.hasWifiActivityReporting() &&
profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_IDLE) != 0 &&
profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_RX) != 0 &&
profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_TX) != 0;
}
mHasWifiActivityReporting的默认值为false，故WIFI计算方式默认采用WifiPowerEstimator方式。
（2） 硬件与软件排行榜，功耗项对比：
其中√代表包含此功耗项。
（3） 硬件与软件排行榜，可配置项对比：
对于wifi的统计存在两种方式.
只有通过配置文件，精确地配置好每一项的基础功耗值，才能有一个精确的功耗统计结果。
android电量计算（软硬件）： http://gityuan.com/2016/01/10/power_rank/
android耗电统计算法 ：
http://gityuan.com/2016/01/10/power_rank/
基于Android 6.0的源码剖析
一、 概述
Android系统中的耗电统计分为软件排行榜和硬件排行榜，软件排序榜是统计每个App的耗电总量的排行榜，硬件排行榜则是统计主要硬件的耗电总量的排行榜。
涉及耗电统计相关的核心类：
/framework/base/core/res/res/xml/power_profile.xml
/framework/base/core/java/com/andorid/internal/os/PowerProfile.java
/framework/base/core/java/com/andorid/internal/os/BatteryStatsHelper.java
/framework/base/core/java/com/andorid/internal/os/BatterySipper.java
• PowerProfile.java用于获取各个组件的电流数值；power_profile.xml是一个可配置的功耗数据文件。
• 软件排行榜的计算算法：BatteryStatsHelper类中的processAppUsage()方法
• 硬件排行榜的计算算法：BatteryStatsHelper类中的processMiscUsage()方法
下面直接切入主题，分别讲述软件和硬件的耗电统计
二、软件排行榜
processAppUsage统计每个App的耗电情况
private void processAppUsage(SparseArray<UserHandle> asUsers) {
//判断是否统计所有用户的App耗电使用情况，目前该参数为true
final boolean forAllUsers = (asUsers.get(UserHandle.USER_ALL) != null);
mStatsPeriod = mTypeBatteryRealtime; //耗电的统计时长
BatterySipper osSipper = null;
//获取每个uid的统计信息
final SparseArray<? extends Uid> uidStats = mStats.getUidStats();
final int NU = uidStats.size();
// 开始遍历每个uid的耗电情况
for (int iu = 0; iu < NU; iu++) {
final Uid u = uidStats.valueAt(iu);
final BatterySipper app = new BatterySipper(BatterySipper.DrainType.APP, u, 0);
mCpuPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mWakelockPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mMobileRadioPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mWifiPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mBluetoothPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mSensorPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mCameraPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
mFlashlightPowerCalculator.calculateApp(app, u, mRawRealtime, mRawUptime, mStatsType);
final double totalPower = app.sumPower(); //对App的8项耗电再进行累加。
//将app添加到 app list, WiFi, Bluetooth等，或其他用户列表
if (totalPower != 0 || u.getUid() == 0) {
final int uid = app.getUid();
final int userId = UserHandle.getUserId(uid);
if (uid == Process.WIFI_UID) { //uid为wifi的情况
mWifiSippers.add(app);
} else if (uid == Process.BLUETOOTH_UID) {//uid为蓝牙的情况
mBluetoothSippers.add(app);
} else if (!forAllUsers && asUsers.get(userId) == null
&& UserHandle.getAppId(uid) >= Process.FIRST_APPLICATION_UID) {
//就目前来说 forAllUsers=true，不会进入此分支。
List<BatterySipper> list = mUserSippers.get(userId);
if (list == null) {
list = new ArrayList<>();
mUserSippers.put(userId, list);
}
list.add(app);
} else {
mUsageList.add(app); //把app耗电加入到mUsageList
}
if (uid == 0) {
osSipper = app; // root用户，代表操作系统的耗电量
}
}
}
//app之外的耗电量
if (osSipper != null) {
mWakelockPowerCalculator.calculateRemaining(osSipper, mStats, mRawRealtime, mRawUptime, mStatsType);
osSipper.sumPower();
}
}
流程分析：
mTypeBatteryRealtime
mTypeBatteryRealtime = mStats.computeBatteryRealtime(rawRealtimeUs, mStatsType);
private int mStatsType = BatteryStats.STATS_SINCE_CHARGED;
BatteryStats.STATS_SINCE_CHARGED，计算规则是从上次充满电后数据；另外STATS_SINCE_UNPLUGGED是拔掉USB线后的数据。说明充电时间的计算是从上一次拔掉设备到现在的耗电量统计。
耗电计算项
8大模块的耗电计算器，都继承与PowerCalculator抽象类
| 计算项 | Class文件 |
|---|---|
| CPU功耗 | mCpuPowerCalculator.java |
| Wakelock功耗 | mWakelockPowerCalculator.java |
| 无线电功耗 | mMobileRadioPowerCalculator.java |
| WIFI功耗 | mWifiPowerCalculator.java |
| 蓝牙功耗 | mBluetoothPowerCalculator.java |
| Sensor功耗 | mSensorPowerCalculator.java |
| 相机功耗 | mCameraPowerCalculator.java |
| 闪光灯功耗 | mFlashlightPowerCalculator.java |
• mWifiSippers.add(app)： uid为wifi的情况
• mBluetoothSippers.add(app)： uid为蓝牙的情况
• mUsageList.add(app)： app耗电加入到mUsageList
• osSipper： root用户，代表操作系统的耗电量，app之外的wakelock耗电也计算该项
公式
processAppUsage统计的是Uid。一般地来说每个App都对应一个Uid，但存在以下特殊情况，如果两个或多个App签名和 sharedUserId相同，则在运行时，他们拥有相同Uid。对于系统应用uid为system，则统一算入system应用的耗电量。
Uid_Power = process_1_Power + … + process_N_Power，其中所有进程都是属于同一个uid。 当同一的uid下，只有一个进程时，Uid_Power = process_Power;
其中process_Power = CPU功耗 + Wakelock功耗 + 无线电功耗 + WIFI功耗 + 蓝牙功耗 + Sensor功耗 + 相机功耗 + 闪光灯功耗。
接下来开始分配说明每一项的功耗计算公式。
2.1 CPU
CPU功耗项的计算是通过CpuPowerCalculator类
初始化
public CpuPowerCalculator(PowerProfile profile) {
final int speedSteps = profile.getNumSpeedSteps(); //获取cpu的主频等级的级数
mPowerCpuNormal = new double[speedSteps]; //用于记录不同频率下的功耗值
mSpeedStepTimes = new long[speedSteps];
for (int p = 0; p < speedSteps; p++) {
mPowerCpuNormal[p] = profile.getAveragePower(PowerProfile.POWER_CPU_ACTIVE, p);
}
}
从对象的构造方法，可以看出PowerProfile类提供相应所需的基础功耗值，而真正的功耗值数据来源于power_profile.xml文件，故可以通过配置合理的基础功耗值，来达到较为精准的功耗统计结果。后续所有的PowerCalculator子类在构造方法中都有会相应所需的功耗配置项。
CPU功耗可配置项：
• POWER_CPU_SPEEDS = “cpu.speeds” 所对应的数组，配置CPU的频点，频点个数取决于CPU硬件特性
• POWER_CPU_ACTIVE = “cpu.active” 所对应的数组，配置CPU频点所对应的单位功耗(mAh)
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
final int speedSteps = mSpeedStepTimes.length;
long totalTimeAtSpeeds = 0;
for (int step = 0; step < speedSteps; step++) {
//获取Cpu不同频点下的运行时间
mSpeedStepTimes[step] = u.getTimeAtCpuSpeed(step, statsType);
totalTimeAtSpeeds += mSpeedStepTimes[step];
}
totalTimeAtSpeeds = Math.max(totalTimeAtSpeeds, 1); //获取Cpu总共的运行时间
app.cpuTimeMs = (u.getUserCpuTimeUs(statsType) + u.getSystemCpuTimeUs(statsType)) / 1000; //获取cpu在用户态和内核态的执行时长
double cpuPowerMaMs = 0;
// 计算Cpu的耗电量
for (int step = 0; step < speedSteps; step++) {
final double ratio = (double) mSpeedStepTimes[step] / totalTimeAtSpeeds;
final double cpuSpeedStepPower = ratio * app.cpuTimeMs * mPowerCpuNormal[step];
cpuPowerMaMs += cpuSpeedStepPower;
}
//追踪不同进程的耗电情况
double highestDrain = 0;
app.cpuFgTimeMs = 0;
final ArrayMap<String, ? extends BatteryStats.Uid.Proc> processStats = u.getProcessStats();
final int processStatsCount = processStats.size();
//统计同一个uid的不同进程的耗电情况
for (int i = 0; i < processStatsCount; i++) {
final BatteryStats.Uid.Proc ps = processStats.valueAt(i);
final String processName = processStats.keyAt(i);
app.cpuFgTimeMs += ps.getForegroundTime(statsType);
final long costValue = ps.getUserTime(statsType) + ps.getSystemTime(statsType) + ps.getForegroundTime(statsType);
//App可以有多个packages和多个不同的进程，跟踪耗电最大的进程
if (app.packageWithHighestDrain == null ||
app.packageWithHighestDrain.startsWith("*")) {
highestDrain = costValue;
app.packageWithHighestDrain = processName;
} else if (highestDrain < costValue && !processName.startsWith("*")) {
highestDrain = costValue;
app.packageWithHighestDrain = processName;
}
}
//当Cpu前台时间 大于Cpu时间，将cpuFgTimeMs赋值为cpuTimeMs
if (app.cpuFgTimeMs > app.cpuTimeMs) {
app.cpuTimeMs = app.cpuFgTimeMs;
}
app.cpuPowerMah = cpuPowerMaMs / (60 * 60 * 1000); //转换为mAh
}
}
子公式
cpuPower = ratio_1 * cpu_time * cpu_ratio_1_power + … +ratio_n * cpu_time * cpu_ratio_n_power
其中： ratio_i = cpu_speed_time/ cpu_speeds_total_time，（i=1,2,…,N，N为CPU频点个数）
2.2 Wakelock
Wakelock功耗项的计算是通过WakelockPowerCalculator类
初始化
public WakelockPowerCalculator(PowerProfile profile) {
mPowerWakelock = profile.getAveragePower(PowerProfile.POWER_CPU_AWAKE);
}
Wakelock功耗可配置项：
power_profile.xml文件：
• POWER_CPU_AWAKE = “cpu.awake” 所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
long wakeLockTimeUs = 0;
final ArrayMap<String, ? extends BatteryStats.Uid.Wakelock> wakelockStats =
u.getWakelockStats();
final int wakelockStatsCount = wakelockStats.size();
for (int i = 0; i < wakelockStatsCount; i++) {
final BatteryStats.Uid.Wakelock wakelock = wakelockStats.valueAt(i);
//只统计partial wake locks，由于 full wake locks在灭屏后会自动取消
BatteryStats.Timer timer = wakelock.getWakeTime(BatteryStats.WAKE_TYPE_PARTIAL);
if (timer != null) {
wakeLockTimeUs += timer.getTotalTimeLocked(rawRealtimeUs, statsType);
}
}
app.wakeLockTimeMs = wakeLockTimeUs / 1000; //转换单位为秒
mTotalAppWakelockTimeMs += app.wakeLockTimeMs;
//计算唤醒功耗
app.wakeLockPowerMah = (app.wakeLockTimeMs * mPowerWakelock) / (1000*60*60);
}
子公式
wakeLockPowerMah = (app.wakeLockTimeMs * mPowerWakelock) / (10006060);
2.3 Wifi
WifiPowerCalculator
Wifi功耗项的计算是通过WifiPowerCalculator类
初始化
public WifiPowerCalculator(PowerProfile profile) {
mIdleCurrentMa = profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_IDLE);
mTxCurrentMa = profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_TX);
mRxCurrentMa = profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_RX);
}
Wifi功耗可配置项：
• POWER_WIFI_CONTROLLER_IDLE = “wifi.controller.idle” 项所对应的值
• POWER_WIFI_CONTROLLER_RX = “wifi.controller.rx” 项所对应的值
• POWER_WIFI_CONTROLLER_TX = “wifi.controller.tx” 项所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
final long idleTime = u.getWifiControllerActivity(BatteryStats.CONTROLLER_IDLE_TIME, statsType);
final long txTime = u.getWifiControllerActivity(BatteryStats.CONTROLLER_TX_TIME, statsType);
final long rxTime = u.getWifiControllerActivity(BatteryStats.CONTROLLER_RX_TIME, statsType);
app.wifiRunningTimeMs = idleTime + rxTime + txTime; //计算wifi的时间
app.wifiPowerMah = ((idleTime * mIdleCurrentMa) + (txTime * mTxCurrentMa) + (rxTime * mRxCurrentMa)) / (1000*60*60);
mTotalAppPowerDrain += app.wifiPowerMah;
app.wifiRxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_WIFI_RX_DATA,
statsType);
app.wifiTxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_WIFI_TX_DATA,
statsType);
app.wifiRxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_WIFI_RX_DATA,
statsType);
app.wifiTxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_WIFI_TX_DATA,
statsType);
}
子公式
wifiPowerMah = ((idleTime * mIdleCurrentMa) + (txTime * mTxCurrentMa) + (rxTime * mRxCurrentMa)) / (1000* 60* 60);
WifiPowerEstimator
可配置项
• POWER_WIFI_ACTIVE = “wifi.active”（用于计算mWifiPowerPerPacket）
• POWER_WIFI_ON=”wifi.on”
• POWER_WIFI_SCAN = “wifi.scan”
• POWER_WIFI_BATCHED_SCAN = “wifi.batchedscan”;
功耗计算-
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
app.wifiRxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_WIFI_RX_DATA,
statsType);
app.wifiTxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_WIFI_TX_DATA,
statsType);
app.wifiRxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_WIFI_RX_DATA,
statsType);
app.wifiTxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_WIFI_TX_DATA,
statsType);
final double wifiPacketPower = (app.wifiRxPackets + app.wifiTxPackets)
* mWifiPowerPerPacket;
app.wifiRunningTimeMs = u.getWifiRunningTime(rawRealtimeUs, statsType) / 1000;
mTotalAppWifiRunningTimeMs += app.wifiRunningTimeMs;
final double wifiLockPower = (app.wifiRunningTimeMs * mWifiPowerOn) / (1000*60*60);
final long wifiScanTimeMs = u.getWifiScanTime(rawRealtimeUs, statsType) / 1000;
final double wifiScanPower = (wifiScanTimeMs * mWifiPowerScan) / (1000*60*60);
double wifiBatchScanPower = 0;
for (int bin = 0; bin < BatteryStats.Uid.NUM_WIFI_BATCHED_SCAN_BINS; bin++) {
final long batchScanTimeMs =
u.getWifiBatchedScanTime(bin, rawRealtimeUs, statsType) / 1000;
final double batchScanPower = (batchScanTimeMs * mWifiPowerBatchScan) / (1000*60*60);
wifiBatchScanPower += batchScanPower;
}
app.wifiPowerMah = wifiPacketPower + wifiLockPower + wifiScanPower + wifiBatchScanPower;
}
其中 BatteryStats.Uid.NUM_WIFI_BATCHED_SCAN_BINS=5
另外
private static double getWifiPowerPerPacket(PowerProfile profile) {
final long WIFI_BPS = 1000000; //初略估算每秒的收发1000000bit
final double WIFI_POWER = profile.getAveragePower(PowerProfile.POWER_WIFI_ACTIVE)
/ 3600;
return (WIFI_POWER / (((double)WIFI_BPS) / 8 / 2048)) / (60*60);
}
子公式
wifiPowerMah = wifiPacketPower + wifiLockPower + wifiScanPower + wifiBatchScanPower;
wifiPacketPower = (wifiRxPackets + wifiTxPackets) * mWifiPowerPerPacket; wifiLockPower = (wifiRunningTimeMs * mWifiPowerOn) / (1000* 60* 60); wifiScanPower = (wifiScanTimeMs * mWifiPowerScan) / (1000* 60* 60);
wifiBatchScanPower = ∑ (batchScanTimeMs * mWifiPowerBatchScan) / (1000* 60* 60) ，5次相加。
2.4 Bluetooth
Bluetooth功耗项的计算是通过BluetoothPowerCalculator类
初始化
public BluetoothPowerCalculator(PowerProfile profile) {
mIdleMa = profile.getAveragePower(PowerProfile.POWER_BLUETOOTH_CONTROLLER_IDLE);
mRxMa = profile.getAveragePower(PowerProfile.POWER_BLUETOOTH_CONTROLLER_RX);
mTxMa = profile.getAveragePower(PowerProfile.POWER_BLUETOOTH_CONTROLLER_TX);
}
Bluetooth功耗可配置项(目前蓝牙功耗计算的方法为空，此配置暂可忽略)：
• POWER_BLUETOOTH_CONTROLLER_IDLE = “bluetooth.controller.idle” 所对应的值
• POWER_BLUETOOTH_CONTROLLER_RX = “bluetooth.controller.rx” 所对应的值
• POWER_BLUETOOTH_CONTROLLER_TX = “bluetooth.controller.tx” 所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
// No per-app distribution yet.
}
子公式
bluePower = 0;
还没有给每个App统计蓝牙的算法。
2.5 Camera
Camera功耗项的计算是通过CameraPowerCalculator类
初始化
public CameraPowerCalculator(PowerProfile profile) {
mCameraPowerOnAvg = profile.getAveragePower(PowerProfile.POWER_CAMERA);
}
Camera功耗可配置项：
• POWER_CAMERA = “camera.avg” 所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
//对于camera功耗的评估比较粗，camera打开认定功耗一致
final BatteryStats.Timer timer = u.getCameraTurnedOnTimer();
if (timer != null) {
final long totalTime = timer.getTotalTimeLocked(rawRealtimeUs, statsType) / 1000;
app.cameraTimeMs = totalTime;
app.cameraPowerMah = (totalTime * mCameraPowerOnAvg) / (1000*60*60);
} else {
app.cameraTimeMs = 0;
app.cameraPowerMah = 0;
}
}
子公式
cameraPowerMah = (totalTime * mCameraPowerOnAvg) / (10006060);
2.6 Flashlight
Flashlight功耗项的计算是通过FlashlightPowerCalculator类
初始化
public FlashlightPowerCalculator(PowerProfile profile) {
mFlashlightPowerOnAvg = profile.getAveragePower(PowerProfile.POWER_FLASHLIGHT);
}
Flashlight功耗可配置项：
• POWER_FLASHLIGHT = “camera.flashlight” 所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
final BatteryStats.Timer timer = u.getFlashlightTurnedOnTimer();
if (timer != null) {
final long totalTime = timer.getTotalTimeLocked(rawRealtimeUs, statsType) / 1000;
app.flashlightTimeMs = totalTime;
app.flashlightPowerMah = (totalTime * mFlashlightPowerOnAvg) / (1000*60*60);
} else {
app.flashlightTimeMs = 0;
app.flashlightPowerMah = 0;
}
}
子公式
flashlightPowerMah = (totalTime * mFlashlightPowerOnAvg) / (10006060);
flashlight计算方式与Camera功耗计算思路一样。
2.7 MobileRadio
无线电功耗项的计算是通过MobileRadioPowerCalculator类
初始化
public MobileRadioPowerCalculator(PowerProfile profile, BatteryStats stats) {
mPowerRadioOn = profile.getAveragePower(PowerProfile.POWER_RADIO_ACTIVE);
for (int i = 0; i < mPowerBins.length; i++) {
mPowerBins[i] = profile.getAveragePower(PowerProfile.POWER_RADIO_ON, i);
}
mPowerScan = profile.getAveragePower(PowerProfile.POWER_RADIO_SCANNING);
mStats = stats;
}
无线电功耗可配置项：
• POWER_RADIO_ACTIVE = “radio.active” 所对应的值
功耗计算
public void calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
app.mobileRxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_MOBILE_RX_DATA, statsType);
app.mobileTxPackets = u.getNetworkActivityPackets(BatteryStats.NETWORK_MOBILE_TX_DATA, statsType);
app.mobileActive = u.getMobileRadioActiveTime(statsType) / 1000;
app.mobileActiveCount = u.getMobileRadioActiveCount(statsType);
app.mobileRxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_MOBILE_RX_DATA,
statsType);
app.mobileTxBytes = u.getNetworkActivityBytes(BatteryStats.NETWORK_MOBILE_TX_DATA,
statsType);
if (app.mobileActive > 0) {
// 当追踪信号的开头，则采用mobileActive时间乘以相应功耗
mTotalAppMobileActiveMs += app.mobileActive;
app.mobileRadioPowerMah = (app.mobileActive * mPowerRadioOn) / (1000*60*60);
} else {
//当没有追踪信号开关，则采用收发数据包来评估功耗
app.mobileRadioPowerMah = (app.mobileRxPackets + app.mobileTxPackets) * getMobilePowerPerPacket(rawRealtimeUs, statsType);
}
}
计算出每收/发一个数据包的功耗值
private double getMobilePowerPerPacket(long rawRealtimeUs, int statsType) {
final long MOBILE_BPS = 200000; //Extract average bit rates from system
final double MOBILE_POWER = mPowerRadioOn / 3600;
final long mobileRx = mStats.getNetworkActivityPackets(BatteryStats.NETWORK_MOBILE_RX_DATA,
statsType);
final long mobileTx = mStats.getNetworkActivityPackets(BatteryStats.NETWORK_MOBILE_TX_DATA,
statsType);
final long mobileData = mobileRx + mobileTx;
final long radioDataUptimeMs =
mStats.getMobileRadioActiveTime(rawRealtimeUs, statsType) / 1000;
final double mobilePps = (mobileData != 0 && radioDataUptimeMs != 0)
? (mobileData / (double)radioDataUptimeMs)
: (((double)MOBILE_BPS) / 8 / 2048);
return (MOBILE_POWER / mobilePps) / (60*60);
}
子公式
情况一：当追踪信号活动时间，即mobileActive > 0，采用：
mobileRadioPowerMah = (app.mobileActive * mPowerRadioOn) / (1000* 60* 60);
情况二：当没有追踪信号活动时间，则采用：
mobileRadioPowerMah = (app.mobileRxPackets + app.mobileTxPackets) * MobilePowerPerPacket
其中MobilePowerPerPacket = (（mPowerRadioOn / 3600） / mobilePps) / (60*60)， mobilePps= （mobileRx + mobileTx）/radioDataUptimeMs
2.8 Sensor
Sensor功耗项的计算是通过SensorPowerCalculator类
初始化
public SensorPowerCalculator(PowerProfile profile, SensorManager sensorManager) {
mSensors = sensorManager.getSensorList(Sensor.TYPE_ALL);
mGpsPowerOn = profile.getAveragePower(PowerProfile.POWER_GPS_ON);
}
Sensor功耗可配置项：
• POWER_GPS_ON = “gps.on” 所对应的值
功耗计算
d calculateApp(BatterySipper app, BatteryStats.Uid u, long rawRealtimeUs, long rawUptimeUs, int statsType) {
// 计算没有个Uid
final SparseArray<? extends BatteryStats.Uid.Sensor> sensorStats = u.getSensorStats();
final int NSE = sensorStats.size();
for (int ise = 0; ise < NSE; ise++) {
final BatteryStats.Uid.Sensor sensor = sensorStats.valueAt(ise);
final int sensorHandle = sensorStats.keyAt(ise);
final BatteryStats.Timer timer = sensor.getSensorTime();
final long sensorTime = timer.getTotalTimeLocked(rawRealtimeUs, statsType) / 1000;
switch (sensorHandle) {
case BatteryStats.Uid.Sensor.GPS: //对于uid为GPS的情况
app.gpsTimeMs = sensorTime;
app.gpsPowerMah = (app.gpsTimeMs * mGpsPowerOn) / (1000*60*60);
break;
default:
final int sensorsCount = mSensors.size();
for (int i = 0; i < sensorsCount; i++) { //统计所有的sensor情况
final Sensor s = mSensors.get(i);
if (s.getHandle() == sensorHandle) {
app.sensorPowerMah += (sensorTime * s.getPower()) / (1000*60*60);
break;
}
}
break;
}
}
}
GPS的功耗计算与sensor的计算方法放在一块
子公式
gpsPowerMah = (app.gpsTimeMs * mGpsPowerOn) / (1000* 60* 60);
软件功耗总公式
BatterySipper中，功耗计算方法：
public double sumPower() {
return totalPowerMah = usagePowerMah + wifiPowerMah + gpsPowerMah + cpuPowerMah +
sensorPowerMah + mobileRadioPowerMah + wakeLockPowerMah + cameraPowerMah +
flashlightPowerMah;
}
软件功耗的子项共分为9项：
| 功耗项 | 解释 |
|---|---|
| usage | 通用的功耗 |
| cpu | cpu的消耗 |
| wakelock | 唤醒带来的功耗 |
| mobileRadio | 移动无线的功耗 |
| wifi | wifi功耗 |
| gps | 定位的功耗 |
| sensor | 传感器的功耗 |
| camera | 相机功耗 |
| flashlight | 闪光灯功耗 |
软件功耗总公式
三、 硬件排行榜
processMiscUsage()
private void processMiscUsage() {
addUserUsage();
addPhoneUsage();
addScreenUsage();
addWiFiUsage();
addBluetoothUsage();
addIdleUsage();
if (!mWifiOnly) { //对于只有wifi上网功能的设备，将不算计此项
addRadioUsage();
}
}
硬件功耗的子项共分为7项：
| 功耗项 | 解释 |
|---|---|
| UserUsage | 用户功耗 |
| PhoneUsage | 通话功耗 |
| ScreenUsage | 屏幕功耗 |
| WiFiUsage | Wifi功耗 |
| BluetoothUsage | 蓝牙消耗 |
| IdleUsage | CPU Idle功耗 |
| RadioUsage | 移动无线功耗 |
用户功耗的类型DrainType.USER
功耗计算
private void addUserUsage() {
for (int i = 0; i < mUserSippers.size(); i++) {
final int userId = mUserSippers.keyAt(i);
BatterySipper bs = new BatterySipper(DrainType.USER, null, 0);
bs.userId = userId;
aggregateSippers(bs, mUserSippers.valueAt(i), "User"); //将UserSippers中的功耗都合入bs.
mUsageList.add(bs);
}
}
合计
private void aggregateSippers(BatterySipper bs, List<BatterySipper> from, String tag) {
for (int i=0; i<from.size(); i++) {
BatterySipper wbs = from.get(i);
bs.add(wbs); //将from中的功耗数据合入bs
}
bs.computeMobilemspp();
bs.sumPower(); //计算总功耗
}
子公式
user_power = user_1_power + user_2_power + … + user_n_power; (n为所有的user的总数)
3.2 Phone
通话功耗的类型为DrainType.PHONE
通话功耗可配置项：
• POWER_RADIO_ACTIVE = “radio.active” 所对应的值
功耗计算
private void addPhoneUsage() {
long phoneOnTimeMs = mStats.getPhoneOnTime(mRawRealtime, mStatsType) / 1000;
double phoneOnPower = mPowerProfile.getAveragePower(PowerProfile.POWER_RADIO_ACTIVE) * phoneOnTimeMs / (60*60*1000);
if (phoneOnPower != 0) {
addEntry(BatterySipper.DrainType.PHONE, phoneOnTimeMs, phoneOnPower);
}
}
子公式
phone_powers = (phoneOnTimeMs * phoneOnPower) / (60* 60* 1000)
3.3 CPU Idle
CPU Idle功耗的类型为DrainType.IDLE
CPU Idle功耗可配置项：
• PowerProfile.POWER_CPU_IDLE = “cpu.idle” 所对应的值
功耗计算
private void addIdleUsage() {
long idleTimeMs = (mTypeBatteryRealtime - mStats.getScreenOnTime(mRawRealtime, mStatsType)) / 1000;
double idlePower = (idleTimeMs * mPowerProfile.getAveragePower(PowerProfile.POWER_CPU_IDLE)) / (60*60*1000);
if (idlePower != 0) {
addEntry(BatterySipper.DrainType.IDLE, idleTimeMs, idlePower);
}
}
子公式
idlePower = (idleTimeMs * cpuIdlePower) / (60* 60* 1000)
3.4 Screen
屏幕功耗的类型为DrainType.SCREEN
屏幕功耗可配置项
• POWER_SCREEN_ON = “screen.on” 所对应的值
• POWER_SCREEN_FULL = “screen.full” 所对应的值
功耗计算
private void addScreenUsage() {
double power = 0;
long screenOnTimeMs = mStats.getScreenOnTime(mRawRealtime, mStatsType) / 1000;
power += screenOnTimeMs * mPowerProfile.getAveragePower(PowerProfile.POWER_SCREEN_ON);
final double screenFullPower =
mPowerProfile.getAveragePower(PowerProfile.POWER_SCREEN_FULL);
for (int i = 0; i < BatteryStats.NUM_SCREEN_BRIGHTNESS_BINS; i++) {
double screenBinPower = screenFullPower * (i + 0.5f)
/ BatteryStats.NUM_SCREEN_BRIGHTNESS_BINS;
long brightnessTime = mStats.getScreenBrightnessTime(i, mRawRealtime, mStatsType) / 1000;
double p = screenBinPower*brightnessTime;
power += p;
}
power /= (60*60*1000); // To hours
if (power != 0) {
addEntry(BatterySipper.DrainType.SCREEN, screenOnTimeMs, power);
}
}
其中参数：
BatteryStats.NUM_SCREEN_BRIGHTNESS_BINS = 5；
static final String[] SCREEN_BRIGHTNESS_NAMES = {
"dark", "dim", "medium", "light", "bright"
};
static final String[] SCREEN_BRIGHTNESS_SHORT_NAMES = {
"0", "1", "2", "3", "4"
};
子公式
公式：screen_power = screenOnTimeMs * screenOnPower + backlight_power
其中：backlight_power = 0.1 * dark_brightness_time * screenFullPower + 0.3 * dim_brightness_time * screenFullPower + 0.5 * medium_brightness_time * screenFullPower + 0.7 * light_brightness_time + 0.9 * bright_brightness_time * screenFullPower;
3.5 Wifi
WifiPowerCalculater
Wifi的硬件功耗的类型DrainType.WIFI。
Wifi功耗可配置项
power_profile.xml文件：
• POWER_WIFI_CONTROLLER_IDLE = “wifi.controller.idle” 所对应的值
• POWER_WIFI_CONTROLLER_RX = “wifi.controller.rx” 所对应的值
• POWER_WIFI_CONTROLLER_TX = “wifi.controller.tx” 所对应的值
功耗计算
wifi的硬件功耗是指除去App消耗之外的剩余wifi功耗
private void addWiFiUsage() {
BatterySipper bs = new BatterySipper(DrainType.WIFI, null, 0);
mWifiPowerCalculator.calculateRemaining(bs, mStats, mRawRealtime, mRawUptime, mStatsType); //计算wifi硬件功耗
aggregateSippers(bs, mWifiSippers, "WIFI"); //将Wifi硬件合计入总功耗
if (bs.totalPowerMah > 0) {
mUsageList.add(bs);
}
}
计算
@Override
public void calculateRemaining(BatterySipper app, BatteryStats stats, long rawRealtimeUs, long rawUptimeUs, int statsType) {
final long idleTimeMs = stats.getWifiControllerActivity(BatteryStats.CONTROLLER_IDLE_TIME, statsType);
final long rxTimeMs = stats.getWifiControllerActivity(BatteryStats.CONTROLLER_RX_TIME, statsType);
final long txTimeMs = stats.getWifiControllerActivity(BatteryStats.CONTROLLER_TX_TIME, statsType);
app.wifiRunningTimeMs = idleTimeMs + rxTimeMs + txTimeMs;
double powerDrainMah = stats.getWifiControllerActivity(BatteryStats.CONTROLLER_POWER_DRAIN, statsType) / (double)(1000*60*60);
if (powerDrainMah == 0) {
//对于不直接报告功耗的组件，可通过直接计算的方式来获取
powerDrainMah = ((idleTimeMs * mIdleCurrentMa) + (txTimeMs * mTxCurrentMa) + (rxTimeMs * mRxCurrentMa)) / (1000*60*60);
}
app.wifiPowerMah = Math.max(0, powerDrainMah - mTotalAppPowerDrain);
}
子公式 公式：wifiPowerMah = powerDrainMah - mTotalAppPowerDrain；
powerDrainMah = ((idleTimeMs * mIdleCurrentMa) + (txTimeMs * mTxCurrentMa) +(rxTimeMs * mRxCurrentMa)；
mTotalAppPowerDrain是通过calculateApp计算过程中获取，记录所有App的wifi功耗值之和。
WifiPowerEstimator
可配置项
POWER_WIFI_ON=”wifi.on”
功耗计算
public void calculateRemaining(BatterySipper app, BatteryStats stats, long rawRealtimeUs, long rawUptimeUs, int statsType) {
final long totalRunningTimeMs = stats.getGlobalWifiRunningTime(rawRealtimeUs, statsType) / 1000;
final double powerDrain = ((totalRunningTimeMs - mTotalAppWifiRunningTimeMs) * mWifiPowerOn) / (1000*60*60);
app.wifiRunningTimeMs = totalRunningTimeMs;
app.wifiPowerMah = Math.max(0, powerDrain);
}
子公式
wifiPowerMah = ((totalRunningTimeMs - mTotalAppWifiRunningTimeMs) * mWifiPowerOn) / (1000* 60* 60)；
3.6 Bluetooth
蓝牙功耗的类型DrainType.BLUETOOTH
蓝牙功耗可配置项
• POWER_BLUETOOTH_CONTROLLER_IDLE = “bluetooth.controller.idle” 所对应的值
• POWER_BLUETOOTH_CONTROLLER_RX = “bluetooth.controller.rx” 所对应的值
• POWER_BLUETOOTH_CONTROLLER_TX = “bluetooth.controller.tx” 所对应的值
功耗计算
private void addBluetoothUsage() {
BatterySipper bs = new BatterySipper(BatterySipper.DrainType.BLUETOOTH, null, 0);
mBluetoothPowerCalculator.calculateRemaining(bs, mStats, mRawRealtime, mRawUptime, mStatsType);
aggregateSippers(bs, mBluetoothSippers, "Bluetooth"); //将蓝牙功耗合计入总功耗
if (bs.totalPowerMah > 0) {
mUsageList.add(bs);
}
}
计算：
public void calculateRemaining(BatterySipper app, BatteryStats stats, long rawRealtimeUs,
long rawUptimeUs, int statsType) {
final long idleTimeMs = stats.getBluetoothControllerActivity(
BatteryStats.CONTROLLER_IDLE_TIME, statsType);
final long txTimeMs = stats.getBluetoothControllerActivity(
BatteryStats.CONTROLLER_TX_TIME, statsType);
final long rxTimeMs = stats.getBluetoothControllerActivity(
BatteryStats.CONTROLLER_RX_TIME, statsType);
final long totalTimeMs = idleTimeMs + txTimeMs + rxTimeMs;
double powerMah = stats.getBluetoothControllerActivity(
BatteryStats.CONTROLLER_POWER_DRAIN, statsType) / (double)(1000*60*60);
if (powerMah == 0) {
//对于不直接报告功耗的组件，可通过直接计算的方式来获取
powerMah = ((idleTimeMs * mIdleMa) + (rxTimeMs * mRxMa) + (txTimeMs * mTxMa)) / (1000*60*60);
}
app.usagePowerMah = powerMah;
app.usageTimeMs = totalTimeMs;
}
子公式
公式：usagePowerMah = ((idleTimeMs * mIdleMa) + (rxTimeMs * mRxMa) + (txTimeMs * mTxMa)) / (1000 * 60 * 60);
蓝牙的计算与3.5 wifi计算方式相仿。
3.7 MobileRadio
无线电功耗的类型为DrainType.CELL
无线电功耗可配置项
power_profile.xml文件：
• POWER_RADIO_ON = “radio.on” 所对应的数组，该数组大小为NUM_SIGNAL_STRENGTH_BINS = 5
• POWER_RADIO_SCANNING = “radio.scanning” 所对应的值
功耗计算
对于只支持wifi的设备则不需要计算该项
private void addRadioUsage() {
BatterySipper radio = new BatterySipper(BatterySipper.DrainType.CELL, null, 0);
mMobileRadioPowerCalculator.calculateRemaining(radio, mStats, mRawRealtime, mRawUptime, mStatsType);
radio.sumPower();
if (radio.totalPowerMah > 0) {
mUsageList.add(radio);
}
}
计算
@Override
public void calculateRemaining(BatterySipper app, BatteryStats stats, long rawRealtimeUs, long rawUptimeUs, int statsType) {
double power = 0;
long signalTimeMs = 0;
long noCoverageTimeMs = 0;
for (int i = 0; i < mPowerBins.length; i++) {
long strengthTimeMs = stats.getPhoneSignalStrengthTime(i, rawRealtimeUs, statsType)
/ 1000;
final double p = (strengthTimeMs * mPowerBins[i]) / (60*60*1000);
power += p;
signalTimeMs += strengthTimeMs;
if (i == 0) {
noCoverageTimeMs = strengthTimeMs;
}
}
final long scanningTimeMs = stats.getPhoneSignalScanningTime(rawRealtimeUs, statsType)
/ 1000;
final double p = (scanningTimeMs * mPowerScan) / (60*60*1000);
power += p;
long radioActiveTimeMs = mStats.getMobileRadioActiveTime(rawRealtimeUs, statsType) / 1000;
long remainingActiveTimeMs = radioActiveTimeMs - mTotalAppMobileActiveMs;
if (remainingActiveTimeMs > 0) {
power += (mPowerRadioOn * remainingActiveTimeMs) / (1000*60*60);
}
if (power != 0) {
if (signalTimeMs != 0) {
app.noCoveragePercent = noCoverageTimeMs * 100.0 / signalTimeMs;
}
app.mobileActive = remainingActiveTimeMs;
app.mobileActiveCount = stats.getMobileRadioActiveUnknownCount(statsType);
app.mobileRadioPowerMah = power;
}
}
常量：
public static final int NUM_SIGNAL_STRENGTH_BINS = 5;
public static final String[] SIGNAL_STRENGTH_NAMES = {
"none", "poor", "moderate", "good", "great"
};
子公式
mobileRadioPowerMah = strengthOnPower + scanningPower + remainingActivePower
其中： strengthOnPower = none_strength_Ms * none_strength_Power + poor_strength_Ms * poor_strength_Power + moderate_strength_Ms * moderate_strength_Power + good_strength_Ms * good_strength_Power + great_strength_Ms * great_strength_Power；
scanningPower = scanningTimeMs * mPowerScan；
remainingActivePower = （radioActiveTimeMs - mTotalAppMobileActiveMs）* mPowerRadioOn；
硬件耗电总公式
四、总结
(1) 关于WifiPowerCalculator && WifiPowerEstimator的选择问题
在 BatteryStatsHelper.java中：
final boolean hasWifiPowerReporting = checkHasWifiPowerReporting(mStats, mPowerProfile);
if (mWifiPowerCalculator == null || hasWifiPowerReporting != mHasWifiPowerReporting) {
mWifiPowerCalculator = hasWifiPowerReporting ?
new WifiPowerCalculator(mPowerProfile) :
new WifiPowerEstimator(mPowerProfile);
mHasWifiPowerReporting = hasWifiPowerReporting;
}
• 当hasWifiPowerReporting = true时，采用WifiPowerCalculator算法；
• 当hasWifiPowerReporting = false时，采用WifiPowerEstimator算法；
其中
public static boolean checkHasWifiPowerReporting(BatteryStats stats, PowerProfile profile) {
return stats.hasWifiActivityReporting() &&
profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_IDLE) != 0 &&
profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_RX) != 0 &&
profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_TX) != 0;
}
mHasWifiActivityReporting的默认值为false，故WIFI计算方式默认采用WifiPowerEstimator方式。
（2） 硬件与软件排行榜，功耗项对比：
| 功耗项 | 软件榜 | 硬件榜 |
|---|---|---|
| CPU | √ | √ |
| 无线电 | √ | √ |
| WIFI | √ | √ |
| 蓝牙 | √ | √ |
| Wakelock | √ | - |
| Sensor | √ | - |
| 相机 | √ | - |
| 闪光灯 | √ | - |
| 通话 | - | √ |
| 屏幕 | - | √ |
| 用户 | - | √ |
（3） 硬件与软件排行榜，可配置项对比：
对于wifi的统计存在两种方式.
| 功耗项 | 软件榜 | 硬件榜 |
|---|---|---|
| CPU | cpu.active | cpu.idle |
| 无线电 | radio.active | radio.on/scanning |
| WIFI_Calculater | wifi.controller.idle/rx/tx | wifi.controller.idle/rx/tx |
| WIFI_Estimator | wifi.on/ scan/ batchedscan | wifi.on |
| 蓝牙 | bluetooth.controller.idle/rx/tx | bluetooth.controller.idle/rx/tx |
| Wakelock | cpu.awake | - |
| Sensor | gps.on | - |
| 相机 | camera.avg | - |
| 闪光灯 | camera.flashlight | - |
| 通话 | - | radio.active |
| 屏幕 | - | screen.on |
| 用户 | - |
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