Keep track of battery drain rate in various states...

... and print in dumpsys power.

Bug: 72229630
Test: manual test with dumpsys power, etc
Test:  atest $ANDROID_BUILD_TOP/frameworks/base/services/tests/servicestests/src/com/android/server/power/batterysaver/BatterySavingStatsTest.java

Change-Id: I43949129ff03c1e0b0fa3aa603e0678b728538ee

7 files changed, 668 insertions, 2 deletions

diff --git a/core/java/android/os/BatteryManagerInternal.java b/core/java/android/os/BatteryManagerInternal.java
index f3a95b90d5c1..a86237dd271f 100644
--- a/core/java/android/os/BatteryManagerInternal.java
+++ b/core/java/android/os/BatteryManagerInternal.java
@@ -24,26 +24,63 @@ package android.os;
 public abstract class BatteryManagerInternal {
     /**
      * Returns true if the device is plugged into any of the specified plug types.
+     *
+     * This is a simple accessor that's safe to be called from any locks, but internally it may
+     * wait on the battery service lock.
      */
     public abstract boolean isPowered(int plugTypeSet);
 
     /**
      * Returns the current plug type.
+     *
+     * This is a simple accessor that's safe to be called from any locks, but internally it may
+     * wait on the battery service lock.
      */
     public abstract int getPlugType();
 
     /**
      * Returns battery level as a percentage.
+     *
+     * This is a simple accessor that's safe to be called from any locks, but internally it may
+     * wait on the battery service lock.
      */
     public abstract int getBatteryLevel();
 
     /**
+     * Instantaneous battery capacity in uA-h, as defined in the HealthInfo HAL struct.
+     * Please note apparently it could be bigger than {@link #getBatteryFullCharge}.
+     *
+     * This is a simple accessor that's safe to be called from any locks, but internally it may
+     * wait on the battery service lock.
+     *
+     * @see android.hardware.health.V1_0.HealthInfo#batteryChargeCounter
+     */
+    public abstract int getBatteryChargeCounter();
+
+    /**
+     * Battery charge value when it is considered to be "full" in uA-h , as defined in the
+     * HealthInfo HAL struct.
+     *
+     * This is a simple accessor that's safe to be called from any locks, but internally it may
+     * wait on the battery service lock.
+     *
+     * @see android.hardware.health.V1_0.HealthInfo#batteryFullCharge
+     */
+    public abstract int getBatteryFullCharge();
+
+    /**
      * Returns whether we currently consider the battery level to be low.
+     *
+     * This is a simple accessor that's safe to be called from any locks, but internally it may
+     * wait on the battery service lock.
      */
     public abstract boolean getBatteryLevelLow();
 
     /**
      * Returns a non-zero value if an unsupported charger is attached.
+     *
+     * This is a simple accessor that's safe to be called from any locks, but internally it may
+     * wait on the battery service lock.
      */
     public abstract int getInvalidCharger();
 }
diff --git a/services/core/java/com/android/server/BatteryService.java b/services/core/java/com/android/server/BatteryService.java
index ba9883b4de59..8265262d3824 100644
--- a/services/core/java/com/android/server/BatteryService.java
+++ b/services/core/java/com/android/server/BatteryService.java
@@ -835,6 +835,9 @@ public final class BatteryService extends SystemService {
                         case "level":
                             mHealthInfo.batteryLevel = Integer.parseInt(value);
                             break;
+                        case "counter":
+                            mHealthInfo.batteryChargeCounter = Integer.parseInt(value);
+                            break;
                         case "temp":
                             mHealthInfo.batteryTemperature = Integer.parseInt(value);
                             break;
@@ -1164,6 +1167,20 @@ public final class BatteryService extends SystemService {
         }
 
         @Override
+        public int getBatteryChargeCounter() {
+            synchronized (mLock) {
+                return mHealthInfo.batteryChargeCounter;
+            }
+        }
+
+        @Override
+        public int getBatteryFullCharge() {
+            synchronized (mLock) {
+                return mHealthInfo.batteryFullCharge;
+            }
+        }
+
+        @Override
         public boolean getBatteryLevelLow() {
             synchronized (mLock) {
                 return mBatteryLevelLow;
diff --git a/services/core/java/com/android/server/EventLogTags.logtags b/services/core/java/com/android/server/EventLogTags.logtags
index 732ac66b41de..219facd0b002 100644
--- a/services/core/java/com/android/server/EventLogTags.logtags
+++ b/services/core/java/com/android/server/EventLogTags.logtags
@@ -34,6 +34,7 @@ option java_package com.android.server
 2731 power_soft_sleep_requested (savedwaketimems|2)
 # Power save state has changed. See BatterySaverController.java for the details.
 2739 battery_saver_mode (prevOffOrOn|1|5),(nowOffOrOn|1|5),(interactive|1|5),(features|3|5)
+27390 battery_saving_stats (batterySaver|1|5),(interactive|1|5),(doze|1|5),(delta_duration|2|3),(delta_battery_drain|1|6),(total_duration|2|3),(total_battery_drain|1|6)
 
 #
 # Leave IDs through 2740 for more power logs (2730 used by battery_discharge above)
diff --git a/services/core/java/com/android/server/power/BatterySaverPolicy.java b/services/core/java/com/android/server/power/BatterySaverPolicy.java
index a538967e501d..847c90a08c5c 100644
--- a/services/core/java/com/android/server/power/BatterySaverPolicy.java
+++ b/services/core/java/com/android/server/power/BatterySaverPolicy.java
@@ -33,6 +33,7 @@ import android.util.Slog;
 import com.android.internal.R;
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.power.batterysaver.BatterySavingStats;
 import com.android.server.power.batterysaver.CpuFrequencies;
 
 import java.io.PrintWriter;
@@ -498,6 +499,8 @@ public class BatterySaverPolicy extends ContentObserver {
             pw.print("  Noninteractive File values:\n");
             dumpMap(pw, "    ", mFilesForNoninteractive);
             pw.println();
+            pw.println();
+            BatterySavingStats.getInstance().dump(pw, "  ");
         }
     }
 
diff --git a/services/core/java/com/android/server/power/batterysaver/BatterySaverController.java b/services/core/java/com/android/server/power/batterysaver/BatterySaverController.java
index d4627c2da07e..32f38b7cf772 100644
--- a/services/core/java/com/android/server/power/batterysaver/BatterySaverController.java
+++ b/services/core/java/com/android/server/power/batterysaver/BatterySaverController.java
@@ -28,6 +28,7 @@ import android.content.Intent;
 import android.content.IntentFilter;
 import android.hardware.power.V1_0.PowerHint;
 import android.net.Uri;
+import android.os.BatteryManager;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
@@ -50,6 +51,9 @@ import com.android.server.LocalServices;
 import com.android.server.power.BatterySaverPolicy;
 import com.android.server.power.BatterySaverPolicy.BatterySaverPolicyListener;
 import com.android.server.power.PowerManagerService;
+import com.android.server.power.batterysaver.BatterySavingStats.BatterySaverState;
+import com.android.server.power.batterysaver.BatterySavingStats.DozeState;
+import com.android.server.power.batterysaver.BatterySavingStats.InteractiveState;
 
 import java.util.ArrayList;
 
@@ -70,6 +74,8 @@ public class BatterySaverController implements BatterySaverPolicyListener {
 
     private final BatterySaverPolicy mBatterySaverPolicy;
 
+    private final BatterySavingStats mBatterySavingStats;
+
     private static final String WARNING_LINK_URL = "http://goto.google.com/extreme-battery-saver";
 
     @GuardedBy("mLock")
@@ -78,6 +84,9 @@ public class BatterySaverController implements BatterySaverPolicyListener {
     @GuardedBy("mLock")
     private boolean mEnabled;
 
+    @GuardedBy("mLock")
+    private boolean mIsPluggedIn;
+
     /**
      * Previously enabled or not; only for the event logging. Only use it from
      * {@link #handleBatterySaverStateChanged}.
@@ -104,15 +113,28 @@ public class BatterySaverController implements BatterySaverPolicyListener {
     private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
+            if (DEBUG) {
+                Slog.d(TAG, "onReceive: " + intent);
+            }
             switch (intent.getAction()) {
                 case Intent.ACTION_SCREEN_ON:
                 case Intent.ACTION_SCREEN_OFF:
                     if (!isEnabled()) {
+                        updateBatterySavingStats();
                         return; // No need to send it if not enabled.
                     }
                     // Don't send the broadcast, because we never did so in this case.
                     mHandler.postStateChanged(/*sendBroadcast=*/ false);
                     break;
+                case Intent.ACTION_BATTERY_CHANGED:
+                    synchronized (mLock) {
+                        mIsPluggedIn = (intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, 0) != 0);
+                    }
+                    // Fall-through.
+                case PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED:
+                case PowerManager.ACTION_LIGHT_DEVICE_IDLE_MODE_CHANGED:
+                    updateBatterySavingStats();
+                    break;
             }
         }
     };
@@ -126,6 +148,7 @@ public class BatterySaverController implements BatterySaverPolicyListener {
         mBatterySaverPolicy = policy;
         mBatterySaverPolicy.addListener(this);
         mFileUpdater = new FileUpdater(context);
+        mBatterySavingStats = BatterySavingStats.getInstance();
 
         // Initialize plugins.
         final ArrayList<Plugin> plugins = new ArrayList<>();
@@ -149,6 +172,9 @@ public class BatterySaverController implements BatterySaverPolicyListener {
     public void systemReady() {
         final IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
         filter.addAction(Intent.ACTION_SCREEN_OFF);
+        filter.addAction(Intent.ACTION_BATTERY_CHANGED);
+        filter.addAction(PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED);
+        filter.addAction(PowerManager.ACTION_LIGHT_DEVICE_IDLE_MODE_CHANGED);
         mContext.registerReceiver(mReceiver, filter);
 
         mFileUpdater.systemReady(LocalServices.getService(ActivityManagerInternal.class)
@@ -280,7 +306,6 @@ public class BatterySaverController implements BatterySaverPolicyListener {
             enabled = mEnabled;
             mIsInteractive = isInteractive;
 
-
             if (enabled) {
                 fileValues = mBatterySaverPolicy.getFileValues(isInteractive);
             } else {
@@ -293,6 +318,8 @@ public class BatterySaverController implements BatterySaverPolicyListener {
             pmi.powerHint(PowerHint.LOW_POWER, enabled ? 1 : 0);
         }
 
+        updateBatterySavingStats();
+
         if (ArrayUtils.isEmpty(fileValues)) {
             mFileUpdater.restoreDefault();
         } else {
@@ -332,7 +359,6 @@ public class BatterySaverController implements BatterySaverPolicyListener {
             mContext.sendBroadcastAsUser(intent, UserHandle.ALL,
                     Manifest.permission.DEVICE_POWER);
 
-
             for (LowPowerModeListener listener : listeners) {
                 final PowerSaveState result =
                         mBatterySaverPolicy.getBatterySaverPolicy(
@@ -388,4 +414,28 @@ public class BatterySaverController implements BatterySaverPolicyListener {
                     foregroundUser);
         }
     }
+
+    private void updateBatterySavingStats() {
+        final PowerManager pm = getPowerManager();
+        if (pm == null) {
+            Slog.wtf(TAG, "PowerManager not initialized");
+            return;
+        }
+        final boolean isInteractive = pm.isInteractive();
+        final int dozeMode =
+                pm.isDeviceIdleMode() ? DozeState.DEEP
+                        : pm.isLightDeviceIdleMode() ? DozeState.LIGHT
+                        : DozeState.NOT_DOZING;
+
+        synchronized (mLock) {
+            if (mIsPluggedIn) {
+                mBatterySavingStats.startCharging();
+                return;
+            }
+            mBatterySavingStats.transitionState(
+                    mEnabled ? BatterySaverState.ON : BatterySaverState.OFF,
+                    isInteractive ? InteractiveState.INTERACTIVE : InteractiveState.NON_INTERACTIVE,
+                    dozeMode);
+        }
+    }
 }
diff --git a/services/core/java/com/android/server/power/batterysaver/BatterySavingStats.java b/services/core/java/com/android/server/power/batterysaver/BatterySavingStats.java
new file mode 100644
index 000000000000..df4f8eca5595
--- /dev/null
+++ b/services/core/java/com/android/server/power/batterysaver/BatterySavingStats.java
@@ -0,0 +1,353 @@
+/*
+ * Copyright (C) 2018 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.power.batterysaver;
+
+import android.os.BatteryManagerInternal;
+import android.os.SystemClock;
+import android.util.ArrayMap;
+import android.util.Slog;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.EventLogTags;
+import com.android.server.LocalServices;
+import com.android.server.power.BatterySaverPolicy;
+
+import java.io.PrintWriter;
+
+/**
+ * This class keeps track of battery drain rate.
+ *
+ * Test:
+ atest $ANDROID_BUILD_TOP/frameworks/base/services/tests/servicestests/src/com/android/server/power/batterysaver/BatterySavingStatsTest.java
+ */
+public class BatterySavingStats {
+
+    private static final String TAG = "BatterySavingStats";
+
+    private static final boolean DEBUG = BatterySaverPolicy.DEBUG;
+
+    private final Object mLock = new Object();
+
+    /** Whether battery saver is on or off. */
+    interface BatterySaverState {
+        int OFF = 0;
+        int ON = 1;
+
+        int SHIFT = 0;
+        int BITS = 1;
+        int MASK = (1 << BITS) - 1;
+
+        static int fromIndex(int index) {
+            return (index >> SHIFT) & MASK;
+        }
+    }
+
+    /** Whether the device is interactive (i.e. screen on) or not. */
+    interface InteractiveState {
+        int NON_INTERACTIVE = 0;
+        int INTERACTIVE = 1;
+
+        int SHIFT = BatterySaverState.SHIFT + BatterySaverState.BITS;
+        int BITS = 1;
+        int MASK = (1 << BITS) - 1;
+
+        static int fromIndex(int index) {
+            return (index >> SHIFT) & MASK;
+        }
+    }
+
+    /** Doze mode. */
+    interface DozeState {
+        int NOT_DOZING = 0;
+        int LIGHT = 1;
+        int DEEP = 2;
+
+        int SHIFT = InteractiveState.SHIFT + InteractiveState.BITS;
+        int BITS = 2;
+        int MASK = (1 << BITS) - 1;
+
+        static int fromIndex(int index) {
+            return (index >> SHIFT) & MASK;
+        }
+    }
+
+    /**
+     * Various stats in each state.
+     */
+    static class Stat {
+        public long startTime;
+        public long endTime;
+
+        public int startBatteryLevel;
+        public int endBatteryLevel;
+
+        public long totalTimeMillis;
+        public int totalBatteryDrain;
+
+        public long totalMinutes() {
+            return totalTimeMillis / 60_000;
+        }
+
+        public double drainPerHour() {
+            if (totalTimeMillis == 0) {
+                return 0;
+            }
+            return (double) totalBatteryDrain / (totalTimeMillis / (60.0 * 60 * 1000));
+        }
+
+        @VisibleForTesting
+        String toStringForTest() {
+            return "{" + totalMinutes() + "m," + totalBatteryDrain + ","
+                    + String.format("%.2f", drainPerHour()) + "}";
+        }
+    }
+
+    private static BatterySavingStats sInstance;
+
+    private BatteryManagerInternal mBatteryManagerInternal;
+
+    private static final int STATE_NOT_INITIALIZED = -1;
+    private static final int STATE_CHARGING = -2;
+
+    /**
+     * Current state, one of STATE_* or values returned by {@link #statesToIndex}.
+     */
+    @GuardedBy("mLock")
+    private int mCurrentState = STATE_NOT_INITIALIZED;
+
+    /**
+     * Stats in each state.
+     */
+    @VisibleForTesting
+    @GuardedBy("mLock")
+    final ArrayMap<Integer, Stat> mStats = new ArrayMap<>();
+
+    /**
+     * Don't call it directly -- use {@link #getInstance()}. Not private for testing.
+     */
+    @VisibleForTesting
+    BatterySavingStats() {
+        mBatteryManagerInternal = LocalServices.getService(BatteryManagerInternal.class);
+    }
+
+    public static synchronized BatterySavingStats getInstance() {
+        if (sInstance == null) {
+            sInstance = new BatterySavingStats();
+        }
+        return sInstance;
+    }
+
+    private BatteryManagerInternal getBatteryManagerInternal() {
+        if (mBatteryManagerInternal == null) {
+            mBatteryManagerInternal = LocalServices.getService(BatteryManagerInternal.class);
+        }
+        return mBatteryManagerInternal;
+    }
+
+    /**
+     * Takes a state triplet and generates a state index.
+     */
+    @VisibleForTesting
+    static int statesToIndex(
+            int batterySaverState, int interactiveState, int dozeState) {
+        int ret = batterySaverState & BatterySaverState.MASK;
+        ret |= (interactiveState & InteractiveState.MASK) << InteractiveState.SHIFT;
+        ret |= (dozeState & DozeState.MASK) << DozeState.SHIFT;
+        return ret;
+    }
+
+    /**
+     * Takes a state index and returns a string for logging.
+     */
+    @VisibleForTesting
+    static String stateToString(int state) {
+        switch (state) {
+            case STATE_NOT_INITIALIZED:
+                return "NotInitialized";
+            case STATE_CHARGING:
+                return "Charging";
+        }
+        return "BS=" + BatterySaverState.fromIndex(state)
+                + ",I=" + InteractiveState.fromIndex(state)
+                + ",D=" + DozeState.fromIndex(state);
+    }
+
+    /**
+     * @return {@link Stat} fo a given state.
+     */
+    @VisibleForTesting
+    Stat getStat(int stateIndex) {
+        synchronized (mLock) {
+            Stat stat = mStats.get(stateIndex);
+            if (stat == null) {
+                stat = new Stat();
+                mStats.put(stateIndex, stat);
+            }
+            return stat;
+        }
+    }
+
+    /**
+     * @return {@link Stat} fo a given state triplet.
+     */
+    private Stat getStat(int batterySaverState, int interactiveState, int dozeState) {
+        return getStat(statesToIndex(batterySaverState, interactiveState, dozeState));
+    }
+
+    long injectCurrentTime() {
+        return SystemClock.elapsedRealtime();
+    }
+
+    int injectBatteryLevel() {
+        final BatteryManagerInternal bmi = getBatteryManagerInternal();
+        if (bmi == null) {
+            Slog.wtf(TAG, "BatteryManagerInternal not initialized");
+            return 0;
+        }
+        return bmi.getBatteryChargeCounter();
+    }
+
+    /**
+     * Called from the outside whenever any of the states changes, when the device is not plugged
+     * in.
+     */
+    public void transitionState(int batterySaverState, int interactiveState, int dozeState) {
+        synchronized (mLock) {
+
+            final int newState = statesToIndex(
+                    batterySaverState, interactiveState, dozeState);
+            if (mCurrentState == newState) {
+                return;
+            }
+
+            endLastStateLocked();
+            startNewStateLocked(newState);
+        }
+    }
+
+    /**
+     * Called from the outside when the device is plugged in.
+     */
+    public void startCharging() {
+        synchronized (mLock) {
+            if (mCurrentState < 0) {
+                return;
+            }
+
+            endLastStateLocked();
+            startNewStateLocked(STATE_CHARGING);
+        }
+    }
+
+    private void endLastStateLocked() {
+        if (mCurrentState < 0) {
+            return;
+        }
+        final Stat stat = getStat(mCurrentState);
+
+        stat.endBatteryLevel = injectBatteryLevel();
+        stat.endTime = injectCurrentTime();
+
+        final long deltaTime = stat.endTime - stat.startTime;
+        final int deltaDrain = stat.startBatteryLevel - stat.endBatteryLevel;
+
+        stat.totalTimeMillis += deltaTime;
+        stat.totalBatteryDrain += deltaDrain;
+
+        if (DEBUG) {
+            Slog.d(TAG, "State summary: " + stateToString(mCurrentState)
+                    + ": " + (deltaTime / 1_000) + "s "
+                    + "Start level: " + stat.startBatteryLevel + "uA "
+                    + "End level: " + stat.endBatteryLevel + "uA "
+                    + deltaDrain + "uA");
+        }
+        EventLogTags.writeBatterySavingStats(
+                BatterySaverState.fromIndex(mCurrentState),
+                InteractiveState.fromIndex(mCurrentState),
+                DozeState.fromIndex(mCurrentState),
+                deltaTime,
+                deltaDrain,
+                stat.totalTimeMillis,
+                stat.totalBatteryDrain);
+    }
+
+    private void startNewStateLocked(int newState) {
+        if (DEBUG) {
+            Slog.d(TAG, "New state: " + stateToString(newState));
+        }
+        mCurrentState = newState;
+
+        if (mCurrentState < 0) {
+            return;
+        }
+
+        final Stat stat = getStat(mCurrentState);
+        stat.startBatteryLevel = injectBatteryLevel();
+        stat.startTime = injectCurrentTime();
+        stat.endTime = 0;
+    }
+
+    public void dump(PrintWriter pw, String indent) {
+        synchronized (mLock) {
+            pw.print(indent);
+            pw.println("Battery Saving Stats:");
+
+            indent = indent + "  ";
+
+            pw.print(indent);
+            pw.println("Battery Saver:       Off                                 On");
+            dumpLineLocked(pw, indent, InteractiveState.NON_INTERACTIVE, "NonIntr",
+                    DozeState.NOT_DOZING, "NonDoze");
+            dumpLineLocked(pw, indent, InteractiveState.INTERACTIVE, "   Intr",
+                    DozeState.NOT_DOZING, "       ");
+
+            dumpLineLocked(pw, indent, InteractiveState.NON_INTERACTIVE, "NonIntr",
+                    DozeState.DEEP, "Deep   ");
+            dumpLineLocked(pw, indent, InteractiveState.INTERACTIVE, "   Intr",
+                    DozeState.DEEP, "       ");
+
+            dumpLineLocked(pw, indent, InteractiveState.NON_INTERACTIVE, "NonIntr",
+                    DozeState.LIGHT, "Light  ");
+            dumpLineLocked(pw, indent, InteractiveState.INTERACTIVE, "   Intr",
+                    DozeState.LIGHT, "       ");
+
+            pw.println();
+        }
+    }
+
+    private void dumpLineLocked(PrintWriter pw, String indent,
+            int interactiveState, String interactiveLabel,
+            int dozeState, String dozeLabel) {
+        pw.print(indent);
+        pw.print(dozeLabel);
+        pw.print(" ");
+        pw.print(interactiveLabel);
+        pw.print(": ");
+
+        final Stat offStat = getStat(BatterySaverState.OFF, interactiveState, dozeState);
+        final Stat onStat = getStat(BatterySaverState.ON, interactiveState, dozeState);
+
+        pw.println(String.format("%6dm %6dmA %8.1fmA/h      %6dm %6dmA %8.1fmA/h",
+                offStat.totalMinutes(),
+                offStat.totalBatteryDrain / 1000,
+                offStat.drainPerHour() / 1000.0,
+                onStat.totalMinutes(),
+                onStat.totalBatteryDrain / 1000,
+                onStat.drainPerHour() / 1000.0));
+    }
+}
+
diff --git a/services/tests/servicestests/src/com/android/server/power/batterysaver/BatterySavingStatsTest.java b/services/tests/servicestests/src/com/android/server/power/batterysaver/BatterySavingStatsTest.java
new file mode 100644
index 000000000000..f788caccbdce
--- /dev/null
+++ b/services/tests/servicestests/src/com/android/server/power/batterysaver/BatterySavingStatsTest.java
@@ -0,0 +1,205 @@
+/*
+ * Copyright (C) 2018 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.power.batterysaver;
+
+import static org.junit.Assert.assertEquals;
+
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+
+import com.android.server.power.batterysaver.BatterySavingStats.BatterySaverState;
+import com.android.server.power.batterysaver.BatterySavingStats.DozeState;
+import com.android.server.power.batterysaver.BatterySavingStats.InteractiveState;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintWriter;
+
+/**
+ atest $ANDROID_BUILD_TOP/frameworks/base/services/tests/servicestests/src/com/android/server/power/batterysaver/BatterySavingStatsTest.java
+ */
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public class BatterySavingStatsTest {
+    private class BatterySavingStatsTestable extends BatterySavingStats {
+        private long mTime = 1_000_000; // Some random starting time.
+
+        private int mBatteryLevel = 100;
+
+        @Override
+        long injectCurrentTime() {
+            return mTime;
+        }
+
+        @Override
+        int injectBatteryLevel() {
+            return mBatteryLevel;
+        }
+
+        void assertDumpable() {
+            final ByteArrayOutputStream out = new ByteArrayOutputStream();
+            dump(new PrintWriter(out), ""); // Just make sure it won't crash.
+        }
+
+        void advanceClock(int minutes) {
+            mTime += 60_000 * minutes;
+        }
+
+        void drainBattery(int percent) {
+            mBatteryLevel -= percent;
+            if (mBatteryLevel < 0) {
+                mBatteryLevel = 0;
+            }
+        }
+
+        String toDebugString() {
+            final StringBuilder sb = new StringBuilder();
+            String sep = "";
+            for (int i = 0; i < mStats.size(); i++) {
+                sb.append(sep);
+                sb.append(stateToString(mStats.keyAt(i)));
+                sb.append(":");
+                sb.append(mStats.valueAt(i).toStringForTest());
+                sep = "\n";
+            }
+            return sb.toString();
+        }
+    }
+
+    @Test
+    public void testAll() {
+        final BatterySavingStatsTestable target = new BatterySavingStatsTestable();
+
+        target.assertDumpable();
+
+        target.advanceClock(1);
+        target.drainBattery(2);
+
+        target.transitionState(
+                BatterySaverState.OFF,
+                InteractiveState.INTERACTIVE,
+                DozeState.NOT_DOZING);
+
+        target.advanceClock(4);
+        target.drainBattery(1);
+
+        target.transitionState(
+                BatterySaverState.OFF,
+                InteractiveState.NON_INTERACTIVE,
+                DozeState.NOT_DOZING);
+
+        target.advanceClock(2);
+        target.drainBattery(5);
+
+        target.transitionState(
+                BatterySaverState.OFF,
+                InteractiveState.INTERACTIVE,
+                DozeState.NOT_DOZING);
+
+        target.advanceClock(4);
+        target.drainBattery(1);
+
+        target.transitionState(
+                BatterySaverState.OFF,
+                InteractiveState.NON_INTERACTIVE,
+                DozeState.NOT_DOZING);
+
+        target.advanceClock(2);
+        target.drainBattery(5);
+
+        target.transitionState(
+                BatterySaverState.OFF,
+                InteractiveState.INTERACTIVE,
+                DozeState.NOT_DOZING);
+
+        target.advanceClock(3);
+        target.drainBattery(1);
+
+        target.transitionState(
+                BatterySaverState.OFF,
+                InteractiveState.NON_INTERACTIVE,
+                DozeState.LIGHT);
+
+        target.advanceClock(5);
+        target.drainBattery(1);
+
+        target.transitionState(
+                BatterySaverState.OFF,
+                InteractiveState.NON_INTERACTIVE,
+                DozeState.DEEP);
+
+        target.advanceClock(1);
+        target.drainBattery(2);
+
+        target.transitionState(
+                BatterySaverState.ON,
+                InteractiveState.INTERACTIVE,
+                DozeState.NOT_DOZING);
+
+        target.advanceClock(1);
+        target.drainBattery(3);
+
+        target.transitionState(
+                BatterySaverState.OFF,
+                InteractiveState.INTERACTIVE,
+                DozeState.NOT_DOZING);
+
+        target.advanceClock(3);
+        target.drainBattery(5);
+
+        target.transitionState(
+                BatterySaverState.ON,
+                InteractiveState.INTERACTIVE,
+                DozeState.NOT_DOZING);
+
+        target.advanceClock(3);
+        target.drainBattery(5);
+
+        target.startCharging();
+
+        target.advanceClock(5);
+        target.drainBattery(10);
+
+        target.transitionState(
+                BatterySaverState.ON,
+                InteractiveState.INTERACTIVE,
+                DozeState.NOT_DOZING);
+
+        target.advanceClock(5);
+        target.drainBattery(1);
+
+        target.startCharging();
+
+        target.assertDumpable();
+
+        assertEquals(
+                "BS=0,I=0,D=0:{4m,10,150.00}\n" +
+                "BS=1,I=0,D=0:{0m,0,0.00}\n" +
+                "BS=0,I=1,D=0:{14m,8,34.29}\n" +
+                "BS=1,I=1,D=0:{9m,9,60.00}\n" +
+                "BS=0,I=0,D=1:{5m,1,12.00}\n" +
+                "BS=1,I=0,D=1:{0m,0,0.00}\n" +
+                "BS=0,I=1,D=1:{0m,0,0.00}\n" +
+                "BS=1,I=1,D=1:{0m,0,0.00}\n" +
+                "BS=0,I=0,D=2:{1m,2,120.00}\n" +
+                "BS=1,I=0,D=2:{0m,0,0.00}\n" +
+                "BS=0,I=1,D=2:{0m,0,0.00}\n" +
+                "BS=1,I=1,D=2:{0m,0,0.00}",
+                target.toDebugString());
+    }
+}