Merge "Break infinite refresh loop in battery estimates" into qt-dev

am: e418874921

Change-Id: Ibf5d75ffec22c0948d89c3cdfc5feb7197869f30

src/com/android/settings/fuelgauge/BatteryUtils.java

@@ -55,6 +55,8 @@ import com.android.settingslib.utils.ThreadUtils;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import java.time.Duration;
+import java.time.Instant;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
@@ -450,16 +452,10 @@ public class BatteryUtils {
                 SystemClock.elapsedRealtime());
         final BatteryStats stats = statsHelper.getStats();
         BatteryInfo batteryInfo;
-        Estimate estimate = null;
+        Estimate estimate = getEnhancedEstimate();
-        // Get enhanced prediction if available
-        if (mPowerUsageFeatureProvider != null &&
-                mPowerUsageFeatureProvider.isEnhancedBatteryPredictionEnabled(mContext)) {
-            estimate = mPowerUsageFeatureProvider.getEnhancedBatteryPrediction(mContext);
-        }
 
-        if (estimate != null) {
+        // couldn't get estimate from cache or provider, use fallback
-            Estimate.storeCachedEstimate(mContext, estimate);
+        if (estimate == null) {
-        } else {
             estimate = new Estimate(
                     PowerUtil.convertUsToMs(stats.computeBatteryTimeRemaining(elapsedRealtimeUs)),
                     false /* isBasedOnUsage */,
@@ -474,6 +470,23 @@ public class BatteryUtils {
         return batteryInfo;
     }
 
+    @VisibleForTesting
+    Estimate getEnhancedEstimate() {
+        Estimate estimate = null;
+        // Get enhanced prediction if available
+        if (Duration.between(Estimate.getLastCacheUpdateTime(mContext), Instant.now())
+                .compareTo(Duration.ofSeconds(10)) < 0) {
+            estimate = Estimate.getCachedEstimateIfAvailable(mContext);
+        } else if (mPowerUsageFeatureProvider != null &&
+                mPowerUsageFeatureProvider.isEnhancedBatteryPredictionEnabled(mContext)) {
+            estimate = mPowerUsageFeatureProvider.getEnhancedBatteryPrediction(mContext);
+            if (estimate != null) {
+                Estimate.storeCachedEstimate(mContext, estimate);
+            }
+        }
+        return estimate;
+    }
+
     /**
      * Find the {@link BatterySipper} with the corresponding {@link BatterySipper.DrainType}
      */

tests/robotests/src/com/android/settings/fuelgauge/BatteryUtilsTest.java

@@ -62,6 +62,7 @@ import com.android.settings.fuelgauge.batterytip.AnomalyInfo;
 import com.android.settings.fuelgauge.batterytip.BatteryDatabaseManager;
 import com.android.settings.testutils.FakeFeatureFactory;
 import com.android.settings.testutils.shadow.ShadowThreadUtils;
+import com.android.settingslib.fuelgauge.Estimate;
 import com.android.settingslib.fuelgauge.PowerWhitelistBackend;
 
 import org.junit.Before;
@@ -728,4 +729,17 @@ public class BatteryUtilsTest {
         //Should not crash
         assertThat(mBatteryUtils.getBatteryInfo(mBatteryStatsHelper, TAG)).isNotNull();
     }
+
+    @Test
+    public void getEnhancedEstimate_doesNotUpdateCache_ifEstimateFresh() {
+        Estimate estimate = new Estimate(1000, true, 1000);
+        Estimate.storeCachedEstimate(mContext, estimate);
+
+        estimate = mBatteryUtils.getEnhancedEstimate();
+
+        // only pass if estimate has not changed
+        assertThat(estimate).isNotNull();
+        assertThat(estimate.isBasedOnUsage()).isTrue();
+        assertThat(estimate.getAverageDischargeTime()).isEqualTo(1000);
+    }
 }