Start using NitzSignal.ageMillis (b648473b) · Commits · e / os / android_frameworks_opt_telephony

src/java/com/android/internal/telephony/NitzSignal.java

+25 −1

Original line number	Diff line number	Diff line
		@@ -19,6 +19,7 @@ package com.android.internal.telephony;
		import android.annotation.DurationMillisLong;
		import android.annotation.ElapsedRealtimeLong;
		import android.annotation.NonNull;
		import android.os.TimestampedValue;

		import java.time.Duration;
		import java.util.Objects;
		@@ -76,6 +77,28 @@ public final class NitzSignal {
		return mAgeMillis;
		}

		/**
		* Returns a derived property of {@code receiptElapsedMillis - ageMillis}, i.e. the time
		* according to the elapsed realtime clock when the NITZ signal was actually received by this
		* device taking into time it was cached by layers before the RIL.
		*/
		@ElapsedRealtimeLong
		public long getAgeAdjustedElapsedRealtimeMillis() {
		return mReceiptElapsedMillis - mAgeMillis;
		}

		/**
		* Creates a {@link android.os.TimestampedValue} containing the UTC time as the number of
		* milliseconds since the start of the Unix epoch. The reference time is the time according to
		* the elapsed realtime clock when that would have been the time, accounting for receipt time
		* and age.
		*/
		public TimestampedValue<Long> createTimeSignal() {
		return new TimestampedValue<>(
		getAgeAdjustedElapsedRealtimeMillis(),
		getNitzData().getCurrentTimeInMillis());
		}

		@Override
		public boolean equals(Object o) {
		if (this == o) {
		@@ -85,7 +108,8 @@ public final class NitzSignal {
		return false;
		}
		NitzSignal that = (NitzSignal) o;
		return mReceiptElapsedMillis == that.mReceiptElapsedMillis && mAgeMillis == that.mAgeMillis
		return mReceiptElapsedMillis == that.mReceiptElapsedMillis
		&& mAgeMillis == that.mAgeMillis
		&& mNitzData.equals(that.mNitzData);
		}

src/java/com/android/internal/telephony/NitzStateMachine.java

+6 −6

Original line number	Diff line number	Diff line
		@@ -89,14 +89,14 @@ public interface NitzStateMachine {
		interface DeviceState {

		/**
		* If time between NITZ updates is less than {@link #getNitzUpdateSpacingMillis()} the
		* update may be ignored.
		* If elapsed time between two NITZ signals is less than this value then the second signal
		* can be ignored.
		*/
		int getNitzUpdateSpacingMillis();

		/**
		* If {@link #getNitzUpdateSpacingMillis()} hasn't been exceeded but update is >
		* {@link #getNitzUpdateDiffMillis()} do the update
		* If UTC time between two NITZ signals is less than this value then the second signal can
		* be ignored.
		*/
		int getNitzUpdateDiffMillis();

		@@ -108,7 +108,7 @@ public interface NitzStateMachine {
		/**
		* Returns the same value as {@link SystemClock#elapsedRealtime()}.
		*/
		long elapsedRealtime();
		long elapsedRealtimeMillis();

		/**
		* Returns the same value as {@link System#currentTimeMillis()}.
		@@ -157,7 +157,7 @@ public interface NitzStateMachine {
		}

		@Override
		public long elapsedRealtime() {
		public long elapsedRealtimeMillis() {
		return SystemClock.elapsedRealtime();
		}

src/java/com/android/internal/telephony/nitz/NitzSignalInputFilterPredicateFactory.java

+25 −15

Original line number	Diff line number	Diff line
		@@ -132,7 +132,7 @@ public final class NitzSignalInputFilterPredicateFactory {
		// Acquire the wake lock as we are reading the elapsed realtime clock below.
		wakeLock.acquire();

		long elapsedRealtime = deviceState.elapsedRealtime();
		long elapsedRealtime = deviceState.elapsedRealtimeMillis();
		long millisSinceNitzReceived =
		elapsedRealtime - newSignal.getReceiptElapsedRealtimeMillis();
		if (millisSinceNitzReceived < 0 \|\| millisSinceNitzReceived > Integer.MAX_VALUE) {
		@@ -196,26 +196,36 @@ public final class NitzSignalInputFilterPredicateFactory {
		return true;
		}

		// Now check the continuous NitzData field (time) to see if it is sufficiently
		// different.
		int nitzUpdateSpacing = deviceState.getNitzUpdateSpacingMillis();
		int nitzUpdateDiff = deviceState.getNitzUpdateDiffMillis();
		// Check the time-related NitzData fields to see if they are sufficiently different.

		// Calculate the elapsed time between the new signal and the last signal.
		// See if the NITZ signals have been received sufficiently far apart. If yes, we
		// want to process the new one.
		int nitzUpdateSpacing = deviceState.getNitzUpdateSpacingMillis();
		long elapsedRealtimeSinceLastSaved = newSignal.getReceiptElapsedRealtimeMillis()
		- previousSignal.getReceiptElapsedRealtimeMillis();
		if (elapsedRealtimeSinceLastSaved > nitzUpdateSpacing) {
		return true;
		}

		// Calculate the UTC difference between the time the two signals hold.
		// See if the NITZ signals have sufficiently different encoded UTC times. If yes,
		// then we want to process the new one.
		int nitzUpdateDiff = deviceState.getNitzUpdateDiffMillis();

		// Calculate the UTC difference between the time the two signals hold, accounting
		// for any difference in receipt time and age.
		long utcTimeDifferenceMillis = newNitzData.getCurrentTimeInMillis()
		- previousNitzData.getCurrentTimeInMillis();

		// Ideally the difference between elapsedRealtimeSinceLastSaved and
		// utcTimeDifferenceMillis would be zero.
		long millisGainedOrLost = Math
		.abs(utcTimeDifferenceMillis - elapsedRealtimeSinceLastSaved);

		if (elapsedRealtimeSinceLastSaved > nitzUpdateSpacing
		\|\| millisGainedOrLost > nitzUpdateDiff) {
		long ageAdjustedElapsedRealtimeDifferenceMillis =
		newSignal.getAgeAdjustedElapsedRealtimeMillis()
		- previousSignal.getAgeAdjustedElapsedRealtimeMillis();

		// In ideal conditions, the difference between
		// ageAdjustedElapsedRealtimeSinceLastSaved and utcTimeDifferenceMillis will be zero
		// if two NITZ signals are consistent and if the elapsed realtime clock is ticking
		// at the correct rate.
		long millisGainedOrLost = Math.abs(
		utcTimeDifferenceMillis - ageAdjustedElapsedRealtimeDifferenceMillis);
		if (millisGainedOrLost > nitzUpdateDiff) {
		return true;
		}

src/java/com/android/internal/telephony/nitz/NitzStateMachineImpl.java

+1 −3

Original line number	Diff line number	Diff line
		@@ -319,9 +319,7 @@ public final class NitzStateMachineImpl implements NitzStateMachine {
		builder.addDebugInfo("Clearing time suggestion"
		+ " reason=" + reason);
		} else {
		TimestampedValue<Long> newNitzTime = new TimestampedValue<>(
		nitzSignal.getReceiptElapsedRealtimeMillis(),
		nitzSignal.getNitzData().getCurrentTimeInMillis());
		TimestampedValue<Long> newNitzTime = nitzSignal.createTimeSignal();
		builder.setUtcTime(newNitzTime);
		builder.addDebugInfo("Sending new time suggestion"
		+ " nitzSignal=" + nitzSignal

tests/telephonytests/src/com/android/internal/telephony/NitzSignalTest.java

0 → 100644

+76 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2021 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.internal.telephony;

		import static org.junit.Assert.assertEquals;
		import static org.junit.Assert.assertNotEquals;

		import org.junit.Test;

		public class NitzSignalTest {

		/** Sample cases for equals() and hashCode(). Not exhaustive. */
		@Test
		public void testEqualsAndHashCode() {
		long receiptElapsedMillis1 = 1111;
		NitzData nitzData1 = NitzData.createForTests(0, 0, 1234, null);
		long ageMillis1 = 11;
		NitzSignal nitzSignal1 = new NitzSignal(receiptElapsedMillis1, nitzData1, ageMillis1);
		assertEquals(nitzSignal1, nitzSignal1);
		assertEquals(nitzSignal1.hashCode(), nitzSignal1.hashCode());

		NitzSignal nitzSignal1v2 = new NitzSignal(receiptElapsedMillis1, nitzData1, ageMillis1);
		assertEquals(nitzSignal1, nitzSignal1v2);
		assertEquals(nitzSignal1v2, nitzSignal1);
		assertEquals(nitzSignal1.hashCode(), nitzSignal1v2.hashCode());

		long receiptElapsedMillis2 = 2222;
		NitzData nitzData2 = NitzData.createForTests(0, 0, 2345, null);
		long ageMillis2 = 11;
		NitzSignal nitzSignal2 = new NitzSignal(receiptElapsedMillis2, nitzData2, ageMillis2);
		assertNotEquals(nitzSignal1, nitzSignal2);
		assertNotEquals(nitzSignal2, nitzSignal1);
		}

		@Test
		public void testGetAgeAdjustedRealtimeMillis_zeroAge() {
		NitzData nitzData = NitzData.createForTests(0, 0, 1234, null);
		long receiptElapsedRealtimeMillis = 1111;
		long ageMillis = 0;
		NitzSignal nitzSignal =
		new NitzSignal(receiptElapsedRealtimeMillis, nitzData, ageMillis);
		assertEquals(receiptElapsedRealtimeMillis,
		nitzSignal.getReceiptElapsedRealtimeMillis());
		assertEquals(ageMillis, nitzSignal.getAgeMillis());
		assertEquals(receiptElapsedRealtimeMillis - ageMillis,
		nitzSignal.getAgeAdjustedElapsedRealtimeMillis());
		}

		@Test
		public void testGetAgeAdjustedRealtimeMillis_withAge() {
		NitzData nitzData = NitzData.createForTests(0, 0, 1234, null);
		long receiptElapsedRealtimeMillis = 1111;
		long ageMillis = 5000;
		NitzSignal nitzSignal =
		new NitzSignal(receiptElapsedRealtimeMillis, nitzData, ageMillis);
		assertEquals(receiptElapsedRealtimeMillis,
		nitzSignal.getReceiptElapsedRealtimeMillis());
		assertEquals(ageMillis, nitzSignal.getAgeMillis());
		assertEquals(receiptElapsedRealtimeMillis - ageMillis,
		nitzSignal.getAgeAdjustedElapsedRealtimeMillis());
		}
		}