Reduce duplication of time zone detection logic (1fef4399) · Commits · e / os / android_frameworks_opt_telephony

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

+130 −170

Original line number	Diff line number	Diff line
		@@ -119,10 +119,12 @@ public class NitzStateMachine {
		private TimeStampedValue<NitzData> mLatestNitzSignal;

		/**
		* Sometimes we get the NITZ time before we know what country we are in. We can find the time
		* zone once we know the country by using {@link #mLatestNitzSignal}.
		* Records whether the device should have a country code available via
		* {@link DeviceState#getNetworkCountryIsoForPhone()}. Before this an NITZ signal
		* received is (almost always) not enough to determine time zone. On test networks the country
		* code should be available but can still be an empty string but this flag indicates that the
		* information available is unlikely to improve.
		*/
		private boolean mNeedCountryCodeForNitz = false;
		private boolean mGotCountryCode = false;

		/**
		@@ -198,95 +200,146 @@ public class NitzStateMachine {
		* probably hasn't
		*/
		public void handleNetworkCountryCodeSet(boolean countryChanged) {
		boolean hadCountryCode = mGotCountryCode;
		mGotCountryCode = true;

		String isoCountryCode = mDeviceState.getNetworkCountryIsoForPhone();
		if (!TextUtils.isEmpty(isoCountryCode) && !mNitzTimeZoneDetectionSuccessful) {
		updateTimeZoneByNetworkCountryCode(isoCountryCode);
		updateTimeZoneFromNetworkCountryCode(isoCountryCode);
		}

		if (countryChanged \|\| mNeedCountryCodeForNitz) {
		if (mLatestNitzSignal != null && (countryChanged \|\| !hadCountryCode)) {
		updateTimeZoneFromCountryAndNitz();
		}
		}

		private void updateTimeZoneFromCountryAndNitz() {
		String isoCountryCode = mDeviceState.getNetworkCountryIsoForPhone();
		TimeStampedValue<NitzData> nitzSignal = mLatestNitzSignal;

		// TimeZone.getDefault() returns a default zone (GMT) even when time zone have never
		// been set which makes it difficult to tell if it's what the user / time zone detection
		// has chosen. isTimeZoneSettingInitialized() tells us whether the time zone of the
		// device has ever been explicit set by the user or code.
		final boolean isTimeZoneSettingInitialized =
		mTimeServiceHelper.isTimeZoneSettingInitialized();

		if (DBG) {
		Rlog.d(LOG_TAG, "handleNetworkCountryCodeSet:"
		Rlog.d(LOG_TAG, "updateTimeZoneFromCountryAndNitz:"
		+ " isTimeZoneSettingInitialized=" + isTimeZoneSettingInitialized
		+ " mLatestNitzSignal=" + mLatestNitzSignal
		+ " nitzSignal=" + nitzSignal
		+ " isoCountryCode=" + isoCountryCode);
		}

		try {
		NitzData nitzData = nitzSignal.mValue;

		String zoneId;
		if (TextUtils.isEmpty(isoCountryCode) && mNeedCountryCodeForNitz) {
		// Country code not found. This is likely a test network.
		// Get a TimeZone based only on the NITZ parameters (best guess).

		// mNeedCountryCodeForNitz is only set to true after an NITZ signal has been
		// received and so mLatestNitzSign must be non-null.
		OffsetResult lookupResult =
		mTimeZoneLookupHelper.lookupByNitz(mLatestNitzSignal.mValue);
		if (nitzData.getEmulatorHostTimeZone() != null) {
		zoneId = nitzData.getEmulatorHostTimeZone().getID();
		} else if (!mGotCountryCode) {
		// We don't have a country code so we won't try to look up the time zone.
		zoneId = null;
		} else if (TextUtils.isEmpty(isoCountryCode)) {
		// We have a country code but it's empty. This is most likely because we're on a
		// test network that's using a bogus MCC (eg, "001"). Obtain a TimeZone based only
		// on the NITZ parameters: it's only going to be correct in a few cases but it
		// should at least have the correct offset.
		OffsetResult lookupResult = mTimeZoneLookupHelper.lookupByNitz(nitzData);
		String logMsg = "updateTimeZoneFromCountryAndNitz: lookupByNitz returned"
		+ " lookupResult=" + lookupResult;
		if (DBG) {
		Rlog.d(LOG_TAG, "handleNetworkCountryCodeSet: guessZoneIdByNitz() returned"
		+ " lookupResult=" + lookupResult);
		Rlog.d(LOG_TAG, logMsg);
		}
		// We log this in the time zone log because it has been a source of bugs.
		mTimeZoneLog.log(logMsg);

		zoneId = lookupResult != null ? lookupResult.zoneId : null;
		} else if (mLatestNitzSignal == null) {
		zoneId = null;
		if (DBG) {
		Rlog.d(LOG_TAG, "handleNetworkCountryCodeSet: No cached NITZ data available,"
		Rlog.d(LOG_TAG,
		"updateTimeZoneFromCountryAndNitz: No cached NITZ data available,"
		+ " not setting zone");
		}
		} else { // mLatestNitzSignal != null
		if (isNitzSignalOffsetInfoBogus(mLatestNitzSignal, isoCountryCode)) {
		String logMsg = "handleNetworkCountryCodeSet: Stored NITZ looks bogus, "
		zoneId = null;
		} else if (isNitzSignalOffsetInfoBogus(nitzSignal, isoCountryCode)) {
		String logMsg = "updateTimeZoneFromCountryAndNitz: Received NITZ looks bogus, "
		+ " isoCountryCode=" + isoCountryCode
		+ " mLatestNitzSignal=" + mLatestNitzSignal;
		+ " nitzSignal=" + nitzSignal;
		if (DBG) {
		Rlog.d(LOG_TAG, logMsg);
		}
		// We log this in the time zone log because it has been a source of bugs.
		mTimeZoneLog.log(logMsg);

		// No zone can be determined.
		zoneId = null;
		} else {
		NitzData nitzData = mLatestNitzSignal.mValue;
		OffsetResult lookupResult =
		mTimeZoneLookupHelper.lookupByNitzCountry(nitzData, isoCountryCode);
		OffsetResult lookupResult = mTimeZoneLookupHelper.lookupByNitzCountry(
		nitzData, isoCountryCode);
		if (DBG) {
		Rlog.d(LOG_TAG, "handleNetworkCountryCodeSet: using"
		+ " guessZoneIdByNitzCountry(nitzData, isoCountryCode),"
		Rlog.d(LOG_TAG, "updateTimeZoneFromCountryAndNitz: using"
		+ " lookupByNitzCountry(nitzData, isoCountryCode),"
		+ " nitzData=" + nitzData
		+ " isoCountryCode=" + isoCountryCode
		+ " lookupResult=" + lookupResult);
		}
		zoneId = lookupResult != null ? lookupResult.zoneId : null;
		}
		}
		final String tmpLog = "handleNetworkCountryCodeSet:"

		// Log the action taken to the dedicated time zone log.
		final String tmpLog = "updateTimeZoneFromCountryAndNitz:"
		+ " isTimeZoneSettingInitialized=" + isTimeZoneSettingInitialized
		+ " mLatestNitzSignal=" + mLatestNitzSignal
		+ " isoCountryCode=" + isoCountryCode
		+ " mNeedCountryCodeForNitz=" + mNeedCountryCodeForNitz
		+ " zoneId=" + zoneId;
		+ " nitzSignal=" + nitzSignal
		+ " zoneId=" + zoneId
		+ " isTimeZoneDetectionEnabled()="
		+ mTimeServiceHelper.isTimeZoneDetectionEnabled();
		mTimeZoneLog.log(tmpLog);

		// Set state as needed.
		if (zoneId != null) {
		Rlog.d(LOG_TAG, "handleNetworkCountryCodeSet: zoneId != null, zoneId=" + zoneId);
		if (DBG) {
		Rlog.d(LOG_TAG, "updateTimeZoneFromCountryAndNitz: zoneId=" + zoneId);
		}
		if (mTimeServiceHelper.isTimeZoneDetectionEnabled()) {
		setAndBroadcastNetworkSetTimeZone(zoneId);
		} else {
		Rlog.d(LOG_TAG, "handleNetworkCountryCodeSet: skip changing zone as"
		+ " isTimeZoneDetectionEnabled() is false");
		if (DBG) {
		Rlog.d(LOG_TAG, "updateTimeZoneFromCountryAndNitz: skip changing zone"
		+ " as isTimeZoneDetectionEnabled() is false");
		}
		}
		mSavedTimeZoneId = zoneId;
		mNitzTimeZoneDetectionSuccessful = true;
		} else {
		Rlog.d(LOG_TAG, "handleNetworkCountryCodeSet: lookupResult == null, do nothing");
		if (DBG) {
		Rlog.d(LOG_TAG,
		"updateTimeZoneFromCountryAndNitz: zoneId == null, do nothing");
		}
		mNeedCountryCodeForNitz = false;
		}
		} catch (RuntimeException ex) {
		Rlog.e(LOG_TAG, "updateTimeZoneFromCountryAndNitz: Processing NITZ data"
		+ " nitzSignal=" + nitzSignal
		+ " isoCountryCode=" + isoCountryCode
		+ " isTimeZoneSettingInitialized=" + isTimeZoneSettingInitialized
		+ " ex=" + ex);
		}
		}

		/**
		* Returns true if the NITZ signal is definitely bogus, assuming that the country is correct.
		*/
		private boolean isNitzSignalOffsetInfoBogus(
		TimeStampedValue<NitzData> nitzSignal, String isoCountryCode) {

		if (TextUtils.isEmpty(isoCountryCode)) {
		// We cannot say for sure.
		return false;
		}

		NitzData newNitzData = nitzSignal.mValue;
		boolean zeroOffsetNitz = newNitzData.getLocalOffsetMillis() == 0 && !newNitzData.isDst();
		return zeroOffsetNitz && !countryUsesUtc(isoCountryCode, nitzSignal);
		}

		private boolean countryUsesUtc(
		@@ -327,111 +380,19 @@ public class NitzStateMachine {
		// Always store the latest NITZ signal received.
		mLatestNitzSignal = nitzSignal;

		handleTimeZoneFromNitz(nitzSignal);
		handleTimeFromNitz(nitzSignal);
		}

		/**
		* Returns true if the NITZ signal is definitely bogus, assuming that the country is correct.
		*/
		private boolean isNitzSignalOffsetInfoBogus(
		TimeStampedValue<NitzData> nitzSignal, String isoCountryCode) {

		if (TextUtils.isEmpty(isoCountryCode)) {
		// We cannot say for sure.
		return false;
		}

		NitzData newNitzData = nitzSignal.mValue;
		boolean zeroOffsetNitz = newNitzData.getLocalOffsetMillis() == 0 && !newNitzData.isDst();
		return zeroOffsetNitz && !countryUsesUtc(isoCountryCode, nitzSignal);
		}

		private void handleTimeZoneFromNitz(TimeStampedValue<NitzData> nitzSignal) {
		try {
		NitzData newNitzData = nitzSignal.mValue;
		String isoCountryCode = mDeviceState.getNetworkCountryIsoForPhone();

		boolean needCountryCode;
		String zoneId;
		if (newNitzData.getEmulatorHostTimeZone() != null) {
		zoneId = newNitzData.getEmulatorHostTimeZone().getID();
		needCountryCode = false;
		} else {
		if (!mGotCountryCode) {
		// We don't have a country code so we won't try to look up the time zone.
		zoneId = null;
		needCountryCode = true;
		} else if (TextUtils.isEmpty(isoCountryCode)) {
		// We have a country code but it's empty. This is most likely because we're on a
		// test network that's using a bogus MCC (eg, "001"), so get a TimeZone
		// based only on the NITZ parameters.
		OffsetResult lookupResult = mTimeZoneLookupHelper.lookupByNitz(newNitzData);
		if (DBG) {
		Rlog.d(LOG_TAG, "handleTimeZoneFromNitz: guessZoneIdByNitz returned"
		+ " lookupResult=" + lookupResult);
		}
		zoneId = lookupResult != null ? lookupResult.zoneId : null;
		needCountryCode = false;
		} else if (isNitzSignalOffsetInfoBogus(nitzSignal, isoCountryCode)) {
		String logMsg = "handleNitzReceived: Received NITZ looks bogus, "
		+ " isoCountryCode=" + isoCountryCode
		+ " nitzSignal=" + nitzSignal;
		if (DBG) {
		Rlog.d(LOG_TAG, logMsg);
		}
		mTimeZoneLog.log(logMsg);

		zoneId = null;
		needCountryCode = false;
		} else {
		OffsetResult lookupResult = mTimeZoneLookupHelper.lookupByNitzCountry(
		newNitzData, isoCountryCode);
		zoneId = lookupResult != null ? lookupResult.zoneId : null;
		needCountryCode = false;
		}
		updateTimeZoneFromCountryAndNitz();
		updateTimeFromNitz();
		}

		// Set state as needed.
		if (needCountryCode) {
		mNeedCountryCodeForNitz = true;
		} else {
		mNeedCountryCodeForNitz = false;
		if (zoneId != null) {
		if (mTimeServiceHelper.isTimeZoneDetectionEnabled()) {
		setAndBroadcastNetworkSetTimeZone(zoneId);
		}
		mSavedTimeZoneId = zoneId;
		mNitzTimeZoneDetectionSuccessful = true;
		}
		}

		String tmpLog = "handleTimeZoneFromNitz: nitzSignal=" + nitzSignal
		+ " zoneId=" + zoneId
		+ " mGotCountryCode=" + mGotCountryCode
		+ " isoCountryCode=" + isoCountryCode
		+ " mNeedCountryCodeForNitz=" + mNeedCountryCodeForNitz
		+ " mNitzTimeZoneDetectionSuccessful=" + mNitzTimeZoneDetectionSuccessful
		+ " mSavedTimeZoneId=" + mSavedTimeZoneId
		+ " isTimeZoneDetectionEnabled()="
		+ mTimeServiceHelper.isTimeZoneDetectionEnabled();
		if (DBG) {
		Rlog.d(LOG_TAG, tmpLog);
		}
		mTimeZoneLog.log(tmpLog);
		} catch (RuntimeException ex) {
		Rlog.e(LOG_TAG, "handleTimeZoneFromNitz: Processing NITZ data"
		+ " nitzSignal=" + nitzSignal
		+ " ex=" + ex);
		}
		}

		private void handleTimeFromNitz(TimeStampedValue<NitzData> nitzSignal) {
		private void updateTimeFromNitz() {
		TimeStampedValue<NitzData> nitzSignal = mLatestNitzSignal;
		try {
		boolean ignoreNitz = mDeviceState.getIgnoreNitz();
		if (ignoreNitz) {
		if (DBG) {
		Rlog.d(LOG_TAG,
		"handleTimeFromNitz: Not setting clock because gsm.ignore-nitz is set");
		"updateTimeFromNitz: Not setting clock because gsm.ignore-nitz is set");
		}
		return;
		}

		@@ -445,7 +406,7 @@ public class NitzStateMachine {
		long millisSinceNitzReceived = elapsedRealtime - nitzSignal.mElapsedRealtime;
		if (millisSinceNitzReceived < 0 \|\| millisSinceNitzReceived > Integer.MAX_VALUE) {
		if (DBG) {
		Rlog.d(LOG_TAG, "handleTimeFromNitz: not setting time, unexpected"
		Rlog.d(LOG_TAG, "updateTimeFromNitz: not setting time, unexpected"
		+ " elapsedRealtime=" + elapsedRealtime
		+ " nitzSignal=" + nitzSignal);
		}
		@@ -458,7 +419,7 @@ public class NitzStateMachine {
		long gained = adjustedCurrentTimeMillis - mTimeServiceHelper.currentTimeMillis();

		if (mTimeServiceHelper.isTimeDetectionEnabled()) {
		String logMsg = "handleTimeFromNitz:"
		String logMsg = "updateTimeFromNitz:"
		+ " nitzSignal=" + nitzSignal
		+ " adjustedCurrentTimeMillis=" + adjustedCurrentTimeMillis
		+ " millisSinceNitzReceived= " + millisSinceNitzReceived
		@@ -502,7 +463,7 @@ public class NitzStateMachine {
		mWakeLock.release();
		}
		} catch (RuntimeException ex) {
		Rlog.e(LOG_TAG, "handleTimeFromNitz: Processing NITZ data"
		Rlog.e(LOG_TAG, "updateTimeFromNitz: Processing NITZ data"
		+ " nitzSignal=" + nitzSignal
		+ " ex=" + ex);
		}
		@@ -578,7 +539,6 @@ public class NitzStateMachine {
		pw.println(" mSavedTime=" + mSavedNitzTime);

		// Time Zone Detection State
		pw.println(" mNeedCountryCodeForNitz=" + mNeedCountryCodeForNitz);
		pw.println(" mLatestNitzSignal=" + mLatestNitzSignal);
		pw.println(" mGotCountryCode=" + mGotCountryCode);
		pw.println(" mSavedTimeZoneId=" + mSavedTimeZoneId);
		@@ -610,13 +570,13 @@ public class NitzStateMachine {
		*
		* @param iso Country code from network MCC
		*/
		private void updateTimeZoneByNetworkCountryCode(String iso) {
		private void updateTimeZoneFromNetworkCountryCode(String iso) {
		CountryResult lookupResult = mTimeZoneLookupHelper.lookupByCountry(
		iso, mTimeServiceHelper.currentTimeMillis());
		if (lookupResult != null && lookupResult.allZonesHaveSameOffset) {
		String logMsg = "updateTimeZoneByNetworkCountryCode: set time"
		+ " lookupResult=" + lookupResult
		+ " iso=" + iso;
		String logMsg = "updateTimeZoneFromNetworkCountryCode: tz result found"
		+ " iso=" + iso
		+ " lookupResult=" + lookupResult;
		if (DBG) {
		Rlog.d(LOG_TAG, logMsg);
		}
		@@ -628,7 +588,7 @@ public class NitzStateMachine {
		mSavedTimeZoneId = zoneId;
		} else {
		if (DBG) {
		Rlog.d(LOG_TAG, "updateTimeZoneByNetworkCountryCode: no good zone for"
		Rlog.d(LOG_TAG, "updateTimeZoneFromNetworkCountryCode: no good zone for"
		+ " iso=" + iso
		+ " lookupResult=" + lookupResult);
		}

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

+119 −0

Original line number	Diff line number	Diff line
		@@ -667,6 +667,125 @@ public class NitzStateMachineTest extends TelephonyTest {
		assertNull(mNitzStateMachine.getSavedTimeZoneId());
		}

		@Test
		public void test_emulatorNitzExtensionUsedForTimeZone() throws Exception {
		Scenario scenario = UNIQUE_US_ZONE_SCENARIO;
		Device device = new DeviceBuilder()
		.setClocksFromScenario(scenario)
		.setTimeDetectionEnabled(false)
		.setTimeZoneDetectionEnabled(true)
		.setTimeZoneSettingInitialized(true)
		.initialize();
		Script script = new Script(device);

		TimeStampedValue<NitzData> originalNitzSignal = scenario.getNitzSignal();

		// Create an NITZ signal with an explicit time zone (as can happen on emulators)
		NitzData originalNitzData = originalNitzSignal.mValue;
		// A time zone that is obviously not in the US, but it should not be questioned.
		String emulatorTimeZoneId = "Europe/London";
		NitzData emulatorNitzData = NitzData.createForTests(
		originalNitzData.getLocalOffsetMillis(),
		originalNitzData.getDstAdjustmentMillis(),
		originalNitzData.getCurrentTimeInMillis(),
		java.util.TimeZone.getTimeZone(emulatorTimeZoneId) /* emulatorHostTimeZone */);
		TimeStampedValue<NitzData> emulatorNitzSignal = new TimeStampedValue<>(
		emulatorNitzData, originalNitzSignal.mElapsedRealtime);

		// Simulate receiving the emulator NITZ signal.
		script.nitzReceived(emulatorNitzSignal)
		.verifyOnlyTimeZoneWasSetAndReset(emulatorTimeZoneId);

		// Check NitzStateMachine state.
		assertTrue(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(emulatorNitzSignal.mValue, mNitzStateMachine.getCachedNitzData());
		assertEquals(emulatorTimeZoneId, mNitzStateMachine.getSavedTimeZoneId());
		}

		@Test
		public void test_emptyCountryStringUsTime_countryReceivedFirst() throws Exception {
		Scenario scenario = UNIQUE_US_ZONE_SCENARIO;
		Device device = new DeviceBuilder()
		.setClocksFromScenario(scenario)
		.setTimeDetectionEnabled(true)
		.setTimeZoneDetectionEnabled(true)
		.setTimeZoneSettingInitialized(true)
		.initialize();
		Script script = new Script(device);

		String expectedZoneId = checkNitzOnlyLookupIsAmbiguousAndReturnZoneId(scenario);

		// Nothing should be set. The country is not valid.
		script.countryReceived("").verifyNothingWasSetAndReset();

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertNull(mNitzStateMachine.getCachedNitzData());
		assertNull(mNitzStateMachine.getSavedTimeZoneId());

		// Simulate receiving the NITZ signal.
		script.nitzReceived(scenario.getNitzSignal())
		.verifyTimeAndZoneSetAndReset(scenario.getActualTimeMillis(), expectedZoneId);

		// Check NitzStateMachine state.
		assertTrue(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(scenario.getNitzSignal().mValue, mNitzStateMachine.getCachedNitzData());
		assertEquals(expectedZoneId, mNitzStateMachine.getSavedTimeZoneId());
		}

		@Test
		public void test_emptyCountryStringUsTime_nitzReceivedFirst() throws Exception {
		Scenario scenario = UNIQUE_US_ZONE_SCENARIO;
		Device device = new DeviceBuilder()
		.setClocksFromScenario(scenario)
		.setTimeDetectionEnabled(true)
		.setTimeZoneDetectionEnabled(true)
		.setTimeZoneSettingInitialized(true)
		.initialize();
		Script script = new Script(device);

		String expectedZoneId = checkNitzOnlyLookupIsAmbiguousAndReturnZoneId(scenario);

		// Simulate receiving the NITZ signal.
		script.nitzReceived(scenario.getNitzSignal())
		.verifyOnlyTimeWasSetAndReset(scenario.getActualTimeMillis());

		// Check NitzStateMachine state.
		assertFalse(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(scenario.getNitzSignal().mValue, mNitzStateMachine.getCachedNitzData());
		assertNull(mNitzStateMachine.getSavedTimeZoneId());

		// The time zone should be set (but the country is not valid so it's unlikely to be
		// correct).
		script.countryReceived("").verifyOnlyTimeZoneWasSetAndReset(expectedZoneId);

		// Check NitzStateMachine state.
		assertTrue(mNitzStateMachine.getNitzTimeZoneDetectionSuccessful());
		assertEquals(scenario.getNitzSignal().mValue, mNitzStateMachine.getCachedNitzData());
		assertEquals(expectedZoneId, mNitzStateMachine.getSavedTimeZoneId());
		}

		/**
		* Asserts a test scenario has the properties we expect for NITZ-only lookup. There are
		* usually multiple zones that will share the same UTC offset so we get a low quality / low
		* confidence answer, but the zone we find should at least have the correct offset.
		*/
		private String checkNitzOnlyLookupIsAmbiguousAndReturnZoneId(Scenario scenario) {
		OffsetResult result =
		mRealTimeZoneLookupHelper.lookupByNitz(scenario.getNitzSignal().mValue);
		String expectedZoneId = result.zoneId;
		// All our scenarios should return multiple matches. The only cases where this wouldn't be
		// true are places that use offsets like XX:15, XX:30 and XX:45.
		assertFalse(result.isOnlyMatch);
		assertSameOffset(scenario.getActualTimeMillis(), expectedZoneId, scenario.getTimeZoneId());
		return expectedZoneId;
		}

		private static void assertSameOffset(long timeMillis, String zoneId1, String zoneId2) {
		assertEquals(TimeZone.getTimeZone(zoneId1).getOffset(timeMillis),
		TimeZone.getTimeZone(zoneId2).getOffset(timeMillis));
		}

		private static long createUtcTime(int year, int monthInYear, int day, int hourOfDay, int minute,
		int second) {
		Calendar cal = new GregorianCalendar(TimeZone.getTimeZone("Etc/UTC"));