Merge "Improve time zone detection by leveraging MNC info" (06755a77) · Commits · e / os / android_frameworks_opt_telephony

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

+108 −26

Original line number	Diff line number	Diff line
		@@ -42,6 +42,7 @@ import android.text.TextUtils;
		import android.util.LocalLog;

		import com.android.internal.annotations.VisibleForTesting;
		import com.android.internal.telephony.MccTable.MccMnc;
		import com.android.internal.util.IndentingPrintWriter;

		import java.io.FileDescriptor;
		@@ -282,23 +283,16 @@ public class LocaleTracker extends Handler {
		private String getMccFromCellInfo() {
		String selectedMcc = null;
		if (mCellInfoList != null) {
		Map<String, Integer> countryCodeMap = new HashMap<>();
		Map<String, Integer> mccMap = new HashMap<>();
		int maxCount = 0;
		for (CellInfo cellInfo : mCellInfoList) {
		String mcc = null;
		if (cellInfo instanceof CellInfoGsm) {
		mcc = ((CellInfoGsm) cellInfo).getCellIdentity().getMccString();
		} else if (cellInfo instanceof CellInfoLte) {
		mcc = ((CellInfoLte) cellInfo).getCellIdentity().getMccString();
		} else if (cellInfo instanceof CellInfoWcdma) {
		mcc = ((CellInfoWcdma) cellInfo).getCellIdentity().getMccString();
		}
		String mcc = getNetworkMcc(cellInfo);
		if (mcc != null) {
		int count = 1;
		if (countryCodeMap.containsKey(mcc)) {
		count = countryCodeMap.get(mcc) + 1;
		if (mccMap.containsKey(mcc)) {
		count = mccMap.get(mcc) + 1;
		}
		countryCodeMap.put(mcc, count);
		mccMap.put(mcc, count);
		// This is unlikely, but if MCC from cell info looks different, we choose the
		// MCC that occurs most.
		if (count > maxCount) {
		@@ -311,6 +305,67 @@ public class LocaleTracker extends Handler {
		return selectedMcc;
		}

		/**
		* Get the most frequent MCC + MNC combination with the specified MCC using cell tower
		* information. If no one combination is more frequent than any other an arbitrary MCC + MNC is
		* returned with the matching MCC. The MNC value returned can be null if it is not provided by
		* the cell tower information.
		*
		* @param mccToMatch the MCC to match
		* @return a matching {@link MccMnc}. Null if the information is not available.
		*/
		@Nullable
		private MccMnc getMccMncFromCellInfo(String mccToMatch) {
		MccMnc selectedMccMnc = null;
		if (mCellInfoList != null) {
		Map<MccMnc, Integer> mccMncMap = new HashMap<>();
		int maxCount = 0;
		for (CellInfo cellInfo : mCellInfoList) {
		String mcc = getNetworkMcc(cellInfo);
		if (Objects.equals(mcc, mccToMatch)) {
		String mnc = getNetworkMnc(cellInfo);
		MccMnc mccMnc = new MccMnc(mcc, mnc);
		int count = 1;
		if (mccMncMap.containsKey(mccMnc)) {
		count = mccMncMap.get(mccMnc) + 1;
		}
		mccMncMap.put(mccMnc, count);
		// This is unlikely, but if MCC from cell info looks different, we choose the
		// MCC that occurs most.
		if (count > maxCount) {
		maxCount = count;
		selectedMccMnc = mccMnc;
		}
		}
		}
		}
		return selectedMccMnc;
		}

		private static String getNetworkMcc(CellInfo cellInfo) {
		String mccString = null;
		if (cellInfo instanceof CellInfoGsm) {
		mccString = ((CellInfoGsm) cellInfo).getCellIdentity().getMccString();
		} else if (cellInfo instanceof CellInfoLte) {
		mccString = ((CellInfoLte) cellInfo).getCellIdentity().getMccString();
		} else if (cellInfo instanceof CellInfoWcdma) {
		mccString = ((CellInfoWcdma) cellInfo).getCellIdentity().getMccString();
		}
		return mccString;
		}

		private static String getNetworkMnc(CellInfo cellInfo) {
		String mccString = null;
		if (cellInfo instanceof CellInfoGsm) {
		mccString = ((CellInfoGsm) cellInfo).getCellIdentity().getMncString();
		} else if (cellInfo instanceof CellInfoLte) {
		mccString = ((CellInfoLte) cellInfo).getCellIdentity().getMncString();
		} else if (cellInfo instanceof CellInfoWcdma) {
		mccString = ((CellInfoWcdma) cellInfo).getCellIdentity().getMncString();
		}
		return mccString;
		}

		/**
		* Called when SIM card state changed. Only when we absolutely know the SIM is absent, we get
		* cell info from the network. Other SIM states like NOT_READY might be just a transitioning
		@@ -457,15 +512,23 @@ public class LocaleTracker extends Handler {
		String countryIso = getCarrierCountry();
		String countryIsoDebugInfo = "getCarrierCountry()";

		// For time zone detection we want the best geographical match we can get, which may differ
		// from the countryIso.
		String timeZoneCountryIso = null;
		String timeZoneCountryIsoDebugInfo = null;

		if (!TextUtils.isEmpty(mOperatorNumeric)) {
		try {
		String mcc = mOperatorNumeric.substring(0, 3);
		countryIso = MccTable.countryCodeForMcc(mcc);
		MccMnc mccMnc = MccMnc.fromOperatorNumeric(mOperatorNumeric);
		if (mccMnc != null) {
		countryIso = MccTable.countryCodeForMcc(mccMnc.mcc);
		countryIsoDebugInfo = "OperatorNumeric(" + mOperatorNumeric
		+ "): MccTable.countryCodeForMcc(\"" + mcc + "\")";
		} catch (StringIndexOutOfBoundsException ex) {
		+ "): MccTable.countryCodeForMcc(\"" + mccMnc.mcc + "\")";
		timeZoneCountryIso = MccTable.geoCountryCodeForMccMnc(mccMnc);
		timeZoneCountryIsoDebugInfo =
		"OperatorNumeric: MccTable.geoCountryCodeForMccMnc(" + mccMnc + ")";
		} else {
		loge("updateLocale: Can't get country from operator numeric. mOperatorNumeric = "
		+ mOperatorNumeric + ". ex=" + ex);
		+ mOperatorNumeric);
		}
		}

		@@ -475,19 +538,27 @@ public class LocaleTracker extends Handler {
		String mcc = getMccFromCellInfo();
		countryIso = MccTable.countryCodeForMcc(mcc);
		countryIsoDebugInfo = "CellInfo: MccTable.countryCodeForMcc(\"" + mcc + "\")";

		MccMnc mccMnc = getMccMncFromCellInfo(mcc);
		if (mccMnc != null) {
		timeZoneCountryIso = MccTable.geoCountryCodeForMccMnc(mccMnc);
		timeZoneCountryIsoDebugInfo =
		"CellInfo: MccTable.geoCountryCodeForMccMnc(" + mccMnc + ")";
		}
		}

		if (mCountryOverride != null) {
		countryIso = mCountryOverride;
		countryIsoDebugInfo = "mCountryOverride = \"" + mCountryOverride + "\"";
		log("Override current country to " + mCountryOverride);
		timeZoneCountryIso = countryIso;
		timeZoneCountryIsoDebugInfo = countryIsoDebugInfo;
		}

		log("updateLocale: countryIso = " + countryIso
		+ ", countryIsoDebugInfo = " + countryIsoDebugInfo);
		if (!Objects.equals(countryIso, mCurrentCountryIso)) {
		String msg = "updateLocale: Change the current country to \"" + countryIso
		+ "\", countryIsoDebugInfo = " + countryIsoDebugInfo
		String msg = "updateLocale: Change the current country to \"" + countryIso + "\""
		+ ", countryIsoDebugInfo = " + countryIsoDebugInfo
		+ ", mCellInfoList = " + mCellInfoList;
		log(msg);
		mLocalLog.log(msg);
		@@ -502,19 +573,30 @@ public class LocaleTracker extends Handler {
		mPhone.getContext().sendBroadcast(intent);
		}

		// For a test cell, the NitzStateMachine requires handleCountryDetected("") to pass
		// compliance tests. http://b/142840879
		// Pass the geographical country information to the telephony time zone detection code.

		boolean isTestMcc = false;
		if (!TextUtils.isEmpty(mOperatorNumeric)) {
		// For a test cell (MCC 001), the NitzStateMachine requires handleCountryDetected("") in
		// order to pass compliance tests. http://b/142840879
		if (mOperatorNumeric.startsWith("001")) {
		isTestMcc = true;
		countryIso = "";
		timeZoneCountryIso = "";
		timeZoneCountryIsoDebugInfo = "Test cell: " + mOperatorNumeric;
		}
		}
		if (TextUtils.isEmpty(countryIso) && !isTestMcc) {
		if (timeZoneCountryIso == null) {
		// After this timeZoneCountryIso may still be null.
		timeZoneCountryIso = countryIso;
		timeZoneCountryIsoDebugInfo = "Defaulted: " + countryIsoDebugInfo;
		}
		log("updateLocale: timeZoneCountryIso = " + timeZoneCountryIso
		+ ", timeZoneCountryIsoDebugInfo = " + timeZoneCountryIsoDebugInfo);

		if (TextUtils.isEmpty(timeZoneCountryIso) && !isTestMcc) {
		mNitzStateMachine.handleCountryUnavailable();
		} else {
		mNitzStateMachine.handleCountryDetected(countryIso);
		mNitzStateMachine.handleCountryDetected(timeZoneCountryIso);
		}
		}

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

+137 −9

Original line number	Diff line number	Diff line
		@@ -16,6 +16,8 @@

		package com.android.internal.telephony;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.annotation.UnsupportedAppUsage;
		import android.app.ActivityManager;
		import android.content.Context;
		@@ -27,9 +29,15 @@ import android.os.SystemProperties;
		import android.text.TextUtils;
		import android.util.Slog;

		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.annotations.VisibleForTesting;
		import com.android.internal.app.LocaleStore;
		import com.android.internal.app.LocaleStore.LocaleInfo;

		import libcore.timezone.TelephonyLookup;
		import libcore.timezone.TelephonyNetwork;
		import libcore.timezone.TelephonyNetworkFinder;

		import java.util.ArrayList;
		import java.util.Arrays;
		import java.util.Collections;
		@@ -37,6 +45,7 @@ import java.util.HashMap;
		import java.util.List;
		import java.util.Locale;
		import java.util.Map;
		import java.util.Objects;

		/**
		* Mobile Country Code
		@@ -46,6 +55,9 @@ import java.util.Map;
		public final class MccTable {
		static final String LOG_TAG = "MccTable";

		@GuardedBy("MccTable.class")
		private static TelephonyNetworkFinder sTelephonyNetworkFinder;

		static ArrayList<MccEntry> sTable;

		static class MccEntry implements Comparable<MccEntry> {
		@@ -58,11 +70,11 @@ public final class MccTable {
		final String mIso;
		final int mSmallestDigitsMnc;

		MccEntry(int mnc, String iso, int smallestDigitsMCC) {
		MccEntry(int mcc, String iso, int smallestDigitsMCC) {
		if (iso == null) {
		throw new NullPointerException();
		}
		mMcc = mnc;
		mMcc = mcc;
		mIso = iso;
		mSmallestDigitsMnc = smallestDigitsMCC;
		}
		@@ -73,6 +85,77 @@ public final class MccTable {
		}
		}

		/**
		* A combination of MCC and MNC. The MNC is optional and may be null.
		*
		* @hide
		*/
		@VisibleForTesting
		public static class MccMnc {
		@NonNull
		public final String mcc;

		@Nullable
		public final String mnc;

		/**
		* Splits the supplied String in two: the first three characters are treated as the MCC,
		* the remaining characters are treated as the MNC.
		*/
		@Nullable
		public static MccMnc fromOperatorNumeric(@NonNull String operatorNumeric) {
		Objects.requireNonNull(operatorNumeric);
		String mcc;
		try {
		mcc = operatorNumeric.substring(0, 3);
		} catch (StringIndexOutOfBoundsException e) {
		return null;
		}

		String mnc;
		try {
		mnc = operatorNumeric.substring(3);
		} catch (StringIndexOutOfBoundsException e) {
		mnc = null;
		}
		return new MccMnc(mcc, mnc);
		}

		/**
		* Creates an MccMnc using the supplied values.
		*/
		public MccMnc(@NonNull String mcc, @Nullable String mnc) {
		this.mcc = Objects.requireNonNull(mcc);
		this.mnc = mnc;
		}

		@Override
		public boolean equals(Object o) {
		if (this == o) {
		return true;
		}
		if (o == null \|\| getClass() != o.getClass()) {
		return false;
		}
		MccMnc mccMnc = (MccMnc) o;
		return mcc.equals(mccMnc.mcc)
		&& Objects.equals(mnc, mccMnc.mnc);
		}

		@Override
		public int hashCode() {
		return Objects.hash(mcc, mnc);
		}

		@Override
		public String toString() {
		return "MccMnc{"
		+ "mcc='" + mcc + '\''
		+ ", mnc='" + mnc + '\''
		+ '}';
		}
		}

		@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.Q,
		publicAlternatives = "There is no alternative for {@code MccTable.entryForMcc}, "
		+ "but it was included in hidden APIs due to a static analysis false positive "
		@@ -91,11 +174,11 @@ public final class MccTable {
		}

		/**
		* Given a GSM Mobile Country Code, returns
		* an ISO two-character country code if available.
		* Returns "" if unavailable.
		* Given a GSM Mobile Country Code, returns a lower-case ISO 3166 alpha-2 country code if
		* available. Returns empty string if unavailable.
		*/
		@UnsupportedAppUsage
		@NonNull
		public static String countryCodeForMcc(int mcc) {
		MccEntry entry = entryForMcc(mcc);

		@@ -107,11 +190,11 @@ public final class MccTable {
		}

		/**
		* Given a GSM Mobile Country Code, returns
		* an ISO two-character country code if available.
		* Returns empty string if unavailable.
		* Given a GSM Mobile Country Code, returns a lower-case ISO 3166 alpha-2 country code if
		* available. Returns empty string if unavailable.
		*/
		public static String countryCodeForMcc(String mcc) {
		@NonNull
		public static String countryCodeForMcc(@NonNull String mcc) {
		try {
		return countryCodeForMcc(Integer.parseInt(mcc));
		} catch (NumberFormatException ex) {
		@@ -119,6 +202,51 @@ public final class MccTable {
		}
		}

		/**
		* Given a combination of MCC and MNC, returns a lower case ISO 3166 alpha-2 country code for
		* the device's geographical location.
		*
		* <p>This can give a better geographical result than {@link #countryCodeForMcc(String)}
		* (which provides the official "which country is the MCC assigned to?" answer) for cases when
		* MNC is also available: Sometimes an MCC can be used by multiple countries and the MNC can
		* help distinguish, or the MCC assigned to a country isn't used for geopolitical reasons.
		* When the geographical country is needed (e.g. time zone detection) this version can provide
		* more pragmatic results than the official MCC-only answer. This method falls back to calling
		* {@link #countryCodeForMcc(int)} if no special MCC+MNC cases are found.
		* Returns empty string if no code can be determined.
		*/
		@NonNull
		public static String geoCountryCodeForMccMnc(@NonNull MccMnc mccMnc) {
		String countryCode = null;
		if (mccMnc.mnc != null) {
		countryCode = countryCodeForMccMncNoFallback(mccMnc);
		}
		if (TextUtils.isEmpty(countryCode)) {
		// Try the MCC-only fallback.
		countryCode = MccTable.countryCodeForMcc(mccMnc.mcc);
		}
		return countryCode;
		}

		@Nullable
		private static String countryCodeForMccMncNoFallback(MccMnc mccMnc) {
		synchronized (MccTable.class) {
		if (sTelephonyNetworkFinder == null) {
		sTelephonyNetworkFinder = TelephonyLookup.getInstance().getTelephonyNetworkFinder();
		}
		}
		if (sTelephonyNetworkFinder == null) {
		// This should not happen under normal circumstances, only when the data is missing.
		return null;
		}
		TelephonyNetwork network =
		sTelephonyNetworkFinder.findNetworkByMccMnc(mccMnc.mcc, mccMnc.mnc);
		if (network == null) {
		return null;
		}
		return network.getCountryIsoCode();
		}

		/**
		* Given a GSM Mobile Country Code, returns
		* an ISO 2-3 character language code if available.

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

+42 −20

Original line number	Diff line number	Diff line
		@@ -16,33 +16,51 @@

		package com.android.internal.telephony;

		import android.test.AndroidTestCase;
		import static org.junit.Assert.assertEquals;

		import android.content.Context;
		import android.test.suitebuilder.annotation.SmallTest;

		import org.junit.Ignore;
		import androidx.test.InstrumentationRegistry;

		import com.android.internal.telephony.MccTable.MccMnc;

		import org.junit.Test;

		import java.util.Locale;

		// TODO try using InstrumentationRegistry.getContext() instead of the default
		// AndroidTestCase context
		public class MccTableTest extends AndroidTestCase {
		private final static String LOG_TAG = "GSM";
		public class MccTableTest {

		@SmallTest
		@Test
		public void testCountryCodeForMcc() throws Exception {
		checkMccLookupWithNoMnc("lu", 270);
		checkMccLookupWithNoMnc("gr", 202);
		checkMccLookupWithNoMnc("fk", 750);
		checkMccLookupWithNoMnc("mg", 646);
		checkMccLookupWithNoMnc("us", 314);
		checkMccLookupWithNoMnc("", 300); // mcc not defined, hence default
		checkMccLookupWithNoMnc("", 0); // mcc not defined, hence default
		checkMccLookupWithNoMnc("", 2000); // mcc not defined, hence default
		}

		private void checkMccLookupWithNoMnc(String expectedCountryIsoCode, int mcc) {
		assertEquals(expectedCountryIsoCode, MccTable.countryCodeForMcc(mcc));
		assertEquals(expectedCountryIsoCode, MccTable.countryCodeForMcc(mcc));
		assertEquals(expectedCountryIsoCode, MccTable.countryCodeForMcc("" + mcc));
		assertEquals(expectedCountryIsoCode,
		MccTable.geoCountryCodeForMccMnc(new MccMnc("" + mcc, "999")));
		}

		@SmallTest
		@Ignore
		public void testCountryCode() throws Exception {
		assertEquals("lu", MccTable.countryCodeForMcc(270));
		assertEquals("gr", MccTable.countryCodeForMcc(202));
		assertEquals("fk", MccTable.countryCodeForMcc(750));
		assertEquals("mg", MccTable.countryCodeForMcc(646));
		assertEquals("us", MccTable.countryCodeForMcc(314));
		assertEquals("", MccTable.countryCodeForMcc(300)); // mcc not defined, hence default
		assertEquals("", MccTable.countryCodeForMcc(0)); // mcc not defined, hence default
		assertEquals("", MccTable.countryCodeForMcc(2000)); // mcc not defined, hence default
		@Test
		public void testGeoCountryCodeForMccMnc() throws Exception {
		// This test is possibly fragile as this data is configurable.
		assertEquals("gu", MccTable.geoCountryCodeForMccMnc(new MccMnc("310", "370")));
		}

		@SmallTest
		@Ignore
		@Test
		public void testLang() throws Exception {
		assertEquals("en", MccTable.defaultLanguageForMcc(311));
		assertEquals("de", MccTable.defaultLanguageForMcc(232));
		@@ -54,7 +72,7 @@ public class MccTableTest extends AndroidTestCase {
		}

		@SmallTest
		@Ignore
		@Test
		public void testLang_India() throws Exception {
		assertEquals("en", MccTable.defaultLanguageForMcc(404));
		assertEquals("en", MccTable.defaultLanguageForMcc(405));
		@@ -62,7 +80,7 @@ public class MccTableTest extends AndroidTestCase {
		}

		@SmallTest
		@Ignore
		@Test
		public void testLocale() throws Exception {
		assertEquals(Locale.forLanguageTag("en-CA"),
		MccTable.getLocaleFromMcc(getContext(), 302, null));
		@@ -78,8 +96,12 @@ public class MccTableTest extends AndroidTestCase {
		MccTable.getLocaleFromMcc(getContext(), 466, null));
		}

		private Context getContext() {
		return InstrumentationRegistry.getContext();
		}

		@SmallTest
		@Ignore
		@Test
		public void testSmDigits() throws Exception {
		assertEquals(3, MccTable.smallestDigitsMccForMnc(312));
		assertEquals(2, MccTable.smallestDigitsMccForMnc(430));