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A library jar that provides APIs for Applications written for the Google Android Platform.
/*
* Copyright 2017 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 android.content.Context;
import android.os.PowerManager;
import android.telephony.Rlog;
import android.text.TextUtils;
import android.util.LocalLog;
import android.util.TimestampedValue;
import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.telephony.TimeZoneLookupHelper.CountryResult;
import com.android.internal.telephony.TimeZoneLookupHelper.OffsetResult;
import com.android.internal.telephony.metrics.TelephonyMetrics;
import com.android.internal.util.IndentingPrintWriter;
import java.io.FileDescriptor;
import java.io.PrintWriter;
/**
* {@hide}
*/
public final class OldNitzStateMachine implements NitzStateMachine {
private static final String LOG_TAG = ServiceStateTracker.LOG_TAG;
private static final boolean DBG = ServiceStateTracker.DBG;
// Time detection state.
/**
* The last NITZ-sourced time considered. If auto time detection was off at the time this may
* not have been used to set the device time, but it can be used if auto time detection is
* re-enabled.
*/
private TimestampedValue mSavedNitzTime;
// Time Zone detection state.
/** We always keep the last NITZ signal received in mLatestNitzSignal. */
private TimestampedValue 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 mGotCountryCode = false;
/**
* The last time zone ID that has been determined. It may not have been set as the device time
* zone if automatic time zone detection is disabled but may later be used to set the time zone
* if the user enables automatic time zone detection.
*/
private String mSavedTimeZoneId;
/**
* Boolean is {@code true} if NITZ has been used to determine a time zone (which may not
* ultimately have been used due to user settings). Cleared by {@link #handleNetworkAvailable()}
* and {@link #handleNetworkCountryCodeUnavailable()}. The flag can be used when historic NITZ
* data may no longer be valid. {@code false} indicates it is reasonable to try to set the time
* zone using less reliable algorithms than NITZ-based detection such as by just using network
* country code.
*/
private boolean mNitzTimeZoneDetectionSuccessful = false;
// Miscellaneous dependencies and helpers not related to detection state.
private final LocalLog mTimeLog = new LocalLog(15);
private final LocalLog mTimeZoneLog = new LocalLog(15);
private final GsmCdmaPhone mPhone;
private final DeviceState mDeviceState;
private final OldTimeServiceHelper mTimeServiceHelper;
private final TimeZoneLookupHelper mTimeZoneLookupHelper;
/** Wake lock used while setting time of day. */
private final PowerManager.WakeLock mWakeLock;
private static final String WAKELOCK_TAG = "NitzStateMachine";
public OldNitzStateMachine(GsmCdmaPhone phone) {
this(phone,
new OldTimeServiceHelper(phone.getContext()),
new DeviceState(phone),
new TimeZoneLookupHelper());
}
@VisibleForTesting
public OldNitzStateMachine(GsmCdmaPhone phone, OldTimeServiceHelper timeServiceHelper,
DeviceState deviceState, TimeZoneLookupHelper timeZoneLookupHelper) {
mPhone = phone;
Context context = phone.getContext();
PowerManager powerManager =
(PowerManager) context.getSystemService(Context.POWER_SERVICE);
mWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, WAKELOCK_TAG);
mDeviceState = deviceState;
mTimeZoneLookupHelper = timeZoneLookupHelper;
mTimeServiceHelper = timeServiceHelper;
mTimeServiceHelper.setListener(new OldTimeServiceHelper.Listener() {
@Override
public void onTimeDetectionChange(boolean enabled) {
if (enabled) {
handleAutoTimeEnabled();
}
}
@Override
public void onTimeZoneDetectionChange(boolean enabled) {
if (enabled) {
handleAutoTimeZoneEnabled();
}
}
});
}
@Override
public void handleNetworkCountryCodeSet(boolean countryChanged) {
boolean hadCountryCode = mGotCountryCode;
mGotCountryCode = true;
String isoCountryCode = mDeviceState.getNetworkCountryIsoForPhone();
if (!TextUtils.isEmpty(isoCountryCode) && !mNitzTimeZoneDetectionSuccessful) {
updateTimeZoneFromNetworkCountryCode(isoCountryCode);
}
if (mLatestNitzSignal != null && (countryChanged || !hadCountryCode)) {
updateTimeZoneFromCountryAndNitz();
}
}
private void updateTimeZoneFromCountryAndNitz() {
String isoCountryCode = mDeviceState.getNetworkCountryIsoForPhone();
TimestampedValue 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, "updateTimeZoneFromCountryAndNitz:"
+ " isTimeZoneSettingInitialized=" + isTimeZoneSettingInitialized
+ " nitzSignal=" + nitzSignal
+ " isoCountryCode=" + isoCountryCode);
}
try {
NitzData nitzData = nitzSignal.getValue();
String zoneId;
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, 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) {
if (DBG) {
Rlog.d(LOG_TAG,
"updateTimeZoneFromCountryAndNitz: No cached NITZ data available,"
+ " not setting zone");
}
zoneId = null;
} else if (isNitzSignalOffsetInfoBogus(nitzSignal, isoCountryCode)) {
String logMsg = "updateTimeZoneFromCountryAndNitz: Received NITZ looks bogus, "
+ " isoCountryCode=" + isoCountryCode
+ " 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);
zoneId = null;
} else {
OffsetResult lookupResult = mTimeZoneLookupHelper.lookupByNitzCountry(
nitzData, isoCountryCode);
if (DBG) {
Rlog.d(LOG_TAG, "updateTimeZoneFromCountryAndNitz: using"
+ " lookupByNitzCountry(nitzData, isoCountryCode),"
+ " nitzData=" + nitzData
+ " isoCountryCode=" + isoCountryCode
+ " lookupResult=" + lookupResult);
}
zoneId = lookupResult != null ? lookupResult.zoneId : null;
}
// Log the action taken to the dedicated time zone log.
final String tmpLog = "updateTimeZoneFromCountryAndNitz:"
+ " isTimeZoneSettingInitialized=" + isTimeZoneSettingInitialized
+ " isoCountryCode=" + isoCountryCode
+ " nitzSignal=" + nitzSignal
+ " zoneId=" + zoneId
+ " isTimeZoneDetectionEnabled()="
+ mTimeServiceHelper.isTimeZoneDetectionEnabled();
mTimeZoneLog.log(tmpLog);
// Set state as needed.
if (zoneId != null) {
if (DBG) {
Rlog.d(LOG_TAG, "updateTimeZoneFromCountryAndNitz: zoneId=" + zoneId);
}
if (mTimeServiceHelper.isTimeZoneDetectionEnabled()) {
setAndBroadcastNetworkSetTimeZone(zoneId);
} else {
if (DBG) {
Rlog.d(LOG_TAG, "updateTimeZoneFromCountryAndNitz: skip changing zone"
+ " as isTimeZoneDetectionEnabled() is false");
}
}
mSavedTimeZoneId = zoneId;
mNitzTimeZoneDetectionSuccessful = true;
} else {
if (DBG) {
Rlog.d(LOG_TAG,
"updateTimeZoneFromCountryAndNitz: zoneId == null, do nothing");
}
}
} 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 nitzSignal, String isoCountryCode) {
if (TextUtils.isEmpty(isoCountryCode)) {
// We cannot say for sure.
return false;
}
NitzData newNitzData = nitzSignal.getValue();
boolean zeroOffsetNitz = newNitzData.getLocalOffsetMillis() == 0 && !newNitzData.isDst();
return zeroOffsetNitz && !countryUsesUtc(isoCountryCode, nitzSignal);
}
private boolean countryUsesUtc(
String isoCountryCode, TimestampedValue nitzSignal) {
return mTimeZoneLookupHelper.countryUsesUtc(
isoCountryCode,
nitzSignal.getValue().getCurrentTimeInMillis());
}
@Override
public void handleNetworkAvailable() {
if (DBG) {
Rlog.d(LOG_TAG, "handleNetworkAvailable: mNitzTimeZoneDetectionSuccessful="
+ mNitzTimeZoneDetectionSuccessful
+ ", Setting mNitzTimeZoneDetectionSuccessful=false");
}
mNitzTimeZoneDetectionSuccessful = false;
}
@Override
public void handleNetworkCountryCodeUnavailable() {
if (DBG) {
Rlog.d(LOG_TAG, "handleNetworkCountryCodeUnavailable");
}
mGotCountryCode = false;
mNitzTimeZoneDetectionSuccessful = false;
}
@Override
public void handleNitzReceived(TimestampedValue nitzSignal) {
// Always store the latest NITZ signal received.
mLatestNitzSignal = nitzSignal;
updateTimeZoneFromCountryAndNitz();
updateTimeFromNitz();
}
private void updateTimeFromNitz() {
TimestampedValue nitzSignal = mLatestNitzSignal;
try {
boolean ignoreNitz = mDeviceState.getIgnoreNitz();
if (ignoreNitz) {
if (DBG) {
Rlog.d(LOG_TAG,
"updateTimeFromNitz: Not setting clock because gsm.ignore-nitz is set");
}
return;
}
try {
// Acquire the wake lock as we are reading the elapsed realtime clock and system
// clock.
mWakeLock.acquire();
// Validate the nitzTimeSignal to reject obviously bogus elapsedRealtime values.
long elapsedRealtime = mTimeServiceHelper.elapsedRealtime();
long millisSinceNitzReceived =
elapsedRealtime - nitzSignal.getReferenceTimeMillis();
if (millisSinceNitzReceived < 0 || millisSinceNitzReceived > Integer.MAX_VALUE) {
if (DBG) {
Rlog.d(LOG_TAG, "updateTimeFromNitz: not setting time, unexpected"
+ " elapsedRealtime=" + elapsedRealtime
+ " nitzSignal=" + nitzSignal);
}
return;
}
// Adjust the NITZ time by the delay since it was received to get the time now.
long adjustedCurrentTimeMillis =
nitzSignal.getValue().getCurrentTimeInMillis() + millisSinceNitzReceived;
long gained = adjustedCurrentTimeMillis - mTimeServiceHelper.currentTimeMillis();
if (mTimeServiceHelper.isTimeDetectionEnabled()) {
String logMsg = "updateTimeFromNitz:"
+ " nitzSignal=" + nitzSignal
+ " adjustedCurrentTimeMillis=" + adjustedCurrentTimeMillis
+ " millisSinceNitzReceived= " + millisSinceNitzReceived
+ " gained=" + gained;
if (mSavedNitzTime == null) {
logMsg += ": First update received.";
setAndBroadcastNetworkSetTime(logMsg, adjustedCurrentTimeMillis);
} else {
long elapsedRealtimeSinceLastSaved = mTimeServiceHelper.elapsedRealtime()
- mSavedNitzTime.getReferenceTimeMillis();
int nitzUpdateSpacing = mDeviceState.getNitzUpdateSpacingMillis();
int nitzUpdateDiff = mDeviceState.getNitzUpdateDiffMillis();
if (elapsedRealtimeSinceLastSaved > nitzUpdateSpacing
|| Math.abs(gained) > nitzUpdateDiff) {
// Either it has been a while since we received an update, or the gain
// is sufficiently large that we want to act on it.
logMsg += ": New update received.";
setAndBroadcastNetworkSetTime(logMsg, adjustedCurrentTimeMillis);
} else {
if (DBG) {
Rlog.d(LOG_TAG, logMsg + ": Update throttled.");
}
// Return early. This means that we don't reset the
// mSavedNitzTime for next time and that we may act on more
// NITZ time signals overall but should end up with a system clock that
// tracks NITZ more closely than if we saved throttled values (which
// would reset mSavedNitzTime.elapsedRealtime used to calculate time
// since the last NITZ signal was received).
return;
}
}
}
// Save the last NITZ time signal used so we can return to it later
// if auto-time detection is toggled.
mSavedNitzTime = new TimestampedValue<>(
nitzSignal.getReferenceTimeMillis(),
nitzSignal.getValue().getCurrentTimeInMillis());
} finally {
mWakeLock.release();
}
} catch (RuntimeException ex) {
Rlog.e(LOG_TAG, "updateTimeFromNitz: Processing NITZ data"
+ " nitzSignal=" + nitzSignal
+ " ex=" + ex);
}
}
private void setAndBroadcastNetworkSetTimeZone(String zoneId) {
if (DBG) {
Rlog.d(LOG_TAG, "setAndBroadcastNetworkSetTimeZone: zoneId=" + zoneId);
}
mTimeServiceHelper.setDeviceTimeZone(zoneId);
if (DBG) {
Rlog.d(LOG_TAG,
"setAndBroadcastNetworkSetTimeZone: called setDeviceTimeZone()"
+ " zoneId=" + zoneId);
}
}
private void setAndBroadcastNetworkSetTime(String msg, long time) {
if (!mWakeLock.isHeld()) {
Rlog.w(LOG_TAG, "setAndBroadcastNetworkSetTime: Wake lock not held while setting device"
+ " time (msg=" + msg + ")");
}
msg = "setAndBroadcastNetworkSetTime: [Setting time to time=" + time + "]:" + msg;
if (DBG) {
Rlog.d(LOG_TAG, msg);
}
mTimeLog.log(msg);
mTimeServiceHelper.setDeviceTime(time);
TelephonyMetrics.getInstance().writeNITZEvent(mPhone.getPhoneId(), time);
}
private void handleAutoTimeEnabled() {
if (DBG) {
Rlog.d(LOG_TAG, "handleAutoTimeEnabled: Reverting to NITZ Time:"
+ " mSavedNitzTime=" + mSavedNitzTime);
}
if (mSavedNitzTime != null) {
try {
// Acquire the wakelock as we're reading the elapsed realtime clock here.
mWakeLock.acquire();
long elapsedRealtime = mTimeServiceHelper.elapsedRealtime();
String msg = "mSavedNitzTime: Reverting to NITZ time"
+ " elapsedRealtime=" + elapsedRealtime
+ " mSavedNitzTime=" + mSavedNitzTime;
long adjustedCurrentTimeMillis = mSavedNitzTime.getValue()
+ (elapsedRealtime - mSavedNitzTime.getReferenceTimeMillis());
setAndBroadcastNetworkSetTime(msg, adjustedCurrentTimeMillis);
} finally {
mWakeLock.release();
}
}
}
private void handleAutoTimeZoneEnabled() {
String tmpLog = "handleAutoTimeZoneEnabled: Reverting to NITZ TimeZone:"
+ " mSavedTimeZoneId=" + mSavedTimeZoneId;
if (DBG) {
Rlog.d(LOG_TAG, tmpLog);
}
mTimeZoneLog.log(tmpLog);
if (mSavedTimeZoneId != null) {
setAndBroadcastNetworkSetTimeZone(mSavedTimeZoneId);
}
}
@Override
public void dumpState(PrintWriter pw) {
// Time Detection State
pw.println(" mSavedTime=" + mSavedNitzTime);
// Time Zone Detection State
pw.println(" mLatestNitzSignal=" + mLatestNitzSignal);
pw.println(" mGotCountryCode=" + mGotCountryCode);
pw.println(" mSavedTimeZoneId=" + mSavedTimeZoneId);
pw.println(" mNitzTimeZoneDetectionSuccessful=" + mNitzTimeZoneDetectionSuccessful);
// Miscellaneous
pw.println(" mWakeLock=" + mWakeLock);
pw.flush();
}
@Override
public void dumpLogs(FileDescriptor fd, IndentingPrintWriter ipw, String[] args) {
ipw.println(" Time Logs:");
ipw.increaseIndent();
mTimeLog.dump(fd, ipw, args);
ipw.decreaseIndent();
ipw.println(" Time zone Logs:");
ipw.increaseIndent();
mTimeZoneLog.dump(fd, ipw, args);
ipw.decreaseIndent();
}
/**
* Update time zone by network country code, works well on countries which only have one time
* zone or multiple zones with the same offset.
*
* @param iso Country code from network MCC
*/
private void updateTimeZoneFromNetworkCountryCode(String iso) {
CountryResult lookupResult = mTimeZoneLookupHelper.lookupByCountry(
iso, mTimeServiceHelper.currentTimeMillis());
if (lookupResult != null && lookupResult.allZonesHaveSameOffset) {
String logMsg = "updateTimeZoneFromNetworkCountryCode: tz result found"
+ " iso=" + iso
+ " lookupResult=" + lookupResult;
if (DBG) {
Rlog.d(LOG_TAG, logMsg);
}
mTimeZoneLog.log(logMsg);
String zoneId = lookupResult.zoneId;
if (mTimeServiceHelper.isTimeZoneDetectionEnabled()) {
setAndBroadcastNetworkSetTimeZone(zoneId);
}
mSavedTimeZoneId = zoneId;
} else {
if (DBG) {
Rlog.d(LOG_TAG, "updateTimeZoneFromNetworkCountryCode: no good zone for"
+ " iso=" + iso
+ " lookupResult=" + lookupResult);
}
}
}
public boolean getNitzTimeZoneDetectionSuccessful() {
return mNitzTimeZoneDetectionSuccessful;
}
@Override
public NitzData getCachedNitzData() {
return mLatestNitzSignal != null ? mLatestNitzSignal.getValue() : null;
}
@Override
public String getSavedTimeZoneId() {
return mSavedTimeZoneId;
}
}
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