telecomm/java/android/telecom/Log.java - platform/frameworks/base - Git at Google

 /*
  * Copyright 2014, 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 android.telecom;

 import android.content.Context;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Build;
 import android.telecom.Logging.EventManager;
 import android.telecom.Logging.Session;
 import android.telecom.Logging.SessionManager;
 import android.telephony.PhoneNumberUtils;
 import android.text.TextUtils;

 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.IndentingPrintWriter;

 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.IllegalFormatException;
 import java.util.Locale;

 /**
  * Manages logging for the entire module.
  *
  * @hide
  */
 public class Log {

     private static final long EXTENDED_LOGGING_DURATION_MILLIS = 60000 * 30; // 30 minutes

     private static final int EVENTS_TO_CACHE = 10;
     private static final int EVENTS_TO_CACHE_DEBUG = 20;

     // Generic tag for all Telecom logging
     @VisibleForTesting
     public static String TAG = "TelecomFramework";
     public static boolean DEBUG = isLoggable(android.util.Log.DEBUG);
     public static boolean INFO = isLoggable(android.util.Log.INFO);
     public static boolean VERBOSE = isLoggable(android.util.Log.VERBOSE);
     public static boolean WARN = isLoggable(android.util.Log.WARN);
     public static boolean ERROR = isLoggable(android.util.Log.ERROR);

     private static final boolean FORCE_LOGGING = false; /* STOP SHIP if true */
     private static final boolean USER_BUILD = Build.IS_USER;

     // Used to synchronize singleton logging lazy initialization
     private static final Object sSingletonSync = new Object();
     private static EventManager sEventManager;
     private static SessionManager sSessionManager;

     /**
      * Tracks whether user-activated extended logging is enabled.
      */
     private static boolean sIsUserExtendedLoggingEnabled = false;

     /**
      * The time when user-activated extended logging should be ended.  Used to determine when
      * extended logging should automatically be disabled.
      */
     private static long sUserExtendedLoggingStopTime = 0;

     private Log() {
     }

     public static void d(String prefix, String format, Object... args) {
         if (sIsUserExtendedLoggingEnabled) {
             maybeDisableLogging();
             android.util.Slog.i(TAG, buildMessage(prefix, format, args));
         } else if (DEBUG) {
             android.util.Slog.d(TAG, buildMessage(prefix, format, args));
         }
     }

     public static void d(Object objectPrefix, String format, Object... args) {
         if (sIsUserExtendedLoggingEnabled) {
             maybeDisableLogging();
             android.util.Slog.i(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
         } else if (DEBUG) {
             android.util.Slog.d(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
         }
     }

     public static void i(String prefix, String format, Object... args) {
         if (INFO) {
             android.util.Slog.i(TAG, buildMessage(prefix, format, args));
         }
     }

     public static void i(Object objectPrefix, String format, Object... args) {
         if (INFO) {
             android.util.Slog.i(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
         }
     }

     public static void v(String prefix, String format, Object... args) {
         if (sIsUserExtendedLoggingEnabled) {
             maybeDisableLogging();
             android.util.Slog.i(TAG, buildMessage(prefix, format, args));
         } else if (VERBOSE) {
             android.util.Slog.v(TAG, buildMessage(prefix, format, args));
         }
     }

     public static void v(Object objectPrefix, String format, Object... args) {
         if (sIsUserExtendedLoggingEnabled) {
             maybeDisableLogging();
             android.util.Slog.i(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
         } else if (VERBOSE) {
             android.util.Slog.v(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
         }
     }

     public static void w(String prefix, String format, Object... args) {
         if (WARN) {
             android.util.Slog.w(TAG, buildMessage(prefix, format, args));
         }
     }

     public static void w(Object objectPrefix, String format, Object... args) {
         if (WARN) {
             android.util.Slog.w(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
         }
     }

     public static void e(String prefix, Throwable tr, String format, Object... args) {
         if (ERROR) {
             android.util.Slog.e(TAG, buildMessage(prefix, format, args), tr);
         }
     }

     public static void e(Object objectPrefix, Throwable tr, String format, Object... args) {
         if (ERROR) {
             android.util.Slog.e(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args),
                     tr);
         }
     }

     public static void wtf(String prefix, Throwable tr, String format, Object... args) {
         android.util.Slog.wtf(TAG, buildMessage(prefix, format, args), tr);
     }

     public static void wtf(Object objectPrefix, Throwable tr, String format, Object... args) {
         android.util.Slog.wtf(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args),
                 tr);
     }

     public static void wtf(String prefix, String format, Object... args) {
         String msg = buildMessage(prefix, format, args);
         android.util.Slog.wtf(TAG, msg, new IllegalStateException(msg));
     }

     public static void wtf(Object objectPrefix, String format, Object... args) {
         String msg = buildMessage(getPrefixFromObject(objectPrefix), format, args);
         android.util.Slog.wtf(TAG, msg, new IllegalStateException(msg));
     }

     /**
      * The ease of use methods below only act mostly as proxies to the Session and Event Loggers.
      * They also control the lazy loaders of the singleton instances, which will never be loaded if
      * the proxy methods aren't used.
      *
      * Please see each method's documentation inside of their respective implementations in the
      * loggers.
      */

     public static void setSessionContext(Context context) {
         getSessionManager().setContext(context);
     }

     public static void startSession(String shortMethodName) {
         getSessionManager().startSession(shortMethodName, null);
     }

     public static void startSession(Session.Info info, String shortMethodName) {
         getSessionManager().startSession(info, shortMethodName, null);
     }

     public static void startSession(String shortMethodName, String callerIdentification) {
         getSessionManager().startSession(shortMethodName, callerIdentification);
     }

     public static void startSession(Session.Info info, String shortMethodName,
             String callerIdentification) {
         getSessionManager().startSession(info, shortMethodName, callerIdentification);
     }

     public static Session createSubsession() {
         return getSessionManager().createSubsession();
     }

     public static Session.Info getExternalSession() {
         return getSessionManager().getExternalSession();
     }

     public static void cancelSubsession(Session subsession) {
         getSessionManager().cancelSubsession(subsession);
     }

     public static void continueSession(Session subsession, String shortMethodName) {
         getSessionManager().continueSession(subsession, shortMethodName);
     }

     public static void endSession() {
         getSessionManager().endSession();
     }

     public static void registerSessionListener(SessionManager.ISessionListener l) {
         getSessionManager().registerSessionListener(l);
     }

     public static String getSessionId() {
         // If the Session logger has not been initialized, then there have been no sessions logged.
         // Don't load it now!
         synchronized (sSingletonSync) {
             if (sSessionManager != null) {
                 return getSessionManager().getSessionId();
             } else {
                 return "";
             }
         }
     }

     public static void addEvent(EventManager.Loggable recordEntry, String event) {
         getEventManager().event(recordEntry, event, null);
     }

     public static void addEvent(EventManager.Loggable recordEntry, String event, Object data) {
         getEventManager().event(recordEntry, event, data);
     }

     public static void addEvent(EventManager.Loggable recordEntry, String event, String format,
             Object... args) {
         getEventManager().event(recordEntry, event, format, args);
     }

     public static void registerEventListener(EventManager.EventListener e) {
         getEventManager().registerEventListener(e);
     }

     public static void addRequestResponsePair(EventManager.TimedEventPair p) {
         getEventManager().addRequestResponsePair(p);
     }

     public static void dumpEvents(IndentingPrintWriter pw) {
         // If the Events logger has not been initialized, then there have been no events logged.
         // Don't load it now!
         synchronized (sSingletonSync) {
             if (sEventManager != null) {
                 getEventManager().dumpEvents(pw);
             } else {
                 pw.println("No Historical Events Logged.");
             }
         }
     }

     /**
      * Dumps the events in a timeline format.
      * @param pw The {@link IndentingPrintWriter} to write to.
      * @hide
      */
     public static void dumpEventsTimeline(IndentingPrintWriter pw) {
         // If the Events logger has not been initialized, then there have been no events logged.
         // Don't load it now!
         synchronized (sSingletonSync) {
             if (sEventManager != null) {
                 getEventManager().dumpEventsTimeline(pw);
             } else {
                 pw.println("No Historical Events Logged.");
             }
         }
     }

     /**
      * Enable or disable extended telecom logging.
      *
      * @param isExtendedLoggingEnabled {@code true} if extended logging should be enabled,
      *          {@code false} if it should be disabled.
      */
     public static void setIsExtendedLoggingEnabled(boolean isExtendedLoggingEnabled) {
         // If the state hasn't changed, bail early.
         if (sIsUserExtendedLoggingEnabled == isExtendedLoggingEnabled) {
             return;
         }

         if (sEventManager != null) {
             sEventManager.changeEventCacheSize(isExtendedLoggingEnabled ?
                     EVENTS_TO_CACHE_DEBUG : EVENTS_TO_CACHE);
         }

         sIsUserExtendedLoggingEnabled = isExtendedLoggingEnabled;
         if (sIsUserExtendedLoggingEnabled) {
             sUserExtendedLoggingStopTime = System.currentTimeMillis()
                     + EXTENDED_LOGGING_DURATION_MILLIS;
         } else {
             sUserExtendedLoggingStopTime = 0;
         }
     }

     private static EventManager getEventManager() {
         // Checking for null again outside of synchronization because we only need to synchronize
         // during the lazy loading of the events logger. We don't need to synchronize elsewhere.
         if (sEventManager == null) {
             synchronized (sSingletonSync) {
                 if (sEventManager == null) {
                     sEventManager = new EventManager(Log::getSessionId);
                     return sEventManager;
                 }
             }
         }
         return sEventManager;
     }

     @VisibleForTesting
     public static SessionManager getSessionManager() {
         // Checking for null again outside of synchronization because we only need to synchronize
         // during the lazy loading of the session logger. We don't need to synchronize elsewhere.
         if (sSessionManager == null) {
             synchronized (sSingletonSync) {
                 if (sSessionManager == null) {
                     sSessionManager = new SessionManager();
                     return sSessionManager;
                 }
             }
         }
         return sSessionManager;
     }

     private static MessageDigest sMessageDigest;

     public static void initMd5Sum() {
         new AsyncTask<Void, Void, Void>() {
             @Override
             public Void doInBackground(Void... args) {
                 MessageDigest md;
                 try {
                     md = MessageDigest.getInstance("SHA-1");
                 } catch (NoSuchAlgorithmException e) {
                     md = null;
                 }
                 sMessageDigest = md;
                 return null;
             }
         }.execute();
     }

     public static void setTag(String tag) {
         TAG = tag;
         DEBUG = isLoggable(android.util.Log.DEBUG);
         INFO = isLoggable(android.util.Log.INFO);
         VERBOSE = isLoggable(android.util.Log.VERBOSE);
         WARN = isLoggable(android.util.Log.WARN);
         ERROR = isLoggable(android.util.Log.ERROR);
     }

     /**
      * If user enabled extended logging is enabled and the time limit has passed, disables the
      * extended logging.
      */
     private static void maybeDisableLogging() {
         if (!sIsUserExtendedLoggingEnabled) {
             return;
         }

         if (sUserExtendedLoggingStopTime < System.currentTimeMillis()) {
             sUserExtendedLoggingStopTime = 0;
             sIsUserExtendedLoggingEnabled = false;
         }
     }

     public static boolean isLoggable(int level) {
         return FORCE_LOGGING || android.util.Log.isLoggable(TAG, level);
     }

     public static String piiHandle(Object pii) {
         if (pii == null || VERBOSE) {
             return String.valueOf(pii);
         }

         StringBuilder sb = new StringBuilder();
         if (pii instanceof Uri) {
             Uri uri = (Uri) pii;
             String scheme = uri.getScheme();

             if (!TextUtils.isEmpty(scheme)) {
                 sb.append(scheme).append(":");
             }

             String textToObfuscate = uri.getSchemeSpecificPart();
             if (PhoneAccount.SCHEME_TEL.equals(scheme)) {
                 for (int i = 0; i < textToObfuscate.length(); i++) {
                     char c = textToObfuscate.charAt(i);
                     sb.append(PhoneNumberUtils.isDialable(c) ? "*" : c);
                 }
             } else if (PhoneAccount.SCHEME_SIP.equals(scheme)) {
                 for (int i = 0; i < textToObfuscate.length(); i++) {
                     char c = textToObfuscate.charAt(i);
                     if (c != '@' && c != '.') {
                         c = '*';
                     }
                     sb.append(c);
                 }
             } else {
                 sb.append(pii(pii));
             }
         }

         return sb.toString();
     }

     /**
      * Redact personally identifiable information for production users.
      * If we are running in verbose mode, return the original string,
      * and return "****" if we are running on the user build, otherwise
      * return a SHA-1 hash of the input string.
      */
     public static String pii(Object pii) {
         if (pii == null || VERBOSE) {
             return String.valueOf(pii);
         }
         return "[" + secureHash(String.valueOf(pii).getBytes()) + "]";
     }

     private static String secureHash(byte[] input) {
         // Refrain from logging user personal information in user build.
         if (USER_BUILD) {
             return "****";
         }

         if (sMessageDigest != null) {
             sMessageDigest.reset();
             sMessageDigest.update(input);
             byte[] result = sMessageDigest.digest();
             return encodeHex(result);
         } else {
             return "Uninitialized SHA1";
         }
     }

     private static String encodeHex(byte[] bytes) {
         StringBuffer hex = new StringBuffer(bytes.length * 2);

         for (int i = 0; i < bytes.length; i++) {
             int byteIntValue = bytes[i] & 0xff;
             if (byteIntValue < 0x10) {
                 hex.append("0");
             }
             hex.append(Integer.toString(byteIntValue, 16));
         }

         return hex.toString();
     }

     private static String getPrefixFromObject(Object obj) {
         return obj == null ? "<null>" : obj.getClass().getSimpleName();
     }

     private static String buildMessage(String prefix, String format, Object... args) {
         // Incorporate thread ID and calling method into prefix
         String sessionName = getSessionId();
         String sessionPostfix = TextUtils.isEmpty(sessionName) ? "" : ": " + sessionName;

         String msg;
         try {
             msg = (args == null || args.length == 0) ? format
                     : String.format(Locale.US, format, args);
         } catch (IllegalFormatException ife) {
             e(TAG, ife, "Log: IllegalFormatException: formatString='%s' numArgs=%d", format,
                     args.length);
             msg = format + " (An error occurred while formatting the message.)";
         }
         return String.format(Locale.US, "%s: %s%s", prefix, msg, sessionPostfix);
     }
 }
	/*
	* Copyright 2014, 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 android.telecom;

	import android.content.Context;
	import android.net.Uri;
	import android.os.AsyncTask;
	import android.os.Build;
	import android.telecom.Logging.EventManager;
	import android.telecom.Logging.Session;
	import android.telecom.Logging.SessionManager;
	import android.telephony.PhoneNumberUtils;
	import android.text.TextUtils;

	import com.android.internal.annotations.VisibleForTesting;
	import com.android.internal.util.IndentingPrintWriter;

	import java.security.MessageDigest;
	import java.security.NoSuchAlgorithmException;
	import java.util.IllegalFormatException;
	import java.util.Locale;

	/**
	* Manages logging for the entire module.
	*
	* @hide
	*/
	public class Log {

	private static final long EXTENDED_LOGGING_DURATION_MILLIS = 60000 * 30; // 30 minutes

	private static final int EVENTS_TO_CACHE = 10;
	private static final int EVENTS_TO_CACHE_DEBUG = 20;

	// Generic tag for all Telecom logging
	@VisibleForTesting
	public static String TAG = "TelecomFramework";
	public static boolean DEBUG = isLoggable(android.util.Log.DEBUG);
	public static boolean INFO = isLoggable(android.util.Log.INFO);
	public static boolean VERBOSE = isLoggable(android.util.Log.VERBOSE);
	public static boolean WARN = isLoggable(android.util.Log.WARN);
	public static boolean ERROR = isLoggable(android.util.Log.ERROR);

	private static final boolean FORCE_LOGGING = false; /* STOP SHIP if true */
	private static final boolean USER_BUILD = Build.IS_USER;

	// Used to synchronize singleton logging lazy initialization
	private static final Object sSingletonSync = new Object();
	private static EventManager sEventManager;
	private static SessionManager sSessionManager;

	/**
	* Tracks whether user-activated extended logging is enabled.
	*/
	private static boolean sIsUserExtendedLoggingEnabled = false;

	/**
	* The time when user-activated extended logging should be ended. Used to determine when
	* extended logging should automatically be disabled.
	*/
	private static long sUserExtendedLoggingStopTime = 0;

	private Log() {
	}

	public static void d(String prefix, String format, Object... args) {
	if (sIsUserExtendedLoggingEnabled) {
	maybeDisableLogging();
	android.util.Slog.i(TAG, buildMessage(prefix, format, args));
	} else if (DEBUG) {
	android.util.Slog.d(TAG, buildMessage(prefix, format, args));
	}
	}

	public static void d(Object objectPrefix, String format, Object... args) {
	if (sIsUserExtendedLoggingEnabled) {
	maybeDisableLogging();
	android.util.Slog.i(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
	} else if (DEBUG) {
	android.util.Slog.d(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
	}
	}

	public static void i(String prefix, String format, Object... args) {
	if (INFO) {
	android.util.Slog.i(TAG, buildMessage(prefix, format, args));
	}
	}

	public static void i(Object objectPrefix, String format, Object... args) {
	if (INFO) {
	android.util.Slog.i(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
	}
	}

	public static void v(String prefix, String format, Object... args) {
	if (sIsUserExtendedLoggingEnabled) {
	maybeDisableLogging();
	android.util.Slog.i(TAG, buildMessage(prefix, format, args));
	} else if (VERBOSE) {
	android.util.Slog.v(TAG, buildMessage(prefix, format, args));
	}
	}

	public static void v(Object objectPrefix, String format, Object... args) {
	if (sIsUserExtendedLoggingEnabled) {
	maybeDisableLogging();
	android.util.Slog.i(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
	} else if (VERBOSE) {
	android.util.Slog.v(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
	}
	}

	public static void w(String prefix, String format, Object... args) {
	if (WARN) {
	android.util.Slog.w(TAG, buildMessage(prefix, format, args));
	}
	}

	public static void w(Object objectPrefix, String format, Object... args) {
	if (WARN) {
	android.util.Slog.w(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
	}
	}

	public static void e(String prefix, Throwable tr, String format, Object... args) {
	if (ERROR) {
	android.util.Slog.e(TAG, buildMessage(prefix, format, args), tr);
	}
	}

	public static void e(Object objectPrefix, Throwable tr, String format, Object... args) {
	if (ERROR) {
	android.util.Slog.e(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args),
	tr);
	}
	}

	public static void wtf(String prefix, Throwable tr, String format, Object... args) {
	android.util.Slog.wtf(TAG, buildMessage(prefix, format, args), tr);
	}

	public static void wtf(Object objectPrefix, Throwable tr, String format, Object... args) {
	android.util.Slog.wtf(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args),
	tr);
	}

	public static void wtf(String prefix, String format, Object... args) {
	String msg = buildMessage(prefix, format, args);
	android.util.Slog.wtf(TAG, msg, new IllegalStateException(msg));
	}

	public static void wtf(Object objectPrefix, String format, Object... args) {
	String msg = buildMessage(getPrefixFromObject(objectPrefix), format, args);
	android.util.Slog.wtf(TAG, msg, new IllegalStateException(msg));
	}

	/**
	* The ease of use methods below only act mostly as proxies to the Session and Event Loggers.
	* They also control the lazy loaders of the singleton instances, which will never be loaded if
	* the proxy methods aren't used.
	*
	* Please see each method's documentation inside of their respective implementations in the
	* loggers.
	*/

	public static void setSessionContext(Context context) {
	getSessionManager().setContext(context);
	}

	public static void startSession(String shortMethodName) {
	getSessionManager().startSession(shortMethodName, null);
	}

	public static void startSession(Session.Info info, String shortMethodName) {
	getSessionManager().startSession(info, shortMethodName, null);
	}

	public static void startSession(String shortMethodName, String callerIdentification) {
	getSessionManager().startSession(shortMethodName, callerIdentification);
	}

	public static void startSession(Session.Info info, String shortMethodName,
	String callerIdentification) {
	getSessionManager().startSession(info, shortMethodName, callerIdentification);
	}

	public static Session createSubsession() {
	return getSessionManager().createSubsession();
	}

	public static Session.Info getExternalSession() {
	return getSessionManager().getExternalSession();
	}

	public static void cancelSubsession(Session subsession) {
	getSessionManager().cancelSubsession(subsession);
	}

	public static void continueSession(Session subsession, String shortMethodName) {
	getSessionManager().continueSession(subsession, shortMethodName);
	}

	public static void endSession() {
	getSessionManager().endSession();
	}

	public static void registerSessionListener(SessionManager.ISessionListener l) {
	getSessionManager().registerSessionListener(l);
	}

	public static String getSessionId() {
	// If the Session logger has not been initialized, then there have been no sessions logged.
	// Don't load it now!
	synchronized (sSingletonSync) {
	if (sSessionManager != null) {
	return getSessionManager().getSessionId();
	} else {
	return "";
	}
	}
	}

	public static void addEvent(EventManager.Loggable recordEntry, String event) {
	getEventManager().event(recordEntry, event, null);
	}

	public static void addEvent(EventManager.Loggable recordEntry, String event, Object data) {
	getEventManager().event(recordEntry, event, data);
	}

	public static void addEvent(EventManager.Loggable recordEntry, String event, String format,
	Object... args) {
	getEventManager().event(recordEntry, event, format, args);
	}

	public static void registerEventListener(EventManager.EventListener e) {
	getEventManager().registerEventListener(e);
	}

	public static void addRequestResponsePair(EventManager.TimedEventPair p) {
	getEventManager().addRequestResponsePair(p);
	}

	public static void dumpEvents(IndentingPrintWriter pw) {
	// If the Events logger has not been initialized, then there have been no events logged.
	// Don't load it now!
	synchronized (sSingletonSync) {
	if (sEventManager != null) {
	getEventManager().dumpEvents(pw);
	} else {
	pw.println("No Historical Events Logged.");
	}
	}
	}

	/**
	* Dumps the events in a timeline format.
	* @param pw The {@link IndentingPrintWriter} to write to.
	* @hide
	*/
	public static void dumpEventsTimeline(IndentingPrintWriter pw) {
	// If the Events logger has not been initialized, then there have been no events logged.
	// Don't load it now!
	synchronized (sSingletonSync) {
	if (sEventManager != null) {
	getEventManager().dumpEventsTimeline(pw);
	} else {
	pw.println("No Historical Events Logged.");
	}
	}
	}

	/**
	* Enable or disable extended telecom logging.
	*
	* @param isExtendedLoggingEnabled {@code true} if extended logging should be enabled,
	* {@code false} if it should be disabled.
	*/
	public static void setIsExtendedLoggingEnabled(boolean isExtendedLoggingEnabled) {
	// If the state hasn't changed, bail early.
	if (sIsUserExtendedLoggingEnabled == isExtendedLoggingEnabled) {
	return;
	}

	if (sEventManager != null) {
	sEventManager.changeEventCacheSize(isExtendedLoggingEnabled ?
	EVENTS_TO_CACHE_DEBUG : EVENTS_TO_CACHE);
	}

	sIsUserExtendedLoggingEnabled = isExtendedLoggingEnabled;
	if (sIsUserExtendedLoggingEnabled) {
	sUserExtendedLoggingStopTime = System.currentTimeMillis()
	+ EXTENDED_LOGGING_DURATION_MILLIS;
	} else {
	sUserExtendedLoggingStopTime = 0;
	}
	}

	private static EventManager getEventManager() {
	// Checking for null again outside of synchronization because we only need to synchronize
	// during the lazy loading of the events logger. We don't need to synchronize elsewhere.
	if (sEventManager == null) {
	synchronized (sSingletonSync) {
	if (sEventManager == null) {
	sEventManager = new EventManager(Log::getSessionId);
	return sEventManager;
	}
	}
	}
	return sEventManager;
	}

	@VisibleForTesting
	public static SessionManager getSessionManager() {
	// Checking for null again outside of synchronization because we only need to synchronize
	// during the lazy loading of the session logger. We don't need to synchronize elsewhere.
	if (sSessionManager == null) {
	synchronized (sSingletonSync) {
	if (sSessionManager == null) {
	sSessionManager = new SessionManager();
	return sSessionManager;
	}
	}
	}
	return sSessionManager;
	}

	private static MessageDigest sMessageDigest;

	public static void initMd5Sum() {
	new AsyncTask<Void, Void, Void>() {
	@Override
	public Void doInBackground(Void... args) {
	MessageDigest md;
	try {
	md = MessageDigest.getInstance("SHA-1");
	} catch (NoSuchAlgorithmException e) {
	md = null;
	}
	sMessageDigest = md;
	return null;
	}
	}.execute();
	}

	public static void setTag(String tag) {
	TAG = tag;
	DEBUG = isLoggable(android.util.Log.DEBUG);
	INFO = isLoggable(android.util.Log.INFO);
	VERBOSE = isLoggable(android.util.Log.VERBOSE);
	WARN = isLoggable(android.util.Log.WARN);
	ERROR = isLoggable(android.util.Log.ERROR);
	}

	/**
	* If user enabled extended logging is enabled and the time limit has passed, disables the
	* extended logging.
	*/
	private static void maybeDisableLogging() {
	if (!sIsUserExtendedLoggingEnabled) {
	return;
	}

	if (sUserExtendedLoggingStopTime < System.currentTimeMillis()) {
	sUserExtendedLoggingStopTime = 0;
	sIsUserExtendedLoggingEnabled = false;
	}
	}

	public static boolean isLoggable(int level) {
	return FORCE_LOGGING \|\| android.util.Log.isLoggable(TAG, level);
	}

	public static String piiHandle(Object pii) {
	if (pii == null \|\| VERBOSE) {
	return String.valueOf(pii);
	}

	StringBuilder sb = new StringBuilder();
	if (pii instanceof Uri) {
	Uri uri = (Uri) pii;
	String scheme = uri.getScheme();

	if (!TextUtils.isEmpty(scheme)) {
	sb.append(scheme).append(":");
	}

	String textToObfuscate = uri.getSchemeSpecificPart();
	if (PhoneAccount.SCHEME_TEL.equals(scheme)) {
	for (int i = 0; i < textToObfuscate.length(); i++) {
	char c = textToObfuscate.charAt(i);
	sb.append(PhoneNumberUtils.isDialable(c) ? "*" : c);
	}
	} else if (PhoneAccount.SCHEME_SIP.equals(scheme)) {
	for (int i = 0; i < textToObfuscate.length(); i++) {
	char c = textToObfuscate.charAt(i);
	if (c != '@' && c != '.') {
	c = '*';
	}
	sb.append(c);
	}
	} else {
	sb.append(pii(pii));
	}
	}

	return sb.toString();
	}

	/**
	* Redact personally identifiable information for production users.
	* If we are running in verbose mode, return the original string,
	* and return "****" if we are running on the user build, otherwise
	* return a SHA-1 hash of the input string.
	*/
	public static String pii(Object pii) {
	if (pii == null \|\| VERBOSE) {
	return String.valueOf(pii);
	}
	return "[" + secureHash(String.valueOf(pii).getBytes()) + "]";
	}

	private static String secureHash(byte[] input) {
	// Refrain from logging user personal information in user build.
	if (USER_BUILD) {
	return "****";
	}

	if (sMessageDigest != null) {
	sMessageDigest.reset();
	sMessageDigest.update(input);
	byte[] result = sMessageDigest.digest();
	return encodeHex(result);
	} else {
	return "Uninitialized SHA1";
	}
	}

	private static String encodeHex(byte[] bytes) {
	StringBuffer hex = new StringBuffer(bytes.length * 2);

	for (int i = 0; i < bytes.length; i++) {
	int byteIntValue = bytes[i] & 0xff;
	if (byteIntValue < 0x10) {
	hex.append("0");
	}
	hex.append(Integer.toString(byteIntValue, 16));
	}

	return hex.toString();
	}

	private static String getPrefixFromObject(Object obj) {
	return obj == null ? "<null>" : obj.getClass().getSimpleName();
	}

	private static String buildMessage(String prefix, String format, Object... args) {
	// Incorporate thread ID and calling method into prefix
	String sessionName = getSessionId();
	String sessionPostfix = TextUtils.isEmpty(sessionName) ? "" : ": " + sessionName;

	String msg;
	try {
	msg = (args == null \|\| args.length == 0) ? format
	: String.format(Locale.US, format, args);
	} catch (IllegalFormatException ife) {
	e(TAG, ife, "Log: IllegalFormatException: formatString='%s' numArgs=%d", format,
	args.length);
	msg = format + " (An error occurred while formatting the message.)";
	}
	return String.format(Locale.US, "%s: %s%s", prefix, msg, sessionPostfix);
	}
	}