java/src/com/android/inputmethod/research/LogUnit.java - platform/packages/inputmethods/LatinIME - Git at Google

 /*
  * Copyright (C) 2012 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.inputmethod.research;

 import android.os.SystemClock;
 import android.text.TextUtils;
 import android.util.JsonWriter;
 import android.util.Log;

 import com.android.inputmethod.latin.SuggestedWords;
 import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
 import com.android.inputmethod.latin.define.ProductionFlag;

 import java.io.IOException;
 import java.io.StringWriter;
 import java.util.ArrayList;
 import java.util.List;

 /**
  * A group of log statements related to each other.
  *
  * A LogUnit is collection of LogStatements, each of which is generated by at a particular point
  * in the code.  (There is no LogStatement class; the data is stored across the instance variables
  * here.)  A single LogUnit's statements can correspond to all the calls made while in the same
  * composing region, or all the calls between committing the last composing region, and the first
  * character of the next composing region.
  *
  * Individual statements in a log may be marked as potentially private.  If so, then they are only
  * published to a ResearchLog if the ResearchLogger determines that publishing the entire LogUnit
  * will not violate the user's privacy.  Checks for this may include whether other LogUnits have
  * been published recently, or whether the LogUnit contains numbers, etc.
  */
 public class LogUnit {
     private static final String TAG = LogUnit.class.getSimpleName();
     private static final boolean DEBUG = false
             && ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS_DEBUG;

     private final ArrayList<LogStatement> mLogStatementList;
     private final ArrayList<Object[]> mValuesList;
     // Assume that mTimeList is sorted in increasing order.  Do not insert null values into
     // mTimeList.
     private final ArrayList<Long> mTimeList;
     // Word that this LogUnit generates.  Should be null if the LogUnit does not generate a genuine
     // word (i.e. separators alone do not count as a word).  Should never be empty.
     private String mWord;
     private boolean mMayContainDigit;
     private boolean mIsPartOfMegaword;
     private boolean mContainsCorrection;

     // mCorrectionType indicates whether the word was corrected at all, and if so, whether it was
     // to a different word or just a "typo" correction.  It is considered a "typo" if the final
     // word was listed in the suggestions available the first time the word was gestured or
     // tapped.
     private int mCorrectionType;
     public static final int CORRECTIONTYPE_NO_CORRECTION = 0;
     public static final int CORRECTIONTYPE_CORRECTION = 1;
     public static final int CORRECTIONTYPE_DIFFERENT_WORD = 2;
     public static final int CORRECTIONTYPE_TYPO = 3;

     private SuggestedWords mSuggestedWords;

     public LogUnit() {
         mLogStatementList = new ArrayList<LogStatement>();
         mValuesList = new ArrayList<Object[]>();
         mTimeList = new ArrayList<Long>();
         mIsPartOfMegaword = false;
         mCorrectionType = CORRECTIONTYPE_NO_CORRECTION;
         mSuggestedWords = null;
     }

     private LogUnit(final ArrayList<LogStatement> logStatementList,
             final ArrayList<Object[]> valuesList,
             final ArrayList<Long> timeList,
             final boolean isPartOfMegaword) {
         mLogStatementList = logStatementList;
         mValuesList = valuesList;
         mTimeList = timeList;
         mIsPartOfMegaword = isPartOfMegaword;
         mCorrectionType = CORRECTIONTYPE_NO_CORRECTION;
         mSuggestedWords = null;
     }

     private static final Object[] NULL_VALUES = new Object[0];
     /**
      * Adds a new log statement.  The time parameter in successive calls to this method must be
      * monotonically increasing, or splitByTime() will not work.
      */
     public void addLogStatement(final LogStatement logStatement, final long time,
             Object... values) {
         if (values == null) {
             values = NULL_VALUES;
         }
         mLogStatementList.add(logStatement);
         mValuesList.add(values);
         mTimeList.add(time);
     }

     /**
      * Publish the contents of this LogUnit to {@code researchLog}.
      *
      * For each publishable {@code LogStatement}, invoke {@link LogStatement#outputToLocked}.
      *
      * @param researchLog where to publish the contents of this {@code LogUnit}
      * @param canIncludePrivateData whether the private data in this {@code LogUnit} should be
      * included
      */
     public synchronized void publishTo(final ResearchLog researchLog,
             final boolean canIncludePrivateData) {
         // Write out any logStatement that passes the privacy filter.
         final int size = mLogStatementList.size();
         if (size != 0) {
             // Note that jsonWriter is only set to a non-null value if the logUnit start text is
             // output and at least one logStatement is output.
             JsonWriter jsonWriter = null;
             for (int i = 0; i < size; i++) {
                 final LogStatement logStatement = mLogStatementList.get(i);
                 if (!canIncludePrivateData && logStatement.isPotentiallyPrivate()) {
                     continue;
                 }
                 if (mIsPartOfMegaword && logStatement.isPotentiallyRevealing()) {
                     continue;
                 }
                 // Only retrieve the jsonWriter if we need to.  If we don't get this far, then
                 // researchLog.getInitializedJsonWriterLocked() will not ever be called, and the
                 // file will not have been opened for writing.
                 if (jsonWriter == null) {
                     jsonWriter = researchLog.getInitializedJsonWriterLocked();
                     outputLogUnitStart(jsonWriter, canIncludePrivateData);
                 }
                 logStatement.outputToLocked(jsonWriter, mTimeList.get(i), mValuesList.get(i));
             }
             if (jsonWriter != null) {
                 // We must have called logUnitStart earlier, so emit a logUnitStop.
                 outputLogUnitStop(jsonWriter);
             }
         }
     }

     private static final String WORD_KEY = "_wo";
     private static final String CORRECTION_TYPE_KEY = "_corType";
     private static final String LOG_UNIT_BEGIN_KEY = "logUnitStart";
     private static final String LOG_UNIT_END_KEY = "logUnitEnd";

     final LogStatement LOGSTATEMENT_LOG_UNIT_BEGIN_WITH_PRIVATE_DATA =
             new LogStatement(LOG_UNIT_BEGIN_KEY, false /* isPotentiallyPrivate */,
                     false /* isPotentiallyRevealing */, WORD_KEY, CORRECTION_TYPE_KEY);
     final LogStatement LOGSTATEMENT_LOG_UNIT_BEGIN_WITHOUT_PRIVATE_DATA =
             new LogStatement(LOG_UNIT_BEGIN_KEY, false /* isPotentiallyPrivate */,
                     false /* isPotentiallyRevealing */);
     private void outputLogUnitStart(final JsonWriter jsonWriter,
             final boolean canIncludePrivateData) {
         final LogStatement logStatement;
         if (canIncludePrivateData) {
             LOGSTATEMENT_LOG_UNIT_BEGIN_WITH_PRIVATE_DATA.outputToLocked(jsonWriter,
                     SystemClock.uptimeMillis(), getWord(), getCorrectionType());
         } else {
             LOGSTATEMENT_LOG_UNIT_BEGIN_WITHOUT_PRIVATE_DATA.outputToLocked(jsonWriter,
                     SystemClock.uptimeMillis());
         }
     }

     final LogStatement LOGSTATEMENT_LOG_UNIT_END =
             new LogStatement(LOG_UNIT_END_KEY, false /* isPotentiallyPrivate */,
                     false /* isPotentiallyRevealing */);
     private void outputLogUnitStop(final JsonWriter jsonWriter) {
         LOGSTATEMENT_LOG_UNIT_END.outputToLocked(jsonWriter, SystemClock.uptimeMillis());
     }

     /**
      * Mark the current logUnit as containing data to generate {@code word}.
      *
      * If {@code setWord()} was previously called for this LogUnit, then the method will try to
      * determine what kind of correction it is, and update its internal state of the correctionType
      * accordingly.
      *
      * @param word The word this LogUnit generates.  Caller should not pass null or the empty
      * string.
      */
     public void setWord(final String word) {
         if (hasWord()) {
             // The word was already set once, and it is now being changed.  See if the new word
             // is close to the old word.  If so, then the change is probably a typo correction.
             // If not, the user may have decided to enter a different word, so flag it.
             if (mSuggestedWords != null) {
                 if (isInSuggestedWords(word, mSuggestedWords)) {
                     mCorrectionType = CORRECTIONTYPE_TYPO;
                 } else {
                     mCorrectionType = CORRECTIONTYPE_DIFFERENT_WORD;
                 }
             } else {
                 // No suggested words, so it's not clear whether it's a typo or different word.
                 // Mark it as a generic correction.
                 mCorrectionType = CORRECTIONTYPE_CORRECTION;
             }
         }
         mWord = word;
     }

     public String getWord() {
         return mWord;
     }

     public boolean hasWord() {
         return mWord != null && !TextUtils.isEmpty(mWord.trim());
     }

     public void setMayContainDigit() {
         mMayContainDigit = true;
     }

     public boolean mayContainDigit() {
         return mMayContainDigit;
     }

     public void setContainsCorrection() {
         mContainsCorrection = true;
     }

     public boolean containsCorrection() {
         return mContainsCorrection;
     }

     public void setCorrectionType(final int correctionType) {
         mCorrectionType = correctionType;
     }

     public int getCorrectionType() {
         return mCorrectionType;
     }

     public boolean isEmpty() {
         return mLogStatementList.isEmpty();
     }

     /**
      * Split this logUnit, with all events before maxTime staying in the current logUnit, and all
      * events after maxTime going into a new LogUnit that is returned.
      */
     public LogUnit splitByTime(final long maxTime) {
         // Assume that mTimeList is in sorted order.
         final int length = mTimeList.size();
         // TODO: find time by binary search, e.g. using Collections#binarySearch()
         for (int index = 0; index < length; index++) {
             if (mTimeList.get(index) > maxTime) {
                 final List<LogStatement> laterLogStatements =
                         mLogStatementList.subList(index, length);
                 final List<Object[]> laterValues = mValuesList.subList(index, length);
                 final List<Long> laterTimes = mTimeList.subList(index, length);

                 // Create the LogUnit containing the later logStatements and associated data.
                 final LogUnit newLogUnit = new LogUnit(
                         new ArrayList<LogStatement>(laterLogStatements),
                         new ArrayList<Object[]>(laterValues),
                         new ArrayList<Long>(laterTimes),
                         true /* isPartOfMegaword */);
                 newLogUnit.mWord = null;
                 newLogUnit.mMayContainDigit = mMayContainDigit;
                 newLogUnit.mContainsCorrection = mContainsCorrection;

                 // Purge the logStatements and associated data from this LogUnit.
                 laterLogStatements.clear();
                 laterValues.clear();
                 laterTimes.clear();
                 mIsPartOfMegaword = true;

                 return newLogUnit;
             }
         }
         return new LogUnit();
     }

     public void append(final LogUnit logUnit) {
         mLogStatementList.addAll(logUnit.mLogStatementList);
         mValuesList.addAll(logUnit.mValuesList);
         mTimeList.addAll(logUnit.mTimeList);
         mWord = null;
         if (logUnit.mWord != null) {
             setWord(logUnit.mWord);
         }
         mMayContainDigit = mMayContainDigit || logUnit.mMayContainDigit;
         mContainsCorrection = mContainsCorrection || logUnit.mContainsCorrection;
         mIsPartOfMegaword = false;
     }

     public SuggestedWords getSuggestions() {
         return mSuggestedWords;
     }

     /**
      * Initialize the suggestions.
      *
      * Once set to a non-null value, the suggestions may not be changed again.  This is to keep
      * track of the list of words that are close to the user's initial effort to type the word.
      * Only words that are close to the initial effort are considered typo corrections.
      */
     public void initializeSuggestions(final SuggestedWords suggestedWords) {
         if (mSuggestedWords == null) {
             mSuggestedWords = suggestedWords;
         }
     }

     private static boolean isInSuggestedWords(final String queryWord,
             final SuggestedWords suggestedWords) {
         if (TextUtils.isEmpty(queryWord)) {
             return false;
         }
         final int size = suggestedWords.size();
         for (int i = 0; i < size; i++) {
             final SuggestedWordInfo wordInfo = suggestedWords.getInfo(i);
             if (queryWord.equals(wordInfo.mWord)) {
                 return true;
             }
         }
         return false;
     }

     /**
      * Remove data associated with selecting the Research button.
      *
      * A LogUnit will capture all user interactions with the IME, including the "meta-interactions"
      * of using the Research button to control the logging (e.g. by starting and stopping recording
      * of a test case).  Because meta-interactions should not be part of the normal log, calling
      * this method will set a field in the LogStatements of the motion events to indiciate that
      * they should be disregarded.
      *
      * This implementation assumes that the data recorded by the meta-interaction takes the
      * form of all events following the first MotionEvent.ACTION_DOWN before the first long-press
      * before the last onCodeEvent containing a code matching {@code LogStatement.VALUE_RESEARCH}.
      *
      * @returns true if data was removed
      */
     public boolean removeResearchButtonInvocation() {
         // This method is designed to be idempotent.

         // First, find last invocation of "research" key
         final int indexOfLastResearchKey = findLastIndexContainingKeyValue(
                 LogStatement.TYPE_POINTER_TRACKER_CALL_LISTENER_ON_CODE_INPUT,
                 LogStatement.KEY_CODE, LogStatement.VALUE_RESEARCH);
         if (indexOfLastResearchKey < 0) {
             // Could not find invocation of "research" key.  Leave log as is.
             if (DEBUG) {
                 Log.d(TAG, "Could not find research key");
             }
             return false;
         }

         // Look for the long press that started the invocation of the research key code input.
         final int indexOfLastLongPressBeforeResearchKey =
                 findLastIndexBefore(LogStatement.TYPE_MAIN_KEYBOARD_VIEW_ON_LONG_PRESS,
                         indexOfLastResearchKey);

         // Look for DOWN event preceding the long press
         final int indexOfLastDownEventBeforeLongPress =
                 findLastIndexContainingKeyValueBefore(LogStatement.TYPE_MOTION_EVENT,
                         LogStatement.ACTION, LogStatement.VALUE_DOWN,
                         indexOfLastLongPressBeforeResearchKey);

         // Flag all LatinKeyboardViewProcessMotionEvents from the DOWN event to the research key as
         // logging-related
         final int startingIndex = indexOfLastDownEventBeforeLongPress == -1 ? 0
                 : indexOfLastDownEventBeforeLongPress;
         for (int index = startingIndex; index < indexOfLastResearchKey; index++) {
             final LogStatement logStatement = mLogStatementList.get(index);
             final String type = logStatement.getType();
             final Object[] values = mValuesList.get(index);
             if (type.equals(LogStatement.TYPE_MOTION_EVENT)) {
                 logStatement.setValue(LogStatement.KEY_IS_LOGGING_RELATED, values, true);
             }
         }
         return true;
     }

     /**
      * Find the index of the last LogStatement before {@code startingIndex} of type {@code type}.
      *
      * @param queryType a String that must be {@code String.equals()} to the LogStatement type
      * @param startingIndex the index to start the backward search from.  Must be less than the
      * length of mLogStatementList, or an IndexOutOfBoundsException is thrown.  Can be negative,
      * in which case -1 is returned.
      *
      * @return The index of the last LogStatement, -1 if none exists.
      */
     private int findLastIndexBefore(final String queryType, final int startingIndex) {
         return findLastIndexContainingKeyValueBefore(queryType, null, null, startingIndex);
     }

     /**
      * Find the index of the last LogStatement before {@code startingIndex} of type {@code type}
      * containing the given key-value pair.
      *
      * @param queryType a String that must be {@code String.equals()} to the LogStatement type
      * @param queryKey a String that must be {@code String.equals()} to a key in the LogStatement
      * @param queryValue an Object that must be {@code String.equals()} to the key's corresponding
      * value
      *
      * @return The index of the last LogStatement, -1 if none exists.
      */
     private int findLastIndexContainingKeyValue(final String queryType, final String queryKey,
             final Object queryValue) {
         return findLastIndexContainingKeyValueBefore(queryType, queryKey, queryValue,
                 mLogStatementList.size() - 1);
     }

     /**
      * Find the index of the last LogStatement before {@code startingIndex} of type {@code type}
      * containing the given key-value pair.
      *
      * @param queryType a String that must be {@code String.equals()} to the LogStatement type
      * @param queryKey a String that must be {@code String.equals()} to a key in the LogStatement
      * @param queryValue an Object that must be {@code String.equals()} to the key's corresponding
      * value
      * @param startingIndex the index to start the backward search from.  Must be less than the
      * length of mLogStatementList, or an IndexOutOfBoundsException is thrown.  Can be negative,
      * in which case -1 is returned.
      *
      * @return The index of the last LogStatement, -1 if none exists.
      */
     private int findLastIndexContainingKeyValueBefore(final String queryType, final String queryKey,
             final Object queryValue, final int startingIndex) {
         if (startingIndex < 0) {
             return -1;
         }
         for (int index = startingIndex; index >= 0; index--) {
             final LogStatement logStatement = mLogStatementList.get(index);
             final String type = logStatement.getType();
             if (type.equals(queryType) && (queryKey == null
                     || logStatement.containsKeyValuePair(queryKey, queryValue,
                             mValuesList.get(index)))) {
                 return index;
             }
         }
         return -1;
     }
 }
	/*
	* Copyright (C) 2012 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.inputmethod.research;

	import android.os.SystemClock;
	import android.text.TextUtils;
	import android.util.JsonWriter;
	import android.util.Log;

	import com.android.inputmethod.latin.SuggestedWords;
	import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
	import com.android.inputmethod.latin.define.ProductionFlag;

	import java.io.IOException;
	import java.io.StringWriter;
	import java.util.ArrayList;
	import java.util.List;

	/**
	* A group of log statements related to each other.
	*
	* A LogUnit is collection of LogStatements, each of which is generated by at a particular point
	* in the code. (There is no LogStatement class; the data is stored across the instance variables
	* here.) A single LogUnit's statements can correspond to all the calls made while in the same
	* composing region, or all the calls between committing the last composing region, and the first
	* character of the next composing region.
	*
	* Individual statements in a log may be marked as potentially private. If so, then they are only
	* published to a ResearchLog if the ResearchLogger determines that publishing the entire LogUnit
	* will not violate the user's privacy. Checks for this may include whether other LogUnits have
	* been published recently, or whether the LogUnit contains numbers, etc.
	*/
	public class LogUnit {
	private static final String TAG = LogUnit.class.getSimpleName();
	private static final boolean DEBUG = false
	&& ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS_DEBUG;

	private final ArrayList<LogStatement> mLogStatementList;
	private final ArrayList<Object[]> mValuesList;
	// Assume that mTimeList is sorted in increasing order. Do not insert null values into
	// mTimeList.
	private final ArrayList<Long> mTimeList;
	// Word that this LogUnit generates. Should be null if the LogUnit does not generate a genuine
	// word (i.e. separators alone do not count as a word). Should never be empty.
	private String mWord;
	private boolean mMayContainDigit;
	private boolean mIsPartOfMegaword;
	private boolean mContainsCorrection;

	// mCorrectionType indicates whether the word was corrected at all, and if so, whether it was
	// to a different word or just a "typo" correction. It is considered a "typo" if the final
	// word was listed in the suggestions available the first time the word was gestured or
	// tapped.
	private int mCorrectionType;
	public static final int CORRECTIONTYPE_NO_CORRECTION = 0;
	public static final int CORRECTIONTYPE_CORRECTION = 1;
	public static final int CORRECTIONTYPE_DIFFERENT_WORD = 2;
	public static final int CORRECTIONTYPE_TYPO = 3;

	private SuggestedWords mSuggestedWords;

	public LogUnit() {
	mLogStatementList = new ArrayList<LogStatement>();
	mValuesList = new ArrayList<Object[]>();
	mTimeList = new ArrayList<Long>();
	mIsPartOfMegaword = false;
	mCorrectionType = CORRECTIONTYPE_NO_CORRECTION;
	mSuggestedWords = null;
	}

	private LogUnit(final ArrayList<LogStatement> logStatementList,
	final ArrayList<Object[]> valuesList,
	final ArrayList<Long> timeList,
	final boolean isPartOfMegaword) {
	mLogStatementList = logStatementList;
	mValuesList = valuesList;
	mTimeList = timeList;
	mIsPartOfMegaword = isPartOfMegaword;
	mCorrectionType = CORRECTIONTYPE_NO_CORRECTION;
	mSuggestedWords = null;
	}

	private static final Object[] NULL_VALUES = new Object[0];
	/**
	* Adds a new log statement. The time parameter in successive calls to this method must be
	* monotonically increasing, or splitByTime() will not work.
	*/
	public void addLogStatement(final LogStatement logStatement, final long time,
	Object... values) {
	if (values == null) {
	values = NULL_VALUES;
	}
	mLogStatementList.add(logStatement);
	mValuesList.add(values);
	mTimeList.add(time);
	}

	/**
	* Publish the contents of this LogUnit to {@code researchLog}.
	*
	* For each publishable {@code LogStatement}, invoke {@link LogStatement#outputToLocked}.
	*
	* @param researchLog where to publish the contents of this {@code LogUnit}
	* @param canIncludePrivateData whether the private data in this {@code LogUnit} should be
	* included
	*/
	public synchronized void publishTo(final ResearchLog researchLog,
	final boolean canIncludePrivateData) {
	// Write out any logStatement that passes the privacy filter.
	final int size = mLogStatementList.size();
	if (size != 0) {
	// Note that jsonWriter is only set to a non-null value if the logUnit start text is
	// output and at least one logStatement is output.
	JsonWriter jsonWriter = null;
	for (int i = 0; i < size; i++) {
	final LogStatement logStatement = mLogStatementList.get(i);
	if (!canIncludePrivateData && logStatement.isPotentiallyPrivate()) {
	continue;
	}
	if (mIsPartOfMegaword && logStatement.isPotentiallyRevealing()) {
	continue;
	}
	// Only retrieve the jsonWriter if we need to. If we don't get this far, then
	// researchLog.getInitializedJsonWriterLocked() will not ever be called, and the
	// file will not have been opened for writing.
	if (jsonWriter == null) {
	jsonWriter = researchLog.getInitializedJsonWriterLocked();
	outputLogUnitStart(jsonWriter, canIncludePrivateData);
	}
	logStatement.outputToLocked(jsonWriter, mTimeList.get(i), mValuesList.get(i));
	}
	if (jsonWriter != null) {
	// We must have called logUnitStart earlier, so emit a logUnitStop.
	outputLogUnitStop(jsonWriter);
	}
	}
	}

	private static final String WORD_KEY = "_wo";
	private static final String CORRECTION_TYPE_KEY = "_corType";
	private static final String LOG_UNIT_BEGIN_KEY = "logUnitStart";
	private static final String LOG_UNIT_END_KEY = "logUnitEnd";

	final LogStatement LOGSTATEMENT_LOG_UNIT_BEGIN_WITH_PRIVATE_DATA =
	new LogStatement(LOG_UNIT_BEGIN_KEY, false /* isPotentiallyPrivate */,
	false /* isPotentiallyRevealing */, WORD_KEY, CORRECTION_TYPE_KEY);
	final LogStatement LOGSTATEMENT_LOG_UNIT_BEGIN_WITHOUT_PRIVATE_DATA =
	new LogStatement(LOG_UNIT_BEGIN_KEY, false /* isPotentiallyPrivate */,
	false /* isPotentiallyRevealing */);
	private void outputLogUnitStart(final JsonWriter jsonWriter,
	final boolean canIncludePrivateData) {
	final LogStatement logStatement;
	if (canIncludePrivateData) {
	LOGSTATEMENT_LOG_UNIT_BEGIN_WITH_PRIVATE_DATA.outputToLocked(jsonWriter,
	SystemClock.uptimeMillis(), getWord(), getCorrectionType());
	} else {
	LOGSTATEMENT_LOG_UNIT_BEGIN_WITHOUT_PRIVATE_DATA.outputToLocked(jsonWriter,
	SystemClock.uptimeMillis());
	}
	}

	final LogStatement LOGSTATEMENT_LOG_UNIT_END =
	new LogStatement(LOG_UNIT_END_KEY, false /* isPotentiallyPrivate */,
	false /* isPotentiallyRevealing */);
	private void outputLogUnitStop(final JsonWriter jsonWriter) {
	LOGSTATEMENT_LOG_UNIT_END.outputToLocked(jsonWriter, SystemClock.uptimeMillis());
	}

	/**
	* Mark the current logUnit as containing data to generate {@code word}.
	*
	* If {@code setWord()} was previously called for this LogUnit, then the method will try to
	* determine what kind of correction it is, and update its internal state of the correctionType
	* accordingly.
	*
	* @param word The word this LogUnit generates. Caller should not pass null or the empty
	* string.
	*/
	public void setWord(final String word) {
	if (hasWord()) {
	// The word was already set once, and it is now being changed. See if the new word
	// is close to the old word. If so, then the change is probably a typo correction.
	// If not, the user may have decided to enter a different word, so flag it.
	if (mSuggestedWords != null) {
	if (isInSuggestedWords(word, mSuggestedWords)) {
	mCorrectionType = CORRECTIONTYPE_TYPO;
	} else {
	mCorrectionType = CORRECTIONTYPE_DIFFERENT_WORD;
	}
	} else {
	// No suggested words, so it's not clear whether it's a typo or different word.
	// Mark it as a generic correction.
	mCorrectionType = CORRECTIONTYPE_CORRECTION;
	}
	}
	mWord = word;
	}

	public String getWord() {
	return mWord;
	}

	public boolean hasWord() {
	return mWord != null && !TextUtils.isEmpty(mWord.trim());
	}

	public void setMayContainDigit() {
	mMayContainDigit = true;
	}

	public boolean mayContainDigit() {
	return mMayContainDigit;
	}

	public void setContainsCorrection() {
	mContainsCorrection = true;
	}

	public boolean containsCorrection() {
	return mContainsCorrection;
	}

	public void setCorrectionType(final int correctionType) {
	mCorrectionType = correctionType;
	}

	public int getCorrectionType() {
	return mCorrectionType;
	}

	public boolean isEmpty() {
	return mLogStatementList.isEmpty();
	}

	/**
	* Split this logUnit, with all events before maxTime staying in the current logUnit, and all
	* events after maxTime going into a new LogUnit that is returned.
	*/
	public LogUnit splitByTime(final long maxTime) {
	// Assume that mTimeList is in sorted order.
	final int length = mTimeList.size();
	// TODO: find time by binary search, e.g. using Collections#binarySearch()
	for (int index = 0; index < length; index++) {
	if (mTimeList.get(index) > maxTime) {
	final List<LogStatement> laterLogStatements =
	mLogStatementList.subList(index, length);
	final List<Object[]> laterValues = mValuesList.subList(index, length);
	final List<Long> laterTimes = mTimeList.subList(index, length);

	// Create the LogUnit containing the later logStatements and associated data.
	final LogUnit newLogUnit = new LogUnit(
	new ArrayList<LogStatement>(laterLogStatements),
	new ArrayList<Object[]>(laterValues),
	new ArrayList<Long>(laterTimes),
	true /* isPartOfMegaword */);
	newLogUnit.mWord = null;
	newLogUnit.mMayContainDigit = mMayContainDigit;
	newLogUnit.mContainsCorrection = mContainsCorrection;

	// Purge the logStatements and associated data from this LogUnit.
	laterLogStatements.clear();
	laterValues.clear();
	laterTimes.clear();
	mIsPartOfMegaword = true;

	return newLogUnit;
	}
	}
	return new LogUnit();
	}

	public void append(final LogUnit logUnit) {
	mLogStatementList.addAll(logUnit.mLogStatementList);
	mValuesList.addAll(logUnit.mValuesList);
	mTimeList.addAll(logUnit.mTimeList);
	mWord = null;
	if (logUnit.mWord != null) {
	setWord(logUnit.mWord);
	}
	mMayContainDigit = mMayContainDigit \|\| logUnit.mMayContainDigit;
	mContainsCorrection = mContainsCorrection \|\| logUnit.mContainsCorrection;
	mIsPartOfMegaword = false;
	}

	public SuggestedWords getSuggestions() {
	return mSuggestedWords;
	}

	/**
	* Initialize the suggestions.
	*
	* Once set to a non-null value, the suggestions may not be changed again. This is to keep
	* track of the list of words that are close to the user's initial effort to type the word.
	* Only words that are close to the initial effort are considered typo corrections.
	*/
	public void initializeSuggestions(final SuggestedWords suggestedWords) {
	if (mSuggestedWords == null) {
	mSuggestedWords = suggestedWords;
	}
	}

	private static boolean isInSuggestedWords(final String queryWord,
	final SuggestedWords suggestedWords) {
	if (TextUtils.isEmpty(queryWord)) {
	return false;
	}
	final int size = suggestedWords.size();
	for (int i = 0; i < size; i++) {
	final SuggestedWordInfo wordInfo = suggestedWords.getInfo(i);
	if (queryWord.equals(wordInfo.mWord)) {
	return true;
	}
	}
	return false;
	}

	/**
	* Remove data associated with selecting the Research button.
	*
	* A LogUnit will capture all user interactions with the IME, including the "meta-interactions"
	* of using the Research button to control the logging (e.g. by starting and stopping recording
	* of a test case). Because meta-interactions should not be part of the normal log, calling
	* this method will set a field in the LogStatements of the motion events to indiciate that
	* they should be disregarded.
	*
	* This implementation assumes that the data recorded by the meta-interaction takes the
	* form of all events following the first MotionEvent.ACTION_DOWN before the first long-press
	* before the last onCodeEvent containing a code matching {@code LogStatement.VALUE_RESEARCH}.
	*
	* @returns true if data was removed
	*/
	public boolean removeResearchButtonInvocation() {
	// This method is designed to be idempotent.

	// First, find last invocation of "research" key
	final int indexOfLastResearchKey = findLastIndexContainingKeyValue(
	LogStatement.TYPE_POINTER_TRACKER_CALL_LISTENER_ON_CODE_INPUT,
	LogStatement.KEY_CODE, LogStatement.VALUE_RESEARCH);
	if (indexOfLastResearchKey < 0) {
	// Could not find invocation of "research" key. Leave log as is.
	if (DEBUG) {
	Log.d(TAG, "Could not find research key");
	}
	return false;
	}

	// Look for the long press that started the invocation of the research key code input.
	final int indexOfLastLongPressBeforeResearchKey =
	findLastIndexBefore(LogStatement.TYPE_MAIN_KEYBOARD_VIEW_ON_LONG_PRESS,
	indexOfLastResearchKey);

	// Look for DOWN event preceding the long press
	final int indexOfLastDownEventBeforeLongPress =
	findLastIndexContainingKeyValueBefore(LogStatement.TYPE_MOTION_EVENT,
	LogStatement.ACTION, LogStatement.VALUE_DOWN,
	indexOfLastLongPressBeforeResearchKey);

	// Flag all LatinKeyboardViewProcessMotionEvents from the DOWN event to the research key as
	// logging-related
	final int startingIndex = indexOfLastDownEventBeforeLongPress == -1 ? 0
	: indexOfLastDownEventBeforeLongPress;
	for (int index = startingIndex; index < indexOfLastResearchKey; index++) {
	final LogStatement logStatement = mLogStatementList.get(index);
	final String type = logStatement.getType();
	final Object[] values = mValuesList.get(index);
	if (type.equals(LogStatement.TYPE_MOTION_EVENT)) {
	logStatement.setValue(LogStatement.KEY_IS_LOGGING_RELATED, values, true);
	}
	}
	return true;
	}

	/**
	* Find the index of the last LogStatement before {@code startingIndex} of type {@code type}.
	*
	* @param queryType a String that must be {@code String.equals()} to the LogStatement type
	* @param startingIndex the index to start the backward search from. Must be less than the
	* length of mLogStatementList, or an IndexOutOfBoundsException is thrown. Can be negative,
	* in which case -1 is returned.
	*
	* @return The index of the last LogStatement, -1 if none exists.
	*/
	private int findLastIndexBefore(final String queryType, final int startingIndex) {
	return findLastIndexContainingKeyValueBefore(queryType, null, null, startingIndex);
	}

	/**
	* Find the index of the last LogStatement before {@code startingIndex} of type {@code type}
	* containing the given key-value pair.
	*
	* @param queryType a String that must be {@code String.equals()} to the LogStatement type
	* @param queryKey a String that must be {@code String.equals()} to a key in the LogStatement
	* @param queryValue an Object that must be {@code String.equals()} to the key's corresponding
	* value
	*
	* @return The index of the last LogStatement, -1 if none exists.
	*/
	private int findLastIndexContainingKeyValue(final String queryType, final String queryKey,
	final Object queryValue) {
	return findLastIndexContainingKeyValueBefore(queryType, queryKey, queryValue,
	mLogStatementList.size() - 1);
	}

	/**
	* Find the index of the last LogStatement before {@code startingIndex} of type {@code type}
	* containing the given key-value pair.
	*
	* @param queryType a String that must be {@code String.equals()} to the LogStatement type
	* @param queryKey a String that must be {@code String.equals()} to a key in the LogStatement
	* @param queryValue an Object that must be {@code String.equals()} to the key's corresponding
	* value
	* @param startingIndex the index to start the backward search from. Must be less than the
	* length of mLogStatementList, or an IndexOutOfBoundsException is thrown. Can be negative,
	* in which case -1 is returned.
	*
	* @return The index of the last LogStatement, -1 if none exists.
	*/
	private int findLastIndexContainingKeyValueBefore(final String queryType, final String queryKey,
	final Object queryValue, final int startingIndex) {
	if (startingIndex < 0) {
	return -1;
	}
	for (int index = startingIndex; index >= 0; index--) {
	final LogStatement logStatement = mLogStatementList.get(index);
	final String type = logStatement.getType();
	if (type.equals(queryType) && (queryKey == null
	\|\| logStatement.containsKeyValuePair(queryKey, queryValue,
	mValuesList.get(index)))) {
	return index;
	}
	}
	return -1;
	}
	}