diff --git a/java/res/values/strings.xml b/java/res/values/strings.xml
index ef24448..70f4c18 100644
--- a/java/res/values/strings.xml
+++ b/java/res/values/strings.xml
@@ -498,6 +498,14 @@
     <string name="read_external_dictionary_confirm_install_message">Really install this file for <xliff:g id="locale_name">%s</xliff:g>?</string>
     <!-- Title for an error dialog that contains the details of the error in the body [CHAR LIMIT=80] -->
     <string name="error">There was an error</string>
+    <!-- Title of the settings for dumpping contacts dictionary file [CHAR LIMIT=35] -->
+    <string name="prefs_dump_contacts_dict">Dump contacts dictionary</string>
+    <!-- Title of the settings for dumpping personal dictionary file [CHAR LIMIT=35] -->
+    <string name="prefs_dump_user_dict">Dump personal dictionary</string>
+    <!-- Title of the settings for dumpping user history dictionary file [CHAR LIMIT=35] -->
+    <string name="prefs_dump_user_history_dict">Dump user history dictionary</string>
+    <!-- Title of the settings for dumpping personalization dictionary file [CHAR LIMIT=35] -->
+    <string name="prefs_dump_personalization_dict">Dump personalization dictionary</string>
 
     <!-- Title of the button to revert to the default value of the device in the settings dialog [CHAR LIMIT=15] -->
     <string name="button_default">Default</string>
diff --git a/java/res/xml/prefs_for_debug.xml b/java/res/xml/prefs_for_debug.xml
index 8d9508e..899e2b8 100644
--- a/java/res/xml/prefs_for_debug.xml
+++ b/java/res/xml/prefs_for_debug.xml
@@ -61,4 +61,21 @@
     <PreferenceScreen
         android:key="read_external_dictionary"
         android:title="@string/prefs_read_external_dictionary" />
+
+    <PreferenceScreen
+        android:key="dump_contacts_dict"
+        android:title="@string/prefs_dump_contacts_dict" />
+
+    <PreferenceScreen
+        android:key="dump_user_dict"
+        android:title="@string/prefs_dump_user_dict" />
+
+    <PreferenceScreen
+        android:key="dump_user_history_dict"
+        android:title="@string/prefs_dump_user_history_dict" />
+
+    <PreferenceScreen
+        android:key="dump_personalization_dict"
+        android:title="@string/prefs_dump_personalization_dict" />
+
 </PreferenceScreen>
diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionary.java b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
index 00eb57c..80a27e2 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
@@ -22,7 +22,10 @@
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.keyboard.ProximityInfo;
 import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
-import com.android.inputmethod.latin.makedict.Word;
+import com.android.inputmethod.latin.makedict.DictionaryHeader;
+import com.android.inputmethod.latin.makedict.FormatSpec;
+import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions;
+import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
 import com.android.inputmethod.latin.settings.NativeSuggestOptions;
 import com.android.inputmethod.latin.utils.CollectionUtils;
 import com.android.inputmethod.latin.utils.JniUtils;
@@ -33,6 +36,7 @@
 import java.io.File;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
 
@@ -138,6 +142,9 @@
             String[] attributeKeyStringArray, String[] attributeValueStringArray);
     private static native long openNative(String sourceDir, long dictOffset, long dictSize,
             boolean isUpdatable);
+    private static native void getHeaderInfoNative(long dict, int[] outHeaderSize,
+            int[] outFormatVersion, ArrayList<int[]> outAttributeKeys,
+            ArrayList<int[]> outAttributeValues);
     private static native void flushNative(long dict, String filePath);
     private static native boolean needsToRunGCNative(long dict, boolean mindsBlockByGC);
     private static native void flushWithGCNative(long dict, String filePath);
@@ -171,7 +178,6 @@
     private static native int setCurrentTimeForTestNative(int currentTime);
     private static native String getPropertyNative(long dict, String query);
 
-    @UsedForTesting
     public static boolean createEmptyDictFile(final String filePath, final long dictVersion,
             final Map<String, String> attributeMap) {
         final String[] keyArray = new String[attributeMap.size()];
@@ -191,6 +197,33 @@
         mNativeDict = openNative(path, startOffset, length, isUpdatable);
     }
 
+    @UsedForTesting
+    public DictionaryHeader getHeader() throws UnsupportedFormatException {
+        if (mNativeDict == 0) {
+            return null;
+        }
+        final int[] outHeaderSize = new int[1];
+        final int[] outFormatVersion = new int[1];
+        final ArrayList<int[]> outAttributeKeys = CollectionUtils.newArrayList();
+        final ArrayList<int[]> outAttributeValues = CollectionUtils.newArrayList();
+        getHeaderInfoNative(mNativeDict, outHeaderSize, outFormatVersion, outAttributeKeys,
+                outAttributeValues);
+        final HashMap<String, String> attributes = new HashMap<String, String>();
+        for (int i = 0; i < outAttributeKeys.size(); i++) {
+            final String attributeKey = StringUtils.getStringFromNullTerminatedCodePointArray(
+                    outAttributeKeys.get(i));
+            final String attributeValue = StringUtils.getStringFromNullTerminatedCodePointArray(
+                    outAttributeValues.get(i));
+            attributes.put(attributeKey, attributeValue);
+        }
+        final boolean hasHistoricalInfo =
+                attributes.get(DictionaryHeader.HAS_HISTORICAL_INFO_KEY).equals(
+                        DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
+        return new DictionaryHeader(outHeaderSize[0], new DictionaryOptions(attributes),
+                new FormatSpec.FormatOptions(outFormatVersion[0], hasHistoricalInfo));
+    }
+
+
     @Override
     public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer,
             final String prevWord, final ProximityInfo proximityInfo,
@@ -308,7 +341,6 @@
         return getBigramProbabilityNative(mNativeDict, codePoints0, codePoints1);
     }
 
-    @UsedForTesting
     public WordProperty getWordProperty(final String word) {
         if (TextUtils.isEmpty(word)) {
             return null;
@@ -348,16 +380,10 @@
      * Method to iterate all words in the dictionary for makedict.
      * If token is 0, this method newly starts iterating the dictionary.
      */
-    @UsedForTesting
     public GetNextWordPropertyResult getNextWordProperty(final int token) {
         final int[] codePoints = new int[MAX_WORD_LENGTH];
         final int nextToken = getNextWordNative(mNativeDict, token, codePoints);
-        int len = 0;
-        // codePoints is null-terminated if its length is shorter than the array length.
-        while (len < MAX_WORD_LENGTH && codePoints[len] != 0) {
-            ++len;
-        }
-        final String word = new String(mOutputCodePoints, 0, len);
+        final String word = StringUtils.getStringFromNullTerminatedCodePointArray(codePoints);
         return new GetNextWordPropertyResult(getWordProperty(word), nextToken);
     }
 
diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java b/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java
index 7e97802..a700837 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java
@@ -22,8 +22,8 @@
 import android.util.Log;
 
 import com.android.inputmethod.latin.makedict.DictDecoder;
+import com.android.inputmethod.latin.makedict.DictionaryHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
 import com.android.inputmethod.latin.utils.CollectionUtils;
 import com.android.inputmethod.latin.utils.DictionaryInfoUtils;
@@ -230,7 +230,7 @@
         try {
             // Read the version of the file
             final DictDecoder dictDecoder = FormatSpec.getDictDecoder(f);
-            final FileHeader header = dictDecoder.readHeader();
+            final DictionaryHeader header = dictDecoder.readHeader();
 
             final String version = header.mDictionaryOptions.mAttributes.get(VERSION_KEY);
             if (null == version) {
diff --git a/java/src/com/android/inputmethod/latin/DictionaryDumpBroadcastReceiver.java b/java/src/com/android/inputmethod/latin/DictionaryDumpBroadcastReceiver.java
new file mode 100644
index 0000000..ee2fdc6
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/DictionaryDumpBroadcastReceiver.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 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 com.android.inputmethod.latin;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.util.Log;
+
+public class DictionaryDumpBroadcastReceiver extends BroadcastReceiver {
+  private static final String TAG = DictionaryDumpBroadcastReceiver.class.getSimpleName();
+
+    private static final String DOMAIN = "com.android.inputmethod.latin";
+    public static final String DICTIONARY_DUMP_INTENT_ACTION = DOMAIN + ".DICT_DUMP";
+    public static final String DICTIONARY_NAME_KEY = "dictName";
+
+    final LatinIME mLatinIme;
+
+    public DictionaryDumpBroadcastReceiver(final LatinIME latinIme) {
+        mLatinIme = latinIme;
+    }
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        final String action = intent.getAction();
+        if (action.equals(DICTIONARY_DUMP_INTENT_ACTION)) {
+            final String dictName = intent.getStringExtra(DICTIONARY_NAME_KEY);
+            if (dictName == null) {
+                Log.e(TAG, "Received dictionary dump intent action " +
+                      "but the dictionary name is not set.");
+                return;
+            }
+            mLatinIme.dumpDictionaryForDebug(dictName);
+        }
+    }
+}
diff --git a/java/src/com/android/inputmethod/latin/DictionaryFacilitatorForSuggest.java b/java/src/com/android/inputmethod/latin/DictionaryFacilitatorForSuggest.java
index 8b02984..e68c6b7 100644
--- a/java/src/com/android/inputmethod/latin/DictionaryFacilitatorForSuggest.java
+++ b/java/src/com/android/inputmethod/latin/DictionaryFacilitatorForSuggest.java
@@ -534,4 +534,25 @@
         mPersonalizationDictionary.addMultipleDictionaryEntriesToDictionary(languageModelParams,
                 callback);
     }
+
+    public void dumpDictionaryForDebug(final String dictName) {
+        final ExpandableBinaryDictionary dictToDump;
+        if (dictName.equals(Dictionary.TYPE_CONTACTS)) {
+            dictToDump = mContactsDictionary;
+        } else if (dictName.equals(Dictionary.TYPE_USER)) {
+            dictToDump = mUserDictionary;
+        } else if (dictName.equals(Dictionary.TYPE_USER_HISTORY)) {
+            dictToDump = mUserHistoryDictionary;
+        } else if (dictName.equals(Dictionary.TYPE_PERSONALIZATION)) {
+            dictToDump = mPersonalizationDictionary;
+        } else {
+            dictToDump = null;
+        }
+        if (dictToDump == null) {
+            Log.e(TAG, "Cannot dump " + dictName + ". "
+                    + "The dictionary is not being used for suggestion or cannot be dumped.");
+            return;
+        }
+        dictToDump.dumpAllWordsForDebug();
+    }
 }
diff --git a/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java b/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
index 4dee84a..f0dc772 100644
--- a/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
@@ -21,6 +21,7 @@
 
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.keyboard.ProximityInfo;
+import com.android.inputmethod.latin.makedict.DictionaryHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec;
 import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
 import com.android.inputmethod.latin.utils.AsyncResultHolder;
@@ -28,6 +29,7 @@
 import com.android.inputmethod.latin.utils.FileUtils;
 import com.android.inputmethod.latin.utils.LanguageModelParam;
 import com.android.inputmethod.latin.utils.PrioritizedSerialExecutor;
+import com.android.inputmethod.latin.utils.WordProperty;
 
 import java.io.File;
 import java.util.ArrayList;
@@ -267,9 +269,9 @@
 
     protected Map<String, String> getHeaderAttributeMap() {
         HashMap<String, String> attributeMap = new HashMap<String, String>();
-        attributeMap.put(FormatSpec.FileHeader.DICTIONARY_ID_KEY, mDictName);
-        attributeMap.put(FormatSpec.FileHeader.DICTIONARY_LOCALE_KEY, mLocale.toString());
-        attributeMap.put(FormatSpec.FileHeader.DICTIONARY_VERSION_KEY,
+        attributeMap.put(DictionaryHeader.DICTIONARY_ID_KEY, mDictName);
+        attributeMap.put(DictionaryHeader.DICTIONARY_LOCALE_KEY, mLocale.toString());
+        attributeMap.put(DictionaryHeader.DICTIONARY_VERSION_KEY,
                 String.valueOf(TimeUnit.MILLISECONDS.toSeconds(System.currentTimeMillis())));
         return attributeMap;
     }
@@ -778,16 +780,24 @@
     }
 
     @UsedForTesting
-    protected void runAfterGcForDebug(final Runnable r) {
-        getExecutor(mDictName).executePrioritized(new Runnable() {
+    public void dumpAllWordsForDebug() {
+        reloadDictionaryIfRequired();
+        getExecutor(mDictName).execute(new Runnable() {
             @Override
             public void run() {
-                try {
-                    mBinaryDictionary.flushWithGC();
-                    r.run();
-                } finally {
-                    mDictNameDictionaryUpdateController.mProcessingLargeTask.set(false);
-                }
+                Log.d(TAG, "dictionary=" + mDictName);
+                int token = 0;
+                do {
+                    final BinaryDictionary.GetNextWordPropertyResult result =
+                            mBinaryDictionary.getNextWordProperty(token);
+                    final WordProperty wordProperty = result.mWordProperty;
+                    if (wordProperty == null) {
+                        Log.d(TAG, " dictionary is empty.");
+                        break;
+                    }
+                    Log.d(TAG, wordProperty.toString());
+                    token = result.mNextToken;
+                } while (token != 0);
             }
         });
     }
diff --git a/java/src/com/android/inputmethod/latin/InputPointers.java b/java/src/com/android/inputmethod/latin/InputPointers.java
index c3bcf37..47bc6b0 100644
--- a/java/src/com/android/inputmethod/latin/InputPointers.java
+++ b/java/src/com/android/inputmethod/latin/InputPointers.java
@@ -17,6 +17,7 @@
 package com.android.inputmethod.latin;
 
 import android.util.Log;
+import android.util.SparseIntArray;
 
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.utils.ResizableIntArray;
@@ -160,15 +161,21 @@
 
     private boolean isValidTimeStamps() {
         final int[] times = mTimes.getPrimitiveArray();
+        final int[] pointerIds = mPointerIds.getPrimitiveArray();
+        final SparseIntArray lastTimeOfPointers = new SparseIntArray();
         final int size = getPointerSize();
-        for (int i = 1; i < size; ++i) {
-            if (times[i] < times[i - 1]) {
+        for (int i = 0; i < size; ++i) {
+            final int pointerId = pointerIds[i];
+            final int time = times[i];
+            final int lastTime = lastTimeOfPointers.get(pointerId, time);
+            if (time < lastTime) {
                 // dump
                 for (int j = 0; j < size; ++j) {
                     Log.d(TAG, "--- (" + j + ") " + times[j]);
                 }
                 return false;
             }
+            lastTimeOfPointers.put(pointerId, time);
         }
         return true;
     }
diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index 6517ef2..2e163c4 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -133,6 +133,9 @@
     private BroadcastReceiver mDictionaryPackInstallReceiver =
             new DictionaryPackInstallBroadcastReceiver(this);
 
+    private BroadcastReceiver mDictionaryDumpBroadcastReceiver =
+            new DictionaryDumpBroadcastReceiver(this);
+
     private AlertDialog mOptionsDialog;
 
     private final boolean mIsHardwareAcceleratedDrawingEnabled;
@@ -487,6 +490,10 @@
         newDictFilter.addAction(DictionaryPackConstants.NEW_DICTIONARY_INTENT_ACTION);
         registerReceiver(mDictionaryPackInstallReceiver, newDictFilter);
 
+        final IntentFilter dictDumpFilter = new IntentFilter();
+        dictDumpFilter.addAction(DictionaryDumpBroadcastReceiver.DICTIONARY_DUMP_INTENT_ACTION);
+        registerReceiver(mDictionaryDumpBroadcastReceiver, dictDumpFilter);
+
         DictionaryDecayBroadcastReciever.setUpIntervalAlarmForDictionaryDecaying(this);
     }
 
@@ -1758,6 +1765,13 @@
         resetSuggest(new Suggest(locale, dictionaryFacilitator));
     }
 
+    public void dumpDictionaryForDebug(final String dictName) {
+        if (mInputLogic.mSuggest == null) {
+            initSuggest();
+        }
+        mInputLogic.mSuggest.mDictionaryFacilitator.dumpDictionaryForDebug(dictName);
+    }
+
     public void debugDumpStateAndCrashWithException(final String context) {
         final SettingsValues settingsValues = mSettings.getCurrent();
         final StringBuilder s = new StringBuilder(settingsValues.toString());
diff --git a/java/src/com/android/inputmethod/latin/debug/ExternalDictionaryGetterForDebug.java b/java/src/com/android/inputmethod/latin/debug/ExternalDictionaryGetterForDebug.java
index 028f78a..800f565 100644
--- a/java/src/com/android/inputmethod/latin/debug/ExternalDictionaryGetterForDebug.java
+++ b/java/src/com/android/inputmethod/latin/debug/ExternalDictionaryGetterForDebug.java
@@ -26,7 +26,7 @@
 import com.android.inputmethod.latin.BinaryDictionaryFileDumper;
 import com.android.inputmethod.latin.BinaryDictionaryGetter;
 import com.android.inputmethod.latin.R;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
+import com.android.inputmethod.latin.makedict.DictionaryHeader;
 import com.android.inputmethod.latin.utils.CollectionUtils;
 import com.android.inputmethod.latin.utils.DictionaryInfoUtils;
 import com.android.inputmethod.latin.utils.LocaleUtils;
@@ -51,7 +51,7 @@
         final File[] files = new File(SOURCE_FOLDER).listFiles();
         final ArrayList<String> eligibleList = CollectionUtils.newArrayList();
         for (File f : files) {
-            final FileHeader header = DictionaryInfoUtils.getDictionaryFileHeaderOrNull(f);
+            final DictionaryHeader header = DictionaryInfoUtils.getDictionaryFileHeaderOrNull(f);
             if (null == header) continue;
             eligibleList.add(f.getName());
         }
@@ -99,7 +99,7 @@
     public static void askInstallFile(final Context context, final String dirPath,
             final String fileName, final Runnable completeRunnable) {
         final File file = new File(dirPath, fileName.toString());
-        final FileHeader header = DictionaryInfoUtils.getDictionaryFileHeaderOrNull(file);
+        final DictionaryHeader header = DictionaryInfoUtils.getDictionaryFileHeaderOrNull(file);
         final StringBuilder message = new StringBuilder();
         final String locale = header.getLocaleString();
         for (String key : header.mDictionaryOptions.mAttributes.keySet()) {
@@ -143,7 +143,7 @@
     }
 
     private static void installFile(final Context context, final File file,
-            final FileHeader header) {
+            final DictionaryHeader header) {
         BufferedOutputStream outputStream = null;
         File tempFile = null;
         try {
diff --git a/java/src/com/android/inputmethod/latin/makedict/AbstractDictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/AbstractDictDecoder.java
index 1a91181..5c7c4b8 100644
--- a/java/src/com/android/inputmethod/latin/makedict/AbstractDictDecoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/AbstractDictDecoder.java
@@ -19,7 +19,6 @@
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
 
@@ -36,7 +35,7 @@
     private static final int ERROR_CANNOT_READ = 1;
     private static final int ERROR_WRONG_FORMAT = 2;
 
-    protected FileHeader readHeader(final DictBuffer headerBuffer)
+    protected DictionaryHeader readHeader(final DictBuffer headerBuffer)
             throws IOException, UnsupportedFormatException {
         if (headerBuffer == null) {
             openDictBuffer();
@@ -57,10 +56,10 @@
         final HashMap<String, String> attributes = HeaderReader.readAttributes(headerBuffer,
                 headerSize);
 
-        final FileHeader header = new FileHeader(headerSize,
+        final DictionaryHeader header = new DictionaryHeader(headerSize,
                 new FusionDictionary.DictionaryOptions(attributes),
-                new FormatOptions(version, FileHeader.ATTRIBUTE_VALUE_TRUE.equals(
-                        attributes.get(FileHeader.HAS_HISTORICAL_INFO_KEY))));
+                new FormatOptions(version, DictionaryHeader.ATTRIBUTE_VALUE_TRUE.equals(
+                        attributes.get(DictionaryHeader.HAS_HISTORICAL_INFO_KEY))));
         return header;
     }
 
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java
index 3174715..3691845 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java
@@ -17,7 +17,6 @@
 package com.android.inputmethod.latin.makedict;
 
 import com.android.inputmethod.annotations.UsedForTesting;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
@@ -598,7 +597,7 @@
     /* package */ static FusionDictionary readDictionaryBinary(final DictDecoder dictDecoder,
             final FusionDictionary dict) throws IOException, UnsupportedFormatException {
         // Read header
-        final FileHeader fileHeader = dictDecoder.readHeader();
+        final DictionaryHeader fileHeader = dictDecoder.readHeader();
 
         Map<Integer, PtNodeArray> reverseNodeArrayMapping = new TreeMap<Integer, PtNodeArray>();
         Map<Integer, PtNode> reversePtNodeMapping = new TreeMap<Integer, PtNode>();
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
index 0dc50d1..dea9f2e 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
@@ -20,7 +20,6 @@
 import com.android.inputmethod.latin.Constants;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.utils.ByteArrayDictBuffer;
@@ -151,7 +150,7 @@
             final Map<Integer, ArrayList<PendingAttribute>> bigrams) throws IOException,
             UnsupportedFormatException {
         // Read header
-        final FileHeader header = dictDecoder.readHeader();
+        final DictionaryHeader header = dictDecoder.readHeader();
         readUnigramsAndBigramsBinaryInner(dictDecoder, header.mBodyOffset, words,
                 frequencies, bigrams, header.mFormatOptions);
     }
@@ -172,7 +171,7 @@
         if (word == null) return FormatSpec.NOT_VALID_WORD;
         dictDecoder.setPosition(0);
 
-        final FileHeader header = dictDecoder.readHeader();
+        final DictionaryHeader header = dictDecoder.readHeader();
         int wordPos = 0;
         final int wordLen = word.codePointCount(0, word.length());
         for (int depth = 0; depth < Constants.DICTIONARY_MAX_WORD_LENGTH; ++depth) {
@@ -311,7 +310,7 @@
      * @param length The length of the data file.
      * @return the header of the specified dictionary file.
      */
-    private static FileHeader getDictionaryFileHeader(
+    private static DictionaryHeader getDictionaryFileHeader(
             final File file, final long offset, final long length)
             throws FileNotFoundException, IOException, UnsupportedFormatException {
         final byte[] buffer = new byte[HEADER_READING_BUFFER_SIZE];
@@ -337,10 +336,10 @@
         return dictDecoder.readHeader();
     }
 
-    public static FileHeader getDictionaryFileHeaderOrNull(final File file, final long offset,
+    public static DictionaryHeader getDictionaryFileHeaderOrNull(final File file, final long offset,
             final long length) {
         try {
-            final FileHeader header = getDictionaryFileHeader(file, offset, length);
+            final DictionaryHeader header = getDictionaryFileHeader(file, offset, length);
             return header;
         } catch (UnsupportedFormatException e) {
             return null;
diff --git a/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java
index b4838f0..bba1d43 100644
--- a/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java
@@ -18,7 +18,6 @@
 
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.utils.ByteArrayDictBuffer;
 
@@ -41,7 +40,7 @@
     /**
      * Reads and returns the file header.
      */
-    public FileHeader readHeader() throws IOException, UnsupportedFormatException;
+    public DictionaryHeader readHeader() throws IOException, UnsupportedFormatException;
 
     /**
      * Reads PtNode from ptNodePos.
diff --git a/java/src/com/android/inputmethod/latin/makedict/DictionaryHeader.java b/java/src/com/android/inputmethod/latin/makedict/DictionaryHeader.java
new file mode 100644
index 0000000..b99e281
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/makedict/DictionaryHeader.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 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 com.android.inputmethod.latin.makedict;
+
+import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
+import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions;
+
+/**
+ * Class representing dictionary header.
+ */
+public final class DictionaryHeader {
+    public final int mBodyOffset;
+    public final DictionaryOptions mDictionaryOptions;
+    public final FormatOptions mFormatOptions;
+
+    // Note that these are corresponding definitions in native code in latinime::HeaderPolicy
+    // and latinime::HeaderReadWriteUtils.
+    // TODO: Standardize the key names and bump up the format version, taking care not to
+    // break format version 2 dictionaries.
+    public static final String DICTIONARY_VERSION_KEY = "version";
+    public static final String DICTIONARY_LOCALE_KEY = "locale";
+    public static final String DICTIONARY_ID_KEY = "dictionary";
+    public static final String DICTIONARY_DESCRIPTION_KEY = "description";
+    public static final String DICTIONARY_DATE_KEY = "date";
+    public static final String HAS_HISTORICAL_INFO_KEY = "HAS_HISTORICAL_INFO";
+    public static final String USES_FORGETTING_CURVE_KEY = "USES_FORGETTING_CURVE";
+    public static final String ATTRIBUTE_VALUE_TRUE = "1";
+
+    public DictionaryHeader(final int headerSize, final DictionaryOptions dictionaryOptions,
+            final FormatOptions formatOptions) throws UnsupportedFormatException {
+        mDictionaryOptions = dictionaryOptions;
+        mFormatOptions = formatOptions;
+        mBodyOffset = formatOptions.mVersion < FormatSpec.VERSION4 ? headerSize : 0;
+        if (null == getLocaleString()) {
+            throw new UnsupportedFormatException("Cannot create a FileHeader without a locale");
+        }
+        if (null == getVersion()) {
+            throw new UnsupportedFormatException(
+                    "Cannot create a FileHeader without a version");
+        }
+        if (null == getId()) {
+            throw new UnsupportedFormatException("Cannot create a FileHeader without an ID");
+        }
+    }
+
+    // Helper method to get the locale as a String
+    public String getLocaleString() {
+        return mDictionaryOptions.mAttributes.get(DICTIONARY_LOCALE_KEY);
+    }
+
+    // Helper method to get the version String
+    public String getVersion() {
+        return mDictionaryOptions.mAttributes.get(DICTIONARY_VERSION_KEY);
+    }
+
+    // Helper method to get the dictionary ID as a String
+    public String getId() {
+        return mDictionaryOptions.mAttributes.get(DICTIONARY_ID_KEY);
+    }
+
+    // Helper method to get the description
+    public String getDescription() {
+        // TODO: Right now each dictionary file comes with a description in its own language.
+        // It will display as is no matter the device's locale. It should be internationalized.
+        return mDictionaryOptions.mAttributes.get(DICTIONARY_DESCRIPTION_KEY);
+    }
+}
\ No newline at end of file
diff --git a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
index 74e3059..5a38073 100644
--- a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
+++ b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
@@ -19,7 +19,6 @@
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.Constants;
 import com.android.inputmethod.latin.makedict.DictDecoder.DictionaryBufferFactory;
-import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions;
 
 import java.io.File;
 
@@ -330,66 +329,6 @@
     }
 
     /**
-     * Class representing file header.
-     */
-    public static final class FileHeader {
-        public final int mBodyOffset;
-        public final DictionaryOptions mDictionaryOptions;
-        public final FormatOptions mFormatOptions;
-
-        // Note that these are corresponding definitions in native code in latinime::HeaderPolicy
-        // and latinime::HeaderReadWriteUtils.
-        // TODO: Standardize the key names and bump up the format version, taking care not to
-        // break format version 2 dictionaries.
-        public static final String DICTIONARY_VERSION_KEY = "version";
-        public static final String DICTIONARY_LOCALE_KEY = "locale";
-        public static final String DICTIONARY_ID_KEY = "dictionary";
-        public static final String DICTIONARY_DESCRIPTION_KEY = "description";
-        public static final String DICTIONARY_DATE_KEY = "date";
-        public static final String HAS_HISTORICAL_INFO_KEY = "HAS_HISTORICAL_INFO";
-        public static final String USES_FORGETTING_CURVE_KEY = "USES_FORGETTING_CURVE";
-        public static final String ATTRIBUTE_VALUE_TRUE = "1";
-        public FileHeader(final int headerSize, final DictionaryOptions dictionaryOptions,
-                final FormatOptions formatOptions) throws UnsupportedFormatException {
-            mDictionaryOptions = dictionaryOptions;
-            mFormatOptions = formatOptions;
-            mBodyOffset = formatOptions.mVersion < VERSION4 ? headerSize : 0;
-            if (null == getLocaleString()) {
-                throw new UnsupportedFormatException("Cannot create a FileHeader without a locale");
-            }
-            if (null == getVersion()) {
-                throw new UnsupportedFormatException(
-                        "Cannot create a FileHeader without a version");
-            }
-            if (null == getId()) {
-                throw new UnsupportedFormatException("Cannot create a FileHeader without an ID");
-            }
-        }
-
-        // Helper method to get the locale as a String
-        public String getLocaleString() {
-            return mDictionaryOptions.mAttributes.get(FileHeader.DICTIONARY_LOCALE_KEY);
-        }
-
-        // Helper method to get the version String
-        public String getVersion() {
-            return mDictionaryOptions.mAttributes.get(FileHeader.DICTIONARY_VERSION_KEY);
-        }
-
-        // Helper method to get the dictionary ID as a String
-        public String getId() {
-            return mDictionaryOptions.mAttributes.get(FileHeader.DICTIONARY_ID_KEY);
-        }
-
-        // Helper method to get the description
-        public String getDescription() {
-            // TODO: Right now each dictionary file comes with a description in its own language.
-            // It will display as is no matter the device's locale. It should be internationalized.
-            return mDictionaryOptions.mAttributes.get(FileHeader.DICTIONARY_DESCRIPTION_KEY);
-        }
-    }
-
-    /**
      * Returns new dictionary decoder.
      *
      * @param dictFile the dictionary file.
diff --git a/java/src/com/android/inputmethod/latin/makedict/Ver2DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/Ver2DictDecoder.java
index ea0a2c6..d35f780 100644
--- a/java/src/com/android/inputmethod/latin/makedict/Ver2DictDecoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/Ver2DictDecoder.java
@@ -19,7 +19,6 @@
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
@@ -90,11 +89,11 @@
     }
 
     @Override
-    public FileHeader readHeader() throws IOException, UnsupportedFormatException {
+    public DictionaryHeader readHeader() throws IOException, UnsupportedFormatException {
         if (mDictBuffer == null) {
             openDictBuffer();
         }
-        final FileHeader header = super.readHeader(mDictBuffer);
+        final DictionaryHeader header = super.readHeader(mDictBuffer);
         final int version = header.mFormatOptions.mVersion;
         if (!(version >= 2 && version <= 3)) {
           throw new UnsupportedFormatException("File header has a wrong version : " + version);
diff --git a/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java
index e459e48..9ddaaf7 100644
--- a/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java
@@ -19,7 +19,6 @@
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
@@ -166,12 +165,12 @@
     }
 
     @Override
-    public FileHeader readHeader() throws IOException, UnsupportedFormatException {
+    public DictionaryHeader readHeader() throws IOException, UnsupportedFormatException {
         if (mHeaderBuffer == null) {
             openDictBuffer();
         }
         mHeaderBuffer.position(0);
-        final FileHeader header = super.readHeader(mHeaderBuffer);
+        final DictionaryHeader header = super.readHeader(mHeaderBuffer);
         final int version = header.mFormatOptions.mVersion;
         if (version != FormatSpec.VERSION4) {
             throw new UnsupportedFormatException("File header has a wrong version : " + version);
diff --git a/java/src/com/android/inputmethod/latin/makedict/Ver4DictEncoder.java b/java/src/com/android/inputmethod/latin/makedict/Ver4DictEncoder.java
index b12f79b..160775d 100644
--- a/java/src/com/android/inputmethod/latin/makedict/Ver4DictEncoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/Ver4DictEncoder.java
@@ -62,7 +62,7 @@
         final BinaryDictionary binaryDict = new BinaryDictionary(mDictPlacedDir.getAbsolutePath(),
                 0l, mDictPlacedDir.length(), true /* useFullEditDistance */,
                 LocaleUtils.constructLocaleFromString(dict.mOptions.mAttributes.get(
-                        FormatSpec.FileHeader.DICTIONARY_LOCALE_KEY)),
+                        DictionaryHeader.DICTIONARY_LOCALE_KEY)),
                 Dictionary.TYPE_USER /* Dictionary type. Does not matter for us */,
                 true /* isUpdatable */);
         if (!binaryDict.isValidDictionary()) {
diff --git a/java/src/com/android/inputmethod/latin/personalization/DecayingExpandableBinaryDictionaryBase.java b/java/src/com/android/inputmethod/latin/personalization/DecayingExpandableBinaryDictionaryBase.java
index d636a25..6a7a336 100644
--- a/java/src/com/android/inputmethod/latin/personalization/DecayingExpandableBinaryDictionaryBase.java
+++ b/java/src/com/android/inputmethod/latin/personalization/DecayingExpandableBinaryDictionaryBase.java
@@ -17,21 +17,15 @@
 package com.android.inputmethod.latin.personalization;
 
 import android.content.Context;
-import android.util.Log;
 
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.Constants;
 import com.android.inputmethod.latin.Dictionary;
 import com.android.inputmethod.latin.ExpandableBinaryDictionary;
-import com.android.inputmethod.latin.makedict.DictDecoder;
-import com.android.inputmethod.latin.makedict.FormatSpec;
-import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
+import com.android.inputmethod.latin.makedict.DictionaryHeader;
 import com.android.inputmethod.latin.utils.LanguageModelParam;
-import com.android.inputmethod.latin.utils.UserHistoryDictIOUtils;
-import com.android.inputmethod.latin.utils.UserHistoryDictIOUtils.OnAddWordListener;
 
 import java.io.File;
-import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Locale;
@@ -44,7 +38,6 @@
  */
 public abstract class DecayingExpandableBinaryDictionaryBase extends ExpandableBinaryDictionary {
     private static final String TAG = DecayingExpandableBinaryDictionaryBase.class.getSimpleName();
-    public static final boolean DBG_SAVE_RESTORE = false;
     private static final boolean DBG_DUMP_ON_CLOSE = false;
 
     /** Any pair being typed or picked */
@@ -53,8 +46,6 @@
     public static final int FREQUENCY_FOR_WORDS_IN_DICTS = FREQUENCY_FOR_TYPED;
     public static final int FREQUENCY_FOR_WORDS_NOT_IN_DICTS = Dictionary.NOT_A_PROBABILITY;
 
-    public static final int REQUIRED_BINARY_DICTIONARY_VERSION = FormatSpec.VERSION4;
-
     /** The locale for this dictionary. */
     public final Locale mLocale;
 
@@ -95,13 +86,13 @@
     @Override
     protected Map<String, String> getHeaderAttributeMap() {
         HashMap<String, String> attributeMap = new HashMap<String, String>();
-        attributeMap.put(FormatSpec.FileHeader.USES_FORGETTING_CURVE_KEY,
-                FormatSpec.FileHeader.ATTRIBUTE_VALUE_TRUE);
-        attributeMap.put(FormatSpec.FileHeader.HAS_HISTORICAL_INFO_KEY,
-                FormatSpec.FileHeader.ATTRIBUTE_VALUE_TRUE);
-        attributeMap.put(FormatSpec.FileHeader.DICTIONARY_ID_KEY, mDictName);
-        attributeMap.put(FormatSpec.FileHeader.DICTIONARY_LOCALE_KEY, mLocale.toString());
-        attributeMap.put(FormatSpec.FileHeader.DICTIONARY_VERSION_KEY,
+        attributeMap.put(DictionaryHeader.USES_FORGETTING_CURVE_KEY,
+                DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
+        attributeMap.put(DictionaryHeader.HAS_HISTORICAL_INFO_KEY,
+                DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
+        attributeMap.put(DictionaryHeader.DICTIONARY_ID_KEY, mDictName);
+        attributeMap.put(DictionaryHeader.DICTIONARY_LOCALE_KEY, mLocale.toString());
+        attributeMap.put(DictionaryHeader.DICTIONARY_VERSION_KEY,
                 String.valueOf(TimeUnit.MILLISECONDS.toSeconds(System.currentTimeMillis())));
         return attributeMap;
     }
@@ -161,57 +152,6 @@
     }
 
     @UsedForTesting
-    public void dumpAllWordsForDebug() {
-        runAfterGcForDebug(new Runnable() {
-            @Override
-            public void run() {
-                dumpAllWordsForDebugLocked();
-            }
-        });
-    }
-
-    private void dumpAllWordsForDebugLocked() {
-        Log.d(TAG, "dumpAllWordsForDebug started.");
-        final OnAddWordListener listener = new OnAddWordListener() {
-            @Override
-            public void setUnigram(final String word, final String shortcutTarget,
-                    final int frequency, final int shortcutFreq) {
-                Log.d(TAG, "load unigram: " + word + "," + frequency);
-            }
-
-            @Override
-            public void setBigram(final String word0, final String word1, final int frequency) {
-                if (word0.length() < Constants.DICTIONARY_MAX_WORD_LENGTH
-                        && word1.length() < Constants.DICTIONARY_MAX_WORD_LENGTH) {
-                    Log.d(TAG, "load bigram: " + word0 + "," + word1 + "," + frequency);
-                } else {
-                    Log.d(TAG, "Skip inserting a too long bigram: " + word0 + "," + word1 + ","
-                            + frequency);
-                }
-            }
-        };
-
-        // Load the dictionary from binary file
-        final File dictFile = new File(mContext.getFilesDir(), mDictName);
-        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(dictFile,
-                DictDecoder.USE_BYTEARRAY);
-        if (dictDecoder == null) {
-            // This is an expected condition: we don't have a user history dictionary for this
-            // language yet. It will be created sometime later.
-            return;
-        }
-
-        try {
-            dictDecoder.openDictBuffer();
-            UserHistoryDictIOUtils.readDictionaryBinary(dictDecoder, listener);
-        } catch (IOException e) {
-            Log.d(TAG, "IOException on opening a bytebuffer", e);
-        } catch (UnsupportedFormatException e) {
-            Log.d(TAG, "Unsupported format, can't read the dictionary", e);
-        }
-    }
-
-    @UsedForTesting
     public void clearAndFlushDictionary() {
         // Clear the node structure on memory
         clear();
diff --git a/java/src/com/android/inputmethod/latin/personalization/UserHistoryDictionaryBigramList.java b/java/src/com/android/inputmethod/latin/personalization/UserHistoryDictionaryBigramList.java
deleted file mode 100644
index 55a90ee..0000000
--- a/java/src/com/android/inputmethod/latin/personalization/UserHistoryDictionaryBigramList.java
+++ /dev/null
@@ -1,128 +0,0 @@
-/*
- * 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.latin.personalization;
-
-import android.util.Log;
-
-import com.android.inputmethod.annotations.UsedForTesting;
-import com.android.inputmethod.latin.utils.CollectionUtils;
-
-import java.util.HashMap;
-import java.util.Set;
-
-/**
- * A store of bigrams which will be updated when the user history dictionary is closed
- * All bigrams including stale ones in SQL DB should be stored in this class to avoid adding stale
- * bigrams when we write to the SQL DB.
- */
-@UsedForTesting
-public final class UserHistoryDictionaryBigramList {
-    public static final byte FORGETTING_CURVE_INITIAL_VALUE = 0;
-    private static final String TAG = UserHistoryDictionaryBigramList.class.getSimpleName();
-    private static final HashMap<String, Byte> EMPTY_BIGRAM_MAP = CollectionUtils.newHashMap();
-    private final HashMap<String, HashMap<String, Byte>> mBigramMap = CollectionUtils.newHashMap();
-    private int mSize = 0;
-
-    public void evictAll() {
-        mSize = 0;
-        mBigramMap.clear();
-    }
-
-    /**
-     * Called when the user typed a word.
-     */
-    @UsedForTesting
-    public void addBigram(String word1, String word2) {
-        addBigram(word1, word2, FORGETTING_CURVE_INITIAL_VALUE);
-    }
-
-    /**
-     * Called when loaded from the SQL DB.
-     */
-    public void addBigram(String word1, String word2, byte fcValue) {
-        if (DecayingExpandableBinaryDictionaryBase.DBG_SAVE_RESTORE) {
-            Log.d(TAG, "--- add bigram: " + word1 + ", " + word2 + ", " + fcValue);
-        }
-        final HashMap<String, Byte> map;
-        if (mBigramMap.containsKey(word1)) {
-            map = mBigramMap.get(word1);
-        } else {
-            map = CollectionUtils.newHashMap();
-            mBigramMap.put(word1, map);
-        }
-        if (!map.containsKey(word2)) {
-            ++mSize;
-            map.put(word2, fcValue);
-        }
-    }
-
-    /**
-     * Called when inserted to the SQL DB.
-     */
-    public void updateBigram(String word1, String word2, byte fcValue) {
-        if (DecayingExpandableBinaryDictionaryBase.DBG_SAVE_RESTORE) {
-            Log.d(TAG, "--- update bigram: " + word1 + ", " + word2 + ", " + fcValue);
-        }
-        final HashMap<String, Byte> map;
-        if (mBigramMap.containsKey(word1)) {
-            map = mBigramMap.get(word1);
-        } else {
-            return;
-        }
-        if (!map.containsKey(word2)) {
-            return;
-        }
-        map.put(word2, fcValue);
-    }
-
-    public int size() {
-        return mSize;
-    }
-
-    public boolean isEmpty() {
-        return mBigramMap.isEmpty();
-    }
-
-    public boolean containsKey(String word) {
-        return mBigramMap.containsKey(word);
-    }
-
-    public Set<String> keySet() {
-        return mBigramMap.keySet();
-    }
-
-    public HashMap<String, Byte> getBigrams(String word1) {
-        if (mBigramMap.containsKey(word1)) return mBigramMap.get(word1);
-        // TODO: lower case according to locale
-        final String lowerWord1 = word1.toLowerCase();
-        if (mBigramMap.containsKey(lowerWord1)) return mBigramMap.get(lowerWord1);
-        return EMPTY_BIGRAM_MAP;
-    }
-
-    public boolean removeBigram(String word1, String word2) {
-        final HashMap<String, Byte> set = getBigrams(word1);
-        if (set.isEmpty()) {
-            return false;
-        }
-        if (set.containsKey(word2)) {
-            set.remove(word2);
-            --mSize;
-            return true;
-        }
-        return false;
-    }
-}
diff --git a/java/src/com/android/inputmethod/latin/settings/DebugSettings.java b/java/src/com/android/inputmethod/latin/settings/DebugSettings.java
index 29bbed8..fa5ae92 100644
--- a/java/src/com/android/inputmethod/latin/settings/DebugSettings.java
+++ b/java/src/com/android/inputmethod/latin/settings/DebugSettings.java
@@ -16,15 +16,18 @@
 
 package com.android.inputmethod.latin.settings;
 
+import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.os.Process;
 import android.preference.CheckBoxPreference;
 import android.preference.Preference;
+import android.preference.Preference.OnPreferenceClickListener;
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceScreen;
 
-import com.android.inputmethod.keyboard.KeyboardSwitcher;
+import com.android.inputmethod.latin.Dictionary;
+import com.android.inputmethod.latin.DictionaryDumpBroadcastReceiver;
 import com.android.inputmethod.latin.LatinImeLogger;
 import com.android.inputmethod.latin.R;
 import com.android.inputmethod.latin.debug.ExternalDictionaryGetterForDebug;
@@ -40,6 +43,11 @@
     public static final String PREF_USE_ONLY_PERSONALIZATION_DICTIONARY_FOR_DEBUG =
             "use_only_personalization_dictionary_for_debug";
     private static final String PREF_READ_EXTERNAL_DICTIONARY = "read_external_dictionary";
+    private static final String PREF_DUMP_CONTACTS_DICT = "dump_contacts_dict";
+    private static final String PREF_DUMP_USER_DICT = "dump_user_dict";
+    private static final String PREF_DUMP_USER_HISTORY_DICT = "dump_user_history_dict";
+    private static final String PREF_DUMP_PERSONALIZATION_DICT = "dump_personalization_dict";
+
     private static final boolean SHOW_STATISTICS_LOGGING = false;
 
     private boolean mServiceNeedsRestart = false;
@@ -83,11 +91,53 @@
                     });
         }
 
+        final OnPreferenceClickListener dictDumpPrefClickListener =
+                new DictDumpPrefClickListener(this);
+        findPreference(PREF_DUMP_CONTACTS_DICT).setOnPreferenceClickListener(
+                dictDumpPrefClickListener);
+        findPreference(PREF_DUMP_USER_DICT).setOnPreferenceClickListener(
+                dictDumpPrefClickListener);
+        findPreference(PREF_DUMP_USER_HISTORY_DICT).setOnPreferenceClickListener(
+                dictDumpPrefClickListener);
+        findPreference(PREF_DUMP_PERSONALIZATION_DICT).setOnPreferenceClickListener(
+                dictDumpPrefClickListener);
+
         mServiceNeedsRestart = false;
         mDebugMode = (CheckBoxPreference) findPreference(PREF_DEBUG_MODE);
         updateDebugMode();
     }
 
+    private static class DictDumpPrefClickListener implements OnPreferenceClickListener {
+        final PreferenceFragment mPreferenceFragment;
+
+        public DictDumpPrefClickListener(final PreferenceFragment preferenceFragment) {
+            mPreferenceFragment = preferenceFragment;
+        }
+
+        @Override
+        public boolean onPreferenceClick(final Preference arg0) {
+            final String dictName;
+            if (arg0.getKey().equals(PREF_DUMP_CONTACTS_DICT)) {
+                dictName = Dictionary.TYPE_CONTACTS;
+            } else if (arg0.getKey().equals(PREF_DUMP_USER_DICT)) {
+                dictName = Dictionary.TYPE_USER;
+            } else if (arg0.getKey().equals(PREF_DUMP_USER_HISTORY_DICT)) {
+                dictName = Dictionary.TYPE_USER_HISTORY;
+            } else if (arg0.getKey().equals(PREF_DUMP_PERSONALIZATION_DICT)) {
+                dictName = Dictionary.TYPE_PERSONALIZATION;
+            } else {
+                dictName = null;
+            }
+            if (dictName != null) {
+                final Intent intent =
+                        new Intent(DictionaryDumpBroadcastReceiver.DICTIONARY_DUMP_INTENT_ACTION);
+                intent.putExtra(DictionaryDumpBroadcastReceiver.DICTIONARY_NAME_KEY, dictName);
+                mPreferenceFragment.getActivity().sendBroadcast(intent);
+            }
+            return true;
+        }
+    }
+
     @Override
     public void onStop() {
         super.onStop();
diff --git a/java/src/com/android/inputmethod/latin/utils/DictionaryInfoUtils.java b/java/src/com/android/inputmethod/latin/utils/DictionaryInfoUtils.java
index 3067357..a155565 100644
--- a/java/src/com/android/inputmethod/latin/utils/DictionaryInfoUtils.java
+++ b/java/src/com/android/inputmethod/latin/utils/DictionaryInfoUtils.java
@@ -29,7 +29,7 @@
 import com.android.inputmethod.latin.Constants;
 import com.android.inputmethod.latin.R;
 import com.android.inputmethod.latin.makedict.BinaryDictIOUtils;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
+import com.android.inputmethod.latin.makedict.DictionaryHeader;
 import com.android.inputmethod.latin.settings.SpacingAndPunctuations;
 
 import java.io.File;
@@ -282,7 +282,7 @@
                 BinaryDictionaryGetter.ID_CATEGORY_SEPARATOR + locale.getLanguage().toString();
     }
 
-    public static FileHeader getDictionaryFileHeaderOrNull(final File file) {
+    public static DictionaryHeader getDictionaryFileHeaderOrNull(final File file) {
         return BinaryDictIOUtils.getDictionaryFileHeaderOrNull(file, 0, file.length());
     }
 
@@ -294,7 +294,7 @@
      */
     private static DictionaryInfo createDictionaryInfoFromFileAddress(
             final AssetFileAddress fileAddress) {
-        final FileHeader header = BinaryDictIOUtils.getDictionaryFileHeaderOrNull(
+        final DictionaryHeader header = BinaryDictIOUtils.getDictionaryFileHeaderOrNull(
                 new File(fileAddress.mFilename), fileAddress.mOffset, fileAddress.mLength);
         if (header == null) {
             return null;
diff --git a/java/src/com/android/inputmethod/latin/utils/StringUtils.java b/java/src/com/android/inputmethod/latin/utils/StringUtils.java
index c632a71..e7932b5 100644
--- a/java/src/com/android/inputmethod/latin/utils/StringUtils.java
+++ b/java/src/com/android/inputmethod/latin/utils/StringUtils.java
@@ -46,7 +46,7 @@
 
     public static String newSingleCodePointString(int codePoint) {
         if (Character.charCount(codePoint) == 1) {
-            // Optimization: avoid creating an temporary array for characters that are
+            // Optimization: avoid creating a temporary array for characters that are
             // represented by a single char value
             return String.valueOf((char) codePoint);
         }
@@ -205,6 +205,24 @@
         return codePoints;
     }
 
+    /**
+     * Construct a String from a code point array
+     *
+     * @param codePoints a code point array that is null terminated when its logical length is
+     * shorter than the array length.
+     * @return a string constructed from the code point array.
+     */
+    public static String getStringFromNullTerminatedCodePointArray(final int[] codePoints) {
+        int stringLength = codePoints.length;
+        for (int i = 0; i < codePoints.length; i++) {
+            if (codePoints[i] == 0) {
+                stringLength = i;
+                break;
+            }
+        }
+        return new String(codePoints, 0 /* offset */, stringLength);
+    }
+
     // This method assumes the text is not null. For the empty string, it returns CAPITALIZE_NONE.
     public static int getCapitalizationType(final String text) {
         // If the first char is not uppercase, then the word is either all lower case or
diff --git a/java/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtils.java b/java/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtils.java
deleted file mode 100644
index 7af03da..0000000
--- a/java/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtils.java
+++ /dev/null
@@ -1,181 +0,0 @@
-/*
- * 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.latin.utils;
-
-import android.util.Log;
-
-import com.android.inputmethod.annotations.UsedForTesting;
-import com.android.inputmethod.latin.makedict.BinaryDictIOUtils;
-import com.android.inputmethod.latin.makedict.DictDecoder;
-import com.android.inputmethod.latin.makedict.DictEncoder;
-import com.android.inputmethod.latin.makedict.FormatSpec;
-import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
-import com.android.inputmethod.latin.makedict.FusionDictionary;
-import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
-import com.android.inputmethod.latin.makedict.PendingAttribute;
-import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
-import com.android.inputmethod.latin.personalization.UserHistoryDictionaryBigramList;
-
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.Map.Entry;
-import java.util.TreeMap;
-import java.util.concurrent.TimeUnit;
-
-/**
- * Reads and writes Binary files for a UserHistoryDictionary.
- *
- * All the methods in this class are static.
- */
-public final class UserHistoryDictIOUtils {
-    private static final String TAG = UserHistoryDictIOUtils.class.getSimpleName();
-    private static final boolean DEBUG = false;
-
-    public interface OnAddWordListener {
-        /**
-         * Callback to be notified when a word is added to the dictionary.
-         * @param word The added word.
-         * @param shortcutTarget A shortcut target for this word, or null if none.
-         * @param frequency The frequency for this word.
-         * @param shortcutFreq The frequency of the shortcut (0~15, with 15 = whitelist).
-         *   Unspecified if shortcutTarget is null - do not rely on its value.
-         */
-        public void setUnigram(final String word, final String shortcutTarget, final int frequency,
-                final int shortcutFreq);
-        public void setBigram(final String word1, final String word2, final int frequency);
-    }
-
-    @UsedForTesting
-    public interface BigramDictionaryInterface {
-        public int getFrequency(final String word1, final String word2);
-    }
-
-    /**
-     * Writes dictionary to file.
-     */
-    @UsedForTesting
-    public static void writeDictionary(final DictEncoder dictEncoder,
-            final BigramDictionaryInterface dict, final UserHistoryDictionaryBigramList bigrams,
-            final FormatOptions formatOptions, final HashMap<String, String> options) {
-        final FusionDictionary fusionDict = constructFusionDictionary(dict, bigrams, options);
-        fusionDict.addOptionAttribute(FormatSpec.FileHeader.USES_FORGETTING_CURVE_KEY,
-            FormatSpec.FileHeader.ATTRIBUTE_VALUE_TRUE);
-        fusionDict.addOptionAttribute(FormatSpec.FileHeader.DICTIONARY_DATE_KEY,
-                String.valueOf(TimeUnit.MILLISECONDS.toSeconds(System.currentTimeMillis())));
-        try {
-            dictEncoder.writeDictionary(fusionDict, formatOptions);
-            Log.d(TAG, "end writing");
-        } catch (IOException e) {
-            Log.e(TAG, "IO exception while writing file", e);
-        } catch (UnsupportedFormatException e) {
-            Log.e(TAG, "Unsupported format", e);
-        }
-    }
-
-    /**
-     * Constructs a new FusionDictionary from BigramDictionaryInterface.
-     */
-    @UsedForTesting
-    static FusionDictionary constructFusionDictionary(final BigramDictionaryInterface dict,
-            final UserHistoryDictionaryBigramList bigrams, final HashMap<String, String> options) {
-        final FusionDictionary fusionDict = new FusionDictionary(new PtNodeArray(),
-                new FusionDictionary.DictionaryOptions(options));
-        int profTotal = 0;
-        for (final String word1 : bigrams.keySet()) {
-            final HashMap<String, Byte> word1Bigrams = bigrams.getBigrams(word1);
-            for (final String word2 : word1Bigrams.keySet()) {
-                final int freq = dict.getFrequency(word1, word2);
-                if (freq == -1) {
-                    // don't add this bigram.
-                    continue;
-                }
-                if (DEBUG) {
-                    if (word1 == null) {
-                        Log.d(TAG, "add unigram: " + word2 + "," + Integer.toString(freq));
-                    } else {
-                        Log.d(TAG, "add bigram: " + word1
-                                + "," + word2 + "," + Integer.toString(freq));
-                    }
-                    profTotal++;
-                }
-                if (word1 == null) { // unigram
-                    fusionDict.add(word2, freq, null, false /* isNotAWord */);
-                } else { // bigram
-                    if (FusionDictionary.findWordInTree(fusionDict.mRootNodeArray, word1) == null) {
-                        fusionDict.add(word1, 2, null, false /* isNotAWord */);
-                    }
-                    fusionDict.setBigram(word1, word2, freq);
-                }
-                bigrams.updateBigram(word1, word2, (byte)freq);
-            }
-        }
-        if (DEBUG) {
-            Log.d(TAG, "add " + profTotal + "words");
-        }
-        return fusionDict;
-    }
-
-    /**
-     * Reads dictionary from file.
-     */
-    public static void readDictionaryBinary(final DictDecoder dictDecoder,
-            final OnAddWordListener dict) {
-        final TreeMap<Integer, String> unigrams = CollectionUtils.newTreeMap();
-        final TreeMap<Integer, Integer> frequencies = CollectionUtils.newTreeMap();
-        final TreeMap<Integer, ArrayList<PendingAttribute>> bigrams = CollectionUtils.newTreeMap();
-        try {
-            dictDecoder.readUnigramsAndBigramsBinary(unigrams, frequencies, bigrams);
-        } catch (IOException e) {
-            Log.e(TAG, "IO exception while reading file", e);
-        } catch (UnsupportedFormatException e) {
-            Log.e(TAG, "Unsupported format", e);
-        } catch (ArrayIndexOutOfBoundsException e) {
-            Log.e(TAG, "ArrayIndexOutOfBoundsException while reading file", e);
-        }
-        addWordsFromWordMap(unigrams, frequencies, bigrams, dict);
-    }
-
-    /**
-     * Adds all unigrams and bigrams in maps to OnAddWordListener.
-     */
-    @UsedForTesting
-    static void addWordsFromWordMap(final TreeMap<Integer, String> unigrams,
-            final TreeMap<Integer, Integer> frequencies,
-            final TreeMap<Integer, ArrayList<PendingAttribute>> bigrams,
-            final OnAddWordListener to) {
-        for (Entry<Integer, String> entry : unigrams.entrySet()) {
-            final String word1 = entry.getValue();
-            final int unigramFrequency = frequencies.get(entry.getKey());
-            to.setUnigram(word1, null /* shortcutTarget */, unigramFrequency, 0 /* shortcutFreq */);
-            final ArrayList<PendingAttribute> attrList = bigrams.get(entry.getKey());
-            if (attrList != null) {
-                for (final PendingAttribute attr : attrList) {
-                    final String word2 = unigrams.get(attr.mAddress);
-                    if (word1 == null || word2 == null) {
-                        Log.e(TAG, "Invalid bigram pair detected: " + word1 + ", " + word2);
-                        continue;
-                    }
-                    to.setBigram(word1, word2,
-                            BinaryDictIOUtils.reconstructBigramFrequency(unigramFrequency,
-                                    attr.mFrequency));
-                }
-            }
-        }
-
-    }
-}
diff --git a/java/src/com/android/inputmethod/latin/utils/WordProperty.java b/java/src/com/android/inputmethod/latin/utils/WordProperty.java
index ba9b114..c6630eb 100644
--- a/java/src/com/android/inputmethod/latin/utils/WordProperty.java
+++ b/java/src/com/android/inputmethod/latin/utils/WordProperty.java
@@ -41,7 +41,7 @@
     // package.
     public static final class ProbabilityInfo {
         public final int mProbability;
-        // wTimestamp, mLevel and mCount are historical info. These values are depend on the
+        // mTimestamp, mLevel and mCount are historical info. These values are depend on the
         // implementation in native code; thus, we must not use them and have any assumptions about
         // them except for tests.
         public final int mTimestamp;
@@ -54,15 +54,11 @@
             mLevel = probabilityInfo[BinaryDictionary.FORMAT_WORD_PROPERTY_LEVEL_INDEX];
             mCount = probabilityInfo[BinaryDictionary.FORMAT_WORD_PROPERTY_COUNT_INDEX];
         }
-    }
 
-    private static int getCodePointCount(final int[] codePoints) {
-        for (int i = 0; i < codePoints.length; i++) {
-            if (codePoints[i] == 0) {
-                return i;
-            }
+        @Override
+        public String toString() {
+            return mTimestamp + ":" + mLevel + ":" + mCount;
         }
-        return codePoints.length;
     }
 
     // This represents invalid word when the probability is BinaryDictionary.NOT_A_PROBABILITY.
@@ -72,7 +68,7 @@
             final ArrayList<int[]> bigramTargets, final ArrayList<int[]> bigramProbabilityInfo,
             final ArrayList<int[]> shortcutTargets,
             final ArrayList<Integer> shortcutProbabilities) {
-        mCodePoints = new String(codePoints, 0 /* offset */, getCodePointCount(codePoints));
+        mCodePoints = StringUtils.getStringFromNullTerminatedCodePointArray(codePoints);
         mIsNotAWord = isNotAWord;
         mIsBlacklisted = isBlacklisted;
         mHasBigrams = hasBigram;
@@ -81,9 +77,8 @@
 
         final int bigramTargetCount = bigramTargets.size();
         for (int i = 0; i < bigramTargetCount; i++) {
-            final int[] bigramTargetCodePointArray = bigramTargets.get(i);
-            final String bigramTargetString = new String(bigramTargetCodePointArray,
-                    0 /* offset */, getCodePointCount(bigramTargetCodePointArray));
+            final String bigramTargetString =
+                    StringUtils.getStringFromNullTerminatedCodePointArray(bigramTargets.get(i));
             final ProbabilityInfo bigramProbability =
                     new ProbabilityInfo(bigramProbabilityInfo.get(i));
             mBigramTargets.add(
@@ -93,9 +88,8 @@
 
         final int shortcutTargetCount = shortcutTargets.size();
         for (int i = 0; i < shortcutTargetCount; i++) {
-            final int[] shortcutTargetCodePointArray = shortcutTargets.get(i);
-            final String shortcutTargetString = new String(shortcutTargetCodePointArray,
-                    0 /* offset */, getCodePointCount(shortcutTargetCodePointArray));
+            final String shortcutTargetString =
+                    StringUtils.getStringFromNullTerminatedCodePointArray(shortcutTargets.get(i));
             mShortcutTargets.add(
                     new WeightedString(shortcutTargetString, shortcutProbabilities.get(i)));
         }
@@ -105,4 +99,44 @@
     public boolean isValid() {
         return mProbabilityInfo.mProbability != BinaryDictionary.NOT_A_PROBABILITY;
     }
+
+    @Override
+    public String toString() {
+        // TODO: Move this logic to CombinedInputOutput.
+        final StringBuffer builder = new StringBuffer();
+        builder.append(" word=" + mCodePoints);
+        builder.append(",");
+        builder.append("f=" + mProbabilityInfo.mProbability);
+        if (mIsNotAWord) {
+            builder.append(",");
+            builder.append("not_a_word=true");
+        }
+        if (mIsBlacklisted) {
+            builder.append(",");
+            builder.append("blacklisted=true");
+        }
+        if (mProbabilityInfo.mTimestamp != BinaryDictionary.NOT_A_VALID_TIMESTAMP) {
+            builder.append(",");
+            builder.append("historicalInfo=" + mProbabilityInfo);
+        }
+        builder.append("\n");
+        for (int i = 0; i < mBigramTargets.size(); i++) {
+            builder.append("  bigram=" + mBigramTargets.get(i).mWord);
+            builder.append(",");
+            builder.append("f=" + mBigramTargets.get(i).mFrequency);
+            if (mBigramProbabilityInfo.get(i).mTimestamp
+                    != BinaryDictionary.NOT_A_VALID_TIMESTAMP) {
+                builder.append(",");
+                builder.append("historicalInfo=" + mBigramProbabilityInfo.get(i));
+            }
+            builder.append("\n");
+        }
+        for (int i = 0; i < mShortcutTargets.size(); i++) {
+            builder.append("  shortcut=" + mShortcutTargets.get(i).mWord);
+            builder.append(",");
+            builder.append("f=" + mShortcutTargets.get(i).mFrequency);
+            builder.append("\n");
+        }
+        return builder.toString();
+    }
 }
\ No newline at end of file
diff --git a/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp b/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
index c919ebd..4372cbe 100644
--- a/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
+++ b/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
@@ -137,6 +137,17 @@
     delete dictionary;
 }
 
+static void latinime_BinaryDictionary_getHeaderInfo(JNIEnv *env, jclass clazz, jlong dict,
+        jintArray outHeaderSize, jintArray outFormatVersion, jobject outAttributeKeys,
+        jobject outAttributeValues) {
+    Dictionary *dictionary = reinterpret_cast<Dictionary *>(dict);
+    if (!dictionary) return;
+    const int formatVersion = dictionary->getFormatVersionNumber();
+    env->SetIntArrayRegion(outFormatVersion, 0 /* start */, 1 /* len */, &formatVersion);
+    // TODO: Implement
+    return;
+}
+
 static int latinime_BinaryDictionary_getFormatVersion(JNIEnv *env, jclass clazz, jlong dict) {
     Dictionary *dictionary = reinterpret_cast<Dictionary *>(dict);
     if (!dictionary) return 0;
@@ -511,6 +522,11 @@
         reinterpret_cast<void *>(latinime_BinaryDictionary_getFormatVersion)
     },
     {
+        const_cast<char *>("getHeaderInfoNative"),
+        const_cast<char *>("(J[I[ILjava/util/ArrayList;Ljava/util/ArrayList;)V"),
+        reinterpret_cast<void *>(latinime_BinaryDictionary_getHeaderInfo)
+    },
+    {
         const_cast<char *>("flushNative"),
         const_cast<char *>("(JLjava/lang/String;)V"),
         reinterpret_cast<void *>(latinime_BinaryDictionary_flush)
diff --git a/native/jni/src/suggest/core/dictionary/suggestions_output_utils.cpp b/native/jni/src/suggest/core/dictionary/suggestions_output_utils.cpp
index b810637..e37811b 100644
--- a/native/jni/src/suggest/core/dictionary/suggestions_output_utils.cpp
+++ b/native/jni/src/suggest/core/dictionary/suggestions_output_utils.cpp
@@ -78,7 +78,8 @@
         outputAutoCommitFirstWordConfidence[0] =
                 computeFirstWordConfidence(&terminals[0]);
     }
-
+    const bool boostExactMatches = traverseSession->getDictionaryStructurePolicy()->
+            getHeaderStructurePolicy()->shouldBoostExactMatches();
     // Output suggestion results here
     for (int terminalIndex = 0; terminalIndex < terminalSize && outputWordIndex < MAX_RESULTS;
             ++terminalIndex) {
@@ -102,7 +103,7 @@
                 && !(isPossiblyOffensiveWord && isFirstCharUppercase);
         const int outputTypeFlags =
                 (isPossiblyOffensiveWord ? Dictionary::KIND_FLAG_POSSIBLY_OFFENSIVE : 0)
-                | (isSafeExactMatch ? Dictionary::KIND_FLAG_EXACT_MATCH : 0);
+                | ((isSafeExactMatch && boostExactMatches) ? Dictionary::KIND_FLAG_EXACT_MATCH : 0);
 
         // Entries that are blacklisted or do not represent a word should not be output.
         const bool isValidWord = !terminalDicNode->isBlacklistedOrNotAWord();
@@ -113,7 +114,8 @@
                 compoundDistance, traverseSession->getInputSize(),
                 terminalDicNode->getContainedErrorTypes(),
                 (forceCommitMultiWords && terminalDicNode->hasMultipleWords())
-                         || (isValidWord && scoringPolicy->doesAutoCorrectValidWord()));
+                         || (isValidWord && scoringPolicy->doesAutoCorrectValidWord()),
+                boostExactMatches);
         if (maxScore < finalScore && isValidWord) {
             maxScore = finalScore;
         }
@@ -147,7 +149,7 @@
                      scoringPolicy->calculateFinalScore(compoundDistance,
                              traverseSession->getInputSize(),
                              terminalDicNode->getContainedErrorTypes(),
-                             true /* forceCommit */) : finalScore;
+                             true /* forceCommit */, boostExactMatches) : finalScore;
             const int updatedOutputWordIndex = outputShortcuts(&shortcutIt,
                     outputWordIndex, shortcutBaseScore, outputCodePoints, frequencies, outputTypes,
                     sameAsTyped);
diff --git a/native/jni/src/suggest/core/policy/dictionary_header_structure_policy.h b/native/jni/src/suggest/core/policy/dictionary_header_structure_policy.h
index b76b139..417620e 100644
--- a/native/jni/src/suggest/core/policy/dictionary_header_structure_policy.h
+++ b/native/jni/src/suggest/core/policy/dictionary_header_structure_policy.h
@@ -40,6 +40,8 @@
     virtual void readHeaderValueOrQuestionMark(const char *const key, int *outValue,
             int outValueSize) const = 0;
 
+    virtual bool shouldBoostExactMatches() const = 0;
+
  protected:
     DictionaryHeaderStructurePolicy() {}
 
diff --git a/native/jni/src/suggest/core/policy/scoring.h b/native/jni/src/suggest/core/policy/scoring.h
index 7833834..e581a97 100644
--- a/native/jni/src/suggest/core/policy/scoring.h
+++ b/native/jni/src/suggest/core/policy/scoring.h
@@ -28,7 +28,8 @@
 class Scoring {
  public:
     virtual int calculateFinalScore(const float compoundDistance, const int inputSize,
-            const ErrorTypeUtils::ErrorType containedErrorTypes, const bool forceCommit) const = 0;
+            const ErrorTypeUtils::ErrorType containedErrorTypes, const bool forceCommit,
+            const bool boostExactMatches) const = 0;
     virtual bool getMostProbableString(const DicTraverseSession *const traverseSession,
             const int terminalSize, const float languageWeight, int *const outputCodePoints,
             int *const type, int *const freq) const = 0;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h b/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h
index a44f9f0..1320c65 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h
@@ -146,6 +146,11 @@
         return mHasHistoricalInfoOfWords;
     }
 
+    AK_FORCE_INLINE bool shouldBoostExactMatches() const {
+        // TODO: Investigate better ways to handle exact matches for personalized dictionaries.
+        return !isDecayingDict();
+    }
+
     void readHeaderValueOrQuestionMark(const char *const key,
             int *outValue, int outValueSize) const;
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_helper.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_helper.cpp
index b918e07..824d442 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_helper.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_helper.cpp
@@ -28,6 +28,14 @@
 const int DynamicPtReadingHelper::MAX_PT_NODE_ARRAY_COUNT_TO_AVOID_INFINITE_LOOP = 100000;
 const size_t DynamicPtReadingHelper::MAX_READING_STATE_STACK_SIZE = MAX_WORD_LENGTH;
 
+bool DynamicPtReadingHelper::TraversePolicyToGetAllTerminalPtNodePositions::onVisitingPtNode(
+        const PtNodeParams *const ptNodeParams) {
+    if (ptNodeParams->isTerminal() && !ptNodeParams->isDeleted()) {
+        mTerminalPositions->push_back(ptNodeParams->getHeadPos());
+    }
+    return true;
+}
+
 // Visits all PtNodes in post-order depth first manner.
 // For example, visits c -> b -> y -> x -> a for the following dictionary:
 // a _ b _ c
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_helper.h b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_helper.h
index a694909..bcc5c78 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_helper.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_helper.h
@@ -59,6 +59,21 @@
         DISALLOW_COPY_AND_ASSIGN(TraversingEventListener);
     };
 
+    class TraversePolicyToGetAllTerminalPtNodePositions : public TraversingEventListener {
+     public:
+        TraversePolicyToGetAllTerminalPtNodePositions(std::vector<int> *const terminalPositions)
+                : mTerminalPositions(terminalPositions) {}
+        bool onAscend() { return true; }
+        bool onDescend(const int ptNodeArrayPos) { return true; }
+        bool onReadingPtNodeArrayTail() { return true; }
+        bool onVisitingPtNode(const PtNodeParams *const ptNodeParams);
+
+     private:
+        DISALLOW_IMPLICIT_CONSTRUCTORS(TraversePolicyToGetAllTerminalPtNodePositions);
+
+        std::vector<int> *const mTerminalPositions;
+    };
+
     DynamicPtReadingHelper(const BufferWithExtendableBuffer *const buffer,
             const PtNodeReader *const ptNodeReader)
             : mIsError(false), mReadingState(), mBuffer(buffer),
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
index 1c420e0..75d8598 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
@@ -392,10 +392,32 @@
             historicalInfo->getCount(), &bigrams, &shortcuts);
 }
 
-int Ver4PatriciaTriePolicy::getNextWordAndNextToken(const int token,
-        int *const outCodePoints) {
-    // TODO: Implement.
-    return 0;
+int Ver4PatriciaTriePolicy::getNextWordAndNextToken(const int token, int *const outCodePoints) {
+    if (token == 0) {
+        mTerminalPtNodePositionsForIteratingWords.clear();
+        DynamicPtReadingHelper::TraversePolicyToGetAllTerminalPtNodePositions traversePolicy(
+                &mTerminalPtNodePositionsForIteratingWords);
+        DynamicPtReadingHelper readingHelper(mDictBuffer, &mNodeReader);
+        readingHelper.initWithPtNodeArrayPos(getRootPosition());
+        readingHelper.traverseAllPtNodesInPostorderDepthFirstManner(&traversePolicy);
+    }
+    const int terminalPtNodePositionsVectorSize =
+            static_cast<int>(mTerminalPtNodePositionsForIteratingWords.size());
+    if (token < 0 || token >= terminalPtNodePositionsVectorSize) {
+        AKLOGE("Given token %d is invalid.", token);
+        return 0;
+    }
+    const int terminalPtNodePos = mTerminalPtNodePositionsForIteratingWords[token];
+    int unigramProbability = NOT_A_PROBABILITY;
+    getCodePointsAndProbabilityAndReturnCodePointCount(terminalPtNodePos, MAX_WORD_LENGTH,
+            outCodePoints, &unigramProbability);
+    const int nextToken = token + 1;
+    if (nextToken >= terminalPtNodePositionsVectorSize) {
+        // All words have been iterated.
+        mTerminalPtNodePositionsForIteratingWords.clear();
+        return 0;
+    }
+    return nextToken;
 }
 
 } // namespace latinime
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
index 1bcd4ce..9ba5be0 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
@@ -17,6 +17,8 @@
 #ifndef LATINIME_VER4_PATRICIA_TRIE_POLICY_H
 #define LATINIME_VER4_PATRICIA_TRIE_POLICY_H
 
+#include <vector>
+
 #include "defines.h"
 #include "suggest/core/policy/dictionary_structure_with_buffer_policy.h"
 #include "suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.h"
@@ -50,7 +52,8 @@
               mUpdatingHelper(mDictBuffer, &mNodeReader, &mNodeWriter),
               mWritingHelper(mBuffers.get()),
               mUnigramCount(mHeaderPolicy->getUnigramCount()),
-              mBigramCount(mHeaderPolicy->getBigramCount()) {};
+              mBigramCount(mHeaderPolicy->getBigramCount()),
+              mTerminalPtNodePositionsForIteratingWords() {};
 
     AK_FORCE_INLINE int getRootPosition() const {
         return 0;
@@ -134,6 +137,7 @@
     Ver4PatriciaTrieWritingHelper mWritingHelper;
     int mUnigramCount;
     int mBigramCount;
+    std::vector<int> mTerminalPtNodePositionsForIteratingWords;
 };
 } // namespace latinime
 #endif // LATINIME_VER4_PATRICIA_TRIE_POLICY_H
diff --git a/native/jni/src/suggest/policyimpl/typing/typing_scoring.h b/native/jni/src/suggest/policyimpl/typing/typing_scoring.h
index c777e72..8b405e8 100644
--- a/native/jni/src/suggest/policyimpl/typing/typing_scoring.h
+++ b/native/jni/src/suggest/policyimpl/typing/typing_scoring.h
@@ -50,14 +50,14 @@
 
     AK_FORCE_INLINE int calculateFinalScore(const float compoundDistance,
             const int inputSize, const ErrorTypeUtils::ErrorType containedErrorTypes,
-            const bool forceCommit) const {
+            const bool forceCommit, const bool boostExactMatches) const {
         const float maxDistance = ScoringParams::DISTANCE_WEIGHT_LANGUAGE
                 + static_cast<float>(inputSize) * ScoringParams::TYPING_MAX_OUTPUT_SCORE_PER_INPUT;
         float score = ScoringParams::TYPING_BASE_OUTPUT_SCORE - compoundDistance / maxDistance;
         if (forceCommit) {
             score += ScoringParams::AUTOCORRECT_OUTPUT_THRESHOLD;
         }
-        if (ErrorTypeUtils::isExactMatch(containedErrorTypes)) {
+        if (boostExactMatches && ErrorTypeUtils::isExactMatch(containedErrorTypes)) {
             score += ScoringParams::EXACT_MATCH_PROMOTION;
             if ((ErrorTypeUtils::MATCH_WITH_CASE_ERROR & containedErrorTypes) != 0) {
                 score -= ScoringParams::CASE_ERROR_PENALTY_FOR_EXACT_MATCH;
diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
index 343ab42..c41bbd7 100644
--- a/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
@@ -22,6 +22,7 @@
 
 import com.android.inputmethod.latin.makedict.CodePointUtils;
 import com.android.inputmethod.latin.makedict.DictDecoder;
+import com.android.inputmethod.latin.makedict.DictionaryHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec;
 import com.android.inputmethod.latin.makedict.FusionDictionary;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
@@ -102,14 +103,14 @@
                 getContext().getCacheDir());
         FileUtils.deleteRecursively(file);
         Map<String, String> attributeMap = new HashMap<String, String>();
-        attributeMap.put(FormatSpec.FileHeader.DICTIONARY_ID_KEY, dictId);
-        attributeMap.put(FormatSpec.FileHeader.DICTIONARY_LOCALE_KEY, dictId);
-        attributeMap.put(FormatSpec.FileHeader.DICTIONARY_VERSION_KEY,
+        attributeMap.put(DictionaryHeader.DICTIONARY_ID_KEY, dictId);
+        attributeMap.put(DictionaryHeader.DICTIONARY_LOCALE_KEY, dictId);
+        attributeMap.put(DictionaryHeader.DICTIONARY_VERSION_KEY,
                 String.valueOf(TimeUnit.MILLISECONDS.toSeconds(System.currentTimeMillis())));
-        attributeMap.put(FormatSpec.FileHeader.USES_FORGETTING_CURVE_KEY,
-                FormatSpec.FileHeader.ATTRIBUTE_VALUE_TRUE);
-        attributeMap.put(FormatSpec.FileHeader.HAS_HISTORICAL_INFO_KEY,
-                FormatSpec.FileHeader.ATTRIBUTE_VALUE_TRUE);
+        attributeMap.put(DictionaryHeader.USES_FORGETTING_CURVE_KEY,
+                DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
+        attributeMap.put(DictionaryHeader.HAS_HISTORICAL_INFO_KEY,
+                DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
         if (BinaryDictionary.createEmptyDictFile(file.getAbsolutePath(),
                 FormatSpec.VERSION4, attributeMap)) {
             return file;
diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
index e39b46f..bab86e5 100644
--- a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
@@ -971,6 +971,99 @@
         }
     }
 
+    public void testIterateAllWords() {
+        testIterateAllWords(FormatSpec.VERSION4);
+    }
+
+    private void testIterateAllWords(final int formatVersion) {
+        final long seed = System.currentTimeMillis();
+        final Random random = new Random(seed);
+        final int UNIGRAM_COUNT = 1000;
+        final int BIGRAM_COUNT = 1000;
+        final int codePointSetSize = 20;
+        final int[] codePointSet = CodePointUtils.generateCodePointSet(codePointSetSize, random);
+
+        File dictFile = null;
+        try {
+            dictFile = createEmptyDictionaryAndGetFile("TestBinaryDictionary", formatVersion);
+        } catch (IOException e) {
+            fail("IOException while writing an initial dictionary : " + e);
+        }
+        final BinaryDictionary binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),
+                0 /* offset */, dictFile.length(), true /* useFullEditDistance */,
+                Locale.getDefault(), TEST_LOCALE, true /* isUpdatable */);
+
+        final WordProperty invalidWordProperty = binaryDictionary.getWordProperty("dummyWord");
+        assertFalse(invalidWordProperty.isValid());
+
+        final ArrayList<String> words = new ArrayList<String>();
+        final HashMap<String, Integer> wordProbabilitiesToCheckLater =
+                new HashMap<String, Integer>();
+        final HashMap<String, HashSet<String>> bigrams = new HashMap<String, HashSet<String>>();
+        final HashMap<Pair<String, String>, Integer> bigramProbabilitiesToCheckLater =
+                new HashMap<Pair<String, String>, Integer>();
+
+        for (int i = 0; i < UNIGRAM_COUNT; i++) {
+            final String word = CodePointUtils.generateWord(random, codePointSet);
+            final int unigramProbability = random.nextInt(0xFF);
+            addUnigramWord(binaryDictionary, word, unigramProbability);
+            if (binaryDictionary.needsToRunGC(false /* mindsBlockByGC */)) {
+                binaryDictionary.flushWithGC();
+            }
+            words.add(word);
+            wordProbabilitiesToCheckLater.put(word, unigramProbability);
+        }
+
+        for (int i = 0; i < BIGRAM_COUNT; i++) {
+            final int word0Index = random.nextInt(wordProbabilitiesToCheckLater.size());
+            final int word1Index = random.nextInt(wordProbabilitiesToCheckLater.size());
+            if (word0Index == word1Index) {
+                continue;
+            }
+            final String word0 = words.get(word0Index);
+            final String word1 = words.get(word1Index);
+            final int bigramProbability = random.nextInt(0xF);
+            binaryDictionary.addBigramWords(word0, word1, bigramProbability,
+                    BinaryDictionary.NOT_A_VALID_TIMESTAMP);
+            if (binaryDictionary.needsToRunGC(false /* mindsBlockByGC */)) {
+                binaryDictionary.flushWithGC();
+            }
+            if (!bigrams.containsKey(word0)) {
+                final HashSet<String> bigramWord1s = new HashSet<String>();
+                bigrams.put(word0, bigramWord1s);
+            }
+            bigrams.get(word0).add(word1);
+            bigramProbabilitiesToCheckLater.put(
+                    new Pair<String, String>(word0, word1), bigramProbability);
+        }
+
+        final HashSet<String> wordSet = new HashSet<String>(words);
+        final HashSet<Pair<String, String>> bigramSet =
+                new HashSet<Pair<String,String>>(bigramProbabilitiesToCheckLater.keySet());
+        int token = 0;
+        do {
+            final BinaryDictionary.GetNextWordPropertyResult result =
+                    binaryDictionary.getNextWordProperty(token);
+            final WordProperty wordProperty = result.mWordProperty;
+            final String word0 = wordProperty.mCodePoints;
+            assertEquals((int)wordProbabilitiesToCheckLater.get(word0),
+                    wordProperty.mProbabilityInfo.mProbability);
+            wordSet.remove(word0);
+            final HashSet<String> bigramWord1s = bigrams.get(word0);
+            for (int j = 0; j < wordProperty.mBigramTargets.size(); j++) {
+                final String word1 = wordProperty.mBigramTargets.get(j).mWord;
+                assertTrue(bigramWord1s.contains(word1));
+                final int probability = wordProperty.mBigramTargets.get(j).mFrequency;
+                final Pair<String, String> bigram = new Pair<String, String>(word0, word1);
+                assertEquals((int)bigramProbabilitiesToCheckLater.get(bigram), probability);
+                bigramSet.remove(bigram);
+            }
+            token = result.mNextToken;
+        } while (token != 0);
+        assertTrue(wordSet.isEmpty());
+        assertTrue(bigramSet.isEmpty());
+    }
+
     public void testAddShortcuts() {
         testAddShortcuts(FormatSpec.VERSION4);
     }
diff --git a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java
index 715db2f..0815819 100644
--- a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java
+++ b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java
@@ -24,7 +24,6 @@
 import com.android.inputmethod.latin.BinaryDictionary;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
@@ -498,7 +497,7 @@
     private String getWordFromBinary(final DictDecoder dictDecoder, final int address) {
         if (dictDecoder.getPosition() != 0) dictDecoder.setPosition(0);
 
-        FileHeader fileHeader = null;
+        DictionaryHeader fileHeader = null;
         try {
             fileHeader = dictDecoder.readHeader();
         } catch (IOException e) {
diff --git a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictUtils.java b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictUtils.java
index 20cf9a5..79f3e0d 100644
--- a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictUtils.java
+++ b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictUtils.java
@@ -16,7 +16,6 @@
 
 package com.android.inputmethod.latin.makedict;
 
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions;
 
@@ -39,14 +38,14 @@
     public static DictionaryOptions makeDictionaryOptions(final String id, final String version,
             final FormatSpec.FormatOptions formatOptions) {
         final DictionaryOptions options = new DictionaryOptions(new HashMap<String, String>());
-        options.mAttributes.put(FileHeader.DICTIONARY_LOCALE_KEY, "en_US");
-        options.mAttributes.put(FileHeader.DICTIONARY_ID_KEY, id);
-        options.mAttributes.put(FileHeader.DICTIONARY_VERSION_KEY, version);
+        options.mAttributes.put(DictionaryHeader.DICTIONARY_LOCALE_KEY, "en_US");
+        options.mAttributes.put(DictionaryHeader.DICTIONARY_ID_KEY, id);
+        options.mAttributes.put(DictionaryHeader.DICTIONARY_VERSION_KEY, version);
         if (formatOptions.mHasTimestamp) {
-            options.mAttributes.put(FileHeader.HAS_HISTORICAL_INFO_KEY,
-                    FileHeader.ATTRIBUTE_VALUE_TRUE);
-            options.mAttributes.put(FileHeader.USES_FORGETTING_CURVE_KEY,
-                    FileHeader.ATTRIBUTE_VALUE_TRUE);
+            options.mAttributes.put(DictionaryHeader.HAS_HISTORICAL_INFO_KEY,
+                    DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
+            options.mAttributes.put(DictionaryHeader.USES_FORGETTING_CURVE_KEY,
+                    DictionaryHeader.ATTRIBUTE_VALUE_TRUE);
         }
         return options;
     }
diff --git a/tests/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtilsTests.java b/tests/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtilsTests.java
deleted file mode 100644
index 93731b3..0000000
--- a/tests/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtilsTests.java
+++ /dev/null
@@ -1,244 +0,0 @@
-/*
- * 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.latin.utils;
-
-import android.content.Context;
-import android.test.AndroidTestCase;
-import android.test.suitebuilder.annotation.LargeTest;
-import android.util.Log;
-
-import com.android.inputmethod.latin.makedict.DictDecoder;
-import com.android.inputmethod.latin.makedict.DictEncoder;
-import com.android.inputmethod.latin.makedict.FormatSpec;
-import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
-import com.android.inputmethod.latin.makedict.FusionDictionary;
-import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode;
-import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
-import com.android.inputmethod.latin.makedict.Ver2DictDecoder;
-import com.android.inputmethod.latin.makedict.Ver2DictEncoder;
-import com.android.inputmethod.latin.personalization.UserHistoryDictionaryBigramList;
-import com.android.inputmethod.latin.utils.UserHistoryDictIOUtils.BigramDictionaryInterface;
-import com.android.inputmethod.latin.utils.UserHistoryDictIOUtils.OnAddWordListener;
-
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-
-/**
- * Unit tests for UserHistoryDictIOUtils
- */
-@LargeTest
-public class UserHistoryDictIOUtilsTests extends AndroidTestCase
-    implements BigramDictionaryInterface {
-
-    private static final String TAG = UserHistoryDictIOUtilsTests.class.getSimpleName();
-    private static final int UNIGRAM_FREQUENCY = 50;
-    private static final int BIGRAM_FREQUENCY = 100;
-    private static final ArrayList<String> NOT_HAVE_BIGRAM = new ArrayList<String>();
-    private static final FormatSpec.FormatOptions FORMAT_OPTIONS = new FormatSpec.FormatOptions(2);
-    private static final String TEST_DICT_FILE_EXTENSION = ".testDict";
-    private static final HashMap<String, String> HEADER_OPTIONS = new HashMap<String, String>();
-    static {
-        HEADER_OPTIONS.put(FileHeader.DICTIONARY_LOCALE_KEY, "en_US");
-        HEADER_OPTIONS.put(FileHeader.DICTIONARY_ID_KEY, "test");
-        HEADER_OPTIONS.put(FileHeader.DICTIONARY_VERSION_KEY, "1000");
-    }
-
-    /**
-     * Return same frequency for all words and bigrams
-     */
-    @Override
-    public int getFrequency(String word1, String word2) {
-        if (word1 == null) return UNIGRAM_FREQUENCY;
-        return BIGRAM_FREQUENCY;
-    }
-
-    // Utilities for Testing
-
-    private void addWord(final String word,
-            final HashMap<String, ArrayList<String> > addedWords) {
-        if (!addedWords.containsKey(word)) {
-            addedWords.put(word, new ArrayList<String>());
-        }
-    }
-
-    private void addBigram(final String word1, final String word2,
-            final HashMap<String, ArrayList<String> > addedWords) {
-        addWord(word1, addedWords);
-        addWord(word2, addedWords);
-        addedWords.get(word1).add(word2);
-    }
-
-    private void addBigramToBigramList(final String word1, final String word2,
-            final HashMap<String, ArrayList<String> > addedWords,
-            final UserHistoryDictionaryBigramList bigramList) {
-        bigramList.addBigram(null, word1);
-        bigramList.addBigram(word1, word2);
-
-        addBigram(word1, word2, addedWords);
-    }
-
-    private void checkWordInFusionDict(final FusionDictionary dict, final String word,
-            final ArrayList<String> expectedBigrams) {
-        final PtNode ptNode = FusionDictionary.findWordInTree(dict.mRootNodeArray, word);
-        assertNotNull(ptNode);
-        assertTrue(ptNode.isTerminal());
-
-        for (final String bigram : expectedBigrams) {
-            assertNotNull(ptNode.getBigram(bigram));
-        }
-    }
-
-    private void checkWordsInFusionDict(final FusionDictionary dict,
-            final HashMap<String, ArrayList<String> > bigrams) {
-        for (final String word : bigrams.keySet()) {
-            if (bigrams.containsKey(word)) {
-                checkWordInFusionDict(dict, word, bigrams.get(word));
-            } else {
-                checkWordInFusionDict(dict, word, NOT_HAVE_BIGRAM);
-            }
-        }
-    }
-
-    private void checkWordInBigramList(
-            final UserHistoryDictionaryBigramList bigramList, final String word,
-            final ArrayList<String> expectedBigrams) {
-        // check unigram
-        final HashMap<String,Byte> unigramMap = bigramList.getBigrams(null);
-        assertTrue(unigramMap.containsKey(word));
-
-        // check bigrams
-        final ArrayList<String> actualBigrams = new ArrayList<String>(
-                bigramList.getBigrams(word).keySet());
-
-        Collections.sort(expectedBigrams);
-        Collections.sort(actualBigrams);
-        assertEquals(expectedBigrams, actualBigrams);
-    }
-
-    private void checkWordsInBigramList(final UserHistoryDictionaryBigramList bigramList,
-            final HashMap<String, ArrayList<String> > addedWords) {
-        for (final String word : addedWords.keySet()) {
-            if (addedWords.containsKey(word)) {
-                checkWordInBigramList(bigramList, word, addedWords.get(word));
-            } else {
-                checkWordInBigramList(bigramList, word, NOT_HAVE_BIGRAM);
-            }
-        }
-    }
-
-    private void writeDictToFile(final File file,
-            final UserHistoryDictionaryBigramList bigramList) {
-        final DictEncoder dictEncoder = new Ver2DictEncoder(file);
-        UserHistoryDictIOUtils.writeDictionary(dictEncoder, this, bigramList, FORMAT_OPTIONS,
-                HEADER_OPTIONS);
-    }
-
-    private void readDictFromFile(final File file, final OnAddWordListener listener)
-            throws IOException, FileNotFoundException, UnsupportedFormatException {
-        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file, DictDecoder.USE_BYTEARRAY);
-        dictDecoder.openDictBuffer();
-        UserHistoryDictIOUtils.readDictionaryBinary(dictDecoder, listener);
-    }
-
-    public void testGenerateFusionDictionary() {
-        final UserHistoryDictionaryBigramList originalList = new UserHistoryDictionaryBigramList();
-
-        final HashMap<String, ArrayList<String> > addedWords =
-                new HashMap<String, ArrayList<String>>();
-        addBigramToBigramList("this", "is", addedWords, originalList);
-        addBigramToBigramList("this", "was", addedWords, originalList);
-        addBigramToBigramList("hello", "world", addedWords, originalList);
-
-        final FusionDictionary fusionDict = UserHistoryDictIOUtils.constructFusionDictionary(
-                this, originalList, HEADER_OPTIONS);
-
-        checkWordsInFusionDict(fusionDict, addedWords);
-    }
-
-    public void testReadAndWrite() throws IOException, FileNotFoundException,
-            UnsupportedFormatException {
-        final Context context = getContext();
-
-        File file = null;
-        try {
-            file = File.createTempFile("testReadAndWrite", TEST_DICT_FILE_EXTENSION,
-                    getContext().getCacheDir());
-        } catch (IOException e) {
-            Log.d(TAG, "IOException while creating a temporary file", e);
-        }
-        assertNotNull(file);
-
-        // make original dictionary
-        final UserHistoryDictionaryBigramList originalList = new UserHistoryDictionaryBigramList();
-        final HashMap<String, ArrayList<String>> addedWords = CollectionUtils.newHashMap();
-        addBigramToBigramList("this" , "is"   , addedWords, originalList);
-        addBigramToBigramList("this" , "was"  , addedWords, originalList);
-        addBigramToBigramList("is"   , "not"  , addedWords, originalList);
-        addBigramToBigramList("hello", "world", addedWords, originalList);
-
-        // write to file
-        writeDictToFile(file, originalList);
-
-        // make result dict.
-        final UserHistoryDictionaryBigramList resultList = new UserHistoryDictionaryBigramList();
-        final OnAddWordListener listener = new OnAddWordListener() {
-            @Override
-            public void setUnigram(final String word, final String shortcutTarget,
-                    final int frequency, final int shortcutFreq) {
-                Log.d(TAG, "in: setUnigram: " + word + "," + frequency);
-                resultList.addBigram(null, word, (byte)frequency);
-            }
-            @Override
-            public void setBigram(final String word1, final String word2, final int frequency) {
-                Log.d(TAG, "in: setBigram: " + word1 + "," + word2 + "," + frequency);
-                resultList.addBigram(word1, word2, (byte)frequency);
-            }
-        };
-
-        // load from file
-        readDictFromFile(file, listener);
-        checkWordsInBigramList(resultList, addedWords);
-
-        // add new bigram
-        addBigramToBigramList("hello", "java", addedWords, resultList);
-
-        // rewrite
-        writeDictToFile(file, resultList);
-        final UserHistoryDictionaryBigramList resultList2 = new UserHistoryDictionaryBigramList();
-        final OnAddWordListener listener2 = new OnAddWordListener() {
-            @Override
-            public void setUnigram(final String word, final String shortcutTarget,
-                    final int frequency, final int shortcutFreq) {
-                Log.d(TAG, "in: setUnigram: " + word + "," + frequency);
-                resultList2.addBigram(null, word, (byte)frequency);
-            }
-            @Override
-            public void setBigram(final String word1, final String word2, final int frequency) {
-                Log.d(TAG, "in: setBigram: " + word1 + "," + word2 + "," + frequency);
-                resultList2.addBigram(word1, word2, (byte)frequency);
-            }
-        };
-
-        // load from file
-        readDictFromFile(file, listener2);
-        checkWordsInBigramList(resultList2, addedWords);
-    }
-}
diff --git a/tools/dicttool/compat/android/util/SparseIntArray.java b/tools/dicttool/compat/android/util/SparseIntArray.java
new file mode 100644
index 0000000..ac8a04c
--- /dev/null
+++ b/tools/dicttool/compat/android/util/SparseIntArray.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2013 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.util;
+
+public class SparseIntArray {
+    private final SparseArray<Integer> mArray;
+
+    public SparseIntArray() {
+        this(10);
+    }
+
+    public SparseIntArray(final int initialCapacity) {
+        mArray = new SparseArray<Integer>(initialCapacity);
+    }
+
+    public int size() {
+        return mArray.size();
+    }
+
+    public void clear() {
+        mArray.clear();
+    }
+
+    public void put(final int key, final int value) {
+        mArray.put(key, value);
+    }
+
+    public int get(final int key) {
+        return get(key, 0);
+    }
+
+    public int get(final int key, final int valueIfKeyNotFound) {
+        return mArray.get(key, valueIfKeyNotFound);
+    }
+
+    public int indexOfKey(final int key) {
+        return mArray.indexOfKey(key);
+    }
+
+    public int keyAt(final int index) {
+        return mArray.keyAt(index);
+    }
+}
diff --git a/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java b/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java
index d8059e4..9ed4dd5 100644
--- a/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java
+++ b/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java
@@ -18,6 +18,7 @@
 
 import com.android.inputmethod.latin.makedict.DictDecoder;
 import com.android.inputmethod.latin.makedict.DictEncoder;
+import com.android.inputmethod.latin.makedict.DictionaryHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary;
@@ -48,9 +49,9 @@
 
         // Create a thrice-compressed dictionary file.
         final DictionaryOptions testOptions = new DictionaryOptions(new HashMap<String, String>());
-        testOptions.mAttributes.put(FormatSpec.FileHeader.DICTIONARY_VERSION_KEY, VERSION);
-        testOptions.mAttributes.put(FormatSpec.FileHeader.DICTIONARY_LOCALE_KEY, LOCALE);
-        testOptions.mAttributes.put(FormatSpec.FileHeader.DICTIONARY_ID_KEY, ID);
+        testOptions.mAttributes.put(DictionaryHeader.DICTIONARY_VERSION_KEY, VERSION);
+        testOptions.mAttributes.put(DictionaryHeader.DICTIONARY_LOCALE_KEY, LOCALE);
+        testOptions.mAttributes.put(DictionaryHeader.DICTIONARY_ID_KEY, ID);
         final FusionDictionary dict = new FusionDictionary(new PtNodeArray(), testOptions);
         dict.add("foo", TEST_FREQ, null, false /* isNotAWord */);
         dict.add("fta", 1, null, false /* isNotAWord */);
@@ -80,11 +81,11 @@
                 null /* dict : an optional dictionary to add words to, or null */,
                 false /* deleteDictIfBroken */);
         assertEquals("Wrong version attribute", VERSION, resultDict.mOptions.mAttributes.get(
-                FormatSpec.FileHeader.DICTIONARY_VERSION_KEY));
+                DictionaryHeader.DICTIONARY_VERSION_KEY));
         assertEquals("Wrong locale attribute", LOCALE, resultDict.mOptions.mAttributes.get(
-                FormatSpec.FileHeader.DICTIONARY_LOCALE_KEY));
+                DictionaryHeader.DICTIONARY_LOCALE_KEY));
         assertEquals("Wrong id attribute", ID, resultDict.mOptions.mAttributes.get(
-                FormatSpec.FileHeader.DICTIONARY_ID_KEY));
+                DictionaryHeader.DICTIONARY_ID_KEY));
         assertEquals("Dictionary can't be read back correctly",
                 FusionDictionary.findWordInTree(resultDict.mRootNodeArray, "foo").getFrequency(),
                 TEST_FREQ);