Merge "Use reentrant lock for main dictionaries."
diff --git a/dictionaries/cs_wordlist.combined.gz b/dictionaries/cs_wordlist.combined.gz
index d69ef64..7829d65 100644
--- a/dictionaries/cs_wordlist.combined.gz
+++ b/dictionaries/cs_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/da_wordlist.combined.gz b/dictionaries/da_wordlist.combined.gz
index 919d28e..e714019 100644
--- a/dictionaries/da_wordlist.combined.gz
+++ b/dictionaries/da_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/de_wordlist.combined.gz b/dictionaries/de_wordlist.combined.gz
index f5cce9d..6a4bd44 100644
--- a/dictionaries/de_wordlist.combined.gz
+++ b/dictionaries/de_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/en_GB_wordlist.combined.gz b/dictionaries/en_GB_wordlist.combined.gz
index afef676..839f3ef 100644
--- a/dictionaries/en_GB_wordlist.combined.gz
+++ b/dictionaries/en_GB_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/en_US_wordlist.combined.gz b/dictionaries/en_US_wordlist.combined.gz
index eafbc9d..5595c75 100644
--- a/dictionaries/en_US_wordlist.combined.gz
+++ b/dictionaries/en_US_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/en_wordlist.combined.gz b/dictionaries/en_wordlist.combined.gz
index 9cbca0b..69c39d5 100644
--- a/dictionaries/en_wordlist.combined.gz
+++ b/dictionaries/en_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/es_wordlist.combined.gz b/dictionaries/es_wordlist.combined.gz
index 53b8607..0a48b6d 100644
--- a/dictionaries/es_wordlist.combined.gz
+++ b/dictionaries/es_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/fi_wordlist.combined.gz b/dictionaries/fi_wordlist.combined.gz
index 2720116..eefbfe5 100644
--- a/dictionaries/fi_wordlist.combined.gz
+++ b/dictionaries/fi_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/fr_wordlist.combined.gz b/dictionaries/fr_wordlist.combined.gz
index 1815e47..1a18320 100644
--- a/dictionaries/fr_wordlist.combined.gz
+++ b/dictionaries/fr_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/hr_wordlist.combined.gz b/dictionaries/hr_wordlist.combined.gz
index 7694a2a..864f676 100644
--- a/dictionaries/hr_wordlist.combined.gz
+++ b/dictionaries/hr_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/it_wordlist.combined.gz b/dictionaries/it_wordlist.combined.gz
index 3b84cd7..dfb1752 100644
--- a/dictionaries/it_wordlist.combined.gz
+++ b/dictionaries/it_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/lt_wordlist.combined.gz b/dictionaries/lt_wordlist.combined.gz
index 316a5af..029722d 100644
--- a/dictionaries/lt_wordlist.combined.gz
+++ b/dictionaries/lt_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/lv_wordlist.combined.gz b/dictionaries/lv_wordlist.combined.gz
index b036ac2..41e1c28 100644
--- a/dictionaries/lv_wordlist.combined.gz
+++ b/dictionaries/lv_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/nb_wordlist.combined.gz b/dictionaries/nb_wordlist.combined.gz
index b6e0d42..b699912 100644
--- a/dictionaries/nb_wordlist.combined.gz
+++ b/dictionaries/nb_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/nl_wordlist.combined.gz b/dictionaries/nl_wordlist.combined.gz
index 48ab0f4..89c2388 100644
--- a/dictionaries/nl_wordlist.combined.gz
+++ b/dictionaries/nl_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/pl_wordlist.combined.gz b/dictionaries/pl_wordlist.combined.gz
index bf02298..2b53f69 100644
--- a/dictionaries/pl_wordlist.combined.gz
+++ b/dictionaries/pl_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/pt_BR_wordlist.combined.gz b/dictionaries/pt_BR_wordlist.combined.gz
index 876eb71..2d22447 100644
--- a/dictionaries/pt_BR_wordlist.combined.gz
+++ b/dictionaries/pt_BR_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/pt_PT_wordlist.combined.gz b/dictionaries/pt_PT_wordlist.combined.gz
index 4068690..1504165 100644
--- a/dictionaries/pt_PT_wordlist.combined.gz
+++ b/dictionaries/pt_PT_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/sl_wordlist.combined.gz b/dictionaries/sl_wordlist.combined.gz
index 41a576b..55e1bb1 100644
--- a/dictionaries/sl_wordlist.combined.gz
+++ b/dictionaries/sl_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/sr_wordlist.combined.gz b/dictionaries/sr_wordlist.combined.gz
index dec6ae8..8488a08 100644
--- a/dictionaries/sr_wordlist.combined.gz
+++ b/dictionaries/sr_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/sv_wordlist.combined.gz b/dictionaries/sv_wordlist.combined.gz
index 0471772..6342520 100644
--- a/dictionaries/sv_wordlist.combined.gz
+++ b/dictionaries/sv_wordlist.combined.gz
Binary files differ
diff --git a/dictionaries/tr_wordlist.combined.gz b/dictionaries/tr_wordlist.combined.gz
index fae79ca..0251778 100644
--- a/dictionaries/tr_wordlist.combined.gz
+++ b/dictionaries/tr_wordlist.combined.gz
Binary files differ
diff --git a/java/res/raw/main_de.dict b/java/res/raw/main_de.dict
index 5d35e64..69796bb 100644
--- a/java/res/raw/main_de.dict
+++ b/java/res/raw/main_de.dict
Binary files differ
diff --git a/java/res/raw/main_en.dict b/java/res/raw/main_en.dict
index 8660c28..bef6b10 100644
--- a/java/res/raw/main_en.dict
+++ b/java/res/raw/main_en.dict
Binary files differ
diff --git a/java/res/raw/main_es.dict b/java/res/raw/main_es.dict
index f5906c2..261ab8c 100644
--- a/java/res/raw/main_es.dict
+++ b/java/res/raw/main_es.dict
Binary files differ
diff --git a/java/res/raw/main_fr.dict b/java/res/raw/main_fr.dict
index 0d2e518..18f5298 100644
--- a/java/res/raw/main_fr.dict
+++ b/java/res/raw/main_fr.dict
Binary files differ
diff --git a/java/res/raw/main_it.dict b/java/res/raw/main_it.dict
index 523f645..e161c24 100644
--- a/java/res/raw/main_it.dict
+++ b/java/res/raw/main_it.dict
Binary files differ
diff --git a/java/res/raw/main_pt_br.dict b/java/res/raw/main_pt_br.dict
index 98a27c7..21bbe7c 100644
--- a/java/res/raw/main_pt_br.dict
+++ b/java/res/raw/main_pt_br.dict
Binary files differ
diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionary.java b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
index 6ec7aee..29c6c04 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
@@ -115,7 +115,7 @@
     private static native long openNative(String sourceDir, long dictOffset, long dictSize,
             boolean isUpdatable);
     private static native void flushNative(long dict, String filePath);
-    private static native boolean needsToRunGCNative(long dict);
+    private static native boolean needsToRunGCNative(long dict, boolean mindsBlockByGC);
     private static native void flushWithGCNative(long dict, String filePath);
     private static native void closeNative(long dict);
     private static native int getProbabilityNative(long dict, int[] word);
@@ -270,7 +270,7 @@
     }
 
     private void runGCIfRequired() {
-        if (needsToRunGCNative(mNativeDict)) {
+        if (needsToRunGC(true /* mindsBlockByGC */)) {
             flushWithGC();
         }
     }
@@ -326,9 +326,15 @@
         reopen();
     }
 
-    public boolean needsToRunGC() {
+    /**
+     * Checks whether GC is needed to run or not.
+     * @param mindsBlockByGC Whether to mind operations blocked by GC. We don't need to care about
+     * the blocking in some situations such as in idle time or just before closing.
+     * @return whether GC is needed to run or not.
+     */
+    public boolean needsToRunGC(final boolean mindsBlockByGC) {
         if (!isValidDictionary()) return false;
-        return needsToRunGCNative(mNativeDict);
+        return needsToRunGCNative(mNativeDict, mindsBlockByGC);
     }
 
     @UsedForTesting
diff --git a/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java b/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
index cbba3f8..2d1ca51 100644
--- a/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
@@ -505,7 +505,7 @@
                     BinaryDictionary.createEmptyDictFile(file.getAbsolutePath(),
                             DICTIONARY_FORMAT_VERSION, getHeaderAttributeMap());
                 } else {
-                    if (mBinaryDictionary.needsToRunGC()) {
+                    if (mBinaryDictionary.needsToRunGC(false /* mindsBlockByGC */)) {
                         mBinaryDictionary.flushWithGC();
                     } else {
                         mBinaryDictionary.flush();
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java
index 6cc0bfb..af61f29 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java
@@ -385,12 +385,14 @@
                         nodeSize + size, ptNode.mChildren));
             }
             nodeSize += getShortcutListSize(ptNode.mShortcutTargets);
-            if (null != ptNode.mBigrams) {
-                for (WeightedString bigram : ptNode.mBigrams) {
-                    final int offset = getOffsetToTargetPtNodeDuringUpdate(ptNodeArray,
-                            nodeSize + size + FormatSpec.PTNODE_ATTRIBUTE_FLAGS_SIZE,
-                            FusionDictionary.findWordInTree(dict.mRootNodeArray, bigram.mWord));
-                    nodeSize += getByteSize(offset) + FormatSpec.PTNODE_ATTRIBUTE_FLAGS_SIZE;
+            if (formatOptions.mVersion < FormatSpec.FIRST_VERSION_WITH_TERMINAL_ID) {
+                if (null != ptNode.mBigrams) {
+                    for (WeightedString bigram : ptNode.mBigrams) {
+                        final int offset = getOffsetToTargetPtNodeDuringUpdate(ptNodeArray,
+                                nodeSize + size + FormatSpec.PTNODE_ATTRIBUTE_FLAGS_SIZE,
+                                FusionDictionary.findWordInTree(dict.mRootNodeArray, bigram.mWord));
+                        nodeSize += getByteSize(offset) + FormatSpec.PTNODE_ATTRIBUTE_FLAGS_SIZE;
+                    }
                 }
             }
             ptNode.mCachedSize = nodeSize;
diff --git a/java/src/com/android/inputmethod/latin/makedict/DynamicBinaryDictIOUtils.java b/java/src/com/android/inputmethod/latin/makedict/DynamicBinaryDictIOUtils.java
index bf3d191..411e265 100644
--- a/java/src/com/android/inputmethod/latin/makedict/DynamicBinaryDictIOUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/DynamicBinaryDictIOUtils.java
@@ -77,7 +77,7 @@
      * @param newParentAddress the absolute address of the parent.
      * @param formatOptions file format options.
      */
-    public static void updateParentAddress(final DictBuffer dictBuffer,
+    private static void updateParentAddress(final DictBuffer dictBuffer,
             final int ptNodeOriginAddress, final int newParentAddress,
             final FormatOptions formatOptions) {
         final int originalPosition = dictBuffer.position();
@@ -109,7 +109,7 @@
      * @param newParentAddress the address to be written.
      * @param formatOptions file format options.
      */
-    public static void updateParentAddresses(final DictBuffer dictBuffer,
+    private static void updateParentAddresses(final DictBuffer dictBuffer,
             final int ptNodeOriginAddress, final int newParentAddress,
             final FormatOptions formatOptions) {
         final int originalPosition = dictBuffer.position();
@@ -136,7 +136,7 @@
      * @param newChildrenAddress the absolute address of the child.
      * @param formatOptions file format options.
      */
-    public static void updateChildrenAddress(final DictBuffer dictBuffer,
+    private static void updateChildrenAddress(final DictBuffer dictBuffer,
             final int ptNodeOriginAddress, final int newChildrenAddress,
             final FormatOptions formatOptions) {
         final int originalPosition = dictBuffer.position();
diff --git a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
index 2765222..9481a8c 100644
--- a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
+++ b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
@@ -265,8 +265,12 @@
     static final String FREQ_FILE_EXTENSION = ".freq";
     // tat = Terminal Address Table
     static final String TERMINAL_ADDRESS_TABLE_FILE_EXTENSION = ".tat";
+    static final String BIGRAM_FILE_EXTENSION = ".bigram";
+    static final String BIGRAM_LOOKUP_TABLE_FILE_EXTENSION = ".bigram_lookup";
+    static final String BIGRAM_ADDRESS_TABLE_FILE_EXTENSION = ".bigram_index";
     static final int FREQUENCY_AND_FLAGS_SIZE = 2;
     static final int TERMINAL_ADDRESS_TABLE_ADDRESS_SIZE = 3;
+    static final int BIGRAM_ADDRESS_TABLE_BLOCK_SIZE = 4;
 
     static final int NO_CHILDREN_ADDRESS = Integer.MIN_VALUE;
     static final int NO_PARENT_ADDRESS = 0;
diff --git a/java/src/com/android/inputmethod/latin/makedict/SparseTable.java b/java/src/com/android/inputmethod/latin/makedict/SparseTable.java
index 0b9cf91..96d057a 100644
--- a/java/src/com/android/inputmethod/latin/makedict/SparseTable.java
+++ b/java/src/com/android/inputmethod/latin/makedict/SparseTable.java
@@ -18,6 +18,9 @@
 
 import com.android.inputmethod.annotations.UsedForTesting;
 
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.ArrayList;
@@ -147,4 +150,45 @@
             BinaryDictEncoderUtils.writeUIntToStream(contentOutStream, index, 4);
         }
     }
+
+    @UsedForTesting
+    public void writeToFiles(final File lookupTableFile, final File contentFile)
+            throws IOException {
+      FileOutputStream lookupTableOutStream = null;
+      FileOutputStream contentOutStream = null;
+        try {
+            lookupTableOutStream = new FileOutputStream(lookupTableFile);
+            contentOutStream = new FileOutputStream(contentFile);
+            write(lookupTableOutStream, contentOutStream);
+        } finally {
+            if (lookupTableOutStream != null) {
+                lookupTableOutStream.close();
+            }
+            if (contentOutStream != null) {
+                contentOutStream.close();
+            }
+        }
+    }
+
+    private static byte[] readFileToByteArray(final File file) throws IOException {
+        final byte[] contents = new byte[(int) file.length()];
+        FileInputStream inStream = null;
+        try {
+            inStream = new FileInputStream(file);
+            inStream.read(contents);
+        } finally {
+            if (inStream != null) {
+                inStream.close();
+            }
+        }
+        return contents;
+    }
+
+    @UsedForTesting
+    public static SparseTable readFromFiles(final File lookupTableFile, final File contentFile,
+            final int blockSize) throws IOException {
+        final byte[] lookupTable = readFileToByteArray(lookupTableFile);
+        final byte[] content = readFileToByteArray(contentFile);
+        return new SparseTable(lookupTable, content, blockSize);
+    }
 }
diff --git a/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java
index 4c8ff8e..0aa4319 100644
--- a/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java
@@ -42,12 +42,15 @@
     private static final int FILETYPE_TRIE = 1;
     private static final int FILETYPE_FREQUENCY = 2;
     private static final int FILETYPE_TERMINAL_ADDRESS_TABLE = 3;
+    private static final int FILETYPE_BIGRAM = 4;
 
     private final File mDictDirectory;
     private final DictionaryBufferFactory mBufferFactory;
     private DictBuffer mDictBuffer;
     private DictBuffer mFrequencyBuffer;
     private DictBuffer mTerminalAddressTableBuffer;
+    private DictBuffer mBigramBuffer;
+    private SparseTable mBigramAddressTable;
 
     @UsedForTesting
     /* package */ Ver4DictDecoder(final File dictDirectory, final int factoryFlag) {
@@ -82,6 +85,9 @@
         } else if (fileType == FILETYPE_TERMINAL_ADDRESS_TABLE) {
             return new File(mDictDirectory,
                     mDictDirectory.getName() + FormatSpec.TERMINAL_ADDRESS_TABLE_FILE_EXTENSION);
+        } else if (fileType == FILETYPE_BIGRAM) {
+            return new File(mDictDirectory,
+                    mDictDirectory.getName() + FormatSpec.BIGRAM_FILE_EXTENSION);
         } else {
             throw new RuntimeException("Unsupported kind of file : " + fileType);
         }
@@ -94,6 +100,8 @@
         mFrequencyBuffer = mBufferFactory.getDictionaryBuffer(getFile(FILETYPE_FREQUENCY));
         mTerminalAddressTableBuffer = mBufferFactory.getDictionaryBuffer(
                 getFile(FILETYPE_TERMINAL_ADDRESS_TABLE));
+        mBigramBuffer = mBufferFactory.getDictionaryBuffer(getFile(FILETYPE_BIGRAM));
+        loadBigramAddressSparseTable();
     }
 
     @Override
@@ -118,6 +126,15 @@
         return header;
     }
 
+    private void loadBigramAddressSparseTable() throws IOException {
+        final File lookupIndexFile = new File(mDictDirectory,
+                mDictDirectory.getName() + FormatSpec.BIGRAM_LOOKUP_TABLE_FILE_EXTENSION);
+        final File contentFile = new File(mDictDirectory,
+                mDictDirectory.getName() + FormatSpec.BIGRAM_ADDRESS_TABLE_FILE_EXTENSION);
+        mBigramAddressTable = SparseTable.readFromFiles(lookupIndexFile, contentFile,
+                FormatSpec.BIGRAM_ADDRESS_TABLE_BLOCK_SIZE);
+    }
+
     protected static class PtNodeReader extends DictDecoder.PtNodeReader {
         protected static int readFrequency(final DictBuffer frequencyBuffer, final int terminalId) {
             frequencyBuffer.position(terminalId * FormatSpec.FREQUENCY_AND_FLAGS_SIZE + 1);
@@ -191,8 +208,21 @@
         final ArrayList<PendingAttribute> bigrams;
         if (0 != (flags & FormatSpec.FLAG_HAS_BIGRAMS)) {
             bigrams = new ArrayList<PendingAttribute>();
-            addressPointer += PtNodeReader.readBigramAddresses(mDictBuffer, bigrams,
-                    addressPointer);
+            final int posOfBigrams = mBigramAddressTable.get(terminalId);
+            mBigramBuffer.position(posOfBigrams);
+            while (bigrams.size() < FormatSpec.MAX_BIGRAMS_IN_A_PTNODE) {
+                // If bigrams.size() reaches FormatSpec.MAX_BIGRAMS_IN_A_PTNODE,
+                // remaining bigram entries are ignored.
+                final int bigramFlags = mBigramBuffer.readUnsignedByte();
+                final int targetTerminalId = mBigramBuffer.readUnsignedInt24();
+                mTerminalAddressTableBuffer.position(
+                        targetTerminalId * FormatSpec.TERMINAL_ADDRESS_TABLE_ADDRESS_SIZE);
+                final int targetAddress = mTerminalAddressTableBuffer.readUnsignedInt24();
+                bigrams.add(new PendingAttribute(
+                        bigramFlags & FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY,
+                        targetAddress));
+                if (0 == (bigramFlags & FormatSpec.FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT)) break;
+            }
             if (bigrams.size() >= FormatSpec.MAX_BIGRAMS_IN_A_PTNODE) {
                 MakedictLog.d("too many bigrams in a node.");
             }
diff --git a/java/src/com/android/inputmethod/latin/makedict/Ver4DictEncoder.java b/java/src/com/android/inputmethod/latin/makedict/Ver4DictEncoder.java
index 4fb8967..4c25faf 100644
--- a/java/src/com/android/inputmethod/latin/makedict/Ver4DictEncoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/Ver4DictEncoder.java
@@ -26,6 +26,7 @@
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
 import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
@@ -43,9 +44,13 @@
     private byte[] mTrieBuf;
     private int mTriePos;
     private int mHeaderSize;
+    private SparseTable mBigramAddressTable;
     private OutputStream mTrieOutStream;
     private OutputStream mFreqOutStream;
     private OutputStream mTerminalAddressTableOutStream;
+    private OutputStream mBigramOutStream;
+    private File mDictDir;
+    private String mBaseFilename;
 
     @UsedForTesting
     public Ver4DictEncoder(final File dictPlacedDir) {
@@ -55,12 +60,14 @@
     private void openStreams(final FormatOptions formatOptions, final DictionaryOptions dictOptions)
             throws FileNotFoundException, IOException {
         final FileHeader header = new FileHeader(0, dictOptions, formatOptions);
-        final String filename = header.getId() + "." + header.getVersion();
-        final File mDictDir = new File(mDictPlacedDir, filename);
-        final File trieFile = new File(mDictDir, filename + FormatSpec.TRIE_FILE_EXTENSION);
-        final File freqFile = new File(mDictDir, filename + FormatSpec.FREQ_FILE_EXTENSION);
+        mBaseFilename = header.getId() + "." + header.getVersion();
+        mDictDir = new File(mDictPlacedDir, mBaseFilename);
+        final File trieFile = new File(mDictDir, mBaseFilename + FormatSpec.TRIE_FILE_EXTENSION);
+        final File freqFile = new File(mDictDir, mBaseFilename + FormatSpec.FREQ_FILE_EXTENSION);
         final File terminalAddressTableFile = new File(mDictDir,
-                filename + FormatSpec.TERMINAL_ADDRESS_TABLE_FILE_EXTENSION);
+                mBaseFilename + FormatSpec.TERMINAL_ADDRESS_TABLE_FILE_EXTENSION);
+        final File bigramFile = new File(mDictDir,
+                mBaseFilename + FormatSpec.BIGRAM_FILE_EXTENSION);
         if (!mDictDir.isDirectory()) {
             if (mDictDir.exists()) mDictDir.delete();
             mDictDir.mkdirs();
@@ -71,6 +78,7 @@
         mTrieOutStream = new FileOutputStream(trieFile);
         mFreqOutStream = new FileOutputStream(freqFile);
         mTerminalAddressTableOutStream = new FileOutputStream(terminalAddressTableFile);
+        mBigramOutStream = new FileOutputStream(bigramFile);
     }
 
     private void close() throws IOException {
@@ -84,10 +92,14 @@
             if (mTerminalAddressTableOutStream != null) {
                 mTerminalAddressTableOutStream.close();
             }
+            if (mBigramOutStream != null) {
+                mBigramOutStream.close();
+            }
         } finally {
             mTrieOutStream = null;
             mFreqOutStream = null;
             mTerminalAddressTableOutStream = null;
+            mBigramOutStream = null;
         }
     }
 
@@ -123,6 +135,10 @@
         if (MakedictLog.DBG) BinaryDictEncoderUtils.checkFlatPtNodeArrayList(flatNodes);
 
         writeTerminalData(flatNodes, terminalCount);
+        mBigramAddressTable = new SparseTable(terminalCount,
+                FormatSpec.BIGRAM_ADDRESS_TABLE_BLOCK_SIZE);
+        writeBigrams(flatNodes, dict);
+        writeBigramAddressSparseTable();
 
         final PtNodeArray lastNodeArray = flatNodes.get(flatNodes.size() - 1);
         final int bufferSize = lastNodeArray.mCachedAddressAfterUpdate + lastNodeArray.mCachedSize;
@@ -230,24 +246,41 @@
                 shortcutByteSize, FormatSpec.PTNODE_SHORTCUT_LIST_SIZE_SIZE);
     }
 
-    private void writeBigrams(ArrayList<WeightedString> bigrams, FusionDictionary dict) {
-        if (bigrams == null) return;
+    private void writeBigrams(final ArrayList<PtNodeArray> flatNodes, final FusionDictionary dict)
+            throws IOException {
+        final ByteArrayOutputStream bigramBuffer = new ByteArrayOutputStream();
 
-        final Iterator<WeightedString> bigramIterator = bigrams.iterator();
-        while (bigramIterator.hasNext()) {
-            final WeightedString bigram = bigramIterator.next();
-            final PtNode target =
-                    FusionDictionary.findWordInTree(dict.mRootNodeArray, bigram.mWord);
-            final int addressOfBigram = target.mCachedAddressAfterUpdate;
-            final int unigramFrequencyForThisWord = target.mFrequency;
-            final int offset = addressOfBigram
-                    - (mTriePos + FormatSpec.PTNODE_ATTRIBUTE_FLAGS_SIZE);
-            int bigramFlags = BinaryDictEncoderUtils.makeBigramFlags(bigramIterator.hasNext(),
-                    offset, bigram.mFrequency, unigramFrequencyForThisWord, bigram.mWord);
-            mTrieBuf[mTriePos++] = (byte) bigramFlags;
-            mTriePos += BinaryDictEncoderUtils.writeChildrenPosition(mTrieBuf,
-                    mTriePos, Math.abs(offset));
+        for (final PtNodeArray nodeArray : flatNodes) {
+            for (final PtNode ptNode : nodeArray.mData) {
+                if (ptNode.mBigrams != null) {
+                    final int startPos = bigramBuffer.size();
+                    mBigramAddressTable.set(ptNode.mTerminalId, startPos);
+                    final Iterator<WeightedString> bigramIterator = ptNode.mBigrams.iterator();
+                    while (bigramIterator.hasNext()) {
+                        final WeightedString bigram = bigramIterator.next();
+                        final PtNode target =
+                            FusionDictionary.findWordInTree(dict.mRootNodeArray, bigram.mWord);
+                        final int unigramFrequencyForThisWord = target.mFrequency;
+                        final int bigramFlags = BinaryDictEncoderUtils.makeBigramFlags(
+                                bigramIterator.hasNext(), 0, bigram.mFrequency,
+                                unigramFrequencyForThisWord, bigram.mWord);
+                        BinaryDictEncoderUtils.writeUIntToStream(bigramBuffer, bigramFlags,
+                                FormatSpec.PTNODE_ATTRIBUTE_FLAGS_SIZE);
+                        BinaryDictEncoderUtils.writeUIntToStream(bigramBuffer, target.mTerminalId,
+                                FormatSpec.PTNODE_ATTRIBUTE_MAX_ADDRESS_SIZE);
+                    }
+                }
+            }
         }
+        bigramBuffer.writeTo(mBigramOutStream);
+    }
+
+    private void writeBigramAddressSparseTable() throws IOException {
+        final File lookupIndexFile =
+                new File(mDictDir, mBaseFilename + FormatSpec.BIGRAM_LOOKUP_TABLE_FILE_EXTENSION);
+        final File contentFile =
+                new File(mDictDir, mBaseFilename + FormatSpec.BIGRAM_ADDRESS_TABLE_FILE_EXTENSION);
+        mBigramAddressTable.writeToFiles(lookupIndexFile, contentFile);
     }
 
     @Override
@@ -267,7 +300,6 @@
         }
         writeChildrenPosition(ptNode, formatOptions);
         writeShortcuts(ptNode.mShortcutTargets);
-        writeBigrams(ptNode.mBigrams, dict);
     }
 
     private void writeTerminalData(final ArrayList<PtNodeArray> flatNodes,
diff --git a/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp b/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
index 85e100e..c5ef264 100644
--- a/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
+++ b/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
@@ -113,10 +113,10 @@
 }
 
 static bool latinime_BinaryDictionary_needsToRunGC(JNIEnv *env, jclass clazz,
-        jlong dict) {
+        jlong dict, jboolean mindsBlockByGC) {
     Dictionary *dictionary = reinterpret_cast<Dictionary *>(dict);
     if (!dictionary) return false;
-    return dictionary->needsToRunGC();
+    return dictionary->needsToRunGC(mindsBlockByGC == JNI_TRUE);
 }
 
 static void latinime_BinaryDictionary_flushWithGC(JNIEnv *env, jclass clazz, jlong dict,
@@ -364,7 +364,7 @@
     },
     {
         const_cast<char *>("needsToRunGCNative"),
-        const_cast<char *>("(J)Z"),
+        const_cast<char *>("(JZ)Z"),
         reinterpret_cast<void *>(latinime_BinaryDictionary_needsToRunGC)
     },
     {
diff --git a/native/jni/src/suggest/core/dictionary/dictionary.cpp b/native/jni/src/suggest/core/dictionary/dictionary.cpp
index 9b4c91a..b1d01ed 100644
--- a/native/jni/src/suggest/core/dictionary/dictionary.cpp
+++ b/native/jni/src/suggest/core/dictionary/dictionary.cpp
@@ -123,8 +123,8 @@
     mDictionaryStructureWithBufferPolicy->flushWithGC(filePath);
 }
 
-bool Dictionary::needsToRunGC() {
-    return mDictionaryStructureWithBufferPolicy->needsToRunGC();
+bool Dictionary::needsToRunGC(const bool mindsBlockByGC) {
+    return mDictionaryStructureWithBufferPolicy->needsToRunGC(mindsBlockByGC);
 }
 
 void Dictionary::getProperty(const char *const query, char *const outResult,
diff --git a/native/jni/src/suggest/core/dictionary/dictionary.h b/native/jni/src/suggest/core/dictionary/dictionary.h
index 5740508..d8a0f3e 100644
--- a/native/jni/src/suggest/core/dictionary/dictionary.h
+++ b/native/jni/src/suggest/core/dictionary/dictionary.h
@@ -81,7 +81,7 @@
 
     void flushWithGC(const char *const filePath);
 
-    bool needsToRunGC();
+    bool needsToRunGC(const bool mindsBlockByGC);
 
     void getProperty(const char *const query, char *const outResult,
             const int maxResultLength) const;
diff --git a/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h b/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
index 2434287..c7ffef0 100644
--- a/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
+++ b/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
@@ -78,7 +78,7 @@
 
     virtual void flushWithGC(const char *const filePath) = 0;
 
-    virtual bool needsToRunGC() const = 0;
+    virtual bool needsToRunGC(const bool mindsBlockByGC) const = 0;
 
     virtual void getProperty(const char *const query, char *const outResult,
             const int maxResultLength) const = 0;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_gc_event_listeners.cpp b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_gc_event_listeners.cpp
index 5eb4733..5f755c3 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_gc_event_listeners.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_gc_event_listeners.cpp
@@ -41,7 +41,7 @@
             return false;
         }
     } else {
-        valueStack.back() += 1;
+        mValueStack.back() += 1;
         if (node->isTerminal()) {
             mValidUnigramCount += 1;
         }
@@ -49,6 +49,23 @@
     return true;
 }
 
+bool DynamicPatriciaTrieGcEventListeners::TraversePolicyToUpdateBigramProbability
+        ::onVisitingPtNode(const DynamicPatriciaTrieNodeReader *const node,
+                const int *const nodeCodePoints) {
+    if (!node->isDeleted()) {
+        int pos = node->getBigramsPos();
+        if (pos != NOT_A_DICT_POS) {
+            int bigramEntryCount = 0;
+            if (!mBigramPolicy->updateAllBigramEntriesAndDeleteUselessEntries(&pos,
+                    &bigramEntryCount)) {
+                return false;
+            }
+            mValidBigramEntryCount += bigramEntryCount;
+        }
+    }
+    return true;
+}
+
 // Writes dummy PtNode array size when the head of PtNode array is read.
 bool DynamicPatriciaTrieGcEventListeners::TraversePolicyToPlaceAndWriteValidPtNodesToBuffer
         ::onDescend(const int ptNodeArrayPos) {
diff --git a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_gc_event_listeners.h b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_gc_event_listeners.h
index aa6e609..3019988 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_gc_event_listeners.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_gc_event_listeners.h
@@ -40,22 +40,22 @@
         TraversePolicyToUpdateUnigramProbabilityAndMarkUselessPtNodesAsDeleted(
                 DynamicPatriciaTrieWritingHelper *const writingHelper,
                 BufferWithExtendableBuffer *const buffer)
-                : mWritingHelper(writingHelper), mBuffer(buffer), valueStack(),
+                : mWritingHelper(writingHelper), mBuffer(buffer), mValueStack(),
                   mChildrenValue(0), mValidUnigramCount(0) {}
 
         ~TraversePolicyToUpdateUnigramProbabilityAndMarkUselessPtNodesAsDeleted() {};
 
         bool onAscend() {
-            if (valueStack.empty()) {
+            if (mValueStack.empty()) {
                 return false;
             }
-            mChildrenValue = valueStack.back();
-            valueStack.pop_back();
+            mChildrenValue = mValueStack.back();
+            mValueStack.pop_back();
             return true;
         }
 
         bool onDescend(const int ptNodeArrayPos) {
-            valueStack.push_back(0);
+            mValueStack.push_back(0);
             return true;
         }
 
@@ -74,7 +74,7 @@
 
         DynamicPatriciaTrieWritingHelper *const mWritingHelper;
         BufferWithExtendableBuffer *const mBuffer;
-        std::vector<int> valueStack;
+        std::vector<int> mValueStack;
         int mChildrenValue;
         int mValidUnigramCount;
     };
@@ -94,20 +94,7 @@
         bool onReadingPtNodeArrayTail() { return true; }
 
         bool onVisitingPtNode(const DynamicPatriciaTrieNodeReader *const node,
-                const int *const nodeCodePoints) {
-            if (!node->isDeleted()) {
-                int pos = node->getBigramsPos();
-                if (pos != NOT_A_DICT_POS) {
-                    int bigramEntryCount = 0;
-                    if (!mBigramPolicy->updateAllBigramEntriesAndDeleteUselessEntries(&pos,
-                            &bigramEntryCount)) {
-                        return false;
-                    }
-                    mValidBigramEntryCount += bigramEntryCount;
-                }
-            }
-            return true;
-        }
+                const int *const nodeCodePoints);
 
         int getValidBigramEntryCount() const {
             return mValidBigramEntryCount;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.cpp
index 4581ec0..8c0890e 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.cpp
@@ -291,7 +291,7 @@
     writingHelper.writeToDictFileWithGC(getRootPosition(), filePath, &mHeaderPolicy);
 }
 
-bool DynamicPatriciaTriePolicy::needsToRunGC() const {
+bool DynamicPatriciaTriePolicy::needsToRunGC(const bool mindsBlockByGC) const {
     if (!mBuffer->isUpdatable()) {
         AKLOGI("Warning: needsToRunGC() is called for non-updatable dictionary.");
         return false;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.h
index 7f9d4d9..bdb436c 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.h
@@ -91,7 +91,7 @@
 
     void flushWithGC(const char *const filePath);
 
-    bool needsToRunGC() const;
+    bool needsToRunGC(const bool mindsBlockByGC) const;
 
     void getProperty(const char *const query, char *const outResult,
             const int maxResultLength) const;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_writing_helper.cpp b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_writing_helper.cpp
index bae5e8c..2a2e9bc 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_writing_helper.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_writing_helper.cpp
@@ -147,7 +147,7 @@
         const HeaderPolicy *const headerPolicy, const int unigramCount, const int bigramCount) {
     BufferWithExtendableBuffer headerBuffer(0 /* originalBuffer */, 0 /* originalBufferSize */);
     const int extendedRegionSize = headerPolicy->getExtendedRegionSize() +
-            mBuffer->getTailPosition() - mBuffer->getOriginalBufferSize();
+            mBuffer->getUsedAdditionalBufferSize();
     if (!headerPolicy->writeHeaderToBuffer(&headerBuffer, false /* updatesLastUpdatedTime */,
             unigramCount, bigramCount, extendedRegionSize)) {
         return;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.cpp
index 78c6c04..9ce9994 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.cpp
@@ -20,7 +20,8 @@
 
 // Note that these are corresponding definitions in Java side in FormatSpec.FileHeader.
 const char *const HeaderPolicy::MULTIPLE_WORDS_DEMOTION_RATE_KEY = "MULTIPLE_WORDS_DEMOTION_RATE";
-const char *const HeaderPolicy::USES_FORGETTING_CURVE_KEY = "USES_FORGETTING_CURVE";
+// TODO: Change attribute string to "IS_DECAYING_DICT".
+const char *const HeaderPolicy::IS_DECAYING_DICT_KEY = "USES_FORGETTING_CURVE";
 const char *const HeaderPolicy::LAST_UPDATED_TIME_KEY = "date";
 const char *const HeaderPolicy::UNIGRAM_COUNT_KEY = "UNIGRAM_COUNT";
 const char *const HeaderPolicy::BIGRAM_COUNT_KEY = "BIGRAM_COUNT";
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 93b9c6f..4261667 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h
@@ -36,8 +36,8 @@
               mSize(HeaderReadWriteUtils::getHeaderSize(dictBuf)),
               mAttributeMap(createAttributeMapAndReadAllAttributes(dictBuf)),
               mMultiWordCostMultiplier(readMultipleWordCostMultiplier()),
-              mUsesForgettingCurve(HeaderReadWriteUtils::readBoolAttributeValue(&mAttributeMap,
-                      USES_FORGETTING_CURVE_KEY, false /* defaultValue */)),
+              mIsDecayingDict(HeaderReadWriteUtils::readBoolAttributeValue(&mAttributeMap,
+                      IS_DECAYING_DICT_KEY, false /* defaultValue */)),
               mLastUpdatedTime(HeaderReadWriteUtils::readIntAttributeValue(&mAttributeMap,
                       LAST_UPDATED_TIME_KEY, time(0) /* defaultValue */)),
               mUnigramCount(HeaderReadWriteUtils::readIntAttributeValue(&mAttributeMap,
@@ -54,8 +54,8 @@
               mDictionaryFlags(HeaderReadWriteUtils::createAndGetDictionaryFlagsUsingAttributeMap(
                       attributeMap)), mSize(0), mAttributeMap(*attributeMap),
               mMultiWordCostMultiplier(readMultipleWordCostMultiplier()),
-              mUsesForgettingCurve(HeaderReadWriteUtils::readBoolAttributeValue(&mAttributeMap,
-                      USES_FORGETTING_CURVE_KEY, false /* defaultValue */)),
+              mIsDecayingDict(HeaderReadWriteUtils::readBoolAttributeValue(&mAttributeMap,
+                      IS_DECAYING_DICT_KEY, false /* defaultValue */)),
               mLastUpdatedTime(HeaderReadWriteUtils::readIntAttributeValue(&mAttributeMap,
                       LAST_UPDATED_TIME_KEY, time(0) /* defaultValue */)),
               mUnigramCount(0), mBigramCount(0), mExtendedRegionSize(0) {}
@@ -82,8 +82,8 @@
         return mMultiWordCostMultiplier;
     }
 
-    AK_FORCE_INLINE bool usesForgettingCurve() const {
-        return mUsesForgettingCurve;
+    AK_FORCE_INLINE bool isDecayingDict() const {
+        return mIsDecayingDict;
     }
 
     AK_FORCE_INLINE int getLastUpdatedTime() const {
@@ -113,7 +113,7 @@
     DISALLOW_IMPLICIT_CONSTRUCTORS(HeaderPolicy);
 
     static const char *const MULTIPLE_WORDS_DEMOTION_RATE_KEY;
-    static const char *const USES_FORGETTING_CURVE_KEY;
+    static const char *const IS_DECAYING_DICT_KEY;
     static const char *const LAST_UPDATED_TIME_KEY;
     static const char *const UNIGRAM_COUNT_KEY;
     static const char *const BIGRAM_COUNT_KEY;
@@ -126,7 +126,7 @@
     const int mSize;
     HeaderReadWriteUtils::AttributeMap mAttributeMap;
     const float mMultiWordCostMultiplier;
-    const bool mUsesForgettingCurve;
+    const bool mIsDecayingDict;
     const int mLastUpdatedTime;
     const int mUnigramCount;
     const int mBigramCount;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.h
index 4277ff5..8d88c68 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.h
@@ -107,7 +107,7 @@
         AKLOGI("Warning: flushWithGC() is called for non-updatable dictionary.");
     }
 
-    bool needsToRunGC() const {
+    bool needsToRunGC(const bool mindsBlockByGC) const {
         // This method should not be called for non-updatable dictionary.
         AKLOGI("Warning: needsToRunGC() is called for non-updatable dictionary.");
         return false;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h b/native/jni/src/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h
index 17d2e39..9dc3482 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h
@@ -42,6 +42,10 @@
         return mOriginalBufferSize + mUsedAdditionalBufferSize;
     }
 
+    AK_FORCE_INLINE int getUsedAdditionalBufferSize() const {
+        return mUsedAdditionalBufferSize;
+    }
+
     /**
      * For reading.
      */
diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.cpp b/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.cpp
index 4fae919..f22e94c 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.cpp
@@ -96,7 +96,7 @@
         fclose(file);
         return false;
     }
-    const int additionalBufSize = buffer->getTailPosition() - buffer->getOriginalBufferSize();
+    const int additionalBufSize = buffer->getUsedAdditionalBufferSize();
     if (additionalBufSize > 0 && fwrite(buffer->getBuffer(true /* usesAdditionalBuffer */),
             additionalBufSize, 1, file) < 1) {
         fclose(file);
diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
index 826c0f7..6a21522 100644
--- a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
@@ -606,7 +606,7 @@
             binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),
                     0 /* offset */, dictFile.length(), true /* useFullEditDistance */,
                     Locale.getDefault(), TEST_LOCALE, true /* isUpdatable */);
-            while(!binaryDictionary.needsToRunGC()) {
+            while(!binaryDictionary.needsToRunGC(true /* mindsBlockByGC */)) {
                 final String word = CodePointUtils.generateWord(random, codePointSet);
                 words.add(word);
                 final int unigramProbability = random.nextInt(0xFF);
diff --git a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtils.java b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtils.java
index 6c4cbcf..bd06e9f 100644
--- a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtils.java
+++ b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtils.java
@@ -80,17 +80,17 @@
     }
 
     /**
-     * Returns a decrypted/uncompressed binary dictionary.
+     * Returns a decrypted/uncompressed dictionary.
      *
-     * This will decrypt/uncompress any number of times as necessary until it finds the binary
+     * This will decrypt/uncompress any number of times as necessary until it finds the
      * dictionary signature, and copy the decoded file to a temporary place.
-     * If this is not a binary dictionary, the method returns null.
+     * If this is not a dictionary, the method returns null.
      */
-    public static DecoderChainSpec getRawBinaryDictionaryOrNull(final File src) {
-        return getRawBinaryDictionaryOrNullInternal(new DecoderChainSpec(), src, 0);
+    public static DecoderChainSpec getRawDictionaryOrNull(final File src) {
+        return getRawDictionaryOrNullInternal(new DecoderChainSpec(), src, 0);
     }
 
-    private static DecoderChainSpec getRawBinaryDictionaryOrNullInternal(
+    private static DecoderChainSpec getRawDictionaryOrNullInternal(
             final DecoderChainSpec spec, final File src, final int depth) {
         // Unfortunately the decoding scheme we use can consider any data to be encrypted
         // and will product some output, meaning it's not possible to reliably detect encrypted
@@ -98,7 +98,8 @@
         // over and over, ending in a stack overflow. Hence we limit the depth at which we try
         // decoding the file.
         if (depth > MAX_DECODE_DEPTH) return null;
-        if (BinaryDictDecoderUtils.isBinaryDictionary(src)) {
+        if (BinaryDictDecoderUtils.isBinaryDictionary(src)
+                || CombinedInputOutput.isCombinedDictionary(src.getAbsolutePath())) {
             spec.mFile = src;
             return spec;
         }
@@ -106,7 +107,7 @@
         final File uncompressedFile = tryGetUncompressedFile(src);
         if (null != uncompressedFile) {
             final DecoderChainSpec newSpec =
-                    getRawBinaryDictionaryOrNullInternal(spec, uncompressedFile, depth + 1);
+                    getRawDictionaryOrNullInternal(spec, uncompressedFile, depth + 1);
             if (null == newSpec) return null;
             return newSpec.addStep(COMPRESSION);
         }
@@ -114,7 +115,7 @@
         final File decryptedFile = tryGetDecryptedFile(src);
         if (null != decryptedFile) {
             final DecoderChainSpec newSpec =
-                    getRawBinaryDictionaryOrNullInternal(spec, decryptedFile, depth + 1);
+                    getRawDictionaryOrNullInternal(spec, decryptedFile, depth + 1);
             if (null == newSpec) return null;
             return newSpec.addStep(ENCRYPTION);
         }
@@ -175,15 +176,16 @@
                 return XmlDictInputOutput.readDictionaryXml(
                         new BufferedInputStream(new FileInputStream(file)),
                         null /* shortcuts */, null /* bigrams */);
-            } else if (CombinedInputOutput.isCombinedDictionary(filename)) {
-                if (report) System.out.println("Format : Combined format");
-                return CombinedInputOutput.readDictionaryCombined(
-                        new BufferedInputStream(new FileInputStream(file)));
             } else {
-                final DecoderChainSpec decodedSpec = getRawBinaryDictionaryOrNull(file);
+                final DecoderChainSpec decodedSpec = getRawDictionaryOrNull(file);
                 if (null == decodedSpec) {
                     crash(filename, new RuntimeException(
                             filename + " does not seem to be a dictionary file"));
+                } else if (CombinedInputOutput.isCombinedDictionary(
+                        decodedSpec.mFile.getAbsolutePath())){
+                    if (report) System.out.println("Format : Combined format");
+                    return CombinedInputOutput.readDictionaryCombined(
+                            new BufferedInputStream(new FileInputStream(decodedSpec.mFile)));
                 } else {
                     final DictDecoder dictDecoder = FormatSpec.getDictDecoder(decodedSpec.mFile,
                             DictDecoder.USE_BYTEARRAY);
diff --git a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Package.java b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Package.java
index 9274dcd..dff3387 100644
--- a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Package.java
+++ b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/Package.java
@@ -79,7 +79,7 @@
                 throw new RuntimeException("Too many/too few arguments for command " + COMMAND);
             }
             final BinaryDictOffdeviceUtils.DecoderChainSpec decodedSpec =
-                    BinaryDictOffdeviceUtils.getRawBinaryDictionaryOrNull(new File(mArgs[0]));
+                    BinaryDictOffdeviceUtils.getRawDictionaryOrNull(new File(mArgs[0]));
             if (null == decodedSpec) {
                 System.out.println(mArgs[0] + " does not seem to be a dictionary");
                 return;
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 1eff497..1baeb7a 100644
--- a/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java
+++ b/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java
@@ -64,7 +64,7 @@
 
         // Test for an actually compressed dictionary and its contents
         final BinaryDictOffdeviceUtils.DecoderChainSpec decodeSpec =
-                BinaryDictOffdeviceUtils.getRawBinaryDictionaryOrNull(dst);
+                BinaryDictOffdeviceUtils.getRawDictionaryOrNull(dst);
         for (final String step : decodeSpec.mDecoderSpec) {
             assertEquals("Wrong decode spec", BinaryDictOffdeviceUtils.COMPRESSION, step);
         }
@@ -90,7 +90,7 @@
 
         // Test that a random data file actually fails
         assertNull("Wrongly identified data file",
-                BinaryDictOffdeviceUtils.getRawBinaryDictionaryOrNull(dst));
+                BinaryDictOffdeviceUtils.getRawDictionaryOrNull(dst));
 
         final File gzDst = File.createTempFile("testGetRawDict", ".tmp");
         gzDst.deleteOnExit();
@@ -103,6 +103,6 @@
 
         // Test that a compressed random data file actually fails
         assertNull("Wrongly identified data file",
-                BinaryDictOffdeviceUtils.getRawBinaryDictionaryOrNull(gzDst));
+                BinaryDictOffdeviceUtils.getRawDictionaryOrNull(gzDst));
     }
 }