diff --git a/tools/dicttool/Android.mk b/tools/dicttool/Android.mk
index f076ef2..3d09c05 100644
--- a/tools/dicttool/Android.mk
+++ b/tools/dicttool/Android.mk
@@ -28,7 +28,7 @@
 LATINIME_CORE_SOURCE_DIRECTORY := $(LATINIME_BASE_SOURCE_DIRECTORY)/latin
 MAKEDICT_CORE_SOURCE_DIRECTORY := $(LATINIME_CORE_SOURCE_DIRECTORY)/makedict
 USED_TARGETTED_UTILS := \
-        $(LATINIME_CORE_SOURCE_DIRECTORY)/utils/ByteArrayWrapper.java \
+        $(LATINIME_CORE_SOURCE_DIRECTORY)/utils/ByteArrayDictBuffer.java \
         $(LATINIME_CORE_SOURCE_DIRECTORY)/utils/CollectionUtils.java \
         $(LATINIME_CORE_SOURCE_DIRECTORY)/utils/JniUtils.java
 
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 4ddfb40..39ba69b 100644
--- a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtils.java
+++ b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtils.java
@@ -16,8 +16,8 @@
 
 package com.android.inputmethod.latin.dicttool;
 
+import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils;
 import com.android.inputmethod.latin.makedict.BinaryDictDecoder;
-import com.android.inputmethod.latin.makedict.BinaryDictReader;
 import com.android.inputmethod.latin.makedict.FusionDictionary;
 import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
 
@@ -97,7 +97,7 @@
         // 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 (BinaryDictDecoder.isBinaryDictionary(src)) {
+        if (BinaryDictDecoderUtils.isBinaryDictionary(src)) {
             spec.mFile = src;
             return spec;
         }
@@ -184,15 +184,15 @@
                     crash(filename, new RuntimeException(
                             filename + " does not seem to be a dictionary file"));
                 } else {
-                    final BinaryDictReader reader = new BinaryDictReader(decodedSpec.mFile);
-                    reader.openBuffer(
-                            new BinaryDictReader.FusionDictionaryBufferFromByteArrayFactory());
+                    final BinaryDictDecoder dictDecoder = new BinaryDictDecoder(decodedSpec.mFile);
+                    dictDecoder.openDictBuffer(
+                            new BinaryDictDecoder.DictionaryBufferFromByteArrayFactory());
                     if (report) {
                         System.out.println("Format : Binary dictionary format");
                         System.out.println("Packaging : " + decodedSpec.describeChain());
                         System.out.println("Uncompressed size : " + decodedSpec.mFile.length());
                     }
-                    return BinaryDictDecoder.readDictionaryBinary(reader, null);
+                    return BinaryDictDecoderUtils.readDictionaryBinary(dictDecoder, null);
                 }
             }
         } catch (IOException e) {
diff --git a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/DictionaryMaker.java b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/DictionaryMaker.java
index 09052c9..f87e972 100644
--- a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/DictionaryMaker.java
+++ b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/DictionaryMaker.java
@@ -16,9 +16,9 @@
 
 package com.android.inputmethod.latin.dicttool;
 
-import com.android.inputmethod.latin.makedict.BinaryDictDecoder;
+import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils;
 import com.android.inputmethod.latin.makedict.BinaryDictEncoder;
-import com.android.inputmethod.latin.makedict.BinaryDictReader;
+import com.android.inputmethod.latin.makedict.BinaryDictDecoder;
 import com.android.inputmethod.latin.makedict.FormatSpec;
 import com.android.inputmethod.latin.makedict.FusionDictionary;
 import com.android.inputmethod.latin.makedict.MakedictLog;
@@ -176,7 +176,7 @@
                                 inputUnigramXml = filename;
                             } else if (CombinedInputOutput.isCombinedDictionary(filename)) {
                                 inputCombined = filename;
-                            } else if (BinaryDictDecoder.isBinaryDictionary(filename)) {
+                            } else if (BinaryDictDecoderUtils.isBinaryDictionary(filename)) {
                                 inputBinary = filename;
                             } else {
                                 throw new IllegalArgumentException(
@@ -198,7 +198,7 @@
                     }
                 } else {
                     if (null == inputBinary && null == inputUnigramXml) {
-                        if (BinaryDictDecoder.isBinaryDictionary(arg)) {
+                        if (BinaryDictDecoderUtils.isBinaryDictionary(arg)) {
                             inputBinary = arg;
                         } else if (CombinedInputOutput.isCombinedDictionary(arg)) {
                             inputCombined = arg;
@@ -266,9 +266,10 @@
     private static FusionDictionary readBinaryFile(final String binaryFilename)
             throws FileNotFoundException, IOException, UnsupportedFormatException {
         final File file = new File(binaryFilename);
-        final BinaryDictReader reader = new BinaryDictReader(file);
-        reader.openBuffer(new BinaryDictReader.FusionDictionaryBufferFromByteBufferFactory());
-        return BinaryDictDecoder.readDictionaryBinary(reader, null);
+        final BinaryDictDecoder dictDecoder = new BinaryDictDecoder(file);
+        dictDecoder.openDictBuffer(
+                new BinaryDictDecoder.DictionaryBufferFromReadOnlyByteBufferFactory());
+        return BinaryDictDecoderUtils.readDictionaryBinary(dictDecoder, null);
     }
 
     /**
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 3bda77f..b960b03 100644
--- a/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java
+++ b/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java
@@ -17,8 +17,8 @@
 package com.android.inputmethod.latin.dicttool;
 
 import com.android.inputmethod.latin.makedict.BinaryDictDecoder;
+import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils;
 import com.android.inputmethod.latin.makedict.BinaryDictEncoder;
-import com.android.inputmethod.latin.makedict.BinaryDictReader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary;
 import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions;
@@ -67,9 +67,10 @@
             assertEquals("Wrong decode spec", BinaryDictOffdeviceUtils.COMPRESSION, step);
         }
         assertEquals("Wrong decode spec", 3, decodeSpec.mDecoderSpec.size());
-        final BinaryDictReader reader = new BinaryDictReader(decodeSpec.mFile);
-        reader.openBuffer(new BinaryDictReader.FusionDictionaryBufferFromByteBufferFactory());
-        final FusionDictionary resultDict = BinaryDictDecoder.readDictionaryBinary(reader,
+        final BinaryDictDecoder dictDecoder = new BinaryDictDecoder(decodeSpec.mFile);
+        dictDecoder.openDictBuffer(
+                new BinaryDictDecoder.DictionaryBufferFromReadOnlyByteBufferFactory());
+        final FusionDictionary resultDict = BinaryDictDecoderUtils.readDictionaryBinary(dictDecoder,
                 null /* dict : an optional dictionary to add words to, or null */);
         assertEquals("Dictionary can't be read back correctly",
                 FusionDictionary.findWordInTree(resultDict.mRootNodeArray, "foo").getFrequency(),