diff --git a/native/jni/Android.mk b/native/jni/Android.mk
index e323742..3aa9738 100644
--- a/native/jni/Android.mk
+++ b/native/jni/Android.mk
@@ -79,8 +79,8 @@
         patricia_trie_policy.cpp \
         patricia_trie_reading_utils.cpp) \
     $(addprefix suggest/policyimpl/dictionary/utils/, \
+        buffer_with_extendable_buffer.cpp \
         byte_array_utils.cpp \
-        extendable_buffer.cpp \
         format_utils.cpp) \
     suggest/policyimpl/gesture/gesture_suggest_policy_factory.cpp \
     $(addprefix suggest/policyimpl/typing/, \
diff --git a/native/jni/src/suggest/policyimpl/dictionary/bigram/dynamic_bigram_list_policy.h b/native/jni/src/suggest/policyimpl/dictionary/bigram/dynamic_bigram_list_policy.h
index 5fb3500..072e85e 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/bigram/dynamic_bigram_list_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/bigram/dynamic_bigram_list_policy.h
@@ -22,7 +22,7 @@
 #include "defines.h"
 #include "suggest/core/policy/dictionary_bigrams_structure_policy.h"
 #include "suggest/policyimpl/dictionary/bigram/bigram_list_reading_utils.h"
-#include "suggest/policyimpl/dictionary/utils/extendable_buffer.h"
+#include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
 
 namespace latinime {
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_node_reader.cpp b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_node_reader.cpp
index 2b5aa26..6bb90fc 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_node_reader.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_node_reader.cpp
@@ -19,7 +19,7 @@
 #include "suggest/core/policy/dictionary_bigrams_structure_policy.h"
 #include "suggest/core/policy/dictionary_shortcuts_structure_policy.h"
 #include "suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_utils.h"
-#include "suggest/policyimpl/dictionary/utils/extendable_buffer.h"
+#include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
 
 namespace latinime {
 
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 63c5ac8..a235ad7 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
@@ -22,7 +22,7 @@
 #include "suggest/policyimpl/dictionary/bigram/dynamic_bigram_list_policy.h"
 #include "suggest/policyimpl/dictionary/header/header_policy.h"
 #include "suggest/policyimpl/dictionary/shortcut/dynamic_shortcut_list_policy.h"
-#include "suggest/policyimpl/dictionary/utils/extendable_buffer.h"
+#include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
 #include "suggest/policyimpl/dictionary/utils/mmapped_buffer.h"
 
 namespace latinime {
diff --git a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_helper.cpp b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_helper.cpp
index d5c8082..2042fcb 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_helper.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_helper.cpp
@@ -16,6 +16,8 @@
 
 #include "suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_helper.h"
 
+#include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
+
 namespace latinime {
 
 // To avoid infinite loop caused by invalid or malicious forward links.
diff --git a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_helper.h b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_helper.h
index 518b232..b108ed5 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_helper.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_helper.h
@@ -21,10 +21,13 @@
 #include "suggest/policyimpl/dictionary/dynamic_patricia_trie_node_reader.h"
 #include "suggest/policyimpl/dictionary/dynamic_patricia_trie_reading_utils.h"
 #include "suggest/policyimpl/dictionary/patricia_trie_reading_utils.h"
-#include "suggest/policyimpl/dictionary/utils/extendable_buffer.h"
 
 namespace latinime {
 
+class BufferWithExtendableBuffer;
+class DictionaryBigramsStructurePolicy;
+class DictionaryShortcutsStructurePolicy;
+
 /*
  * This class is used for traversing dynamic patricia trie. This class supports iterating nodes and
  * dealing with additional buffer. This class counts nodes and node arrays to avoid infinite loop.
diff --git a/native/jni/src/suggest/policyimpl/dictionary/shortcut/dynamic_shortcut_list_policy.h b/native/jni/src/suggest/policyimpl/dictionary/shortcut/dynamic_shortcut_list_policy.h
index 0bc44dd..4bf745f 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/shortcut/dynamic_shortcut_list_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/shortcut/dynamic_shortcut_list_policy.h
@@ -22,7 +22,7 @@
 #include "defines.h"
 #include "suggest/core/policy/dictionary_shortcuts_structure_policy.h"
 #include "suggest/policyimpl/dictionary/shortcut/shortcut_list_reading_utils.h"
-#include "suggest/policyimpl/dictionary/utils/extendable_buffer.h"
+#include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
 
 namespace latinime {
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/extendable_buffer.cpp b/native/jni/src/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.cpp
similarity index 91%
rename from native/jni/src/suggest/policyimpl/dictionary/utils/extendable_buffer.cpp
rename to native/jni/src/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.cpp
index 7f74adc..8582c4b 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/utils/extendable_buffer.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.cpp
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "suggest/policyimpl/dictionary/utils/extendable_buffer.h"
+#include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
 
 namespace latinime {
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/extendable_buffer.h b/native/jni/src/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h
similarity index 97%
rename from native/jni/src/suggest/policyimpl/dictionary/utils/extendable_buffer.h
rename to native/jni/src/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h
index 859894d..f23f1db 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/utils/extendable_buffer.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h
@@ -26,7 +26,6 @@
 
 namespace latinime {
 
-// TODO: change file name according to the class name.
 // This is used as a buffer that can be extended for updatable dictionaries.
 // To optimize performance, raw pointer is directly used for reading buffer. The position has to be
 // adjusted to access additional buffer. On the other hand, this class does not provide writable