Concatenate dict buffers other than header to a single file.

Bug: 13664080
Change-Id: I34c9d8046b339c9b855be378a5fad907382d1359

17 files changed, 234 insertions, 167 deletions

diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/bigram_dict_content.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/bigram_dict_content.h
index 033f18e9e..0ad619462 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/bigram_dict_content.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/bigram_dict_content.h
@@ -17,6 +17,9 @@
 #ifndef LATINIME_BIGRAM_DICT_CONTENT_H
 #define LATINIME_BIGRAM_DICT_CONTENT_H
 
+#include <cstdint>
+#include <cstdio>
+
 #include "defines.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/bigram_entry.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.h"
@@ -27,12 +30,9 @@ namespace latinime {
 
 class BigramDictContent : public SparseTableDictContent {
  public:
-    BigramDictContent(const char *const dictPath, const bool hasHistoricalInfo,
+    BigramDictContent(uint8_t *const *buffers, const int *bufferSizes, const bool hasHistoricalInfo,
             const bool isUpdatable)
-            : SparseTableDictContent(dictPath,
-                      Ver4DictConstants::BIGRAM_LOOKUP_TABLE_FILE_EXTENSION,
-                      Ver4DictConstants::BIGRAM_CONTENT_TABLE_FILE_EXTENSION,
-                      Ver4DictConstants::BIGRAM_FILE_EXTENSION, isUpdatable,
+            : SparseTableDictContent(buffers, bufferSizes, isUpdatable,
                       Ver4DictConstants::BIGRAM_ADDRESS_TABLE_BLOCK_SIZE,
                       Ver4DictConstants::BIGRAM_ADDRESS_TABLE_DATA_SIZE),
               mHasHistoricalInfo(hasHistoricalInfo) {}
@@ -87,10 +87,8 @@ class BigramDictContent : public SparseTableDictContent {
         return getUpdatableAddressLookupTable()->set(terminalId, bigramListPos);
     }
 
-    bool flushToFile(const char *const dictPath) const {
-        return flush(dictPath, Ver4DictConstants::BIGRAM_LOOKUP_TABLE_FILE_EXTENSION,
-                Ver4DictConstants::BIGRAM_CONTENT_TABLE_FILE_EXTENSION,
-                Ver4DictConstants::BIGRAM_FILE_EXTENSION);
+    bool flushToFile(FILE *const file) const {
+        return flush(file);
     }
 
     bool runGC(const TerminalPositionLookupTable::TerminalIdMap *const terminalIdMap,
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/dict_content.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/dict_content.h
index 0c2f47073..c264aeac4 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/dict_content.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/dict_content.h
@@ -24,7 +24,6 @@ namespace latinime {
 class DictContent {
  public:
     virtual ~DictContent() {}
-    virtual bool isValid() const = 0;
 
  protected:
     DictContent() {}
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_dict_content.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_dict_content.cpp
index 3b7c70efd..2425b3b2f 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_dict_content.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_dict_content.cpp
@@ -71,7 +71,7 @@ bool ProbabilityDictContent::setProbabilityEntry(const int terminalId,
     return writeEntry(probabilityEntry, entryPos);
 }
 
-bool ProbabilityDictContent::flushToFile(const char *const dictPath) const {
+bool ProbabilityDictContent::flushToFile(FILE *const file) const {
     if (getEntryPos(mSize) < getBuffer()->getTailPosition()) {
         ProbabilityDictContent probabilityDictContentToWrite(mHasHistoricalInfo);
         for (int i = 0; i < mSize; ++i) {
@@ -81,10 +81,9 @@ bool ProbabilityDictContent::flushToFile(const char *const dictPath) const {
                 return false;
             }
         }
-        return probabilityDictContentToWrite.flush(dictPath,
-                Ver4DictConstants::FREQ_FILE_EXTENSION);
+        return probabilityDictContentToWrite.flush(file);
     } else {
-        return flush(dictPath, Ver4DictConstants::FREQ_FILE_EXTENSION);
+        return flush(file);
     }
 }
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_dict_content.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_dict_content.h
index b065bc954..c4b7a901c 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_dict_content.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_dict_content.h
@@ -17,6 +17,9 @@
 #ifndef LATINIME_PROBABILITY_DICT_CONTENT_H
 #define LATINIME_PROBABILITY_DICT_CONTENT_H
 
+#include <cstdint>
+#include <cstdio>
+
 #include "defines.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/single_dict_content.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.h"
@@ -29,9 +32,9 @@ class ProbabilityEntry;
 
 class ProbabilityDictContent : public SingleDictContent {
  public:
-    ProbabilityDictContent(const char *const dictPath, const bool hasHistoricalInfo,
-            const bool isUpdatable)
-            : SingleDictContent(dictPath, Ver4DictConstants::FREQ_FILE_EXTENSION, isUpdatable),
+    ProbabilityDictContent(uint8_t *const buffer, const int bufferSize,
+            const bool hasHistoricalInfo, const bool isUpdatable)
+            : SingleDictContent(buffer, bufferSize, isUpdatable),
               mHasHistoricalInfo(hasHistoricalInfo),
               mSize(getBuffer()->getTailPosition() / getEntrySize()) {}
 
@@ -42,7 +45,7 @@ class ProbabilityDictContent : public SingleDictContent {
 
     bool setProbabilityEntry(const int terminalId, const ProbabilityEntry *const probabilityEntry);
 
-    bool flushToFile(const char *const dictPath) const;
+    bool flushToFile(FILE *const file) const;
 
     bool runGC(const TerminalPositionLookupTable::TerminalIdMap *const terminalIdMap,
             const ProbabilityDictContent *const originalProbabilityDictContent);
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/shortcut_dict_content.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/shortcut_dict_content.cpp
index 64d7bc0a5..41d9c544c 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/shortcut_dict_content.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/shortcut_dict_content.cpp
@@ -59,12 +59,6 @@ int ShortcutDictContent::getShortcutListHeadPos(const int terminalId) const {
     return addressLookupTable->get(terminalId);
 }
 
-bool ShortcutDictContent::flushToFile(const char *const dictPath) const {
-    return flush(dictPath, Ver4DictConstants::SHORTCUT_LOOKUP_TABLE_FILE_EXTENSION,
-            Ver4DictConstants::SHORTCUT_CONTENT_TABLE_FILE_EXTENSION,
-            Ver4DictConstants::SHORTCUT_FILE_EXTENSION);
-}
-
 bool ShortcutDictContent::runGC(
         const TerminalPositionLookupTable::TerminalIdMap *const terminalIdMap,
         const ShortcutDictContent *const originalShortcutDictContent) {
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/shortcut_dict_content.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/shortcut_dict_content.h
index eaafc27bc..6a0e686ee 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/shortcut_dict_content.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/shortcut_dict_content.h
@@ -17,6 +17,9 @@
 #ifndef LATINIME_SHORTCUT_DICT_CONTENT_H
 #define LATINIME_SHORTCUT_DICT_CONTENT_H
 
+#include <cstdint>
+#include <cstdio>
+
 #include "defines.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.h"
@@ -26,11 +29,8 @@ namespace latinime {
 
 class ShortcutDictContent : public SparseTableDictContent {
  public:
-    ShortcutDictContent(const char *const dictPath, const bool isUpdatable)
-            : SparseTableDictContent(dictPath,
-                      Ver4DictConstants::SHORTCUT_LOOKUP_TABLE_FILE_EXTENSION,
-                      Ver4DictConstants::SHORTCUT_CONTENT_TABLE_FILE_EXTENSION,
-                      Ver4DictConstants::SHORTCUT_FILE_EXTENSION, isUpdatable,
+    ShortcutDictContent(uint8_t *const *buffers, const int *bufferSizes, const bool isUpdatable)
+            : SparseTableDictContent(buffers, bufferSizes, isUpdatable,
                       Ver4DictConstants::SHORTCUT_ADDRESS_TABLE_BLOCK_SIZE,
                       Ver4DictConstants::SHORTCUT_ADDRESS_TABLE_DATA_SIZE) {}
 
@@ -53,7 +53,9 @@ class ShortcutDictContent : public SparseTableDictContent {
    // Returns head position of shortcut list for a PtNode specified by terminalId.
    int getShortcutListHeadPos(const int terminalId) const;
 
-   bool flushToFile(const char *const dictPath) const;
+   bool flushToFile(FILE *const file) const {
+       return flush(file);
+   }
 
    bool runGC(const TerminalPositionLookupTable::TerminalIdMap *const terminalIdMap,
            const ShortcutDictContent *const originalShortcutDictContent);
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/single_dict_content.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/single_dict_content.h
index 215642234..7c5b69f5a 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/single_dict_content.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/single_dict_content.h
@@ -17,35 +17,28 @@
 #ifndef LATINIME_SINGLE_DICT_CONTENT_H
 #define LATINIME_SINGLE_DICT_CONTENT_H
 
+#include <cstdint>
+#include <cstdio>
+
 #include "defines.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/dict_content.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h"
 #include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
 #include "suggest/policyimpl/dictionary/utils/dict_file_writing_utils.h"
-#include "suggest/policyimpl/dictionary/utils/mmapped_buffer.h"
 
 namespace latinime {
 
 class SingleDictContent : public DictContent {
  public:
-    SingleDictContent(const char *const dictPath, const char *const contentFileName,
-            const bool isUpdatable)
-            : mMmappedBuffer(MmappedBuffer::openBuffer(dictPath, contentFileName, isUpdatable)),
-              mExpandableContentBuffer(mMmappedBuffer ? mMmappedBuffer->getBuffer() : nullptr,
-                      mMmappedBuffer ? mMmappedBuffer->getBufferSize() : 0,
-                      BufferWithExtendableBuffer::DEFAULT_MAX_ADDITIONAL_BUFFER_SIZE),
-              mIsValid(mMmappedBuffer) {}
+    SingleDictContent(uint8_t *const buffer, const int bufferSize, const bool isUpdatable)
+            : mExpandableContentBuffer(buffer, bufferSize,
+                      BufferWithExtendableBuffer::DEFAULT_MAX_ADDITIONAL_BUFFER_SIZE) {}
 
     SingleDictContent()
-            : mMmappedBuffer(nullptr),
-              mExpandableContentBuffer(Ver4DictConstants::MAX_DICTIONARY_SIZE), mIsValid(true) {}
+            : mExpandableContentBuffer(Ver4DictConstants::MAX_DICTIONARY_SIZE) {}
 
     virtual ~SingleDictContent() {}
 
-    virtual bool isValid() const {
-        return mIsValid;
-    }
-
     bool isNearSizeLimit() const {
         return mExpandableContentBuffer.isNearSizeLimit();
     }
@@ -59,17 +52,14 @@ class SingleDictContent : public DictContent {
         return &mExpandableContentBuffer;
     }
 
-    bool flush(const char *const dictPath, const char *const contentFileNameSuffix) const {
-        return DictFileWritingUtils::flushBufferToFileWithSuffix(dictPath,
-                contentFileNameSuffix, &mExpandableContentBuffer);
+    bool flush(FILE *const file) const {
+        return DictFileWritingUtils::writeBufferToFileTail(file, &mExpandableContentBuffer);
     }
 
  private:
     DISALLOW_COPY_AND_ASSIGN(SingleDictContent);
 
-    const MmappedBuffer::MmappedBufferPtr mMmappedBuffer;
     BufferWithExtendableBuffer mExpandableContentBuffer;
-    const bool mIsValid;
 };
 } // namespace latinime
 #endif /* LATINIME_SINGLE_DICT_CONTENT_H */
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.cpp
index 63c6ea3a4..896ce6bd2 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.cpp
@@ -16,21 +16,22 @@
 
 #include "suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.h"
 
+#include "suggest/policyimpl/dictionary/utils/dict_file_writing_utils.h"
+
 namespace latinime {
 
-bool SparseTableDictContent::flush(const char *const dictPath,
-        const char *const lookupTableFileNameSuffix, const char *const addressTableFileNameSuffix,
-        const char *const contentFileNameSuffix) const {
-    if (!DictFileWritingUtils::flushBufferToFileWithSuffix(dictPath, lookupTableFileNameSuffix,
-            &mExpandableLookupTableBuffer)){
+const int SparseTableDictContent::LOOKUP_TABLE_BUFFER_INDEX = 0;
+const int SparseTableDictContent::ADDRESS_TABLE_BUFFER_INDEX = 1;
+const int SparseTableDictContent::CONTENT_BUFFER_INDEX = 2;
+
+bool SparseTableDictContent::flush(FILE *const file) const {
+    if (!DictFileWritingUtils::writeBufferToFileTail(file, &mExpandableLookupTableBuffer)) {
         return false;
     }
-    if (!DictFileWritingUtils::flushBufferToFileWithSuffix(dictPath, addressTableFileNameSuffix,
-            &mExpandableAddressTableBuffer)) {
+    if (!DictFileWritingUtils::writeBufferToFileTail(file, &mExpandableAddressTableBuffer)) {
         return false;
     }
-    if (!DictFileWritingUtils::flushBufferToFileWithSuffix(dictPath, contentFileNameSuffix,
-            &mExpandableContentBuffer)) {
+    if (!DictFileWritingUtils::writeBufferToFileTail(file, &mExpandableContentBuffer)) {
         return false;
     }
     return true;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.h
index fb6c88eef..a30ae6fe3 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/sparse_table_dict_content.h
@@ -17,12 +17,13 @@
 #ifndef LATINIME_SPARSE_TABLE_DICT_CONTENT_H
 #define LATINIME_SPARSE_TABLE_DICT_CONTENT_H
 
+#include <cstdint>
+#include <cstdio>
+
 #include "defines.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/dict_content.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h"
 #include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
-#include "suggest/policyimpl/dictionary/utils/dict_file_writing_utils.h"
-#include "suggest/policyimpl/dictionary/utils/mmapped_buffer.h"
 #include "suggest/policyimpl/dictionary/utils/sparse_table.h"
 
 namespace latinime {
@@ -30,45 +31,29 @@ namespace latinime {
 // TODO: Support multiple contents.
 class SparseTableDictContent : public DictContent {
  public:
-    AK_FORCE_INLINE SparseTableDictContent(const char *const dictPath,
-            const char *const lookupTableFileName, const char *const addressTableFileName,
-            const char *const contentFileName, const bool isUpdatable,
-            const int sparseTableBlockSize, const int sparseTableDataSize)
-            : mLookupTableBuffer(
-                      MmappedBuffer::openBuffer(dictPath, lookupTableFileName, isUpdatable)),
-              mAddressTableBuffer(
-                      MmappedBuffer::openBuffer(dictPath, addressTableFileName, isUpdatable)),
-              mContentBuffer(
-                      MmappedBuffer::openBuffer(dictPath, contentFileName, isUpdatable)),
-              mExpandableLookupTableBuffer(
-                      mLookupTableBuffer ? mLookupTableBuffer->getBuffer() : nullptr,
-                      mLookupTableBuffer ? mLookupTableBuffer->getBufferSize() : 0,
+    AK_FORCE_INLINE SparseTableDictContent(uint8_t *const *buffers, const int *bufferSizes,
+            const bool isUpdatable, const int sparseTableBlockSize, const int sparseTableDataSize)
+            : mExpandableLookupTableBuffer(buffers[LOOKUP_TABLE_BUFFER_INDEX],
+                      bufferSizes[LOOKUP_TABLE_BUFFER_INDEX],
                       BufferWithExtendableBuffer::DEFAULT_MAX_ADDITIONAL_BUFFER_SIZE),
-              mExpandableAddressTableBuffer(
-                      mAddressTableBuffer ? mAddressTableBuffer->getBuffer() : nullptr,
-                      mAddressTableBuffer ? mAddressTableBuffer->getBufferSize() : 0,
+              mExpandableAddressTableBuffer(buffers[ADDRESS_TABLE_BUFFER_INDEX],
+                      bufferSizes[ADDRESS_TABLE_BUFFER_INDEX],
                       BufferWithExtendableBuffer::DEFAULT_MAX_ADDITIONAL_BUFFER_SIZE),
-              mExpandableContentBuffer(mContentBuffer ? mContentBuffer->getBuffer() : nullptr,
-                      mContentBuffer ? mContentBuffer->getBufferSize() : 0,
+              mExpandableContentBuffer(buffers[CONTENT_BUFFER_INDEX],
+                      bufferSizes[CONTENT_BUFFER_INDEX],
                       BufferWithExtendableBuffer::DEFAULT_MAX_ADDITIONAL_BUFFER_SIZE),
               mAddressLookupTable(&mExpandableLookupTableBuffer, &mExpandableAddressTableBuffer,
-                      sparseTableBlockSize, sparseTableDataSize),
-              mIsValid(mLookupTableBuffer && mAddressTableBuffer && mContentBuffer) {}
+                      sparseTableBlockSize, sparseTableDataSize) {}
 
     SparseTableDictContent(const int sparseTableBlockSize, const int sparseTableDataSize)
-            : mLookupTableBuffer(), mAddressTableBuffer(), mContentBuffer(),
-              mExpandableLookupTableBuffer(Ver4DictConstants::MAX_DICTIONARY_SIZE),
+            : mExpandableLookupTableBuffer(Ver4DictConstants::MAX_DICTIONARY_SIZE),
               mExpandableAddressTableBuffer(Ver4DictConstants::MAX_DICTIONARY_SIZE),
               mExpandableContentBuffer(Ver4DictConstants::MAX_DICTIONARY_SIZE),
               mAddressLookupTable(&mExpandableLookupTableBuffer, &mExpandableAddressTableBuffer,
-                      sparseTableBlockSize, sparseTableDataSize), mIsValid(true) {}
+                      sparseTableBlockSize, sparseTableDataSize) {}
 
     virtual ~SparseTableDictContent() {}
 
-    virtual bool isValid() const {
-        return mIsValid;
-    }
-
     bool isNearSizeLimit() const {
         return mExpandableLookupTableBuffer.isNearSizeLimit()
                 || mExpandableAddressTableBuffer.isNearSizeLimit()
@@ -92,20 +77,19 @@ class SparseTableDictContent : public DictContent {
         return &mExpandableContentBuffer;
     }
 
-    bool flush(const char *const dictDirPath, const char *const lookupTableFileName,
-            const char *const addressTableFileName, const char *const contentFileName) const;
+    bool flush(FILE *const file) const;
 
  private:
     DISALLOW_IMPLICIT_CONSTRUCTORS(SparseTableDictContent);
 
-    const MmappedBuffer::MmappedBufferPtr mLookupTableBuffer;
-    const MmappedBuffer::MmappedBufferPtr mAddressTableBuffer;
-    const MmappedBuffer::MmappedBufferPtr mContentBuffer;
+    static const int LOOKUP_TABLE_BUFFER_INDEX;
+    static const int ADDRESS_TABLE_BUFFER_INDEX;
+    static const int CONTENT_BUFFER_INDEX;
+
     BufferWithExtendableBuffer mExpandableLookupTableBuffer;
     BufferWithExtendableBuffer mExpandableAddressTableBuffer;
     BufferWithExtendableBuffer mExpandableContentBuffer;
     SparseTable mAddressLookupTable;
-    const bool mIsValid;
 };
 } // namespace latinime
 #endif /* LATINIME_SPARSE_TABLE_DICT_CONTENT_H */
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.cpp
index 0b17a009d..cf238ee5f 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.cpp
@@ -50,7 +50,7 @@ bool TerminalPositionLookupTable::setTerminalPtNodePosition(
             Ver4DictConstants::TERMINAL_ADDRESS_TABLE_ADDRESS_SIZE, getEntryPos(terminalId));
 }
 
-bool TerminalPositionLookupTable::flushToFile(const char *const dictPath) const {
+bool TerminalPositionLookupTable::flushToFile(FILE *const file) const {
     // If the used buffer size is smaller than the actual buffer size, regenerate the lookup
     // table and write the new table to the file.
     if (getEntryPos(mSize) < getBuffer()->getTailPosition()) {
@@ -63,12 +63,11 @@ bool TerminalPositionLookupTable::flushToFile(const char *const dictPath) const
                 return false;
             }
         }
-        return lookupTableToWrite.flush(dictPath,
-                Ver4DictConstants::TERMINAL_ADDRESS_TABLE_FILE_EXTENSION);
+        return lookupTableToWrite.flush(file);
     } else {
         // We can simply use this lookup table because the buffer size has not been
         // changed.
-        return flush(dictPath, Ver4DictConstants::TERMINAL_ADDRESS_TABLE_FILE_EXTENSION);
+        return flush(file);
     }
 }
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.h
index 816059560..c4c93f3f8 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.h
@@ -17,6 +17,8 @@
 #ifndef LATINIME_TERMINAL_POSITION_LOOKUP_TABLE_H
 #define LATINIME_TERMINAL_POSITION_LOOKUP_TABLE_H
 
+#include <cstdint>
+#include <cstdio>
 #include <unordered_map>
 
 #include "defines.h"
@@ -29,9 +31,9 @@ class TerminalPositionLookupTable : public SingleDictContent {
  public:
     typedef std::unordered_map<int, int> TerminalIdMap;
 
-    TerminalPositionLookupTable(const char *const dictPath, const bool isUpdatable)
-            : SingleDictContent(dictPath,
-                      Ver4DictConstants::TERMINAL_ADDRESS_TABLE_FILE_EXTENSION, isUpdatable),
+    TerminalPositionLookupTable(uint8_t *const buffer, const int bufferSize,
+            const bool isUpdatable)
+            : SingleDictContent(buffer, bufferSize, isUpdatable),
               mSize(getBuffer()->getTailPosition()
                       / Ver4DictConstants::TERMINAL_ADDRESS_TABLE_ADDRESS_SIZE) {}
 
@@ -45,7 +47,7 @@ class TerminalPositionLookupTable : public SingleDictContent {
         return mSize;
     }
 
-    bool flushToFile(const char *const dictPath) const;
+    bool flushToFile(FILE *const file) const;
 
     bool runGCTerminalIds(TerminalIdMap *const terminalIdMap);
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.cpp
index 5aa6b9a92..e4087be24 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.cpp
@@ -18,16 +18,19 @@
 
 #include <cerrno>
 #include <cstring>
+#include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <vector>
 
+#include "suggest/policyimpl/dictionary/utils/byte_array_utils.h"
 #include "suggest/policyimpl/dictionary/utils/dict_file_writing_utils.h"
 #include "suggest/policyimpl/dictionary/utils/file_utils.h"
 
 namespace latinime {
 
 /* static */ Ver4DictBuffers::Ver4DictBuffersPtr Ver4DictBuffers::openVer4DictBuffers(
-        const char *const dictPath, MmappedBuffer::MmappedBufferPtr headerBuffer,
+        const char *const dictPath, MmappedBuffer::MmappedBufferPtr &&headerBuffer,
         const FormatUtils::FORMAT_VERSION formatVersion) {
     if (!headerBuffer) {
         ASSERT(false);
@@ -36,8 +39,32 @@ namespace latinime {
     }
     // TODO: take only dictDirPath, and open both header and trie files in the constructor below
     const bool isUpdatable = headerBuffer->isUpdatable();
-    return Ver4DictBuffersPtr(new Ver4DictBuffers(dictPath, std::move(headerBuffer), isUpdatable,
-            formatVersion));
+
+    MmappedBuffer::MmappedBufferPtr bodyBuffer = MmappedBuffer::openBuffer(dictPath,
+            Ver4DictConstants::BODY_FILE_EXTENSION, isUpdatable);
+    if (!bodyBuffer) {
+        return Ver4DictBuffersPtr(nullptr);
+    }
+    std::vector<uint8_t *> buffers;
+    std::vector<int> bufferSizes;
+    uint8_t *const buffer = bodyBuffer->getBuffer();
+    int position = 0;
+    while (position < bodyBuffer->getBufferSize()) {
+        const int bufferSize = ByteArrayUtils::readUint32AndAdvancePosition(buffer, &position);
+        buffers.push_back(buffer + position);
+        bufferSizes.push_back(bufferSize);
+        position += bufferSize;
+        if (bufferSize < 0 || position < 0 || position > bodyBuffer->getBufferSize()) {
+            AKLOGE("The dict body file is corrupted.");
+            return Ver4DictBuffersPtr(nullptr);
+        }
+    }
+    if (buffers.size() != Ver4DictConstants::NUM_OF_CONTENT_BUFFERS_IN_BODY_FILE) {
+        AKLOGE("The dict body file is corrupted.");
+        return Ver4DictBuffersPtr(nullptr);
+    }
+    return Ver4DictBuffersPtr(new Ver4DictBuffers(std::move(headerBuffer), std::move(bodyBuffer),
+            isUpdatable, formatVersion, buffers, bufferSizes));
 }
 
 bool Ver4DictBuffers::flushHeaderAndDictBuffers(const char *const dictDirPath,
@@ -76,30 +103,32 @@ bool Ver4DictBuffers::flushHeaderAndDictBuffers(const char *const dictDirPath,
                 Ver4DictConstants::HEADER_FILE_EXTENSION);
         return false;
     }
-    // Write trie file.
-    if (!DictFileWritingUtils::flushBufferToFileWithSuffix(dictPath,
-            Ver4DictConstants::TRIE_FILE_EXTENSION, &mExpandableTrieBuffer)) {
-        AKLOGE("Dictionary trie file %s%s cannot be written.", tmpDirPath,
-                Ver4DictConstants::TRIE_FILE_EXTENSION);
-        return false;
-    }
-    // Write dictionary contents.
-    if (!mTerminalPositionLookupTable.flushToFile(dictPath)) {
-        AKLOGE("Terminal position lookup table cannot be written. %s", tmpDirPath);
-        return false;
-    }
-    if (!mProbabilityDictContent.flushToFile(dictPath)) {
-        AKLOGE("Probability dict content cannot be written. %s", tmpDirPath);
+
+    // Write body file.
+    const int bodyFilePathBufSize = FileUtils::getFilePathWithSuffixBufSize(dictPath,
+            Ver4DictConstants::BODY_FILE_EXTENSION);
+    char bodyFilePath[bodyFilePathBufSize];
+    FileUtils::getFilePathWithSuffix(dictPath, Ver4DictConstants::BODY_FILE_EXTENSION,
+            bodyFilePathBufSize, bodyFilePath);
+
+    const int fd = open(bodyFilePath, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+    if (fd == -1) {
+        AKLOGE("File %s cannot be opened. errno: %d", bodyFilePath, errno);
+        ASSERT(false);
         return false;
     }
-    if (!mBigramDictContent.flushToFile(dictPath)) {
-        AKLOGE("Bigram dict content cannot be written. %s", tmpDirPath);
+    FILE *const file = fdopen(fd, "wb");
+    if (!file) {
+        AKLOGE("fdopen failed for the file %s. errno: %d", filePath, errno);
+        ASSERT(false);
         return false;
     }
-    if (!mShortcutDictContent.flushToFile(dictPath)) {
-        AKLOGE("Shortcut dict content cannot be written. %s", tmpDirPath);
+
+    if (!flushDictBuffers(file)) {
+        fclose(file);
         return false;
     }
+    fclose(file);
     // Remove existing dictionary.
     if (!FileUtils::removeDirAndFiles(dictDirPath)) {
         AKLOGE("Existing directory %s cannot be removed.", dictDirPath);
@@ -115,23 +144,60 @@ bool Ver4DictBuffers::flushHeaderAndDictBuffers(const char *const dictDirPath,
     return true;
 }
 
-Ver4DictBuffers::Ver4DictBuffers(const char *const dictPath,
-        MmappedBuffer::MmappedBufferPtr headerBuffer, const bool isUpdatable,
-        const FormatUtils::FORMAT_VERSION formatVersion)
-        : mHeaderBuffer(std::move(headerBuffer)),
-          mDictBuffer(MmappedBuffer::openBuffer(dictPath,
-                  Ver4DictConstants::TRIE_FILE_EXTENSION, isUpdatable)),
+bool Ver4DictBuffers::flushDictBuffers(FILE *const file) const {
+    // Write trie.
+    if (!DictFileWritingUtils::writeBufferToFileTail(file, &mExpandableTrieBuffer)) {
+        AKLOGE("Trie cannot be written. %s", tmpDirPath);
+        return false;
+    }
+    // Write terminal position lookup table.
+    if (!mTerminalPositionLookupTable.flushToFile(file)) {
+        AKLOGE("Terminal position lookup table cannot be written. %s", tmpDirPath);
+        return false;
+    }
+    // Write probability dict content.
+    if (!mProbabilityDictContent.flushToFile(file)) {
+        AKLOGE("Probability dict content cannot be written. %s", tmpDirPath);
+        return false;
+    }
+    // Write bigram dict content.
+    if (!mBigramDictContent.flushToFile(file)) {
+        AKLOGE("Bigram dict content cannot be written. %s", tmpDirPath);
+        return false;
+    }
+    // Write shortcut dict content.
+    if (!mShortcutDictContent.flushToFile(file)) {
+        AKLOGE("Shortcut dict content cannot be written. %s", tmpDirPath);
+        return false;
+    }
+    return true;
+}
+
+Ver4DictBuffers::Ver4DictBuffers(MmappedBuffer::MmappedBufferPtr &&headerBuffer,
+        MmappedBuffer::MmappedBufferPtr &&bodyBuffer,
+        const bool isUpdatable, const FormatUtils::FORMAT_VERSION formatVersion,
+        const std::vector<uint8_t *> &contentBuffers, const std::vector<int> &contentBufferSizes)
+        : mHeaderBuffer(std::move(headerBuffer)), mDictBuffer(std::move(bodyBuffer)),
           mHeaderPolicy(mHeaderBuffer->getBuffer(), formatVersion),
           mExpandableHeaderBuffer(mHeaderBuffer ? mHeaderBuffer->getBuffer() : nullptr,
                   mHeaderPolicy.getSize(),
                   BufferWithExtendableBuffer::DEFAULT_MAX_ADDITIONAL_BUFFER_SIZE),
-          mExpandableTrieBuffer(mDictBuffer ? mDictBuffer->getBuffer() : nullptr,
-                  mDictBuffer ? mDictBuffer->getBufferSize() : 0,
+          mExpandableTrieBuffer(contentBuffers[Ver4DictConstants::TRIE_BUFFER_INDEX],
+                  contentBufferSizes[Ver4DictConstants::TRIE_BUFFER_INDEX],
                   BufferWithExtendableBuffer::DEFAULT_MAX_ADDITIONAL_BUFFER_SIZE),
-          mTerminalPositionLookupTable(dictPath, isUpdatable),
-          mProbabilityDictContent(dictPath, mHeaderPolicy.hasHistoricalInfoOfWords(), isUpdatable),
-          mBigramDictContent(dictPath, mHeaderPolicy.hasHistoricalInfoOfWords(), isUpdatable),
-          mShortcutDictContent(dictPath, isUpdatable),
+          mTerminalPositionLookupTable(
+                  contentBuffers[Ver4DictConstants::TERMINAL_ADDRESS_LOOKUP_TABLE_BUFFER_INDEX],
+                  contentBufferSizes[Ver4DictConstants::TERMINAL_ADDRESS_LOOKUP_TABLE_BUFFER_INDEX],
+                  isUpdatable),
+          mProbabilityDictContent(
+                  contentBuffers[Ver4DictConstants::PROBABILITY_BUFFER_INDEX],
+                  contentBufferSizes[Ver4DictConstants::PROBABILITY_BUFFER_INDEX],
+                  mHeaderPolicy.hasHistoricalInfoOfWords(), isUpdatable),
+          mBigramDictContent(&contentBuffers[Ver4DictConstants::BIGRAM_BUFFERS_INDEX],
+                  &contentBufferSizes[Ver4DictConstants::BIGRAM_BUFFERS_INDEX],
+                  mHeaderPolicy.hasHistoricalInfoOfWords(), isUpdatable),
+          mShortcutDictContent(&contentBuffers[Ver4DictConstants::SHORTCUT_BUFFERS_INDEX],
+                  &contentBufferSizes[Ver4DictConstants::SHORTCUT_BUFFERS_INDEX], isUpdatable),
           mIsUpdatable(isUpdatable) {}
 
 Ver4DictBuffers::Ver4DictBuffers(const HeaderPolicy *const headerPolicy, const int maxTrieSize)
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.h
index df177c14a..d2f4f2aed 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.h
@@ -17,6 +17,7 @@
 #ifndef LATINIME_VER4_DICT_BUFFER_H
 #define LATINIME_VER4_DICT_BUFFER_H
 
+#include <cstdio>
 #include <memory>
 
 #include "defines.h"
@@ -36,7 +37,7 @@ class Ver4DictBuffers {
     typedef std::unique_ptr<Ver4DictBuffers> Ver4DictBuffersPtr;
 
     static Ver4DictBuffersPtr openVer4DictBuffers(const char *const dictDirPath,
-            MmappedBuffer::MmappedBufferPtr headerBuffer,
+            MmappedBuffer::MmappedBufferPtr &&headerBuffer,
             const FormatUtils::FORMAT_VERSION formatVersion);
 
     static AK_FORCE_INLINE Ver4DictBuffersPtr createVer4DictBuffers(
@@ -45,9 +46,7 @@ class Ver4DictBuffers {
     }
 
     AK_FORCE_INLINE bool isValid() const {
-        return mHeaderBuffer && mDictBuffer && mHeaderPolicy.isValid()
-                && mProbabilityDictContent.isValid() && mTerminalPositionLookupTable.isValid()
-                && mBigramDictContent.isValid() && mShortcutDictContent.isValid();
+        return mHeaderBuffer && mDictBuffer && mHeaderPolicy.isValid();
     }
 
     AK_FORCE_INLINE bool isNearSizeLimit() const {
@@ -120,12 +119,16 @@ class Ver4DictBuffers {
  private:
     DISALLOW_COPY_AND_ASSIGN(Ver4DictBuffers);
 
-    Ver4DictBuffers(const char *const dictDirPath,
-            const MmappedBuffer::MmappedBufferPtr headerBuffer, const bool isUpdatable,
-            const FormatUtils::FORMAT_VERSION formatVersion);
+    Ver4DictBuffers(MmappedBuffer::MmappedBufferPtr &&headerBuffer,
+            MmappedBuffer::MmappedBufferPtr &&bodyBuffer,
+            const bool isUpdatable, const FormatUtils::FORMAT_VERSION formatVersion,
+            const std::vector<uint8_t *> &contentBuffers,
+            const std::vector<int> &contentBufferSizes);
 
     Ver4DictBuffers(const HeaderPolicy *const headerPolicy, const int maxTrieSize);
 
+    bool flushDictBuffers(FILE *const file) const;
+
     const MmappedBuffer::MmappedBufferPtr mHeaderBuffer;
     const MmappedBuffer::MmappedBufferPtr mDictBuffer;
     const HeaderPolicy mHeaderPolicy;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.cpp
index 345cabbf9..d45dfe377 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.cpp
@@ -18,19 +18,8 @@
 
 namespace latinime {
 
-// These values MUST match the definitions in FormatSpec.java.
-const char *const Ver4DictConstants::TRIE_FILE_EXTENSION = ".trie";
+const char *const Ver4DictConstants::BODY_FILE_EXTENSION = ".body";
 const char *const Ver4DictConstants::HEADER_FILE_EXTENSION = ".header";
-const char *const Ver4DictConstants::FREQ_FILE_EXTENSION = ".freq";
-// tat = Terminal Address Table
-const char *const Ver4DictConstants::TERMINAL_ADDRESS_TABLE_FILE_EXTENSION = ".tat";
-const char *const Ver4DictConstants::BIGRAM_FILE_EXTENSION = ".bigram_freq";
-const char *const Ver4DictConstants::BIGRAM_LOOKUP_TABLE_FILE_EXTENSION = ".bigram_lookup";
-const char *const Ver4DictConstants::BIGRAM_CONTENT_TABLE_FILE_EXTENSION = ".bigram_index_freq";
-const char *const Ver4DictConstants::SHORTCUT_FILE_EXTENSION = ".shortcut_shortcut";
-const char *const Ver4DictConstants::SHORTCUT_LOOKUP_TABLE_FILE_EXTENSION = ".shortcut_lookup";
-const char *const Ver4DictConstants::SHORTCUT_CONTENT_TABLE_FILE_EXTENSION =
-        ".shortcut_index_shortcut";
 
 // Version 4 dictionary size is implicitly limited to 8MB due to 3-byte offsets.
 const int Ver4DictConstants::MAX_DICTIONARY_SIZE = 8 * 1024 * 1024;
@@ -38,6 +27,21 @@ const int Ver4DictConstants::MAX_DICTIONARY_SIZE = 8 * 1024 * 1024;
 // limited to 1MB to prevent from inefficient traversing.
 const int Ver4DictConstants::MAX_DICT_EXTENDED_REGION_SIZE = 1 * 1024 * 1024;
 
+// NUM_OF_BUFFERS_FOR_SINGLE_DICT_CONTENT for Trie, TerminalAddressLookupTable and Probability.
+// NUM_OF_BUFFERS_FOR_SPARSE_TABLE_DICT_CONTENT for bigram and shortcut.
+const size_t Ver4DictConstants::NUM_OF_CONTENT_BUFFERS_IN_BODY_FILE =
+        NUM_OF_BUFFERS_FOR_SINGLE_DICT_CONTENT * 3
+                + NUM_OF_BUFFERS_FOR_SPARSE_TABLE_DICT_CONTENT * 2;
+const int Ver4DictConstants::TRIE_BUFFER_INDEX = 0;
+const int Ver4DictConstants::TERMINAL_ADDRESS_LOOKUP_TABLE_BUFFER_INDEX =
+        TRIE_BUFFER_INDEX + NUM_OF_BUFFERS_FOR_SINGLE_DICT_CONTENT;
+const int Ver4DictConstants::PROBABILITY_BUFFER_INDEX =
+        TERMINAL_ADDRESS_LOOKUP_TABLE_BUFFER_INDEX + NUM_OF_BUFFERS_FOR_SINGLE_DICT_CONTENT;
+const int Ver4DictConstants::BIGRAM_BUFFERS_INDEX =
+        PROBABILITY_BUFFER_INDEX + NUM_OF_BUFFERS_FOR_SINGLE_DICT_CONTENT;
+const int Ver4DictConstants::SHORTCUT_BUFFERS_INDEX =
+        BIGRAM_BUFFERS_INDEX + NUM_OF_BUFFERS_FOR_SPARSE_TABLE_DICT_CONTENT;
+
 const int Ver4DictConstants::NOT_A_TERMINAL_ID = -1;
 const int Ver4DictConstants::PROBABILITY_SIZE = 1;
 const int Ver4DictConstants::FLAGS_IN_PROBABILITY_FILE_SIZE = 1;
@@ -67,4 +71,7 @@ const int Ver4DictConstants::SHORTCUT_FLAGS_FIELD_SIZE = 1;
 const int Ver4DictConstants::SHORTCUT_PROBABILITY_MASK = 0x0F;
 const int Ver4DictConstants::SHORTCUT_HAS_NEXT_MASK = 0x80;
 
+const size_t Ver4DictConstants::NUM_OF_BUFFERS_FOR_SINGLE_DICT_CONTENT = 1;
+const size_t Ver4DictConstants::NUM_OF_BUFFERS_FOR_SPARSE_TABLE_DICT_CONTENT = 3;
+
 } // namespace latinime
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h
index b4effca9c..e8f6739ba 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h
@@ -19,26 +19,26 @@
 
 #include "defines.h"
 
+#include <cstddef>
+
 namespace latinime {
 
 // TODO: Create PtConstants under the pt_common and move some constant values there.
 // Note that there are corresponding definitions in FormatSpec.java.
 class Ver4DictConstants {
  public:
-    static const char *const TRIE_FILE_EXTENSION;
+    static const char *const BODY_FILE_EXTENSION;
     static const char *const HEADER_FILE_EXTENSION;
-    static const char *const FREQ_FILE_EXTENSION;
-    static const char *const TERMINAL_ADDRESS_TABLE_FILE_EXTENSION;
-    static const char *const BIGRAM_FILE_EXTENSION;
-    static const char *const BIGRAM_LOOKUP_TABLE_FILE_EXTENSION;
-    static const char *const BIGRAM_CONTENT_TABLE_FILE_EXTENSION;
-    static const char *const SHORTCUT_FILE_EXTENSION;
-    static const char *const SHORTCUT_LOOKUP_TABLE_FILE_EXTENSION;
-    static const char *const SHORTCUT_CONTENT_TABLE_FILE_EXTENSION;
-
     static const int MAX_DICTIONARY_SIZE;
     static const int MAX_DICT_EXTENDED_REGION_SIZE;
 
+    static const size_t NUM_OF_CONTENT_BUFFERS_IN_BODY_FILE;
+    static const int TRIE_BUFFER_INDEX;
+    static const int TERMINAL_ADDRESS_LOOKUP_TABLE_BUFFER_INDEX;
+    static const int PROBABILITY_BUFFER_INDEX;
+    static const int BIGRAM_BUFFERS_INDEX;
+    static const int SHORTCUT_BUFFERS_INDEX;
+
     static const int NOT_A_TERMINAL_ID;
     static const int PROBABILITY_SIZE;
     static const int FLAGS_IN_PROBABILITY_FILE_SIZE;
@@ -68,6 +68,9 @@ class Ver4DictConstants {
 
  private:
     DISALLOW_IMPLICIT_CONSTRUCTORS(Ver4DictConstants);
+
+    static const size_t NUM_OF_BUFFERS_FOR_SINGLE_DICT_CONTENT;
+    static const size_t NUM_OF_BUFFERS_FOR_SPARSE_TABLE_DICT_CONTENT;
 };
 } // namespace latinime
 #endif /* LATINIME_VER4_DICT_CONSTANTS_H */
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 1d202c3dd..b7e2a7278 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
@@ -34,6 +34,8 @@
 namespace latinime {
 
 const char *const DictFileWritingUtils::TEMP_FILE_SUFFIX_FOR_WRITING_DICT_FILE = ".tmp";
+// Enough size to describe buffer size.
+const int DictFileWritingUtils::SIZE_OF_BUFFER_SIZE_FIELD = 4;
 
 /* static */ bool DictFileWritingUtils::createEmptyDictFile(const char *const filePath,
         const int dictVersion, const std::vector<int> localeAsCodePointVector,
@@ -85,6 +87,18 @@ template<class DictConstants, class DictBuffers, class DictBuffersPtr>
     return flushBufferToFile(filePath, buffer);
 }
 
+/* static */ bool DictFileWritingUtils::writeBufferToFileTail(FILE *const file,
+        const BufferWithExtendableBuffer *const buffer) {
+    uint8_t bufferSize[SIZE_OF_BUFFER_SIZE_FIELD];
+    int writingPos = 0;
+    ByteArrayUtils::writeUintAndAdvancePosition(bufferSize, buffer->getTailPosition(),
+            SIZE_OF_BUFFER_SIZE_FIELD, &writingPos);
+    if (fwrite(bufferSize, SIZE_OF_BUFFER_SIZE_FIELD, 1 /* count */, file) < 1) {
+        return false;
+    }
+    return writeBufferToFile(file, buffer);
+}
+
 /* static */ bool DictFileWritingUtils::flushBufferToFile(const char *const filePath,
         const BufferWithExtendableBuffer *const buffer) {
     const int fd = open(filePath, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
@@ -100,6 +114,7 @@ template<class DictConstants, class DictBuffers, class DictBuffersPtr>
         return false;
     }
     if (!writeBufferToFile(file, buffer)) {
+        fclose(file);
         remove(filePath);
         AKLOGE("Buffer cannot be written to the file %s. size: %d", filePath,
                 buffer->getTailPosition());
@@ -110,20 +125,17 @@ template<class DictConstants, class DictBuffers, class DictBuffersPtr>
     return true;
 }
 
-// This closes file pointer when an error is caused and returns whether the writing was succeeded
-// or not.
+// Returns whether the writing was succeeded or not.
 /* static */ bool DictFileWritingUtils::writeBufferToFile(FILE *const file,
         const BufferWithExtendableBuffer *const buffer) {
     const int originalBufSize = buffer->getOriginalBufferSize();
     if (originalBufSize > 0 && fwrite(buffer->getBuffer(false /* usesAdditionalBuffer */),
             originalBufSize, 1, file) < 1) {
-        fclose(file);
         return false;
     }
     const int additionalBufSize = buffer->getUsedAdditionalBufferSize();
     if (additionalBufSize > 0 && fwrite(buffer->getBuffer(true /* usesAdditionalBuffer */),
             additionalBufSize, 1, file) < 1) {
-        fclose(file);
         return false;
     }
     return true;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.h b/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.h
index 0dd1256ee..4843b3b32 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.h
@@ -38,9 +38,14 @@ class DictFileWritingUtils {
     static bool flushBufferToFileWithSuffix(const char *const basePath, const char *const suffix,
             const BufferWithExtendableBuffer *const buffer);
 
+    static bool writeBufferToFileTail(FILE *const file,
+            const BufferWithExtendableBuffer *const buffer);
+
  private:
     DISALLOW_IMPLICIT_CONSTRUCTORS(DictFileWritingUtils);
 
+    static const int SIZE_OF_BUFFER_SIZE_FIELD;
+
     static bool createEmptyV401DictFile(const char *const filePath,
             const std::vector<int> localeAsCodePointVector,
             const DictionaryHeaderStructurePolicy::AttributeMap *const attributeMap,