diff --git a/native/jni/Android.mk b/native/jni/Android.mk
index 8c3e263..7ca4057 100644
--- a/native/jni/Android.mk
+++ b/native/jni/Android.mk
@@ -48,8 +48,7 @@
 LATIN_IME_CORE_SRC_FILES := \
     suggest/core/suggest.cpp \
     $(addprefix obsolete/, \
-        correction.cpp \
-        words_priority_queue.cpp) \
+        correction.cpp) \
     $(addprefix suggest/core/dicnode/, \
         dic_node.cpp \
         dic_node_utils.cpp \
diff --git a/native/jni/src/obsolete/words_priority_queue.cpp b/native/jni/src/obsolete/words_priority_queue.cpp
deleted file mode 100644
index 563cf91..0000000
--- a/native/jni/src/obsolete/words_priority_queue.cpp
+++ /dev/null
@@ -1,76 +0,0 @@
-/*
- * Copyright (C) 2012, The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "obsolete/words_priority_queue.h"
-
-namespace latinime {
-
-int WordsPriorityQueue::outputSuggestions(const int *before, const int beforeLength,
-        int *frequencies, int *outputCodePoints, int* outputTypes) {
-    mHighestSuggestedWord = 0;
-    const int size = min(MAX_WORDS, static_cast<int>(mSuggestions.size()));
-    SuggestedWord *swBuffer[size];
-    int index = size - 1;
-    while (!mSuggestions.empty() && index >= 0) {
-        SuggestedWord *sw = mSuggestions.top();
-        if (DEBUG_WORDS_PRIORITY_QUEUE) {
-            AKLOGI("dump word. %d", sw->mScore);
-            DUMP_WORD(sw->mWord, sw->mWordLength);
-        }
-        swBuffer[index] = sw;
-        mSuggestions.pop();
-        --index;
-    }
-    if (size >= 2) {
-        SuggestedWord *nsMaxSw = 0;
-        int maxIndex = 0;
-        float maxNs = 0;
-        for (int i = 0; i < size; ++i) {
-            SuggestedWord *tempSw = swBuffer[i];
-            if (!tempSw) {
-                continue;
-            }
-            const float tempNs = getNormalizedScore(tempSw, before, beforeLength, 0, 0, 0);
-            if (tempNs >= maxNs) {
-                maxNs = tempNs;
-                maxIndex = i;
-                nsMaxSw = tempSw;
-            }
-        }
-        if (maxIndex > 0 && nsMaxSw) {
-            memmove(&swBuffer[1], &swBuffer[0], maxIndex * sizeof(swBuffer[0]));
-            swBuffer[0] = nsMaxSw;
-        }
-    }
-    for (int i = 0; i < size; ++i) {
-        SuggestedWord *sw = swBuffer[i];
-        if (!sw) {
-            AKLOGE("SuggestedWord is null %d", i);
-            continue;
-        }
-        const int wordLength = sw->mWordLength;
-        int *targetAddress = outputCodePoints + i * MAX_WORD_LENGTH;
-        frequencies[i] = sw->mScore;
-        outputTypes[i] = sw->mType;
-        memcpy(targetAddress, sw->mWord, wordLength * sizeof(targetAddress[0]));
-        if (wordLength < MAX_WORD_LENGTH) {
-            targetAddress[wordLength] = 0;
-        }
-        sw->mUsed = false;
-    }
-    return size;
-}
-} // namespace latinime
diff --git a/native/jni/src/obsolete/words_priority_queue.h b/native/jni/src/obsolete/words_priority_queue.h
deleted file mode 100644
index 337e3e3..0000000
--- a/native/jni/src/obsolete/words_priority_queue.h
+++ /dev/null
@@ -1,175 +0,0 @@
-/*
- * Copyright (C) 2011 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef LATINIME_WORDS_PRIORITY_QUEUE_H
-#define LATINIME_WORDS_PRIORITY_QUEUE_H
-
-#include <cstring> // for memcpy()
-#include <queue>
-
-#include "defines.h"
-#include "obsolete/correction.h"
-
-namespace latinime {
-
-class WordsPriorityQueue {
- public:
-    struct SuggestedWord {
-        int mScore;
-        int mWord[MAX_WORD_LENGTH];
-        int mWordLength;
-        bool mUsed;
-        int mType;
-
-        void setParams(int score, int *word, int wordLength, int type) {
-            mScore = score;
-            mWordLength = wordLength;
-            memcpy(mWord, word, sizeof(mWord[0]) * wordLength);
-            mUsed = true;
-            mType = type;
-        }
-    };
-
-    WordsPriorityQueue(int maxWords)
-            : mSuggestions(), MAX_WORDS(maxWords),
-              mSuggestedWords(new SuggestedWord[MAX_WORD_LENGTH]), mHighestSuggestedWord(0) {
-        for (int i = 0; i < MAX_WORD_LENGTH; ++i) {
-            mSuggestedWords[i].mUsed = false;
-        }
-    }
-
-    // Non virtual inline destructor -- never inherit this class
-    AK_FORCE_INLINE ~WordsPriorityQueue() {
-        delete[] mSuggestedWords;
-    }
-
-    void push(int score, int *word, int wordLength, int type) {
-        SuggestedWord *sw = 0;
-        if (size() >= MAX_WORDS) {
-            sw = mSuggestions.top();
-            const int minScore = sw->mScore;
-            if (minScore >= score) {
-                return;
-            }
-            sw->mUsed = false;
-            mSuggestions.pop();
-        }
-        if (sw == 0) {
-            sw = getFreeSuggestedWord(score, word, wordLength, type);
-        } else {
-            sw->setParams(score, word, wordLength, type);
-        }
-        if (sw == 0) {
-            AKLOGE("SuggestedWord is accidentally null.");
-            return;
-        }
-        if (DEBUG_WORDS_PRIORITY_QUEUE) {
-            AKLOGI("Push word. %d, %d", score, wordLength);
-            DUMP_WORD(word, wordLength);
-        }
-        mSuggestions.push(sw);
-        if (!mHighestSuggestedWord || mHighestSuggestedWord->mScore < sw->mScore) {
-            mHighestSuggestedWord = sw;
-        }
-    }
-
-    SuggestedWord *top() const {
-        if (mSuggestions.empty()) return 0;
-        SuggestedWord *sw = mSuggestions.top();
-        return sw;
-    }
-
-    int size() const {
-        return static_cast<int>(mSuggestions.size());
-    }
-
-    AK_FORCE_INLINE void clear() {
-        mHighestSuggestedWord = 0;
-        while (!mSuggestions.empty()) {
-            SuggestedWord *sw = mSuggestions.top();
-            if (DEBUG_WORDS_PRIORITY_QUEUE) {
-                AKLOGI("Clear word. %d", sw->mScore);
-                DUMP_WORD(sw->mWord, sw->mWordLength);
-            }
-            sw->mUsed = false;
-            mSuggestions.pop();
-        }
-    }
-
-    AK_FORCE_INLINE void dumpTopWord() const {
-        if (size() <= 0) {
-            return;
-        }
-        DUMP_WORD(mHighestSuggestedWord->mWord, mHighestSuggestedWord->mWordLength);
-    }
-
-    AK_FORCE_INLINE float getHighestNormalizedScore(const int *before, const int beforeLength,
-            int **outWord, int *outScore, int *outLength) const {
-        if (!mHighestSuggestedWord) {
-            return 0.0f;
-        }
-        return getNormalizedScore(mHighestSuggestedWord, before, beforeLength, outWord, outScore,
-                outLength);
-    }
-
-    int outputSuggestions(const int *before, const int beforeLength, int *frequencies,
-            int *outputCodePoints, int* outputTypes);
-
- private:
-    DISALLOW_IMPLICIT_CONSTRUCTORS(WordsPriorityQueue);
-    struct wordComparator {
-        bool operator ()(SuggestedWord * left, SuggestedWord * right) {
-            return left->mScore > right->mScore;
-        }
-    };
-
-    SuggestedWord *getFreeSuggestedWord(int score, int *word, int wordLength, int type) const {
-        for (int i = 0; i < MAX_WORD_LENGTH; ++i) {
-            if (!mSuggestedWords[i].mUsed) {
-                mSuggestedWords[i].setParams(score, word, wordLength, type);
-                return &mSuggestedWords[i];
-            }
-        }
-        return 0;
-    }
-
-    static float getNormalizedScore(SuggestedWord *sw, const int *before, const int beforeLength,
-            int **outWord, int *outScore, int *outLength) {
-        const int score = sw->mScore;
-        int *word = sw->mWord;
-        const int wordLength = sw->mWordLength;
-        if (outScore) {
-            *outScore = score;
-        }
-        if (outWord) {
-            *outWord = word;
-        }
-        if (outLength) {
-            *outLength = wordLength;
-        }
-        return Correction::RankingAlgorithm::calcNormalizedScore(before, beforeLength, word,
-                wordLength, score);
-    }
-
-    typedef std::priority_queue<SuggestedWord *, std::vector<SuggestedWord *>,
-            wordComparator> Suggestions;
-    Suggestions mSuggestions;
-    const int MAX_WORDS;
-    SuggestedWord *mSuggestedWords;
-    SuggestedWord *mHighestSuggestedWord;
-};
-} // namespace latinime
-#endif // LATINIME_WORDS_PRIORITY_QUEUE_H
diff --git a/native/jni/src/obsolete/words_priority_queue_pool.h b/native/jni/src/obsolete/words_priority_queue_pool.h
deleted file mode 100644
index bf04568..0000000
--- a/native/jni/src/obsolete/words_priority_queue_pool.h
+++ /dev/null
@@ -1,96 +0,0 @@
-/*
- * Copyright (C) 2011 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef LATINIME_WORDS_PRIORITY_QUEUE_POOL_H
-#define LATINIME_WORDS_PRIORITY_QUEUE_POOL_H
-
-#include "defines.h"
-#include "obsolete/words_priority_queue.h"
-
-namespace latinime {
-
-class WordsPriorityQueuePool {
- public:
-    WordsPriorityQueuePool(int mainQueueMaxWords, int subQueueMaxWords)
-            // Note: using placement new() requires the caller to call the destructor explicitly.
-            : mMasterQueue(new(mMasterQueueBuf) WordsPriorityQueue(mainQueueMaxWords)) {
-        for (int i = 0, subQueueBufOffset = 0;
-                i < MULTIPLE_WORDS_SUGGESTION_MAX_WORDS * SUB_QUEUE_MAX_COUNT;
-                ++i, subQueueBufOffset += static_cast<int>(sizeof(WordsPriorityQueue))) {
-            mSubQueues[i] = new(mSubQueueBuf + subQueueBufOffset)
-                    WordsPriorityQueue(subQueueMaxWords);
-        }
-    }
-
-    // Non virtual inline destructor -- never inherit this class
-    ~WordsPriorityQueuePool() {
-        // Note: these explicit calls to the destructor match the calls to placement new() above.
-        if (mMasterQueue) mMasterQueue->~WordsPriorityQueue();
-        for (int i = 0; i < MULTIPLE_WORDS_SUGGESTION_MAX_WORDS * SUB_QUEUE_MAX_COUNT; ++i) {
-            if (mSubQueues[i]) mSubQueues[i]->~WordsPriorityQueue();
-        }
-    }
-
-    WordsPriorityQueue *getMasterQueue() const {
-        return mMasterQueue;
-    }
-
-    WordsPriorityQueue *getSubQueue(const int wordIndex, const int inputWordLength) const {
-        if (wordIndex >= MULTIPLE_WORDS_SUGGESTION_MAX_WORDS) {
-            return 0;
-        }
-        if (inputWordLength < 0 || inputWordLength >= SUB_QUEUE_MAX_COUNT) {
-            if (DEBUG_WORDS_PRIORITY_QUEUE) {
-                ASSERT(false);
-            }
-            return 0;
-        }
-        return mSubQueues[wordIndex * SUB_QUEUE_MAX_COUNT + inputWordLength];
-    }
-
-    inline void clearAll() {
-        mMasterQueue->clear();
-        for (int i = 0; i < MULTIPLE_WORDS_SUGGESTION_MAX_WORDS; ++i) {
-            clearSubQueue(i);
-        }
-    }
-
-    AK_FORCE_INLINE void clearSubQueue(const int wordIndex) {
-        for (int i = 0; i < SUB_QUEUE_MAX_COUNT; ++i) {
-            WordsPriorityQueue *queue = getSubQueue(wordIndex, i);
-            if (queue) {
-                queue->clear();
-            }
-        }
-    }
-
-    void dumpSubQueue1TopSuggestions() const {
-        AKLOGI("DUMP SUBQUEUE1 TOP SUGGESTIONS");
-        for (int i = 0; i < SUB_QUEUE_MAX_COUNT; ++i) {
-            getSubQueue(0, i)->dumpTopWord();
-        }
-    }
-
- private:
-    DISALLOW_IMPLICIT_CONSTRUCTORS(WordsPriorityQueuePool);
-    char mMasterQueueBuf[sizeof(WordsPriorityQueue)];
-    char mSubQueueBuf[SUB_QUEUE_MAX_COUNT * MULTIPLE_WORDS_SUGGESTION_MAX_WORDS
-            * sizeof(WordsPriorityQueue)];
-    WordsPriorityQueue *mMasterQueue;
-    WordsPriorityQueue *mSubQueues[SUB_QUEUE_MAX_COUNT * MULTIPLE_WORDS_SUGGESTION_MAX_WORDS];
-};
-} // namespace latinime
-#endif // LATINIME_WORDS_PRIORITY_QUEUE_POOL_H