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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef LATINIME_WORDS_PRIORITY_QUEUE_H
     18 #define LATINIME_WORDS_PRIORITY_QUEUE_H
     19 
     20 #include <cstring> // for memcpy()
     21 #include <queue>
     22 
     23 #include "correction.h"
     24 #include "defines.h"
     25 
     26 namespace latinime {
     27 
     28 class WordsPriorityQueue {
     29  public:
     30     struct SuggestedWord {
     31         int mScore;
     32         int mWord[MAX_WORD_LENGTH];
     33         int mWordLength;
     34         bool mUsed;
     35         int mType;
     36 
     37         void setParams(int score, int *word, int wordLength, int type) {
     38             mScore = score;
     39             mWordLength = wordLength;
     40             memcpy(mWord, word, sizeof(mWord[0]) * wordLength);
     41             mUsed = true;
     42             mType = type;
     43         }
     44     };
     45 
     46     WordsPriorityQueue(int maxWords)
     47             : mSuggestions(), MAX_WORDS(maxWords),
     48               mSuggestedWords(new SuggestedWord[MAX_WORD_LENGTH]), mHighestSuggestedWord(0) {
     49         for (int i = 0; i < MAX_WORD_LENGTH; ++i) {
     50             mSuggestedWords[i].mUsed = false;
     51         }
     52     }
     53 
     54     // Non virtual inline destructor -- never inherit this class
     55     AK_FORCE_INLINE ~WordsPriorityQueue() {
     56         delete[] mSuggestedWords;
     57     }
     58 
     59     void push(int score, int *word, int wordLength, int type) {
     60         SuggestedWord *sw = 0;
     61         if (size() >= MAX_WORDS) {
     62             sw = mSuggestions.top();
     63             const int minScore = sw->mScore;
     64             if (minScore >= score) {
     65                 return;
     66             }
     67             sw->mUsed = false;
     68             mSuggestions.pop();
     69         }
     70         if (sw == 0) {
     71             sw = getFreeSuggestedWord(score, word, wordLength, type);
     72         } else {
     73             sw->setParams(score, word, wordLength, type);
     74         }
     75         if (sw == 0) {
     76             AKLOGE("SuggestedWord is accidentally null.");
     77             return;
     78         }
     79         if (DEBUG_WORDS_PRIORITY_QUEUE) {
     80             AKLOGI("Push word. %d, %d", score, wordLength);
     81             DUMP_WORD(word, wordLength);
     82         }
     83         mSuggestions.push(sw);
     84         if (!mHighestSuggestedWord || mHighestSuggestedWord->mScore < sw->mScore) {
     85             mHighestSuggestedWord = sw;
     86         }
     87     }
     88 
     89     SuggestedWord *top() const {
     90         if (mSuggestions.empty()) return 0;
     91         SuggestedWord *sw = mSuggestions.top();
     92         return sw;
     93     }
     94 
     95     int size() const {
     96         return static_cast<int>(mSuggestions.size());
     97     }
     98 
     99     AK_FORCE_INLINE void clear() {
    100         mHighestSuggestedWord = 0;
    101         while (!mSuggestions.empty()) {
    102             SuggestedWord *sw = mSuggestions.top();
    103             if (DEBUG_WORDS_PRIORITY_QUEUE) {
    104                 AKLOGI("Clear word. %d", sw->mScore);
    105                 DUMP_WORD(sw->mWord, sw->mWordLength);
    106             }
    107             sw->mUsed = false;
    108             mSuggestions.pop();
    109         }
    110     }
    111 
    112     AK_FORCE_INLINE void dumpTopWord() const {
    113         if (size() <= 0) {
    114             return;
    115         }
    116         DUMP_WORD(mHighestSuggestedWord->mWord, mHighestSuggestedWord->mWordLength);
    117     }
    118 
    119     AK_FORCE_INLINE float getHighestNormalizedScore(const int *before, const int beforeLength,
    120             int **outWord, int *outScore, int *outLength) const {
    121         if (!mHighestSuggestedWord) {
    122             return 0.0f;
    123         }
    124         return getNormalizedScore(mHighestSuggestedWord, before, beforeLength, outWord, outScore,
    125                 outLength);
    126     }
    127 
    128     int outputSuggestions(const int *before, const int beforeLength, int *frequencies,
    129             int *outputCodePoints, int* outputTypes);
    130 
    131  private:
    132     DISALLOW_IMPLICIT_CONSTRUCTORS(WordsPriorityQueue);
    133     struct wordComparator {
    134         bool operator ()(SuggestedWord * left, SuggestedWord * right) {
    135             return left->mScore > right->mScore;
    136         }
    137     };
    138 
    139     SuggestedWord *getFreeSuggestedWord(int score, int *word, int wordLength, int type) const {
    140         for (int i = 0; i < MAX_WORD_LENGTH; ++i) {
    141             if (!mSuggestedWords[i].mUsed) {
    142                 mSuggestedWords[i].setParams(score, word, wordLength, type);
    143                 return &mSuggestedWords[i];
    144             }
    145         }
    146         return 0;
    147     }
    148 
    149     static float getNormalizedScore(SuggestedWord *sw, const int *before, const int beforeLength,
    150             int **outWord, int *outScore, int *outLength) {
    151         const int score = sw->mScore;
    152         int *word = sw->mWord;
    153         const int wordLength = sw->mWordLength;
    154         if (outScore) {
    155             *outScore = score;
    156         }
    157         if (outWord) {
    158             *outWord = word;
    159         }
    160         if (outLength) {
    161             *outLength = wordLength;
    162         }
    163         return Correction::RankingAlgorithm::calcNormalizedScore(before, beforeLength, word,
    164                 wordLength, score);
    165     }
    166 
    167     typedef std::priority_queue<SuggestedWord *, std::vector<SuggestedWord *>,
    168             wordComparator> Suggestions;
    169     Suggestions mSuggestions;
    170     const int MAX_WORDS;
    171     SuggestedWord *mSuggestedWords;
    172     SuggestedWord *mHighestSuggestedWord;
    173 };
    174 } // namespace latinime
    175 #endif // LATINIME_WORDS_PRIORITY_QUEUE_H
    176