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      1 /*
      2  * Copyright (C) 2009 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_DICTIONARY_H
     18 #define LATINIME_DICTIONARY_H
     19 
     20 namespace latinime {
     21 
     22 // 22-bit address = ~4MB dictionary size limit, which on average would be about 200k-300k words
     23 #define ADDRESS_MASK 0x3FFFFF
     24 
     25 // The bit that decides if an address follows in the next 22 bits
     26 #define FLAG_ADDRESS_MASK 0x40
     27 // The bit that decides if this is a terminal node for a word. The node could still have children,
     28 // if the word has other endings.
     29 #define FLAG_TERMINAL_MASK 0x80
     30 
     31 #define FLAG_BIGRAM_READ 0x80
     32 #define FLAG_BIGRAM_CHILDEXIST 0x40
     33 #define FLAG_BIGRAM_CONTINUED 0x80
     34 #define FLAG_BIGRAM_FREQ 0x7F
     35 
     36 class Dictionary {
     37 public:
     38     Dictionary(void *dict, int typedLetterMultipler, int fullWordMultiplier);
     39     int getSuggestions(int *codes, int codesSize, unsigned short *outWords, int *frequencies,
     40             int maxWordLength, int maxWords, int maxAlternatives, int skipPos,
     41             int *nextLetters, int nextLettersSize);
     42     int getBigrams(unsigned short *word, int length, int *codes, int codesSize,
     43             unsigned short *outWords, int *frequencies, int maxWordLength, int maxBigrams,
     44             int maxAlternatives);
     45     bool isValidWord(unsigned short *word, int length);
     46     void setAsset(void *asset) { mAsset = asset; }
     47     void *getAsset() { return mAsset; }
     48     ~Dictionary();
     49 
     50 private:
     51 
     52     void getVersionNumber();
     53     bool checkIfDictVersionIsLatest();
     54     int getAddress(int *pos);
     55     int getBigramAddress(int *pos, bool advance);
     56     int getFreq(int *pos);
     57     int getBigramFreq(int *pos);
     58     void searchForTerminalNode(int address, int frequency);
     59 
     60     bool getFirstBitOfByte(int *pos) { return (mDict[*pos] & 0x80) > 0; }
     61     bool getSecondBitOfByte(int *pos) { return (mDict[*pos] & 0x40) > 0; }
     62     bool getTerminal(int *pos) { return (mDict[*pos] & FLAG_TERMINAL_MASK) > 0; }
     63     int getCount(int *pos) { return mDict[(*pos)++] & 0xFF; }
     64     unsigned short getChar(int *pos);
     65     int wideStrLen(unsigned short *str);
     66 
     67     bool sameAsTyped(unsigned short *word, int length);
     68     bool checkFirstCharacter(unsigned short *word);
     69     bool addWord(unsigned short *word, int length, int frequency);
     70     bool addWordBigram(unsigned short *word, int length, int frequency);
     71     unsigned short toLowerCase(unsigned short c);
     72     void getWordsRec(int pos, int depth, int maxDepth, bool completion, int frequency,
     73             int inputIndex, int diffs);
     74     int isValidWordRec(int pos, unsigned short *word, int offset, int length);
     75     void registerNextLetter(unsigned short c);
     76 
     77     unsigned char *mDict;
     78     void *mAsset;
     79 
     80     int *mFrequencies;
     81     int *mBigramFreq;
     82     int mMaxWords;
     83     int mMaxBigrams;
     84     int mMaxWordLength;
     85     unsigned short *mOutputChars;
     86     unsigned short *mBigramChars;
     87     int *mInputCodes;
     88     int mInputLength;
     89     int mMaxAlternatives;
     90     unsigned short mWord[128];
     91     int mSkipPos;
     92     int mMaxEditDistance;
     93 
     94     int mFullWordMultiplier;
     95     int mTypedLetterMultiplier;
     96     int *mNextLettersFrequencies;
     97     int mNextLettersSize;
     98     int mVersion;
     99     int mBigram;
    100 };
    101 
    102 // ----------------------------------------------------------------------------
    103 
    104 }; // namespace latinime
    105 
    106 #endif // LATINIME_DICTIONARY_H
    107