File indexing completed on 2024-04-28 03:53:04

 /*  -*- C++ -*-
     SPDX-FileCopyrightText: 1998 Netscape Communications Corporation <developer@mozilla.org>
 
     SPDX-License-Identifier: MIT
 */
 
 #ifndef NSSBCHARSETPROBER_H
 #define NSSBCHARSETPROBER_H
 
 #include "nsCharSetProber.h"
 
 #define SAMPLE_SIZE 64
 #define SB_ENOUGH_REL_THRESHOLD 1024
 #define POSITIVE_SHORTCUT_THRESHOLD (float)0.95
 #define NEGATIVE_SHORTCUT_THRESHOLD (float)0.05
 #define SYMBOL_CAT_ORDER 250
 #define NUMBER_OF_SEQ_CAT 4
 #define POSITIVE_CAT (NUMBER_OF_SEQ_CAT - 1)
 #define NEGATIVE_CAT 0
 
 namespace kencodingprober
 {
 typedef struct {
     const unsigned char *charToOrderMap; // [256] table use to find a char's order
     const char *precedenceMatrix; // [SAMPLE_SIZE][SAMPLE_SIZE]; table to find a 2-char sequence's frequency
     float mTypicalPositiveRatio; // = freqSeqs / totalSeqs
     bool keepEnglishLetter; // says if this script contains English characters (not implemented)
     const char *charsetName;
 } SequenceModel;
 
 class KCODECS_NO_EXPORT nsSingleByteCharSetProber : public nsCharSetProber
 {
 public:
     explicit nsSingleByteCharSetProber(const SequenceModel *model)
         : mModel(model)
         , mReversed(false)
         , mNameProber(nullptr)
     {
         Reset();
     }
     nsSingleByteCharSetProber(const SequenceModel *model, bool reversed, nsCharSetProber *nameProber)
         : mModel(model)
         , mReversed(reversed)
         , mNameProber(nameProber)
     {
         Reset();
     }
 
     const char *GetCharSetName() override;
     nsProbingState HandleData(const char *aBuf, unsigned int aLen) override;
     nsProbingState GetState(void) override
     {
         return mState;
     }
     void Reset(void) override;
     float GetConfidence(void) override;
     void SetOpion() override
     {
     }
 
     // This feature is not implemented yet. any current language model
     // contain this parameter as false. No one is looking at this
     // parameter or calling this method.
     // Moreover, the nsSBCSGroupProber which calls the HandleData of this
     // prober has a hard-coded call to FilterWithoutEnglishLetters which gets rid
     // of the English letters.
     bool KeepEnglishLetters()
     {
         return mModel->keepEnglishLetter;
     } // (not implemented)
 
 #ifdef DEBUG_PROBE
     void DumpStatus() override;
 #endif
 
 protected:
     nsProbingState mState;
     const SequenceModel *mModel;
     const bool mReversed; // true if we need to reverse every pair in the model lookup
 
     // char order of last character
     unsigned char mLastOrder;
 
     unsigned int mTotalSeqs;
     unsigned int mSeqCounters[NUMBER_OF_SEQ_CAT];
 
     unsigned int mTotalChar;
     // characters that fall in our sampling range
     unsigned int mFreqChar;
 
     // Optional auxiliary prober for name decision. created and destroyed by the GroupProber
     nsCharSetProber *mNameProber;
 };
 
 extern const SequenceModel Koi8rModel;
 extern const SequenceModel Win1251Model;
 extern const SequenceModel Latin5Model;
 extern const SequenceModel MacCyrillicModel;
 extern const SequenceModel Ibm866Model;
 extern const SequenceModel Ibm855Model;
 extern const SequenceModel Latin7Model;
 extern const SequenceModel Win1253Model;
 extern const SequenceModel Latin5BulgarianModel;
 extern const SequenceModel Win1251BulgarianModel;
 extern const SequenceModel Latin2HungarianModel;
 extern const SequenceModel Win1250HungarianModel;
 extern const SequenceModel Win1255Model;
 }
 #endif /* NSSBCHARSETPROBER_H */