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

 /*  -*- C++ -*-
     SPDX-FileCopyrightText: 1998 Netscape Communications Corporation <developer@mozilla.org>
 
     SPDX-License-Identifier: MIT
 */
 
 // for japanese encoding, observe characteristic:
 // 1, kana character (or hankaku?) often have high frequency of appearance
 // 2, kana character often exist in group
 // 3, certain combination of kana is never used in japanese language
 
 #include "nsEUCJPProber.h"
 
 namespace kencodingprober
 {
 void nsEUCJPProber::Reset(void)
 {
     mCodingSM->Reset();
     mState = eDetecting;
     mContextAnalyser.Reset();
     mDistributionAnalyser.Reset();
 }
 
 nsProbingState nsEUCJPProber::HandleData(const char *aBuf, unsigned int aLen)
 {
     if (aLen == 0) {
         return mState;
     }
 
     for (unsigned int i = 0; i < aLen; i++) {
         const nsSMState codingState = mCodingSM->NextState(aBuf[i]);
         if (codingState == eError) {
             mState = eNotMe;
             break;
         }
         if (codingState == eItsMe) {
             mState = eFoundIt;
             break;
         }
         if (codingState == eStart) {
             unsigned int charLen = mCodingSM->GetCurrentCharLen();
 
             if (i == 0) {
                 mLastChar[1] = aBuf[0];
                 mContextAnalyser.HandleOneChar(mLastChar, charLen);
                 mDistributionAnalyser.HandleOneChar(mLastChar, charLen);
             } else {
                 mContextAnalyser.HandleOneChar(aBuf + i - 1, charLen);
                 mDistributionAnalyser.HandleOneChar(aBuf + i - 1, charLen);
             }
         }
     }
 
     mLastChar[0] = aBuf[aLen - 1];
 
     if (mState == eDetecting) {
         if (mContextAnalyser.GotEnoughData() && GetConfidence() > SHORTCUT_THRESHOLD) {
             mState = eFoundIt;
         }
     }
 
     return mState;
 }
 
 float nsEUCJPProber::GetConfidence(void)
 {
     float contxtCf = mContextAnalyser.GetConfidence();
     float distribCf = mDistributionAnalyser.GetConfidence();
 
     return (contxtCf > distribCf ? contxtCf : distribCf);
 }
 }