File indexing completed on 2024-12-22 04:33:42

 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (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.mozilla.org/MPL/
  *
  * Software distributed under the License is distributed on an "AS IS" basis,
  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  * for the specific language governing rights and limitations under the
  * License.
  *
  * The Original Code is Mozilla Universal charset detector code.
  *
  * The Initial Developer of the Original Code is
  * Netscape Communications Corporation.
  * Portions created by the Initial Developer are Copyright (C) 2001
  * the Initial Developer. All Rights Reserved.
  *
  * Contributor(s):
  *          Shy Shalom <shooshX@gmail.com>
  *
  * Alternatively, the contents of this file may be used under the terms of
  * either the GNU General Public License Version 2 or later (the "GPL"), or
  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  * in which case the provisions of the GPL or the LGPL are applicable instead
  * of those above. If you wish to allow use of your version of this file only
  * under the terms of either the GPL or the LGPL, and not to allow others to
  * use your version of this file under the terms of the MPL, indicate your
  * decision by deleting the provisions above and replace them with the notice
  * and other provisions required by the GPL or the LGPL. If you do not delete
  * the provisions above, a recipient may use your version of this file under
  * the terms of any one of the MPL, the GPL or the LGPL.
  *
  * ***** END LICENSE BLOCK ***** */
 
 #pragma GCC visibility push(hidden)
 
 #include <stdio.h>
 #include "nsSBCharSetProber.h"
 
 nsProbingState nsSingleByteCharSetProber::HandleData(const char* aBuf, PRUint32 aLen)
 {
   unsigned char order;
 
   for (PRUint32 i = 0; i < aLen; i++)
   {
     order = mModel->charToOrderMap[(unsigned char)aBuf[i]];
 
     if (order < SYMBOL_CAT_ORDER)
       mTotalChar++;
     if (order < SAMPLE_SIZE)
     {
         mFreqChar++;
 
       if (mLastOrder < SAMPLE_SIZE)
       {
         mTotalSeqs++;
         if (!mReversed)
           ++(mSeqCounters[int(mModel->precedenceMatrix[mLastOrder*SAMPLE_SIZE+order])]);
         else // reverse the order of the letters in the lookup
           ++(mSeqCounters[int(mModel->precedenceMatrix[order*SAMPLE_SIZE+mLastOrder])]);
       }
     }
     mLastOrder = order;
   }
 
   if (mState == eDetecting)
     if (mTotalSeqs > SB_ENOUGH_REL_THRESHOLD)
     {
       float cf = GetConfidence();
       if (cf > POSITIVE_SHORTCUT_THRESHOLD)
         mState = eFoundIt;
       else if (cf < NEGATIVE_SHORTCUT_THRESHOLD)
         mState = eNotMe;
     }
 
   return mState;
 }
 
 void  nsSingleByteCharSetProber::Reset(void)
 {
   mState = eDetecting;
   mLastOrder = 255;
   for (PRUint32 i = 0; i < NUMBER_OF_SEQ_CAT; i++)
     mSeqCounters[i] = 0;
   mTotalSeqs = 0;
   mTotalChar = 0;
   mFreqChar = 0;
 }
 
 //#define NEGATIVE_APPROACH 1
 
 float nsSingleByteCharSetProber::GetConfidence(void)
 {
 #ifdef NEGATIVE_APPROACH
   if (mTotalSeqs > 0)
     if (mTotalSeqs > mSeqCounters[NEGATIVE_CAT]*10 )
       return ((float)(mTotalSeqs - mSeqCounters[NEGATIVE_CAT]*10))/mTotalSeqs * mFreqChar / mTotalChar;
   return (float)0.01;
 #else  //POSITIVE_APPROACH
   float r;
 
   if (mTotalSeqs > 0) {
     r = ((float)1.0) * mSeqCounters[POSITIVE_CAT] / mTotalSeqs / mModel->mTypicalPositiveRatio;
     r = r*mFreqChar/mTotalChar;
     if (r >= (float)1.00)
       r = (float)0.99;
     return r;
   }
   return (float)0.01;
 #endif
 }
 
 const char* nsSingleByteCharSetProber::GetCharSetName() 
 {
   if (!mNameProber)
     return mModel->charsetName;
   return mNameProber->GetCharSetName();
 }
 
 #ifdef DEBUG_chardet
 void nsSingleByteCharSetProber::DumpStatus()
 {
   printf("  SBCS: %1.3f [%s]\r\n", GetConfidence(), GetCharSetName());
 }
 #endif
 
 #pragma GCC visibility pop