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 /* -*- 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 "nsLatin1Prober.h"
 #include "prmem.h"
 #include <stdio.h>
 
 #define UDF    0        // undefined
 #define OTH    1        //other
 #define ASC    2        // ascii capital letter
 #define ASS    3        // ascii small letter
 #define ACV    4        // accent capital vowel
 #define ACO    5        // accent capital other
 #define ASV    6        // accent small vowel
 #define ASO    7        // accent small other
 #define CLASS_NUM   8    // total classes
 
 static unsigned char Latin1_CharToClass[] = 
 {
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 00 - 07
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 08 - 0F
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 10 - 17
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 18 - 1F
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 20 - 27
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 28 - 2F
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 30 - 37
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 38 - 3F
   OTH, ASC, ASC, ASC, ASC, ASC, ASC, ASC,   // 40 - 47
   ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC,   // 48 - 4F
   ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC,   // 50 - 57
   ASC, ASC, ASC, OTH, OTH, OTH, OTH, OTH,   // 58 - 5F
   OTH, ASS, ASS, ASS, ASS, ASS, ASS, ASS,   // 60 - 67
   ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS,   // 68 - 6F
   ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS,   // 70 - 77
   ASS, ASS, ASS, OTH, OTH, OTH, OTH, OTH,   // 78 - 7F
   OTH, UDF, OTH, ASO, OTH, OTH, OTH, OTH,   // 80 - 87
   OTH, OTH, ACO, OTH, ACO, UDF, ACO, UDF,   // 88 - 8F
   UDF, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 90 - 97
   OTH, OTH, ASO, OTH, ASO, UDF, ASO, ACO,   // 98 - 9F
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // A0 - A7
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // A8 - AF
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // B0 - B7
   OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // B8 - BF
   ACV, ACV, ACV, ACV, ACV, ACV, ACO, ACO,   // C0 - C7
   ACV, ACV, ACV, ACV, ACV, ACV, ACV, ACV,   // C8 - CF
   ACO, ACO, ACV, ACV, ACV, ACV, ACV, OTH,   // D0 - D7
   ACV, ACV, ACV, ACV, ACV, ACO, ACO, ACO,   // D8 - DF
   ASV, ASV, ASV, ASV, ASV, ASV, ASO, ASO,   // E0 - E7
   ASV, ASV, ASV, ASV, ASV, ASV, ASV, ASV,   // E8 - EF
   ASO, ASO, ASV, ASV, ASV, ASV, ASV, OTH,   // F0 - F7
   ASV, ASV, ASV, ASV, ASV, ASO, ASO, ASO,   // F8 - FF
 };
 
 
 /* 0 : illegal 
    1 : very unlikely 
    2 : normal 
    3 : very likely
 */
 static unsigned char Latin1ClassModel[] = 
 {
 /*      UDF OTH ASC ASS ACV ACO ASV ASO  */
 /*UDF*/  0,  0,  0,  0,  0,  0,  0,  0,
 /*OTH*/  0,  3,  3,  3,  3,  3,  3,  3,
 /*ASC*/  0,  3,  3,  3,  3,  3,  3,  3, 
 /*ASS*/  0,  3,  3,  3,  1,  1,  3,  3,
 /*ACV*/  0,  3,  3,  3,  1,  2,  1,  2,
 /*ACO*/  0,  3,  3,  3,  3,  3,  3,  3, 
 /*ASV*/  0,  3,  1,  3,  1,  1,  1,  3, 
 /*ASO*/  0,  3,  1,  3,  1,  1,  3,  3,
 };
 
 void  nsLatin1Prober::Reset(void)
 {
   mState = eDetecting;
   mLastCharClass = OTH;
   for (int i = 0; i < FREQ_CAT_NUM; i++)
     mFreqCounter[i] = 0;
 }
 
 
 nsProbingState nsLatin1Prober::HandleData(const char* aBuf, PRUint32 aLen)
 {
   char *newBuf1 = 0;
   PRUint32 newLen1 = 0;
 
   if (!FilterWithEnglishLetters(aBuf, aLen, &newBuf1, newLen1)) {
     newBuf1 = (char*)aBuf;
     newLen1 = aLen;
   }
   
   unsigned char charClass;
   unsigned char freq;
   for (PRUint32 i = 0; i < newLen1; i++)
   {
     charClass = Latin1_CharToClass[(unsigned char)newBuf1[i]];
     freq = Latin1ClassModel[mLastCharClass*CLASS_NUM + charClass];
     if (freq == 0) {
       mState = eNotMe;
       break;
     }
     mFreqCounter[freq]++;
     mLastCharClass = charClass;
   }
 
   if (newBuf1 != aBuf)
     PR_FREEIF(newBuf1);
 
   return mState;
 }
 
 float nsLatin1Prober::GetConfidence(void)
 {
   if (mState == eNotMe)
     return 0.01f;
   
   float confidence;
   PRUint32 total = 0;
   for (PRInt32 i = 0; i < FREQ_CAT_NUM; i++)
     total += mFreqCounter[i];
 
   if(!total)
     confidence = 0.0f;
   else
   {
     confidence = mFreqCounter[3]*1.0f / total;
     confidence -= mFreqCounter[1]*20.0f/total;
   }
 
   if (confidence < 0.0f)
     confidence = 0.0f;
   
   // lower the confidence of latin1 so that other more accurate detector 
   // can take priority.
   confidence *= 0.50f;
 
   return confidence;
 }
 
 #ifdef DEBUG_chardet
 void  nsLatin1Prober::DumpStatus()
 {
   printf(" Latin1Prober: %1.3f [%s]\r\n", GetConfidence(), GetCharSetName());
 }
 #endif
 
 #pragma GCC visibility pop