nsSBCSGroupProber.cpp

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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
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 *
 * 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>
 *
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 * either the GNU General Public License Version 2 or later (the "GPL"), or
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#include <stdio.h>
#include "prmem.h"

#include "nsSBCharSetProber.h"
#include "nsSBCSGroupProber.h"

#include "nsHebrewProber.h"

nsSBCSGroupProber::nsSBCSGroupProber()
{
  mProbers[0] = new nsSingleByteCharSetProber(&Win1251Model);
  mProbers[1] = new nsSingleByteCharSetProber(&Koi8rModel);
  mProbers[2] = new nsSingleByteCharSetProber(&Latin5Model);
  mProbers[3] = new nsSingleByteCharSetProber(&MacCyrillicModel);
  mProbers[4] = new nsSingleByteCharSetProber(&Ibm866Model);
  mProbers[5] = new nsSingleByteCharSetProber(&Ibm855Model);
  mProbers[6] = new nsSingleByteCharSetProber(&Latin7Model);
  mProbers[7] = new nsSingleByteCharSetProber(&Win1253Model);
  mProbers[8] = new nsSingleByteCharSetProber(&Latin5BulgarianModel);
  mProbers[9] = new nsSingleByteCharSetProber(&Win1251BulgarianModel);

  nsHebrewProber *hebprober = new nsHebrewProber();
  // Notice: Any change in these indexes - 10,11,12 must be reflected
  // in the code below as well.
  mProbers[10] = hebprober;
  mProbers[11] = new nsSingleByteCharSetProber(&Win1255Model, PR_FALSE, hebprober); // Logical Hebrew
  mProbers[12] = new nsSingleByteCharSetProber(&Win1255Model, PR_TRUE, hebprober); // Visual Hebrew
  // Tell the Hebrew prober about the logical and visual probers
  if (mProbers[10] && mProbers[11] && mProbers[12]) // all are not null
  {
    hebprober->SetModelProbers(mProbers[11], mProbers[12]);
  }
  else // One or more is null. avoid any Hebrew probing, null them all
  {
    for (PRUint32 i = 10; i <= 12; ++i)
    { 
      delete mProbers[i]; 
      mProbers[i] = 0; 
    }
  }

  // disable latin2 before latin1 is available, otherwise all latin1 
  // will be detected as latin2 because of their similarity.
  //mProbers[10] = new nsSingleByteCharSetProber(&Latin2HungarianModel);
  //mProbers[11] = new nsSingleByteCharSetProber(&Win1250HungarianModel);

  Reset();
}

nsSBCSGroupProber::~nsSBCSGroupProber()
{
  for (PRUint32 i = 0; i < NUM_OF_SBCS_PROBERS; i++)
  {
    delete mProbers[i];
  }
}


const char* nsSBCSGroupProber::GetCharSetName()
{
  //if we have no answer yet
  if (mBestGuess == -1)
  {
    GetConfidence();
    //no charset seems positive
    if (mBestGuess == -1)
      //we will use default.
      mBestGuess = 0;
  }
  return mProbers[mBestGuess]->GetCharSetName();
}

void  nsSBCSGroupProber::Reset(void)
{
  mActiveNum = 0;
  for (PRUint32 i = 0; i < NUM_OF_SBCS_PROBERS; i++)
  {
    if (mProbers[i]) // not null
    {
      mProbers[i]->Reset();
      mIsActive[i] = PR_TRUE;
      ++mActiveNum;
    }
    else
      mIsActive[i] = PR_FALSE;
  }
  mBestGuess = -1;
  mState = eDetecting;
}


nsProbingState nsSBCSGroupProber::HandleData(const char* aBuf, PRUint32 aLen)
{
  nsProbingState st;
  PRUint32 i;
  char *newBuf1 = 0;
  PRUint32 newLen1 = 0;

  //apply filter to original buffer, and we got new buffer back
  //depend on what script it is, we will feed them the new buffer 
  //we got after applying proper filter
  //this is done without any consideration to KeepEnglishLetters
  //of each prober since as of now, there are no probers here which
  //recognize languages with English characters.
  if (!FilterWithoutEnglishLetters(aBuf, aLen, &newBuf1, newLen1))
    goto done;
  
  if (newLen1 == 0)
    goto done; // Nothing to see here, move on.

  for (i = 0; i < NUM_OF_SBCS_PROBERS; i++)
  {
     if (!mIsActive[i])
       continue;
     st = mProbers[i]->HandleData(newBuf1, newLen1);
     if (st == eFoundIt)
     {
       mBestGuess = i;
       mState = eFoundIt;
       break;
     }
     else if (st == eNotMe)
     {
       mIsActive[i] = PR_FALSE;
       mActiveNum--;
       if (mActiveNum <= 0)
       {
         mState = eNotMe;
         break;
       }
     }
  }

done:
  PR_FREEIF(newBuf1);

  return mState;
}

float nsSBCSGroupProber::GetConfidence(void)
{
  PRUint32 i;
  float bestConf = 0.0, cf;

  switch (mState)
  {
  case eFoundIt:
    return (float)0.99; //sure yes
  case eNotMe:
    return (float)0.01;  //sure no
  default:
    for (i = 0; i < NUM_OF_SBCS_PROBERS; i++)
    {
      if (!mIsActive[i])
        continue;
      cf = mProbers[i]->GetConfidence();
      if (bestConf < cf)
      {
        bestConf = cf;
        mBestGuess = i;
      }
    }
  }
  return bestConf;
}

#ifdef DEBUG_chardet
void nsSBCSGroupProber::DumpStatus()
{
  PRUint32 i;
  float cf;
  
  cf = GetConfidence();
  printf(" SBCS Group Prober --------begin status \r\n");
  for (i = 0; i < NUM_OF_SBCS_PROBERS; i++)
  {
    if (!mIsActive[i])
      printf("  inactive: [%s] (i.e. confidence is too low).\r\n", mProbers[i]->GetCharSetName());
    else
      mProbers[i]->DumpStatus();
  }
  printf(" SBCS Group found best match [%s] confidence %f.\r\n",  
         mProbers[mBestGuess]->GetCharSetName(), cf);
}
#endif