extensions/universalchardet/src/base/nsBig5Prober.cpp

   1 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is mozilla.org code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either the GNU General Public License Version 2 or later (the "GPL"), or
  26  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  27  * in which case the provisions of the GPL or the LGPL are applicable instead
  28  * of those above. If you wish to allow use of your version of this file only
  29  * under the terms of either the GPL or the LGPL, and not to allow others to
  30  * use your version of this file under the terms of the MPL, indicate your
  31  * decision by deleting the provisions above and replace them with the notice
  32  * and other provisions required by the GPL or the LGPL. If you do not delete
  33  * the provisions above, a recipient may use your version of this file under
  34  * the terms of any one of the MPL, the GPL or the LGPL.
  35  *
  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #include "nsBig5Prober.h"
  39
  40 void  nsBig5Prober::Reset(void)
  41 {
  42   mCodingSM->Reset();
  43   mState = eDetecting;
  44   mDistributionAnalyser.Reset();
  45 }
  46
  47 nsProbingState nsBig5Prober::HandleData(const char* aBuf, PRUint32 aLen)
  48 {
  49   nsSMState codingState;
  50
  51   for (PRUint32 i = 0; i < aLen; i++)
  52   {
  53     codingState = mCodingSM->NextState(aBuf[i]);
  54     if (codingState == eItsMe)
  55     {
  56       mState = eFoundIt;
  57       break;
  58     }
  59     if (codingState == eStart)
  60     {
  61       PRUint32 charLen = mCodingSM->GetCurrentCharLen();
  62
  63       if (i == 0)
  64       {
  65         mLastChar[1] = aBuf[0];
  66         mDistributionAnalyser.HandleOneChar(mLastChar, charLen);
  67       }
  68       else
  69         mDistributionAnalyser.HandleOneChar(aBuf+i-1, charLen);
  70     }
  71   }
  72
  73   mLastChar[0] = aBuf[aLen-1];
  74
  75   if (mState == eDetecting)
  76     if (mDistributionAnalyser.GotEnoughData() && GetConfidence() > SHORTCUT_THRESHOLD)
  77       mState = eFoundIt;
  78
  79   return mState;
  80 }
  81
  82 float nsBig5Prober::GetConfidence(void)
  83 {
  84   float distribCf = mDistributionAnalyser.GetConfidence(mIsPreferredLanguage);
  85
  86   return (float)distribCf;
  87 }
  88