| 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 "nsUTF8Prober.h" |
| 39 |
|
| 40 |
void nsUTF8Prober::Reset(void) |
| 41 |
{ |
| 42 |
mCodingSM->Reset(); |
| 43 |
mNumOfMBChar = 0; |
| 44 |
mState = eDetecting; |
| 45 |
} |
| 46 |
|
| 47 |
nsProbingState nsUTF8Prober::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 |
if (mCodingSM->GetCurrentCharLen() >= 2) |
| 62 |
mNumOfMBChar++; |
| 63 |
} |
| 64 |
} |
| 65 |
|
| 66 |
if (mState == eDetecting) |
| 67 |
if (GetConfidence() > SHORTCUT_THRESHOLD) |
| 68 |
mState = eFoundIt; |
| 69 |
return mState; |
| 70 |
} |
| 71 |
|
| 72 |
#define ONE_CHAR_PROB (float)0.50 |
| 73 |
|
| 74 |
float nsUTF8Prober::GetConfidence(void) |
| 75 |
{ |
| 76 |
float unlike = (float)0.99; |
| 77 |
|
| 78 |
if (mNumOfMBChar < 6) |
| 79 |
{ |
| 80 |
for (PRUint32 i = 0; i < mNumOfMBChar; i++) |
| 81 |
unlike *= ONE_CHAR_PROB; |
| 82 |
return (float)1.0 - unlike; |
| 83 |
} |
| 84 |
else |
| 85 |
return (float)0.99; |
| 86 |
} |
