Aegisub/vendor/universalchardet/JpCntx.h

140 lines
4.5 KiB
C++

/* -*- Mode: C++; tab-width: 2; 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 Communicator client code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* 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 ***** */
#ifndef __JPCNTX_H__
#define __JPCNTX_H__
#define NUM_OF_CATEGORY 6
#include "nscore.h"
#define ENOUGH_REL_THRESHOLD 100
#define MAX_REL_THRESHOLD 1000
//hiragana frequency category table
extern const PRUint8 jp2CharContext[83][83];
class JapaneseContextAnalysis
{
public:
JapaneseContextAnalysis() {Reset(PR_FALSE);}
void HandleData(const char* aBuf, PRUint32 aLen);
void HandleOneChar(const char* aStr, PRUint32 aCharLen)
{
PRInt32 order;
//if we received enough data, stop here
if (mTotalRel > MAX_REL_THRESHOLD) mDone = PR_TRUE;
if (mDone) return;
//Only 2-bytes characters are of our interest
order = (aCharLen == 2) ? GetOrder(aStr) : -1;
if (order != -1 && mLastCharOrder != -1)
{
mTotalRel++;
//count this sequence to its category counter
mRelSample[jp2CharContext[mLastCharOrder][order]]++;
}
mLastCharOrder = order;
}
float GetConfidence(void);
void Reset(PRBool aIsPreferredLanguage);
void SetOpion(){}
PRBool GotEnoughData() {return mTotalRel > ENOUGH_REL_THRESHOLD;}
protected:
virtual PRInt32 GetOrder(const char* str, PRUint32 *charLen) = 0;
virtual PRInt32 GetOrder(const char* str) = 0;
//category counters, each integer counts sequences in its category
PRUint32 mRelSample[NUM_OF_CATEGORY];
//total sequence received
PRUint32 mTotalRel;
//Number of sequences needed to trigger detection
PRUint32 mDataThreshold;
//The order of previous char
PRInt32 mLastCharOrder;
//if last byte in current buffer is not the last byte of a character, we
//need to know how many byte to skip in next buffer.
PRUint32 mNeedToSkipCharNum;
//If this flag is set to PR_TRUE, detection is done and conclusion has been made
PRBool mDone;
};
class SJISContextAnalysis : public JapaneseContextAnalysis
{
//SJISContextAnalysis(){};
protected:
PRInt32 GetOrder(const char* str, PRUint32 *charLen);
PRInt32 GetOrder(const char* str)
{
//We only interested in Hiragana, so first byte is '\202'
if (*str == '\202' &&
(unsigned char)*(str+1) >= (unsigned char)0x9f &&
(unsigned char)*(str+1) <= (unsigned char)0xf1)
return (unsigned char)*(str+1) - (unsigned char)0x9f;
return -1;
}
};
class EUCJPContextAnalysis : public JapaneseContextAnalysis
{
protected:
PRInt32 GetOrder(const char* str, PRUint32 *charLen);
PRInt32 GetOrder(const char* str)
//We only interested in Hiragana, so first byte is '\244'
{
if (*str == '\244' &&
(unsigned char)*(str+1) >= (unsigned char)0xa1 &&
(unsigned char)*(str+1) <= (unsigned char)0xf3)
return (unsigned char)*(str+1) - (unsigned char)0xa1;
return -1;
}
};
#endif /* __JPCNTX_H__ */