Aegisub/aegisub/universalchardet/nsCharSetProber.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
* 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 ***** */
#include "nsCharSetProber.h"
#include "prmem.h"
//This filter applies to all scripts which do not use English characters
PRBool nsCharSetProber::FilterWithoutEnglishLetters(const char* aBuf, PRUint32 aLen, char** newBuf, PRUint32& newLen)
{
char *newptr;
char *prevPtr, *curPtr;
PRBool meetMSB = PR_FALSE;
newptr = *newBuf = (char*)PR_Malloc(aLen);
if (!newptr)
return PR_FALSE;
for (curPtr = prevPtr = (char*)aBuf; curPtr < aBuf+aLen; curPtr++)
{
if (*curPtr & 0x80)
{
meetMSB = PR_TRUE;
}
else if (*curPtr < 'A' || (*curPtr > 'Z' && *curPtr < 'a') || *curPtr > 'z')
{
//current char is a symbol, most likely a punctuation. we treat it as segment delimiter
if (meetMSB && curPtr > prevPtr)
//this segment contains more than single symbol, and it has upper ASCII, we need to keep it
{
while (prevPtr < curPtr) *newptr++ = *prevPtr++;
prevPtr++;
*newptr++ = ' ';
meetMSB = PR_FALSE;
}
else //ignore current segment. (either because it is just a symbol or just an English word)
prevPtr = curPtr+1;
}
}
if (meetMSB && curPtr > prevPtr)
while (prevPtr < curPtr) *newptr++ = *prevPtr++;
newLen = newptr - *newBuf;
return PR_TRUE;
}
//This filter applies to all scripts which contain both English characters and upper ASCII characters.
PRBool nsCharSetProber::FilterWithEnglishLetters(const char* aBuf, PRUint32 aLen, char** newBuf, PRUint32& newLen)
{
//do filtering to reduce load to probers
char *newptr;
char *prevPtr, *curPtr;
PRBool isInTag = PR_FALSE;
newptr = *newBuf = (char*)PR_Malloc(aLen);
if (!newptr)
return PR_FALSE;
for (curPtr = prevPtr = (char*)aBuf; curPtr < aBuf+aLen; curPtr++)
{
if (*curPtr == '>')
isInTag = PR_FALSE;
else if (*curPtr == '<')
isInTag = PR_TRUE;
if (!(*curPtr & 0x80) &&
(*curPtr < 'A' || (*curPtr > 'Z' && *curPtr < 'a') || *curPtr > 'z') )
{
if (curPtr > prevPtr && !isInTag) // Current segment contains more than just a symbol
// and it is not inside a tag, keep it.
{
while (prevPtr < curPtr) *newptr++ = *prevPtr++;
prevPtr++;
*newptr++ = ' ';
}
else
prevPtr = curPtr+1;
}
}
// If the current segment contains more than just a symbol
// and it is not inside a tag then keep it.
if (!isInTag)
while (prevPtr < curPtr)
*newptr++ = *prevPtr++;
newLen = newptr - *newBuf;
return PR_TRUE;
}