gecko-dev/xpcom/io/nsLinebreakConverter.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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.org code.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#include "nsLinebreakConverter.h"
#include "nsMemory.h"
#include "nsCRT.h"
#if defined(XP_PC) && defined(_MSC_VER) && (_MSC_VER <= 1100)
#define LOSER_CHAR_CAST(t) (char *)(t)
#define LOSER_UNICHAR_CAST(t) (PRUnichar *)(t)
#else
#define LOSER_CHAR_CAST(t) (t)
#define LOSER_UNICHAR_CAST(t) (t)
#endif
/*----------------------------------------------------------------------------
GetLinebreakString
Could make this inline
----------------------------------------------------------------------------*/
static const char* GetLinebreakString(nsLinebreakConverter::ELinebreakType aBreakType)
{
static char* sLinebreaks[] = {
"", // any
NS_LINEBREAK, // platform
LFSTR, // content
CRLF, // net
CRSTR, // Mac
LFSTR, // Unix
CRLF, // Windows
nsnull
};
return sLinebreaks[aBreakType];
}
/*----------------------------------------------------------------------------
AppendLinebreak
Wee inline method to append a line break. Modifies ioDest.
----------------------------------------------------------------------------*/
template<class T>
static void AppendLinebreak(T*& ioDest, const char* lineBreakStr)
{
*ioDest++ = *lineBreakStr;
if (lineBreakStr[1])
*ioDest++ = lineBreakStr[1];
}
/*----------------------------------------------------------------------------
CountChars
Counts occurrences of breakStr in aSrc
----------------------------------------------------------------------------*/
template<class T>
static PRInt32 CountLinebreaks(const T* aSrc, PRInt32 inLen, const char* breakStr)
{
const T* src = aSrc;
const T* srcEnd = aSrc + inLen;
PRInt32 theCount = 0;
while (src < srcEnd)
{
if (*src == *breakStr)
{
src ++;
if (src < srcEnd && breakStr[1] && *src == breakStr[1])
src ++;
theCount ++;
}
else
{
src ++;
}
}
return theCount;
}
/*----------------------------------------------------------------------------
ConvertBreaks
ioLen *includes* a terminating null, if any
----------------------------------------------------------------------------*/
template<class T>
static T* ConvertBreaks(const T* inSrc, PRInt32& ioLen, const char* srcBreak, const char* destBreak)
{
NS_ASSERTION(inSrc && srcBreak && destBreak, "Got a null string");
T* resultString = nsnull;
// handle the no conversion case
if (nsCRT::strcmp(srcBreak, destBreak) == 0)
{
resultString = (T *)nsMemory::Alloc(sizeof(T) * ioLen);
if (!resultString) return nsnull;
nsCRT::memcpy(resultString, inSrc, sizeof(T) * ioLen); // includes the null, if any
return resultString;
}
PRInt32 srcBreakLen = nsCRT::strlen(srcBreak);
PRInt32 destBreakLen = nsCRT::strlen(destBreak);
// handle the easy case, where the string length does not change, and the
// breaks are only 1 char long, i.e. CR <-> LF
if (srcBreakLen == destBreakLen && srcBreakLen == 1)
{
resultString = (T *)nsMemory::Alloc(sizeof(T) * ioLen);
if (!resultString) return nsnull;
const T* src = inSrc;
const T* srcEnd = inSrc + ioLen; // includes null, if any
T* dst = resultString;
char srcBreakChar = *srcBreak; // we know it's one char long already
char dstBreakChar = *destBreak;
while (src < srcEnd)
{
if (*src == srcBreakChar)
{
*dst++ = dstBreakChar;
src++;
}
else
{
*dst++ = *src++;
}
}
// ioLen does not change
}
else
{
// src and dest termination is different length. Do it a slower way.
// count linebreaks in src. Assumes that chars in 2-char linebreaks are unique.
PRInt32 numLinebreaks = CountLinebreaks(inSrc, ioLen, srcBreak);
PRInt32 newBufLen = ioLen - (numLinebreaks * srcBreakLen) + (numLinebreaks * destBreakLen);
resultString = (T *)nsMemory::Alloc(sizeof(T) * newBufLen);
if (!resultString) return nsnull;
const T* src = inSrc;
const T* srcEnd = inSrc + ioLen; // includes null, if any
T* dst = resultString;
while (src < srcEnd)
{
if (*src == *srcBreak)
{
*dst++ = *destBreak;
if (destBreak[1])
*dst++ = destBreak[1];
src ++;
if (src < srcEnd && srcBreak[1] && *src == srcBreak[1])
src ++;
}
else
{
*dst++ = *src++;
}
}
ioLen = newBufLen;
}
return resultString;
}
/*----------------------------------------------------------------------------
ConvertBreaksInSitu
Convert breaks in situ. Can only do this if the linebreak length
does not change.
----------------------------------------------------------------------------*/
template<class T>
static void ConvertBreaksInSitu(T* inSrc, PRInt32 inLen, char srcBreak, char destBreak)
{
T* src = inSrc;
T* srcEnd = inSrc + inLen;
while (src < srcEnd)
{
if (*src == srcBreak)
*src = destBreak;
src ++;
}
}
/*----------------------------------------------------------------------------
ConvertUnknownBreaks
Convert unknown line breaks to the specified break.
This will convert CRLF pairs to one break, and single CR or LF to a break.
----------------------------------------------------------------------------*/
template<class T>
static T* ConvertUnknownBreaks(const T* inSrc, PRInt32& ioLen, const char* destBreak)
{
const T* src = inSrc;
const T* srcEnd = inSrc + ioLen; // includes null, if any
PRInt32 destBreakLen = nsCRT::strlen(destBreak);
PRInt32 finalLen = 0;
while (src < srcEnd)
{
if (*src == CR)
{
if (src < srcEnd && src[1] == LF)
{
// CRLF
finalLen += destBreakLen;
src ++;
}
else
{
// Lone CR
finalLen += destBreakLen;
}
}
else if (*src == LF)
{
// Lone LF
finalLen += destBreakLen;
}
else
{
finalLen ++;
}
src ++;
}
T* resultString = (T *)nsMemory::Alloc(sizeof(T) * finalLen);
if (!resultString) return nsnull;
src = inSrc;
srcEnd = inSrc + ioLen; // includes null, if any
T* dst = resultString;
while (src < srcEnd)
{
if (*src == CR)
{
if (src < srcEnd && src[1] == LF)
{
// CRLF
AppendLinebreak(dst, destBreak);
src ++;
}
else
{
// Lone CR
AppendLinebreak(dst, destBreak);
}
}
else if (*src == LF)
{
// Lone LF
AppendLinebreak(dst, destBreak);
}
else
{
*dst++ = *src;
}
src ++;
}
ioLen = finalLen;
return resultString;
}
#ifdef XP_MAC
#pragma mark -
#endif
/*----------------------------------------------------------------------------
ConvertLineBreaks
----------------------------------------------------------------------------*/
char* nsLinebreakConverter::ConvertLineBreaks(const char* aSrc,
ELinebreakType aSrcBreaks, ELinebreakType aDestBreaks, PRInt32 aSrcLen, PRInt32* outLen)
{
NS_ASSERTION(aDestBreaks != eLinebreakAny, "Invalid parameter");
if (!aSrc) return nsnull;
PRInt32 sourceLen = (aSrcLen == kIgnoreLen) ? nsCRT::strlen(aSrc) + 1 : aSrcLen;
char* resultString;
if (aSrcBreaks == eLinebreakAny)
resultString = ConvertUnknownBreaks(LOSER_CHAR_CAST(aSrc), sourceLen, GetLinebreakString(aDestBreaks));
else
resultString = ConvertBreaks(LOSER_CHAR_CAST(aSrc), sourceLen, GetLinebreakString(aSrcBreaks), GetLinebreakString(aDestBreaks));
if (outLen)
*outLen = sourceLen;
return resultString;
}
/*----------------------------------------------------------------------------
ConvertLineBreaksInSitu
----------------------------------------------------------------------------*/
nsresult nsLinebreakConverter::ConvertLineBreaksInSitu(char **ioBuffer, ELinebreakType aSrcBreaks,
ELinebreakType aDestBreaks, PRInt32 aSrcLen, PRInt32* outLen)
{
NS_ASSERTION(ioBuffer && *ioBuffer, "Null pointer passed");
if (!ioBuffer || !*ioBuffer) return NS_ERROR_NULL_POINTER;
NS_ASSERTION(aDestBreaks != eLinebreakAny, "Invalid parameter");
PRInt32 sourceLen = (aSrcLen == kIgnoreLen) ? nsCRT::strlen(*ioBuffer) + 1 : aSrcLen;
// can we convert in-place?
const char* srcBreaks = GetLinebreakString(aSrcBreaks);
const char* dstBreaks = GetLinebreakString(aDestBreaks);
if ( (aSrcBreaks != eLinebreakAny) &&
(nsCRT::strlen(srcBreaks) == 1) &&
(nsCRT::strlen(dstBreaks) == 1) )
{
ConvertBreaksInSitu(*ioBuffer, sourceLen, *srcBreaks, *dstBreaks);
if (outLen)
*outLen = sourceLen;
}
else
{
char* destBuffer;
if (aSrcBreaks == eLinebreakAny)
destBuffer = ConvertUnknownBreaks(*ioBuffer, sourceLen, dstBreaks);
else
destBuffer = ConvertBreaks(*ioBuffer, sourceLen, srcBreaks, dstBreaks);
if (!destBuffer) return NS_ERROR_OUT_OF_MEMORY;
*ioBuffer = destBuffer;
if (outLen)
*outLen = sourceLen;
}
return NS_OK;
}
/*----------------------------------------------------------------------------
ConvertUnicharLineBreaks
----------------------------------------------------------------------------*/
PRUnichar* nsLinebreakConverter::ConvertUnicharLineBreaks(const PRUnichar* aSrc,
ELinebreakType aSrcBreaks, ELinebreakType aDestBreaks, PRInt32 aSrcLen, PRInt32* outLen)
{
NS_ASSERTION(aDestBreaks != eLinebreakAny, "Invalid parameter");
if (!aSrc) return nsnull;
PRInt32 bufLen = (aSrcLen == kIgnoreLen) ? nsCRT::strlen(aSrc) + 1 : aSrcLen;
PRUnichar* resultString;
if (aSrcBreaks == eLinebreakAny)
resultString = ConvertUnknownBreaks(LOSER_UNICHAR_CAST(aSrc), bufLen, GetLinebreakString(aDestBreaks));
else
resultString = ConvertBreaks(LOSER_UNICHAR_CAST(aSrc), bufLen, GetLinebreakString(aSrcBreaks), GetLinebreakString(aDestBreaks));
if (outLen)
*outLen = bufLen;
return resultString;
}
/*----------------------------------------------------------------------------
ConvertStringLineBreaks
----------------------------------------------------------------------------*/
nsresult nsLinebreakConverter::ConvertUnicharLineBreaksInSitu(PRUnichar **ioBuffer,
ELinebreakType aSrcBreaks, ELinebreakType aDestBreaks, PRInt32 aSrcLen, PRInt32* outLen)
{
NS_ASSERTION(ioBuffer && *ioBuffer, "Null pointer passed");
if (!ioBuffer || !*ioBuffer) return NS_ERROR_NULL_POINTER;
NS_ASSERTION(aDestBreaks != eLinebreakAny, "Invalid parameter");
PRInt32 sourceLen = (aSrcLen == kIgnoreLen) ? nsCRT::strlen(*ioBuffer) + 1 : aSrcLen;
// can we convert in-place?
const char* srcBreaks = GetLinebreakString(aSrcBreaks);
const char* dstBreaks = GetLinebreakString(aDestBreaks);
if ( (aSrcBreaks != eLinebreakAny) &&
(nsCRT::strlen(srcBreaks) == 1) &&
(nsCRT::strlen(dstBreaks) == 1) )
{
ConvertBreaksInSitu(*ioBuffer, sourceLen, *srcBreaks, *dstBreaks);
if (outLen)
*outLen = sourceLen;
}
else
{
PRUnichar* destBuffer;
if (aSrcBreaks == eLinebreakAny)
destBuffer = ConvertUnknownBreaks(*ioBuffer, sourceLen, dstBreaks);
else
destBuffer = ConvertBreaks(*ioBuffer, sourceLen, srcBreaks, dstBreaks);
if (!destBuffer) return NS_ERROR_OUT_OF_MEMORY;
*ioBuffer = destBuffer;
if (outLen)
*outLen = sourceLen;
}
return NS_OK;
}
/*----------------------------------------------------------------------------
ConvertStringLineBreaks
----------------------------------------------------------------------------*/
nsresult nsLinebreakConverter::ConvertStringLineBreaks(nsString& ioString,
ELinebreakType aSrcBreaks, ELinebreakType aDestBreaks)
{
NS_ASSERTION(aDestBreaks != eLinebreakAny, "Invalid parameter");
// nothing to do
if (ioString.Length() == 0) return NS_OK;
// we can't go messing with data we don't own
if (!ioString.mOwnsBuffer) return NS_ERROR_UNEXPECTED;
nsresult rv;
if (ioString.mCharSize == eTwoByte)
{
PRUnichar *stringBuf = ioString.mUStr;
PRInt32 newLen, theLen = ioString.mLength + 1;
rv = ConvertUnicharLineBreaksInSitu(&stringBuf, aSrcBreaks, aDestBreaks, theLen, &newLen);
if (NS_FAILED(rv)) return rv;
if (stringBuf != ioString.mUStr) // we reallocated
{
// this is pretty evil. Is there a better way?
nsMemory::Free(ioString.mUStr);
ioString.mUStr = stringBuf;
ioString.mLength = newLen - 1;
ioString.mCapacity = newLen;
}
}
else
{
char *stringBuf = ioString.mStr;
PRInt32 newLen, theLen = ioString.mLength + 1;
rv = ConvertLineBreaksInSitu(&stringBuf, aSrcBreaks, aDestBreaks, theLen, &newLen);
if (NS_FAILED(rv)) return rv;
if (stringBuf != ioString.mStr) // we reallocated
{
nsMemory::Free(ioString.mStr);
ioString.mStr = stringBuf;
ioString.mLength = newLen - 1;
ioString.mCapacity = newLen;
}
}
return NS_OK;
}