pjs/xpcom/io/nsLinebreakConverter.cpp

466 строки
12 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsLinebreakConverter.h"
#include "nsMemory.h"
#include "nsCRT.h"
/*----------------------------------------------------------------------------
GetLinebreakString
Could make this inline
----------------------------------------------------------------------------*/
static const char* GetLinebreakString(nsLinebreakConverter::ELinebreakType aBreakType)
{
static const char* const sLinebreaks[] = {
"", // any
NS_LINEBREAK, // platform
LFSTR, // content
CRLF, // net
CRSTR, // Mac
LFSTR, // Unix
CRLF, // Windows
" ", // space
nsnull
};
return sLinebreaks[aBreakType];
}
/*----------------------------------------------------------------------------
AppendLinebreak
Wee inline method to append a line break. Modifies ioDest.
----------------------------------------------------------------------------*/
template<class T>
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>
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 (breakStr[1])
{
if (src < srcEnd && *src == breakStr[1])
{
src++;
theCount++;
}
}
else
{
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;
memcpy(resultString, inSrc, sizeof(T) * ioLen); // includes the null, if any
return resultString;
}
PRInt32 srcBreakLen = strlen(srcBreak);
PRInt32 destBreakLen = 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 = strlen(destBreak);
PRInt32 finalLen = 0;
while (src < srcEnd)
{
if (*src == nsCRT::CR)
{
if (src < srcEnd && src[1] == nsCRT::LF)
{
// CRLF
finalLen += destBreakLen;
src++;
}
else
{
// Lone CR
finalLen += destBreakLen;
}
}
else if (*src == nsCRT::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 == nsCRT::CR)
{
if (src < srcEnd && src[1] == nsCRT::LF)
{
// CRLF
AppendLinebreak(dst, destBreak);
src++;
}
else
{
// Lone CR
AppendLinebreak(dst, destBreak);
}
}
else if (*src == nsCRT::LF)
{
// Lone LF
AppendLinebreak(dst, destBreak);
}
else
{
*dst++ = *src;
}
src++;
}
ioLen = finalLen;
return resultString;
}
/*----------------------------------------------------------------------------
ConvertLineBreaks
----------------------------------------------------------------------------*/
char* nsLinebreakConverter::ConvertLineBreaks(const char* aSrc,
ELinebreakType aSrcBreaks, ELinebreakType aDestBreaks, PRInt32 aSrcLen, PRInt32* outLen)
{
NS_ASSERTION(aDestBreaks != eLinebreakAny &&
aSrcBreaks != eLinebreakSpace, "Invalid parameter");
if (!aSrc) return nsnull;
PRInt32 sourceLen = (aSrcLen == kIgnoreLen) ? strlen(aSrc) + 1 : aSrcLen;
char* resultString;
if (aSrcBreaks == eLinebreakAny)
resultString = ConvertUnknownBreaks(aSrc, sourceLen, GetLinebreakString(aDestBreaks));
else
resultString = ConvertBreaks(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 &&
aSrcBreaks != eLinebreakSpace, "Invalid parameter");
PRInt32 sourceLen = (aSrcLen == kIgnoreLen) ? strlen(*ioBuffer) + 1 : aSrcLen;
// can we convert in-place?
const char* srcBreaks = GetLinebreakString(aSrcBreaks);
const char* dstBreaks = GetLinebreakString(aDestBreaks);
if ( (aSrcBreaks != eLinebreakAny) &&
(strlen(srcBreaks) == 1) &&
(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 &&
aSrcBreaks != eLinebreakSpace, "Invalid parameter");
if (!aSrc) return nsnull;
PRInt32 bufLen = (aSrcLen == kIgnoreLen) ? NS_strlen(aSrc) + 1 : aSrcLen;
PRUnichar* resultString;
if (aSrcBreaks == eLinebreakAny)
resultString = ConvertUnknownBreaks(aSrc, bufLen, GetLinebreakString(aDestBreaks));
else
resultString = ConvertBreaks(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 &&
aSrcBreaks != eLinebreakSpace, "Invalid parameter");
PRInt32 sourceLen = (aSrcLen == kIgnoreLen) ? NS_strlen(*ioBuffer) + 1 : aSrcLen;
// can we convert in-place?
const char* srcBreaks = GetLinebreakString(aSrcBreaks);
const char* dstBreaks = GetLinebreakString(aDestBreaks);
if ( (aSrcBreaks != eLinebreakAny) &&
(strlen(srcBreaks) == 1) &&
(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 &&
aSrcBreaks != eLinebreakSpace, "Invalid parameter");
// nothing to do
if (ioString.IsEmpty()) return NS_OK;
nsresult rv;
// remember the old buffer in case
// we blow it away later
nsString::char_iterator stringBuf;
ioString.BeginWriting(stringBuf);
PRInt32 newLen;
rv = ConvertUnicharLineBreaksInSitu(&stringBuf,
aSrcBreaks, aDestBreaks,
ioString.Length() + 1, &newLen);
if (NS_FAILED(rv)) return rv;
if (stringBuf != ioString.get())
ioString.Adopt(stringBuf);
return NS_OK;
}