gecko/intl/uconv/ucvlatin/nsUnicodeToUTF32.cpp

263 lines
8.0 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:expandtab:shiftwidth=2:tabstop=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):
* Jungshik Shin <jshin@mailaps.org>
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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 <string.h>
#include "nsUCSupport.h"
#include "nsUnicodeToUTF32.h"
#ifdef IS_BIG_ENDIAN
#define UCS4_TO_LE_STRING(u, s) \
PR_BEGIN_MACRO \
s[3] = PRUint8(((u) >> 24) & 0xffL); \
s[2] = PRUint8(((u) >> 16) & 0xffL); \
s[1] = PRUint8(((u) >> 8) & 0xffL); \
s[0] = PRUint8((u) & 0xffL); \
PR_END_MACRO
#else
#define UCS4_TO_LE_STRING(u, s) \
PR_BEGIN_MACRO \
*((PRUint32*)(s)) = (u); \
PR_END_MACRO
#endif
#ifdef IS_BIG_ENDIAN
#define UCS4_TO_BE_STRING(u, s) \
PR_BEGIN_MACRO \
*((PRUint32*)(s)) = (u); \
PR_END_MACRO
#else
#define UCS4_TO_BE_STRING(u, s) \
PR_BEGIN_MACRO \
s[0] = PRUint8(((u) >> 24) & 0xffL); \
s[1] = PRUint8(((u) >> 16) & 0xffL); \
s[2] = PRUint8(((u) >> 8) & 0xffL); \
s[3] = PRUint8((u) & 0xffL); \
PR_END_MACRO
#endif
//----------------------------------------------------------------------
// Static functions common to nsUnicodeToUTF32LE and nsUnicodeToUTF32BE
static nsresult ConvertCommon(const PRUnichar * aSrc,
PRInt32 * aSrcLength,
char * aDest,
PRInt32 * aDestLength,
PRUnichar * aHighSurrogate,
PRBool aIsLE)
{
const PRUnichar * src = aSrc;
const PRUnichar * srcEnd = aSrc + *aSrcLength;
char * dest = aDest;
const char * destEnd = aDest + *aDestLength;
PRUint32 ucs4;
// left-over high surroage code point from the prev. run.
if (*aHighSurrogate)
{
if (! *aSrcLength)
{
*aDestLength = 0;
return NS_OK_UENC_MOREINPUT;
}
if (*aDestLength < 4)
{
*aSrcLength = 0;
*aDestLength = 0;
return NS_OK_UENC_MOREOUTPUT;
}
if ((*src & 0xfc00) != 0xdc00) // Not a low surrogate codepoint. Unpaird.
ucs4 = PRUint32(*aHighSurrogate);
else
ucs4 = (((*aHighSurrogate & 0x3ffL) << 10) | (*src & 0x3ffL)) + 0x10000;
++src;
if (aIsLE)
UCS4_TO_LE_STRING(ucs4, dest);
else
UCS4_TO_BE_STRING(ucs4, dest);
dest += 4;
*aHighSurrogate = 0;
}
while (src < srcEnd) {
// regular codepoint or an unpaired low surrogate
if ((src[0] & 0xfc00) != 0xd800)
{
if (destEnd - dest < 4)
goto error_more_output;
ucs4 = PRUint32(src[0]);
}
else // high surrogate
{
if ((src+1) >= srcEnd) {
//we need another surrogate to complete this unicode char
*aHighSurrogate = src[0];
*aDestLength = dest - aDest;
return NS_OK_UENC_MOREINPUT;
}
//handle surrogate
if (destEnd - dest < 4)
goto error_more_output;
if ((src[1] & 0xfc00) != 0xdc00) // unpaired
ucs4 = PRUint32(src[0]);
else
{ // convert surrogate pair to UCS4
ucs4 = (((src[0] & 0x3ffL) << 10) | (src[1] & 0x3ffL)) + 0x10000;
*aHighSurrogate = 0;
++src;
}
}
if (aIsLE)
UCS4_TO_LE_STRING(ucs4, dest);
else
UCS4_TO_BE_STRING(ucs4, dest);
dest += 4;
++src;
}
*aDestLength = dest - aDest;
return NS_OK;
error_more_output:
*aSrcLength = src - aSrc;
*aDestLength = dest - aDest;
return NS_OK_UENC_MOREOUTPUT;
}
static nsresult FinishCommon(char * aDest,
PRInt32 * aDestLength,
PRUnichar * aHighSurrogate,
PRBool aIsLE)
{
char * dest = aDest;
if (*aHighSurrogate) {
if (*aDestLength < 4) {
*aDestLength = 0;
return NS_OK_UENC_MOREOUTPUT;
}
PRUint32 high = PRUint32(*aHighSurrogate);
if (aIsLE)
UCS4_TO_LE_STRING(high, dest);
else
UCS4_TO_BE_STRING(high, dest);
*aHighSurrogate = 0;
*aDestLength = 4;
return NS_OK;
}
*aDestLength = 0;
return NS_OK;
}
//----------------------------------------------------------------------
// Class nsUnicodeToUTF32 [implementation]
NS_IMPL_ISUPPORTS1(nsUnicodeToUTF32, nsIUnicodeEncoder)
//----------------------------------------------------------------------
// Subclassing of nsIUnicodeEncoder class [implementation]
NS_IMETHODIMP nsUnicodeToUTF32::GetMaxLength(const PRUnichar * aSrc,
PRInt32 aSrcLength,
PRInt32 * aDestLength)
{
*aDestLength = aSrcLength * 4;
return NS_OK;
}
NS_IMETHODIMP nsUnicodeToUTF32::FillInfo(PRUint32 *aInfo)
{
memset(aInfo, 0xFF, (0x10000L >> 3));
return NS_OK;
}
//----------------------------------------------------------------------
// Class nsUnicodeToUTF32BE [implementation]
//----------------------------------------------------------------------
// Subclassing of nsUnicodeToUTF32 class [implementation]
NS_IMETHODIMP nsUnicodeToUTF32BE::Convert(const PRUnichar * aSrc,
PRInt32 * aSrcLength,
char * aDest,
PRInt32 * aDestLength)
{
return ConvertCommon(aSrc, aSrcLength, aDest, aDestLength,
&mHighSurrogate, PR_FALSE);
}
NS_IMETHODIMP nsUnicodeToUTF32BE::Finish(char * aDest,
PRInt32 * aDestLength)
{
return FinishCommon(aDest, aDestLength, &mHighSurrogate, PR_FALSE);
}
//----------------------------------------------------------------------
// Class nsUnicodeToUTF32LE [implementation]
//----------------------------------------------------------------------
// Subclassing of nsUnicodeToUTF32 class [implementation]
NS_IMETHODIMP nsUnicodeToUTF32LE::Convert(const PRUnichar * aSrc,
PRInt32 * aSrcLength,
char * aDest,
PRInt32 * aDestLength)
{
return ConvertCommon(aSrc, aSrcLength, aDest, aDestLength,
&mHighSurrogate, PR_TRUE);
}
NS_IMETHODIMP nsUnicodeToUTF32LE::Finish(char * aDest,
PRInt32 * aDestLength)
{
return FinishCommon(aDest, aDestLength, &mHighSurrogate, PR_TRUE);
}