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/* -*- 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/. */
//----------------------------------------------------------------------
// Global functions and data [declaration]
#include "nsUnicodeToUTF8.h"
#include "mozilla/CheckedInt.h"
NS_IMPL_ISUPPORTS(nsUnicodeToUTF8, nsIUnicodeEncoder)
//----------------------------------------------------------------------
// nsUnicodeToUTF8 class [implementation]
NS_IMETHODIMP nsUnicodeToUTF8::GetMaxLength(const char16_t* aSrc,
int32_t aSrcLength,
int32_t* aDestLength)
{
MOZ_ASSERT(aDestLength);
// aSrc is interpreted as UTF16, 3 is normally enough.
// But when previous buffer only contains part of the surrogate pair, we
// need to complete it here. If the first word in following buffer is not
// in valid surrogate range, we need to convert the remaining of last buffer
// to 3 bytes.
mozilla::CheckedInt32 length = aSrcLength;
length *= 3;
length += 3;
if (!length.isValid()) {
return NS_ERROR_OUT_OF_MEMORY;
}
*aDestLength = length.value();
return NS_OK;
}
NS_IMETHODIMP nsUnicodeToUTF8::Convert(const char16_t* aSrc,
int32_t* aSrcLength,
char* aDest,
int32_t* aDestLength)
{
const char16_t* src = aSrc;
const char16_t* srcEnd = aSrc + *aSrcLength;
char* dest = aDest;
int32_t destLen = *aDestLength;
uint32_t n;
//complete remaining of last conversion
if (mHighSurrogate) {
if (src < srcEnd) {
*aDestLength = 0;
return NS_OK_UENC_MOREINPUT;
}
if (*aDestLength < 4) {
*aSrcLength = 0;
*aDestLength = 0;
return NS_OK_UENC_MOREOUTPUT;
}
if (*src < (char16_t)0xdc00 || *src > (char16_t)0xdfff) { //not a pair
*dest++ = (char)0xef; //replacement character
*dest++ = (char)0xbf;
*dest++ = (char)0xbd;
destLen -= 3;
} else {
n = ((mHighSurrogate - (char16_t)0xd800) << 10) +
(*src - (char16_t)0xdc00) + 0x10000;
*dest++ = (char)0xf0 | (n >> 18);
*dest++ = (char)0x80 | ((n >> 12) & 0x3f);
*dest++ = (char)0x80 | ((n >> 6) & 0x3f);
*dest++ = (char)0x80 | (n & 0x3f);
++src;
destLen -= 4;
}
mHighSurrogate = 0;
}
while (src < srcEnd) {
if ( *src <= 0x007f) {
if (destLen < 1)
goto error_more_output;
*dest++ = (char)*src;
--destLen;
} else if (*src <= 0x07ff) {
if (destLen < 2)
goto error_more_output;
*dest++ = (char)0xc0 | (*src >> 6);
*dest++ = (char)0x80 | (*src & 0x003f);
destLen -= 2;
} else if (*src >= (char16_t)0xd800 && *src <= (char16_t)0xdfff) {
if (*src >= (char16_t)0xdc00) { //not a pair
if (destLen < 3)
goto error_more_output;
*dest++ = (char)0xef; //replacement character
*dest++ = (char)0xbf;
*dest++ = (char)0xbd;
destLen -= 3;
++src;
continue;
}
if ((src+1) >= srcEnd) {
//we need another surrogate to complete this unicode char
mHighSurrogate = *src;
*aDestLength = dest - aDest;
return NS_OK_UENC_MOREINPUT;
}
//handle surrogate
if (destLen < 4)
goto error_more_output;
if (*(src+1) < (char16_t)0xdc00 || *(src+1) > 0xdfff) { //not a pair
*dest++ = (char)0xef; //replacement character
*dest++ = (char)0xbf;
*dest++ = (char)0xbd;
destLen -= 3;
} else {
n = ((*src - (char16_t)0xd800) << 10) + (*(src+1) - (char16_t)0xdc00) + (uint32_t)0x10000;
*dest++ = (char)0xf0 | (n >> 18);
*dest++ = (char)0x80 | ((n >> 12) & 0x3f);
*dest++ = (char)0x80 | ((n >> 6) & 0x3f);
*dest++ = (char)0x80 | (n & 0x3f);
destLen -= 4;
++src;
}
} else {
if (destLen < 3)
goto error_more_output;
//treat rest of the character as BMP
*dest++ = (char)0xe0 | (*src >> 12);
*dest++ = (char)0x80 | ((*src >> 6) & 0x003f);
*dest++ = (char)0x80 | (*src & 0x003f);
destLen -= 3;
}
++src;
}
*aDestLength = dest - aDest;
return NS_OK;
error_more_output:
*aSrcLength = src - aSrc;
*aDestLength = dest - aDest;
return NS_OK_UENC_MOREOUTPUT;
}
NS_IMETHODIMP nsUnicodeToUTF8::Finish(char * aDest, int32_t * aDestLength)
{
char * dest = aDest;
if (mHighSurrogate) {
if (*aDestLength < 3) {
*aDestLength = 0;
return NS_OK_UENC_MOREOUTPUT;
}
*dest++ = (char)0xef; //replacement character
*dest++ = (char)0xbf;
*dest++ = (char)0xbd;
mHighSurrogate = 0;
*aDestLength = 3;
return NS_OK;
}
*aDestLength = 0;
return NS_OK;
}
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