gecko-dev/intl/unicharutil/nsSaveAsCharset.cpp

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C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "prmem.h"
#include "prprf.h"
#include "nsSaveAsCharset.h"
#include "nsWhitespaceTokenizer.h"
#include "nsIUnicodeEncoder.h"
#include "mozilla/dom/EncodingUtils.h"
#include "nsComponentManagerUtils.h"
using mozilla::dom::EncodingUtils;
//
// nsISupports methods
//
NS_IMPL_ISUPPORTS(nsSaveAsCharset, nsISaveAsCharset)
//
// nsSaveAsCharset
//
nsSaveAsCharset::nsSaveAsCharset()
{
mAttribute = attr_htmlTextDefault;
mEntityVersion = 0;
mCharsetListIndex = -1;
}
nsSaveAsCharset::~nsSaveAsCharset()
{
}
NS_IMETHODIMP
nsSaveAsCharset::Init(const char *charset, uint32_t attr, uint32_t entityVersion)
{
nsresult rv = NS_OK;
mAttribute = attr;
mEntityVersion = entityVersion;
rv = SetupCharsetList(charset);
NS_ENSURE_SUCCESS(rv, rv);
// set up unicode encoder
rv = SetupUnicodeEncoder(GetNextCharset());
NS_ENSURE_SUCCESS(rv, rv);
// set up entity converter
if (attr_EntityNone != MASK_ENTITY(mAttribute) && !mEntityConverter)
mEntityConverter = do_CreateInstance(NS_ENTITYCONVERTER_CONTRACTID, &rv);
return rv;
}
NS_IMETHODIMP
nsSaveAsCharset::Convert(const char16_t *inString, char **_retval)
{
NS_ENSURE_ARG_POINTER(_retval);
NS_ENSURE_ARG_POINTER(inString);
if (0 == *inString)
return NS_ERROR_ILLEGAL_VALUE;
nsresult rv = NS_OK;
NS_ASSERTION(mEncoder, "need to call Init() before Convert()");
NS_ENSURE_TRUE(mEncoder, NS_ERROR_FAILURE);
*_retval = nullptr;
// make sure to start from the first charset in the list
if (mCharsetListIndex > 0) {
mCharsetListIndex = -1;
rv = SetupUnicodeEncoder(GetNextCharset());
NS_ENSURE_SUCCESS(rv, rv);
}
do {
// fallback to the next charset in the list if the last conversion failed by an unmapped character
if (MASK_CHARSET_FALLBACK(mAttribute) && NS_ERROR_UENC_NOMAPPING == rv) {
const char * charset = GetNextCharset();
if (!charset)
break;
rv = SetupUnicodeEncoder(charset);
NS_ENSURE_SUCCESS(rv, rv);
PR_FREEIF(*_retval);
}
if (attr_EntityBeforeCharsetConv == MASK_ENTITY(mAttribute)) {
NS_ASSERTION(mEntityConverter, "need to call Init() before Convert()");
NS_ENSURE_TRUE(mEntityConverter, NS_ERROR_FAILURE);
char16_t *entity = nullptr;
// do the entity conversion first
rv = mEntityConverter->ConvertToEntities(inString, mEntityVersion, &entity);
if(NS_SUCCEEDED(rv)) {
rv = DoCharsetConversion(entity, _retval);
nsMemory::Free(entity);
}
}
else
rv = DoCharsetConversion(inString, _retval);
} while (MASK_CHARSET_FALLBACK(mAttribute) && NS_ERROR_UENC_NOMAPPING == rv);
return rv;
}
NS_IMETHODIMP
nsSaveAsCharset::GetCharset(char * *aCharset)
{
NS_ENSURE_ARG(aCharset);
NS_ASSERTION(mCharsetListIndex >= 0, "need to call Init() first");
NS_ENSURE_TRUE(mCharsetListIndex >= 0, NS_ERROR_FAILURE);
const char* charset = mCharsetList[mCharsetListIndex].get();
if (!charset) {
*aCharset = nullptr;
NS_ASSERTION(charset, "make sure to call Init() with non empty charset list");
return NS_ERROR_FAILURE;
}
*aCharset = strdup(charset);
return (*aCharset) ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
}
/////////////////////////////////////////////////////////////////////////////////////////
#define RESERVE_FALLBACK_BYTES 512
// do the fallback, reallocate the buffer if necessary
// need to pass destination buffer info (size, current position and estimation of rest of the conversion)
NS_IMETHODIMP
nsSaveAsCharset::HandleFallBack(uint32_t character, char **outString, int32_t *bufferLength,
int32_t *currentPos, int32_t estimatedLength)
{
NS_ENSURE_ARG_POINTER(outString);
NS_ENSURE_ARG_POINTER(bufferLength);
NS_ENSURE_ARG_POINTER(currentPos);
char fallbackStr[256];
nsresult rv = DoConversionFallBack(character, fallbackStr, 256);
if (NS_SUCCEEDED(rv)) {
int32_t tempLen = (int32_t) strlen(fallbackStr);
// reallocate if the buffer is not large enough
if ((tempLen + estimatedLength) >= (*bufferLength - *currentPos)) {
int32_t addLength = tempLen + RESERVE_FALLBACK_BYTES;
// + 1 is for the terminating NUL, don't add that to bufferLength
char *temp = (char *) PR_Realloc(*outString, *bufferLength + addLength + 1);
if (temp) {
// adjust length/pointer after realloc
*bufferLength += addLength;
*outString = temp;
} else {
*outString = nullptr;
*bufferLength = 0;
return NS_ERROR_OUT_OF_MEMORY;
}
}
memcpy((*outString + *currentPos), fallbackStr, tempLen);
*currentPos += tempLen;
}
return rv;
}
NS_IMETHODIMP
nsSaveAsCharset::DoCharsetConversion(const char16_t *inString, char **outString)
{
NS_ENSURE_ARG_POINTER(outString);
*outString = nullptr;
nsresult rv;
int32_t inStringLength = NS_strlen(inString); // original input string length
int32_t bufferLength; // allocated buffer length
int32_t srcLength = inStringLength;
int32_t dstLength;
int32_t pos1, pos2;
nsresult saveResult = NS_OK; // to remember NS_ERROR_UENC_NOMAPPING
// estimate and allocate the target buffer (reserve extra memory for fallback)
rv = mEncoder->GetMaxLength(inString, inStringLength, &dstLength);
if (NS_FAILED(rv)) return rv;
bufferLength = dstLength + RESERVE_FALLBACK_BYTES; // extra bytes for fallback
// + 1 is for the terminating NUL -- we don't add that to bufferLength so that
// we can always write dstPtr[pos2] = '\0' even when the encoder filled the
// buffer.
char *dstPtr = (char *) PR_Malloc(bufferLength + 1);
if (!dstPtr) {
return NS_ERROR_OUT_OF_MEMORY;
}
for (pos1 = 0, pos2 = 0; pos1 < inStringLength;) {
// convert from unicode
dstLength = bufferLength - pos2;
NS_ASSERTION(dstLength >= 0, "out of bounds write");
rv = mEncoder->Convert(&inString[pos1], &srcLength, &dstPtr[pos2], &dstLength);
pos1 += srcLength ? srcLength : 1;
pos2 += dstLength;
dstPtr[pos2] = '\0';
// break: this is usually the case (no error) OR unrecoverable error
if (NS_ERROR_UENC_NOMAPPING != rv) break;
// remember this happened and reset the result
saveResult = rv;
rv = NS_OK;
// finish encoder, give it a chance to write extra data like escape sequences
dstLength = bufferLength - pos2;
rv = mEncoder->Finish(&dstPtr[pos2], &dstLength);
if (NS_SUCCEEDED(rv)) {
pos2 += dstLength;
dstPtr[pos2] = '\0';
}
srcLength = inStringLength - pos1;
// do the fallback
if (!ATTR_NO_FALLBACK(mAttribute)) {
uint32_t unMappedChar;
if (NS_IS_HIGH_SURROGATE(inString[pos1-1]) &&
inStringLength > pos1 && NS_IS_LOW_SURROGATE(inString[pos1])) {
unMappedChar = SURROGATE_TO_UCS4(inString[pos1-1], inString[pos1]);
pos1++;
} else {
unMappedChar = inString[pos1-1];
}
rv = mEncoder->GetMaxLength(inString+pos1, inStringLength-pos1, &dstLength);
if (NS_FAILED(rv))
break;
rv = HandleFallBack(unMappedChar, &dstPtr, &bufferLength, &pos2, dstLength);
if (NS_FAILED(rv))
break;
dstPtr[pos2] = '\0';
}
}
if (NS_SUCCEEDED(rv)) {
// finish encoder, give it a chance to write extra data like escape sequences
dstLength = bufferLength - pos2;
rv = mEncoder->Finish(&dstPtr[pos2], &dstLength);
if (NS_SUCCEEDED(rv)) {
pos2 += dstLength;
dstPtr[pos2] = '\0';
}
}
if (NS_FAILED(rv)) {
PR_FREEIF(dstPtr);
return rv;
}
*outString = dstPtr; // set the result string
// set error code so that the caller can do own fall back
if (NS_ERROR_UENC_NOMAPPING == saveResult) {
rv = NS_ERROR_UENC_NOMAPPING;
}
return rv;
}
NS_IMETHODIMP
nsSaveAsCharset::DoConversionFallBack(uint32_t inUCS4, char *outString, int32_t bufferLength)
{
NS_ENSURE_ARG_POINTER(outString);
*outString = '\0';
nsresult rv = NS_OK;
if (ATTR_NO_FALLBACK(mAttribute)) {
return NS_OK;
}
if (attr_EntityAfterCharsetConv == MASK_ENTITY(mAttribute)) {
char *entity = nullptr;
rv = mEntityConverter->ConvertUTF32ToEntity(inUCS4, mEntityVersion, &entity);
if (NS_SUCCEEDED(rv)) {
if (!entity || (int32_t)strlen(entity) > bufferLength) {
return NS_ERROR_OUT_OF_MEMORY;
}
PL_strcpy(outString, entity);
nsMemory::Free(entity);
return rv;
}
}
switch (MASK_FALLBACK(mAttribute)) {
case attr_FallbackQuestionMark:
if(bufferLength>=2) {
*outString++='?';
*outString='\0';
rv = NS_OK;
} else {
rv = NS_ERROR_FAILURE;
}
break;
case attr_FallbackEscapeU:
if (inUCS4 & 0xff0000)
rv = (PR_snprintf(outString, bufferLength, "\\u%.6x", inUCS4) > 0) ? NS_OK : NS_ERROR_FAILURE;
else
rv = (PR_snprintf(outString, bufferLength, "\\u%.4x", inUCS4) > 0) ? NS_OK : NS_ERROR_FAILURE;
break;
case attr_FallbackDecimalNCR:
rv = ( PR_snprintf(outString, bufferLength, "&#%u;", inUCS4) > 0) ? NS_OK : NS_ERROR_FAILURE;
break;
case attr_FallbackHexNCR:
rv = (PR_snprintf(outString, bufferLength, "&#x%x;", inUCS4) > 0) ? NS_OK : NS_ERROR_FAILURE;
break;
case attr_FallbackNone:
rv = NS_OK;
break;
default:
rv = NS_ERROR_ILLEGAL_VALUE;
break;
}
return rv;
}
nsresult nsSaveAsCharset::SetupUnicodeEncoder(const char* charset)
{
NS_ENSURE_ARG(charset);
nsDependentCString label(charset);
if (label.EqualsLiteral("replacement")) {
// Internal caller. "replacement" doesn't survive another label resolution.
mEncoder = EncodingUtils::EncoderForEncoding(label);
return NS_OK;
}
nsAutoCString encoding;
if (!EncodingUtils::FindEncodingForLabelNoReplacement(label,
encoding)) {
return NS_ERROR_UCONV_NOCONV;
}
mEncoder = EncodingUtils::EncoderForEncoding(encoding);
return NS_OK;
}
nsresult nsSaveAsCharset::SetupCharsetList(const char *charsetList)
{
NS_ENSURE_ARG(charsetList);
NS_ASSERTION(charsetList[0], "charsetList should not be empty");
if (!charsetList[0])
return NS_ERROR_INVALID_ARG;
if (mCharsetListIndex >= 0) {
mCharsetList.Clear();
mCharsetListIndex = -1;
}
nsCWhitespaceTokenizer tokenizer((nsDependentCString(charsetList)));
while (tokenizer.hasMoreTokens()) {
ParseString(tokenizer.nextToken(), ',', mCharsetList);
}
return NS_OK;
}
const char * nsSaveAsCharset::GetNextCharset()
{
if ((mCharsetListIndex + 1) >= int32_t(mCharsetList.Length()))
return nullptr;
// bump the index and return the next charset
return mCharsetList[++mCharsetListIndex].get();
}