gecko-dev/intl/uconv/ucvtw/nsBIG5ToUnicode.cpp
Henri Sivonen b00ce35888 Bug 912470 part 2 - Implement Encoding Standard-compliant big5 encoder. r=emk.
--HG--
rename : intl/uconv/ucvtw/nsBIG5DecoderData.h => intl/uconv/ucvtw/nsBIG5Data.cpp
rename : testing/web-platform/tests/encoding/gbk-encoder.html => testing/web-platform/tests/encoding/big5-encoder.html
2015-09-03 15:21:57 +03:00

166 lines
4.7 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 "nsBIG5ToUnicode.h"
#include "mozilla/BinarySearch.h"
#include "mozilla/ArrayUtils.h"
#include "nsBIG5Data.h"
nsBIG5ToUnicode::nsBIG5ToUnicode()
: mPendingTrail(0)
, mBig5Lead(0)
{
}
NS_IMETHODIMP
nsBIG5ToUnicode::Convert(const char* aSrc,
int32_t* aSrcLength,
char16_t* aDest,
int32_t* aDestLength)
{
// We'll be doing comparisons as unsigned.
const uint8_t* in = reinterpret_cast<const uint8_t*>(aSrc);
const uint8_t* inEnd = in + *aSrcLength;
char16_t* out = aDest;
char16_t* outEnd = out + *aDestLength;
if (mPendingTrail) {
if (out == outEnd) {
*aSrcLength = 0;
*aDestLength = 0;
return NS_OK_UDEC_MOREOUTPUT;
}
*out++ = mPendingTrail;
mPendingTrail = 0;
}
for (;;) {
if (in == inEnd) {
*aSrcLength = in - reinterpret_cast<const uint8_t*>(aSrc);
*aDestLength = out - aDest;
return mBig5Lead ? NS_OK_UDEC_MOREINPUT : NS_OK;
}
if (out == outEnd) {
*aSrcLength = in - reinterpret_cast<const uint8_t*>(aSrc);
*aDestLength = out - aDest;
return NS_OK_UDEC_MOREOUTPUT;
}
uint8_t b = *in++;
if (!mBig5Lead) {
if (b <= 0x7F) {
*out++ = (char16_t)b;
continue;
}
if (b >= 0x81 && b <= 0xFE) {
mBig5Lead = b;
continue;
}
if (mErrBehavior == kOnError_Signal) {
--in;
*aSrcLength = in - reinterpret_cast<const uint8_t*>(aSrc);
*aDestLength = out - aDest;
return NS_ERROR_ILLEGAL_INPUT;
}
*out++ = 0xFFFD;
continue;
}
size_t lead = mBig5Lead;
mBig5Lead = 0;
size_t offset = (b < 0x7F) ? 0x40 : 0x62;
if ((b >= 0x40 && b <= 0x7E) || (b >= 0xA1 && b <= 0xFE)) {
size_t pointer = (lead - 0x81) * 157L + (b - offset);
char16_t outTrail;
switch (pointer) {
case 1133:
*out++ = 0x00CA;
outTrail = 0x0304;
break;
case 1135:
*out++ = 0x00CA;
outTrail = 0x030C;
break;
case 1164:
*out++ = 0x00EA;
outTrail = 0x0304;
break;
case 1166:
*out++ = 0x00EA;
outTrail = 0x030C;
break;
default:
char16_t lowBits = nsBIG5Data::LowBits(pointer);
if (!lowBits) {
if (b <= 0x7F) {
// prepend byte to stream
// Always legal, since we've always just read a byte
// if we come here.
--in;
}
if (mErrBehavior == kOnError_Signal) {
--in;
*aSrcLength = in - reinterpret_cast<const uint8_t*>(aSrc);
*aDestLength = out - aDest;
return NS_ERROR_ILLEGAL_INPUT;
}
*out++ = 0xFFFD;
continue;
}
if (nsBIG5Data::IsAstral(pointer)) {
uint32_t codePoint = uint32_t(lowBits) | 0x20000;
*out++ = char16_t(0xD7C0 + (codePoint >> 10));
outTrail = char16_t(0xDC00 + (codePoint & 0x3FF));
break;
}
*out++ = lowBits;
continue;
}
if (out == outEnd) {
mPendingTrail = outTrail;
*aSrcLength = in - reinterpret_cast<const uint8_t*>(aSrc);
*aDestLength = out - aDest;
return NS_OK_UDEC_MOREOUTPUT;
}
*out++ = outTrail;
continue;
}
// pointer is null
if (b <= 0x7F) {
// prepend byte to stream
// Always legal, since we've always just read a byte
// if we come here.
--in;
}
if (mErrBehavior == kOnError_Signal) {
// Moving in one past the start of aSrc is actually OK per API contract,
// since assigning -1 to aSrcLength means that we want the caller to
// record one U+FFFD and repush the same input buffer.
--in;
*aSrcLength = in - reinterpret_cast<const uint8_t*>(aSrc);
*aDestLength = out - aDest;
return NS_ERROR_ILLEGAL_INPUT;
}
*out++ = 0xFFFD;
continue;
}
}
NS_IMETHODIMP
nsBIG5ToUnicode::GetMaxLength(const char* aSrc,
int32_t aSrcLength,
int32_t* aDestLength)
{
// The length of the output in UTF-16 code units never exceeds the length
// of the input in bytes.
*aDestLength = aSrcLength + (mPendingTrail ? 1 : 0) + (mBig5Lead ? 1 : 0);
return NS_OK;
}
NS_IMETHODIMP
nsBIG5ToUnicode::Reset()
{
mPendingTrail = 0;
mBig5Lead = 0;
return NS_OK;
}