// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
******************************************************************************
*
* Copyright (C) 2000-2016, International Business Machines
* Corporation and others. All Rights Reserved.
*
******************************************************************************
* file name: ucnvscsu.c
* encoding: UTF-8
* tab size: 8 (not used)
* indentation:4
*
* created on: 2000nov18
* created by: Markus W. Scherer
*
* This is an implementation of the Standard Compression Scheme for Unicode
* as defined in https://www.unicode.org/reports/tr6/ .
* Reserved commands and window settings are treated as illegal sequences and
* will result in callback calls.
*/
#include "unicode/utypes.h"
#if !UCONFIG_NO_CONVERSION && !UCONFIG_ONLY_HTML_CONVERSION
#include "unicode/ucnv.h"
#include "unicode/ucnv_cb.h"
#include "unicode/utf16.h"
#include "ucnv_bld.h"
#include "ucnv_cnv.h"
#include "cmemory.h"
/* SCSU definitions --------------------------------------------------------- */
/* SCSU command byte values */
enum {
SQ0=0x01,
/* Quote from window pair 0 */
SQ7=0x08,
/* Quote from window pair 7 */
SDX=0x0B,
/* Define a window as extended */
Srs=0x0C,
/* reserved */
SQU=0x0E,
/* Quote a single Unicode character */
SCU=0x0F,
/* Change to Unicode mode */
SC0=0x10,
/* Select window 0 */
SC7=0x17,
/* Select window 7 */
SD0=0x18,
/* Define and select window 0 */
SD7=0x1F,
/* Define and select window 7 */
UC0=0xE0,
/* Select window 0 */
UC7=0xE7,
/* Select window 7 */
UD0=0xE8,
/* Define and select window 0 */
UD7=0xEF,
/* Define and select window 7 */
UQU=0xF0,
/* Quote a single Unicode character */
UDX=0xF1,
/* Define a Window as extended */
Urs=0xF2
/* reserved */
};
enum {
/*
* Unicode code points from 3400 to E000 are not adressible by
* dynamic window, since in these areas no short run alphabets are
* found. Therefore add gapOffset to all values from gapThreshold.
*/
gapThreshold=0x68,
gapOffset=0xAC00,
/* values between reservedStart and fixedThreshold are reserved */
reservedStart=0xA8,
/* use table of predefined fixed offsets for values from fixedThreshold */
fixedThreshold=0xF9
};
/* constant offsets for the 8 static windows */
static const uint32_t staticOffsets[8]={
0x0000,
/* ASCII for quoted tags */
0x0080,
/* Latin - 1 Supplement (for access to punctuation) */
0x0100,
/* Latin Extended-A */
0x0300,
/* Combining Diacritical Marks */
0x2000,
/* General Punctuation */
0x2080,
/* Currency Symbols */
0x2100,
/* Letterlike Symbols and Number Forms */
0x3000
/* CJK Symbols and punctuation */
};
/* initial offsets for the 8 dynamic (sliding) windows */
static const uint32_t initialDynamicOffsets[8]={
0x0080,
/* Latin-1 */
0x00C0,
/* Latin Extended A */
0x0400,
/* Cyrillic */
0x0600,
/* Arabic */
0x0900,
/* Devanagari */
0x3040,
/* Hiragana */
0x30A0,
/* Katakana */
0xFF00
/* Fullwidth ASCII */
};
/* Table of fixed predefined Offsets */
static const uint32_t fixedOffsets[]={
/* 0xF9 */ 0x00C0, /* Latin-1 Letters + half of Latin Extended A */
/* 0xFA */ 0x0250, /* IPA extensions */
/* 0xFB */ 0x0370, /* Greek */
/* 0xFC */ 0x0530, /* Armenian */
/* 0xFD */ 0x3040, /* Hiragana */
/* 0xFE */ 0x30A0, /* Katakana */
/* 0xFF */ 0xFF60 /* Halfwidth Katakana */
};
/* state values */
enum {
readCommand,
quotePairOne,
quotePairTwo,
quoteOne,
definePairOne,
definePairTwo,
defineOne
};
typedef struct SCSUData {
/* dynamic window offsets, initialize to default values from initialDynamicOffsets */
uint32_t toUDynamicOffsets[8];
uint32_t fromUDynamicOffsets[8];
/* state machine state - toUnicode */
UBool toUIsSingleByteMode;
uint8_t toUState;
int8_t toUQuoteWindow, toUDynamicWindow;
uint8_t toUByteOne;
uint8_t toUPadding[3];
/* state machine state - fromUnicode */
UBool fromUIsSingleByteMode;
int8_t fromUDynamicWindow;
/*
* windowUse[] keeps track of the use of the dynamic windows:
* At nextWindowUseIndex there is the least recently used window,
* and the following windows (in a wrapping manner) are more and more
* recently used.
* At nextWindowUseIndex-1 there is the most recently used window.
*/
uint8_t locale;
int8_t nextWindowUseIndex;
int8_t windowUse[8];
} SCSUData;
static const int8_t initialWindowUse[8]={ 7, 0, 3, 2, 4, 5, 6, 1 };
static const int8_t initialWindowUse_ja[8]={ 3, 2, 4, 1, 0, 7, 5, 6 };
enum {
lGeneric, l_ja
};
/* SCSU setup functions ----------------------------------------------------- */
U_CDECL_BEGIN
static void U_CALLCONV
_SCSUReset(UConverter *cnv, UConverterResetChoice choice) {
SCSUData *scsu=(SCSUData *)cnv->extraInfo;
if(choice<=UCNV_RESET_TO_UNICODE) {
/* reset toUnicode */
uprv_memcpy(scsu->toUDynamicOffsets, initialDynamicOffsets, 32);
scsu->toUIsSingleByteMode=
true;
scsu->toUState=readCommand;
scsu->toUQuoteWindow=scsu->toUDynamicWindow=0;
scsu->toUByteOne=0;
cnv->toULength=0;
}
if(choice!=UCNV_RESET_TO_UNICODE) {
/* reset fromUnicode */
uprv_memcpy(scsu->fromUDynamicOffsets, initialDynamicOffsets, 32);
scsu->fromUIsSingleByteMode=
true;
scsu->fromUDynamicWindow=0;
scsu->nextWindowUseIndex=0;
switch(scsu->locale) {
case l_ja:
uprv_memcpy(scsu->windowUse, initialWindowUse_ja, 8);
break;
default:
uprv_memcpy(scsu->windowUse, initialWindowUse, 8);
break;
}
cnv->fromUChar32=0;
}
}
static void U_CALLCONV
_SCSUOpen(UConverter *cnv,
UConverterLoadArgs *pArgs,
UErrorCode *pErrorCode) {
const char *locale=pArgs->locale;
if(pArgs->onlyTestIsLoadable) {
return;
}
cnv->extraInfo=uprv_malloc(
sizeof(SCSUData));
if(cnv->extraInfo!=nullptr) {
if(locale!=nullptr && locale[0]==
'j' && locale[1]==
'a' && (locale[2]==0 || locale[2]==
'_')) {
((SCSUData *)cnv->extraInfo)->locale=l_ja;
}
else {
((SCSUData *)cnv->extraInfo)->locale=lGeneric;
}
_SCSUReset(cnv, UCNV_RESET_BOTH);
}
else {
*pErrorCode=U_MEMORY_ALLOCATION_ERROR;
}
/* Set the substitution character U+fffd as a Unicode string. */
cnv->subUChars[0]=0xfffd;
cnv->subCharLen=-1;
}
static void U_CALLCONV
_SCSUClose(UConverter *cnv) {
if(cnv->extraInfo!=nullptr) {
if(!cnv->isExtraLocal) {
uprv_free(cnv->extraInfo);
}
cnv->extraInfo=nullptr;
}
}
/* SCSU-to-Unicode conversion functions ------------------------------------- */
static void U_CALLCONV
_SCSUToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
UErrorCode *pErrorCode) {
UConverter *cnv;
SCSUData *scsu;
const uint8_t *source, *sourceLimit;
char16_t *target;
const char16_t *targetLimit;
int32_t *offsets;
UBool isSingleByteMode;
uint8_t state, byteOne;
int8_t quoteWindow, dynamicWindow;
int32_t sourceIndex, nextSourceIndex;
uint8_t b;
/* set up the local pointers */
cnv=pArgs->converter;
scsu=(SCSUData *)cnv->extraInfo;
source=(
const uint8_t *)pArgs->source;
sourceLimit=(
const uint8_t *)pArgs->sourceLimit;
target=pArgs->target;
targetLimit=pArgs->targetLimit;
offsets=pArgs->offsets;
/* get the state machine state */
isSingleByteMode=scsu->toUIsSingleByteMode;
state=scsu->toUState;
quoteWindow=scsu->toUQuoteWindow;
dynamicWindow=scsu->toUDynamicWindow;
byteOne=scsu->toUByteOne;
/* sourceIndex=-1 if the current character began in the previous buffer */
sourceIndex=state==readCommand ? 0 : -1;
nextSourceIndex=0;
/*
* conversion "loop"
*
* For performance, this is not a normal C loop.
* Instead, there are two code blocks for the two SCSU modes.
* The function branches to either one, and a change of the mode is done with a goto to
* the other branch.
*
* Each branch has two conventional loops:
* - a fast-path loop for the most common codes in the mode
* - a loop for all other codes in the mode
* When the fast-path runs into a code that it cannot handle, its loop ends and it
* runs into the following loop to handle the other codes.
* The end of the input or output buffer is also handled by the slower loop.
* The slow loop jumps (goto) to the fast-path loop again as soon as possible.
*
* The callback handling is done by returning with an error code.
* The conversion framework actually calls the callback function.
*/
if(isSingleByteMode) {
/* fast path for single-byte mode */
if(state==readCommand) {
fastSingle:
while(source<sourceLimit && target<targetLimit && (b=*source)>=0x20) {
++source;
++nextSourceIndex;
if(b<=0x7f) {
/* write US-ASCII graphic character or DEL */
*target++=(char16_t)b;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
}
else {
/* write from dynamic window */
uint32_t c=scsu->toUDynamicOffsets[dynamicWindow]+(b&0x7f);
if(c<=0xffff) {
*target++=(char16_t)c;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
}
else {
/* output surrogate pair */
*target++=(char16_t)(0xd7c0+(c>>10));
if(target<targetLimit) {
*target++=(char16_t)(0xdc00|(c&0x3ff));
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex;
}
}
else {
/* target overflow */
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
cnv->UCharErrorBuffer[0]=(char16_t)(0xdc00|(c&0x3ff));
cnv->UCharErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
goto endloop;
}
}
}
sourceIndex=nextSourceIndex;
}
}
/* normal state machine for single-byte mode, minus handling for what fastSingle covers */
singleByteMode:
while(source<sourceLimit) {
if(target>=targetLimit) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
b=*source++;
++nextSourceIndex;
switch(state) {
case readCommand:
/* redundant conditions are commented out */
/* here: b<0x20 because otherwise we would be in fastSingle */
if((1UL<<b)&0x2601
/* binary 0010 0110 0000 0001, check for b==0xd || b==0xa || b==9 || b==0 */) {
/* CR/LF/TAB/NUL */
*target++=(char16_t)b;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
sourceIndex=nextSourceIndex;
goto fastSingle;
}
else if(SC0<=b) {
if(b<=SC7) {
dynamicWindow=(int8_t)(b-SC0);
sourceIndex=nextSourceIndex;
goto fastSingle;
}
else /* if(SD0<=b && b<=SD7) */ {
dynamicWindow=(int8_t)(b-SD0);
state=defineOne;
}
}
else if(
/* SQ0<=b && */ b<=SQ7) {
quoteWindow=(int8_t)(b-SQ0);
state=quoteOne;
}
else if(b==SDX) {
state=definePairOne;
}
else if(b==SQU) {
state=quotePairOne;
}
else if(b==SCU) {
sourceIndex=nextSourceIndex;
isSingleByteMode=
false;
goto fastUnicode;
}
else /* Srs */ {
/* callback(illegal) */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
cnv->toUBytes[0]=b;
cnv->toULength=1;
goto endloop;
}
/* store the first byte of a multibyte sequence in toUBytes[] */
cnv->toUBytes[0]=b;
cnv->toULength=1;
break;
case quotePairOne:
byteOne=b;
cnv->toUBytes[1]=b;
cnv->toULength=2;
state=quotePairTwo;
break;
case quotePairTwo:
*target++=(char16_t)((byteOne<<8)|b);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
sourceIndex=nextSourceIndex;
state=readCommand;
goto fastSingle;
case quoteOne:
if(b<0x80) {
/* all static offsets are in the BMP */
*target++=(char16_t)(staticOffsets[quoteWindow]+b);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
}
else {
/* write from dynamic window */
uint32_t c=scsu->toUDynamicOffsets[quoteWindow]+(b&0x7f);
if(c<=0xffff) {
*target++=(char16_t)c;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
}
else {
/* output surrogate pair */
*target++=(char16_t)(0xd7c0+(c>>10));
if(target<targetLimit) {
*target++=(char16_t)(0xdc00|(c&0x3ff));
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex;
}
}
else {
/* target overflow */
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
cnv->UCharErrorBuffer[0]=(char16_t)(0xdc00|(c&0x3ff));
cnv->UCharErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
goto endloop;
}
}
}
sourceIndex=nextSourceIndex;
state=readCommand;
goto fastSingle;
case definePairOne:
dynamicWindow=(int8_t)((b>>5)&7);
byteOne=(uint8_t)(b&0x1f);
cnv->toUBytes[1]=b;
cnv->toULength=2;
state=definePairTwo;
break;
case definePairTwo:
scsu->toUDynamicOffsets[dynamicWindow]=0x10000+(byteOne<<15UL | b<<7UL);
sourceIndex=nextSourceIndex;
state=readCommand;
goto fastSingle;
case defineOne:
if(b==0) {
/* callback(illegal): Reserved window offset value 0 */
cnv->toUBytes[1]=b;
cnv->toULength=2;
goto endloop;
}
else if(b<gapThreshold) {
scsu->toUDynamicOffsets[dynamicWindow]=b<<7UL;
}
else if((uint8_t)(b-gapThreshold)<(reservedStart-gapThreshold)) {
scsu->toUDynamicOffsets[dynamicWindow]=(b<<7UL)+gapOffset;
}
else if(b>=fixedThreshold) {
scsu->toUDynamicOffsets[dynamicWindow]=fixedOffsets[b-fixedThreshold];
}
else {
/* callback(illegal): Reserved window offset value 0xa8..0xf8 */
cnv->toUBytes[1]=b;
cnv->toULength=2;
goto endloop;
}
sourceIndex=nextSourceIndex;
state=readCommand;
goto fastSingle;
}
}
}
else {
/* fast path for Unicode mode */
if(state==readCommand) {
fastUnicode:
while(source+1<sourceLimit && target<targetLimit && (uint8_t)((b=*source)-UC0)>(Urs-UC0)) {
*target++=(char16_t)((b<<8)|source[1]);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
sourceIndex=nextSourceIndex;
nextSourceIndex+=2;
source+=2;
}
}
/* normal state machine for Unicode mode */
/* unicodeByteMode: */
while(source<sourceLimit) {
if(target>=targetLimit) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
b=*source++;
++nextSourceIndex;
switch(state) {
case readCommand:
if((uint8_t)(b-UC0)>(Urs-UC0)) {
byteOne=b;
cnv->toUBytes[0]=b;
cnv->toULength=1;
state=quotePairTwo;
}
else if(
/* UC0<=b && */ b<=UC7) {
dynamicWindow=(int8_t)(b-UC0);
sourceIndex=nextSourceIndex;
isSingleByteMode=
true;
goto fastSingle;
}
else if(
/* UD0<=b && */ b<=UD7) {
dynamicWindow=(int8_t)(b-UD0);
isSingleByteMode=
true;
cnv->toUBytes[0]=b;
cnv->toULength=1;
state=defineOne;
goto singleByteMode;
}
else if(b==UDX) {
isSingleByteMode=
true;
cnv->toUBytes[0]=b;
cnv->toULength=1;
state=definePairOne;
goto singleByteMode;
}
else if(b==UQU) {
cnv->toUBytes[0]=b;
cnv->toULength=1;
state=quotePairOne;
}
else /* Urs */ {
/* callback(illegal) */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
cnv->toUBytes[0]=b;
cnv->toULength=1;
goto endloop;
}
break;
case quotePairOne:
byteOne=b;
cnv->toUBytes[1]=b;
cnv->toULength=2;
state=quotePairTwo;
break;
case quotePairTwo:
*target++=(char16_t)((byteOne<<8)|b);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
sourceIndex=nextSourceIndex;
state=readCommand;
goto fastUnicode;
}
}
}
endloop:
/* set the converter state back into UConverter */
if(U_FAILURE(*pErrorCode) && *pErrorCode!=U_BUFFER_OVERFLOW_ERROR) {
/* reset to deal with the next character */
state=readCommand;
}
else if(state==readCommand) {
/* not in a multi-byte sequence, reset toULength */
cnv->toULength=0;
}
scsu->toUIsSingleByteMode=isSingleByteMode;
scsu->toUState=state;
scsu->toUQuoteWindow=quoteWindow;
scsu->toUDynamicWindow=dynamicWindow;
scsu->toUByteOne=byteOne;
/* write back the updated pointers */
pArgs->source=(
const char *)source;
pArgs->target=target;
pArgs->offsets=offsets;
}
/*
* Identical to _SCSUToUnicodeWithOffsets but without offset handling.
* If a change is made in the original function, then either
* change this function the same way or
* re-copy the original function and remove the variables
* offsets, sourceIndex, and nextSourceIndex.
*/
static void U_CALLCONV
_SCSUToUnicode(UConverterToUnicodeArgs *pArgs,
UErrorCode *pErrorCode) {
UConverter *cnv;
SCSUData *scsu;
const uint8_t *source, *sourceLimit;
char16_t *target;
const char16_t *targetLimit;
UBool isSingleByteMode;
uint8_t state, byteOne;
int8_t quoteWindow, dynamicWindow;
uint8_t b;
/* set up the local pointers */
cnv=pArgs->converter;
scsu=(SCSUData *)cnv->extraInfo;
source=(
const uint8_t *)pArgs->source;
sourceLimit=(
const uint8_t *)pArgs->sourceLimit;
target=pArgs->target;
targetLimit=pArgs->targetLimit;
/* get the state machine state */
isSingleByteMode=scsu->toUIsSingleByteMode;
state=scsu->toUState;
quoteWindow=scsu->toUQuoteWindow;
dynamicWindow=scsu->toUDynamicWindow;
byteOne=scsu->toUByteOne;
/*
* conversion "loop"
*
* For performance, this is not a normal C loop.
* Instead, there are two code blocks for the two SCSU modes.
* The function branches to either one, and a change of the mode is done with a goto to
* the other branch.
*
* Each branch has two conventional loops:
* - a fast-path loop for the most common codes in the mode
* - a loop for all other codes in the mode
* When the fast-path runs into a code that it cannot handle, its loop ends and it
* runs into the following loop to handle the other codes.
* The end of the input or output buffer is also handled by the slower loop.
* The slow loop jumps (goto) to the fast-path loop again as soon as possible.
*
* The callback handling is done by returning with an error code.
* The conversion framework actually calls the callback function.
*/
if(isSingleByteMode) {
/* fast path for single-byte mode */
if(state==readCommand) {
fastSingle:
while(source<sourceLimit && target<targetLimit && (b=*source)>=0x20) {
++source;
if(b<=0x7f) {
/* write US-ASCII graphic character or DEL */
*target++=(char16_t)b;
}
else {
/* write from dynamic window */
uint32_t c=scsu->toUDynamicOffsets[dynamicWindow]+(b&0x7f);
if(c<=0xffff) {
*target++=(char16_t)c;
}
else {
/* output surrogate pair */
*target++=(char16_t)(0xd7c0+(c>>10));
if(target<targetLimit) {
*target++=(char16_t)(0xdc00|(c&0x3ff));
}
else {
/* target overflow */
cnv->UCharErrorBuffer[0]=(char16_t)(0xdc00|(c&0x3ff));
cnv->UCharErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
goto endloop;
}
}
}
}
}
/* normal state machine for single-byte mode, minus handling for what fastSingle covers */
singleByteMode:
while(source<sourceLimit) {
if(target>=targetLimit) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
b=*source++;
switch(state) {
case readCommand:
/* redundant conditions are commented out */
/* here: b<0x20 because otherwise we would be in fastSingle */
if((1UL<<b)&0x2601
/* binary 0010 0110 0000 0001, check for b==0xd || b==0xa || b==9 || b==0 */) {
/* CR/LF/TAB/NUL */
*target++=(char16_t)b;
goto fastSingle;
}
else if(SC0<=b) {
if(b<=SC7) {
dynamicWindow=(int8_t)(b-SC0);
goto fastSingle;
}
else /* if(SD0<=b && b<=SD7) */ {
dynamicWindow=(int8_t)(b-SD0);
state=defineOne;
}
}
else if(
/* SQ0<=b && */ b<=SQ7) {
quoteWindow=(int8_t)(b-SQ0);
state=quoteOne;
}
else if(b==SDX) {
state=definePairOne;
}
else if(b==SQU) {
state=quotePairOne;
}
else if(b==SCU) {
isSingleByteMode=
false;
goto fastUnicode;
}
else /* Srs */ {
/* callback(illegal) */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
cnv->toUBytes[0]=b;
cnv->toULength=1;
goto endloop;
}
/* store the first byte of a multibyte sequence in toUBytes[] */
cnv->toUBytes[0]=b;
cnv->toULength=1;
break;
case quotePairOne:
byteOne=b;
cnv->toUBytes[1]=b;
cnv->toULength=2;
state=quotePairTwo;
break;
case quotePairTwo:
*target++=(char16_t)((byteOne<<8)|b);
state=readCommand;
goto fastSingle;
case quoteOne:
if(b<0x80) {
/* all static offsets are in the BMP */
*target++=(char16_t)(staticOffsets[quoteWindow]+b);
}
else {
/* write from dynamic window */
uint32_t c=scsu->toUDynamicOffsets[quoteWindow]+(b&0x7f);
if(c<=0xffff) {
*target++=(char16_t)c;
}
else {
/* output surrogate pair */
*target++=(char16_t)(0xd7c0+(c>>10));
if(target<targetLimit) {
*target++=(char16_t)(0xdc00|(c&0x3ff));
}
else {
/* target overflow */
cnv->UCharErrorBuffer[0]=(char16_t)(0xdc00|(c&0x3ff));
cnv->UCharErrorBufferLength=1;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
goto endloop;
}
}
}
state=readCommand;
goto fastSingle;
case definePairOne:
dynamicWindow=(int8_t)((b>>5)&7);
byteOne=(uint8_t)(b&0x1f);
cnv->toUBytes[1]=b;
cnv->toULength=2;
state=definePairTwo;
break;
case definePairTwo:
scsu->toUDynamicOffsets[dynamicWindow]=0x10000+(byteOne<<15UL | b<<7UL);
state=readCommand;
goto fastSingle;
case defineOne:
if(b==0) {
/* callback(illegal): Reserved window offset value 0 */
cnv->toUBytes[1]=b;
cnv->toULength=2;
goto endloop;
}
else if(b<gapThreshold) {
scsu->toUDynamicOffsets[dynamicWindow]=b<<7UL;
}
else if((uint8_t)(b-gapThreshold)<(reservedStart-gapThreshold)) {
scsu->toUDynamicOffsets[dynamicWindow]=(b<<7UL)+gapOffset;
}
else if(b>=fixedThreshold) {
scsu->toUDynamicOffsets[dynamicWindow]=fixedOffsets[b-fixedThreshold];
}
else {
/* callback(illegal): Reserved window offset value 0xa8..0xf8 */
cnv->toUBytes[1]=b;
cnv->toULength=2;
goto endloop;
}
state=readCommand;
goto fastSingle;
}
}
}
else {
/* fast path for Unicode mode */
if(state==readCommand) {
fastUnicode:
while(source+1<sourceLimit && target<targetLimit && (uint8_t)((b=*source)-UC0)>(Urs-UC0)) {
*target++=(char16_t)((b<<8)|source[1]);
source+=2;
}
}
/* normal state machine for Unicode mode */
/* unicodeByteMode: */
while(source<sourceLimit) {
if(target>=targetLimit) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
b=*source++;
switch(state) {
case readCommand:
if((uint8_t)(b-UC0)>(Urs-UC0)) {
byteOne=b;
cnv->toUBytes[0]=b;
cnv->toULength=1;
state=quotePairTwo;
}
else if(
/* UC0<=b && */ b<=UC7) {
dynamicWindow=(int8_t)(b-UC0);
isSingleByteMode=
true;
goto fastSingle;
}
else if(
/* UD0<=b && */ b<=UD7) {
dynamicWindow=(int8_t)(b-UD0);
isSingleByteMode=
true;
cnv->toUBytes[0]=b;
cnv->toULength=1;
state=defineOne;
goto singleByteMode;
}
else if(b==UDX) {
isSingleByteMode=
true;
cnv->toUBytes[0]=b;
cnv->toULength=1;
state=definePairOne;
goto singleByteMode;
}
else if(b==UQU) {
cnv->toUBytes[0]=b;
cnv->toULength=1;
state=quotePairOne;
}
else /* Urs */ {
/* callback(illegal) */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
cnv->toUBytes[0]=b;
cnv->toULength=1;
goto endloop;
}
break;
case quotePairOne:
byteOne=b;
cnv->toUBytes[1]=b;
cnv->toULength=2;
state=quotePairTwo;
break;
case quotePairTwo:
*target++=(char16_t)((byteOne<<8)|b);
state=readCommand;
goto fastUnicode;
}
}
}
endloop:
/* set the converter state back into UConverter */
if(U_FAILURE(*pErrorCode) && *pErrorCode!=U_BUFFER_OVERFLOW_ERROR) {
/* reset to deal with the next character */
state=readCommand;
}
else if(state==readCommand) {
/* not in a multi-byte sequence, reset toULength */
cnv->toULength=0;
}
scsu->toUIsSingleByteMode=isSingleByteMode;
scsu->toUState=state;
scsu->toUQuoteWindow=quoteWindow;
scsu->toUDynamicWindow=dynamicWindow;
scsu->toUByteOne=byteOne;
/* write back the updated pointers */
pArgs->source=(
const char *)source;
pArgs->target=target;
}
U_CDECL_END
/* SCSU-from-Unicode conversion functions ----------------------------------- */
/*
* This SCSU Encoder is fairly simple but uses all SCSU commands to achieve
* reasonable results. The lookahead is minimal.
* Many cases are simple:
* A character fits directly into the current mode, a dynamic or static window,
* or is not compressible. These cases are tested first.
* Real compression heuristics are applied to the rest, in code branches for
* single/Unicode mode and BMP/supplementary code points.
* The heuristics used here are extremely simple.
*/
/* get the number of the window that this character is in, or -1 */
static int8_t
getWindow(
const uint32_t offsets[8], uint32_t c) {
int i;
for(i=0; i<8; ++i) {
if (c - offsets[i] <= 0x7f) {
return static_cast<int8_t>(i);
}
}
return -1;
}
/* is the character in the dynamic window starting at the offset, or in the direct-encoded range? */
static UBool
isInOffsetWindowOrDirect(uint32_t offset, uint32_t c) {
return c<=offset+0x7f &&
(c>=offset || (c<=0x7f &&
(c>=0x20 || (1UL<<c)&0x2601)));
/* binary 0010 0110 0000 0001,
check for b==0xd || b==0xa || b==9 || b==0 */
}
/*
* getNextDynamicWindow returns the next dynamic window to be redefined
*/
static int8_t
getNextDynamicWindow(SCSUData *scsu) {
int8_t window=scsu->windowUse[scsu->nextWindowUseIndex];
if(++scsu->nextWindowUseIndex==8) {
scsu->nextWindowUseIndex=0;
}
return window;
}
/*
* useDynamicWindow() adjusts
* windowUse[] and nextWindowUseIndex for the algorithm to choose
* the next dynamic window to be defined;
* a subclass may override it and provide its own algorithm.
*/
static void
useDynamicWindow(SCSUData *scsu, int8_t window) {
/*
* move the existing window, which just became the most recently used one,
* up in windowUse[] to nextWindowUseIndex-1
*/
/* first, find the index of the window - backwards to favor the more recently used windows */
int i, j;
i=scsu->nextWindowUseIndex;
do {
if(--i<0) {
i=7;
}
}
while(scsu->windowUse[i]!=window);
/* now copy each windowUse[i+1] to [i] */
j=i+1;
if(j==8) {
j=0;
}
while(j!=scsu->nextWindowUseIndex) {
scsu->windowUse[i]=scsu->windowUse[j];
i=j;
if(++j==8) { j=0; }
}
/* finally, set the window into the most recently used index */
scsu->windowUse[i]=window;
}
/*
* calculate the offset and the code for a dynamic window that contains the character
* takes fixed offsets into account
* the offset of the window is stored in the offset variable,
* the code is returned
*
* return offset code: -1 none <=0xff code for SDn/UDn else code for SDX/UDX, subtract 0x200 to get the true code
*/
static int
getDynamicOffset(uint32_t c, uint32_t *pOffset) {
int i;
for(i=0; i<7; ++i) {
if (c - fixedOffsets[i] <= 0x7f) {
*pOffset=fixedOffsets[i];
return 0xf9+i;
}
}
if(c<0x80) {
/* No dynamic window for US-ASCII. */
return -1;
}
else if(c<0x3400 ||
c - 0x10000 < 0x14000 - 0x10000 ||
c - 0x1d000 <= 0x1ffff - 0x1d000
) {
/* This character is in a code range for a "small", i.e., reasonably windowable, script. */
*pOffset=c&0x7fffff80;
return static_cast<
int>(c >> 7);
}
else if(0xe000<=c && c!=0xfeff && c<0xfff0) {
/* For these characters we need to take the gapOffset into account. */
*pOffset=c&0x7fffff80;
return static_cast<
int>((c - gapOffset) >> 7);
}
else {
return -1;
}
}
U_CDECL_BEGIN
/*
* Idea for compression:
* - save SCSUData and other state before really starting work
* - at endloop, see if compression could be better with just unicode mode
* - don't do this if a callback has been called
* - if unicode mode would be smaller, then override the results with it - may need SCU at the beginning
* - different buffer handling!
*
* Drawback or need for corrective handling:
* it is desirable to encode U+feff as SQU fe ff for the SCSU signature, and
* it is desirable to start a document in US-ASCII/Latin-1 for as long as possible
* not only for compression but also for HTML/XML documents with following charset/encoding announcers.
*
* How to achieve both?
* - Only replace the result after an SDX or SCU?
*/
static void U_CALLCONV
_SCSUFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
UErrorCode *pErrorCode) {
UConverter *cnv;
SCSUData *scsu;
const char16_t *source, *sourceLimit;
uint8_t *target;
int32_t targetCapacity;
int32_t *offsets;
UBool isSingleByteMode;
uint8_t dynamicWindow;
uint32_t currentOffset;
uint32_t c, delta;
int32_t sourceIndex, nextSourceIndex;
int32_t length;
/* variables for compression heuristics */
uint32_t offset;
char16_t lead, trail;
int code;
int8_t window;
/* set up the local pointers */
cnv=pArgs->converter;
scsu=(SCSUData *)cnv->extraInfo;
/* set up the local pointers */
source=pArgs->source;
sourceLimit=pArgs->sourceLimit;
target=(uint8_t *)pArgs->target;
targetCapacity=(int32_t)(pArgs->targetLimit-pArgs->target);
offsets=pArgs->offsets;
/* get the state machine state */
isSingleByteMode=scsu->fromUIsSingleByteMode;
dynamicWindow=scsu->fromUDynamicWindow;
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow];
c=cnv->fromUChar32;
/* sourceIndex=-1 if the current character began in the previous buffer */
sourceIndex= c==0 ? 0 : -1;
nextSourceIndex=0;
/* similar conversion "loop" as in toUnicode */
loop:
if(isSingleByteMode) {
if(c!=0 && targetCapacity>0) {
goto getTrailSingle;
}
/* state machine for single-byte mode */
/* singleByteMode: */
while(source<sourceLimit) {
if(targetCapacity<=0) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
c=*source++;
++nextSourceIndex;
if((c-0x20)<=0x5f) {
/* pass US-ASCII graphic character through */
*target++=(uint8_t)c;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
--targetCapacity;
}
else if(c<0x20) {
if((1UL<<c)&0x2601
/* binary 0010 0110 0000 0001, check for b==0xd || b==0xa || b==9 || b==0 */) {
/* CR/LF/TAB/NUL */
*target++=(uint8_t)c;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
--targetCapacity;
}
else {
/* quote C0 control character */
c|=SQ0<<8;
length=2;
goto outputBytes;
}
}
else if((delta=c-currentOffset)<=0x7f) {
/* use the current dynamic window */
*target++=(uint8_t)(delta|0x80);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
--targetCapacity;
}
else if(U16_IS_SURROGATE(c)) {
if(U16_IS_SURROGATE_LEAD(c)) {
getTrailSingle:
lead=(char16_t)c;
if(source<sourceLimit) {
/* test the following code unit */
trail=*source;
if(U16_IS_TRAIL(trail)) {
++source;
++nextSourceIndex;
c=U16_GET_SUPPLEMENTARY(c, trail);
/* convert this surrogate code point */
/* exit this condition tree */
}
else {
/* this is an unmatched lead code unit (1st surrogate) */
/* callback(illegal) */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
goto endloop;
}
}
else {
/* no more input */
break;
}
}
else {
/* this is an unmatched trail code unit (2nd surrogate) */
/* callback(illegal) */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
goto endloop;
}
/* compress supplementary character U+10000..U+10ffff */
if((delta=c-currentOffset)<=0x7f) {
/* use the current dynamic window */
*target++=(uint8_t)(delta|0x80);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
--targetCapacity;
}
else if((window=getWindow(scsu->fromUDynamicOffsets, c))>=0) {
/* there is a dynamic window that contains this character, change to it */
dynamicWindow=window;
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow];
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)(SC0+dynamicWindow)<<8)|(c-currentOffset)|0x80;
length=2;
goto outputBytes;
}
else if((code=getDynamicOffset(c, &offset))>=0) {
/* might check if there are more characters in this window to come */
/* define an extended window with this character */
code-=0x200;
dynamicWindow=getNextDynamicWindow(scsu);
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow]=offset;
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)SDX<<24)|((uint32_t)dynamicWindow<<21)|((uint32_t)code<<8)|(c-currentOffs
et)|0x80;
length=4;
goto outputBytes;
} else {
/* change to Unicode mode and output this (lead, trail) pair */
isSingleByteMode=false;
*target++=(uint8_t)SCU;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
--targetCapacity;
c=((uint32_t)lead<<16)|trail;
length=4;
goto outputBytes;
}
} else if(c<0xa0) {
/* quote C1 control character */
c=(c&0x7f)|(SQ0+1)<<8; /* SQ0+1==SQ1 */
length=2;
goto outputBytes;
} else if(c==0xfeff || c>=0xfff0) {
/* quote signature character=byte order mark and specials */
c|=SQU<<16;
length=3;
goto outputBytes;
} else {
/* compress all other BMP characters */
if((window=getWindow(scsu->fromUDynamicOffsets, c))>=0) {
/* there is a window defined that contains this character - switch to it or quote from it? */
if(source>=sourceLimit || isInOffsetWindowOrDirect(scsu->fromUDynamicOffsets[window], *source)) {
/* change to dynamic window */
dynamicWindow=window;
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow];
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)(SC0+dynamicWindow)<<8)|(c-currentOffset)|0x80;
length=2;
goto outputBytes;
} else {
/* quote from dynamic window */
c=((uint32_t)(SQ0+window)<<8)|(c-scsu->fromUDynamicOffsets[window])|0x80;
length=2;
goto outputBytes;
}
} else if((window=getWindow(staticOffsets, c))>=0) {
/* quote from static window */
c=((uint32_t)(SQ0+window)<<8)|(c-staticOffsets[window]);
length=2;
goto outputBytes;
} else if((code=getDynamicOffset(c, &offset))>=0) {
/* define a dynamic window with this character */
dynamicWindow=getNextDynamicWindow(scsu);
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow]=offset;
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)(SD0+dynamicWindow)<<16)|((uint32_t)code<<8)|(c-currentOffset)|0x80;
length=3;
goto outputBytes;
} else if ((c - 0x3400) < (0xd800 - 0x3400) &&
(source >= sourceLimit || (uint32_t)(*source - 0x3400) < (0xd800 - 0x3400))
) {
/*
* this character is not compressible (a BMP ideograph or similar);
* switch to Unicode mode if this is the last character in the block
* or there is at least one more ideograph following immediately
*/
isSingleByteMode=false;
c|=SCU<<16;
length=3;
goto outputBytes;
} else {
/* quote Unicode */
c|=SQU<<16;
length=3;
goto outputBytes;
}
}
/* normal end of conversion: prepare for a new character */
c=0;
sourceIndex=nextSourceIndex;
}
} else {
if(c!=0 && targetCapacity>0) {
goto getTrailUnicode;
}
/* state machine for Unicode mode */
/* unicodeByteMode: */
while(source<sourceLimit) {
if(targetCapacity<=0) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
c=*source++;
++nextSourceIndex;
if ((c - 0x3400) < (0xd800 - 0x3400)) {
/* not compressible, write character directly */
if(targetCapacity>=2) {
*target++=(uint8_t)(c>>8);
*target++=(uint8_t)c;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
*offsets++=sourceIndex;
}
targetCapacity-=2;
} else {
length=2;
goto outputBytes;
}
} else if (c - 0x3400 >= 0xf300 - 0x3400 /* c<0x3400 || c>=0xf300 */) {
/* compress BMP character if the following one is not an uncompressible ideograph */
if(!(source<sourceLimit && (uint32_t)(*source-0x3400)<(0xd800-0x3400))) {
if (c - 0x30 < 10 || c - 0x61 < 26 || c - 0x41 < 26) {
/* ASCII digit or letter */
isSingleByteMode=true;
c|=((uint32_t)(UC0+dynamicWindow)<<8)|c;
length=2;
goto outputBytes;
} else if((window=getWindow(scsu->fromUDynamicOffsets, c))>=0) {
/* there is a dynamic window that contains this character, change to it */
isSingleByteMode=true;
dynamicWindow=window;
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow];
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)(UC0+dynamicWindow)<<8)|(c-currentOffset)|0x80;
length=2;
goto outputBytes;
} else if((code=getDynamicOffset(c, &offset))>=0) {
/* define a dynamic window with this character */
isSingleByteMode=true;
dynamicWindow=getNextDynamicWindow(scsu);
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow]=offset;
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)(UD0+dynamicWindow)<<16)|((uint32_t)code<<8)|(c-currentOffset)|0x80;
length=3;
goto outputBytes;
}
}
/* don't know how to compress this character, just write it directly */
length=2;
goto outputBytes;
} else if(c<0xe000) {
/* c is a surrogate */
if(U16_IS_SURROGATE_LEAD(c)) {
getTrailUnicode:
lead=(char16_t)c;
if(source<sourceLimit) {
/* test the following code unit */
trail=*source;
if(U16_IS_TRAIL(trail)) {
++source;
++nextSourceIndex;
c=U16_GET_SUPPLEMENTARY(c, trail);
/* convert this surrogate code point */
/* exit this condition tree */
} else {
/* this is an unmatched lead code unit (1st surrogate) */
/* callback(illegal) */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
goto endloop;
}
} else {
/* no more input */
break;
}
} else {
/* this is an unmatched trail code unit (2nd surrogate) */
/* callback(illegal) */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
goto endloop;
}
/* compress supplementary character */
if( (window=getWindow(scsu->fromUDynamicOffsets, c))>=0 &&
!(source<sourceLimit && (uint32_t)(*source-0x3400)<(0xd800-0x3400))
) {
/*
* there is a dynamic window that contains this character and
* the following character is not uncompressible,
* change to the window
*/
isSingleByteMode=true;
dynamicWindow=window;
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow];
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)(UC0+dynamicWindow)<<8)|(c-currentOffset)|0x80;
length=2;
goto outputBytes;
} else if(source<sourceLimit && lead==*source && /* too lazy to check trail in same window as source[1] */
(code=getDynamicOffset(c, &offset))>=0
) {
/* two supplementary characters in (probably) the same window - define an extended one */
isSingleByteMode=true;
code-=0x200;
dynamicWindow=getNextDynamicWindow(scsu);
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow]=offset;
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)UDX<<24)|((uint32_t)dynamicWindow<<21)|((uint32_t)code<<8)|(c-currentOffset)|0x80;
length=4;
goto outputBytes;
} else {
/* don't know how to compress this character, just write it directly */
c=((uint32_t)lead<<16)|trail;
length=4;
goto outputBytes;
}
} else /* 0xe000<=c<0xf300 */ {
/* quote to avoid SCSU tags */
c|=UQU<<16;
length=3;
goto outputBytes;
}
/* normal end of conversion: prepare for a new character */
c=0;
sourceIndex=nextSourceIndex;
}
}
endloop:
/* set the converter state back into UConverter */
scsu->fromUIsSingleByteMode=isSingleByteMode;
scsu->fromUDynamicWindow=dynamicWindow;
cnv->fromUChar32=c;
/* write back the updated pointers */
pArgs->source=source;
pArgs->target=(char *)target;
pArgs->offsets=offsets;
return;
outputBytes:
/* write the output character bytes from c and length [code copied from ucnvmbcs.c] */
/* from the first if in the loop we know that targetCapacity>0 */
if(length<=targetCapacity) {
if(offsets==nullptr) {
switch(length) {
/* each branch falls through to the next one */
case 4:
*target++=(uint8_t)(c>>24);
U_FALLTHROUGH;
case 3:
*target++=(uint8_t)(c>>16);
U_FALLTHROUGH;
case 2:
*target++=(uint8_t)(c>>8);
U_FALLTHROUGH;
case 1:
*target++=(uint8_t)c;
U_FALLTHROUGH;
default:
/* will never occur */
break;
}
} else {
switch(length) {
/* each branch falls through to the next one */
case 4:
*target++=(uint8_t)(c>>24);
*offsets++=sourceIndex;
U_FALLTHROUGH;
case 3:
*target++=(uint8_t)(c>>16);
*offsets++=sourceIndex;
U_FALLTHROUGH;
case 2:
*target++=(uint8_t)(c>>8);
*offsets++=sourceIndex;
U_FALLTHROUGH;
case 1:
*target++=(uint8_t)c;
*offsets++=sourceIndex;
U_FALLTHROUGH;
default:
/* will never occur */
break;
}
}
targetCapacity-=length;
/* normal end of conversion: prepare for a new character */
c=0;
sourceIndex=nextSourceIndex;
goto loop;
} else {
uint8_t *p;
/*
* We actually do this backwards here:
* In order to save an intermediate variable, we output
* first to the overflow buffer what does not fit into the
* regular target.
*/
/* we know that 0<=targetCapacity<length<=4 */
/* targetCapacity==0 when SCU+supplementary where SCU used up targetCapacity==1 */
length-=targetCapacity;
p=(uint8_t *)cnv->charErrorBuffer;
switch(length) {
/* each branch falls through to the next one */
case 4:
*p++=(uint8_t)(c>>24);
U_FALLTHROUGH;
case 3:
*p++=(uint8_t)(c>>16);
U_FALLTHROUGH;
case 2:
*p++=(uint8_t)(c>>8);
U_FALLTHROUGH;
case 1:
*p=(uint8_t)c;
U_FALLTHROUGH;
default:
/* will never occur */
break;
}
cnv->charErrorBufferLength=(int8_t)length;
/* now output what fits into the regular target */
c>>=8*length; /* length was reduced by targetCapacity */
switch(targetCapacity) {
/* each branch falls through to the next one */
case 3:
*target++=(uint8_t)(c>>16);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
U_FALLTHROUGH;
case 2:
*target++=(uint8_t)(c>>8);
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
U_FALLTHROUGH;
case 1:
*target++=(uint8_t)c;
if(offsets!=nullptr) {
*offsets++=sourceIndex;
}
U_FALLTHROUGH;
default:
break;
}
/* target overflow */
targetCapacity=0;
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
c=0;
goto endloop;
}
}
/*
* Identical to _SCSUFromUnicodeWithOffsets but without offset handling.
* If a change is made in the original function, then either
* change this function the same way or
* re-copy the original function and remove the variables
* offsets, sourceIndex, and nextSourceIndex.
*/
static void U_CALLCONV
_SCSUFromUnicode(UConverterFromUnicodeArgs *pArgs,
UErrorCode *pErrorCode) {
UConverter *cnv;
SCSUData *scsu;
const char16_t *source, *sourceLimit;
uint8_t *target;
int32_t targetCapacity;
UBool isSingleByteMode;
uint8_t dynamicWindow;
uint32_t currentOffset;
uint32_t c, delta;
int32_t length;
/* variables for compression heuristics */
uint32_t offset;
char16_t lead, trail;
int code;
int8_t window;
/* set up the local pointers */
cnv=pArgs->converter;
scsu=(SCSUData *)cnv->extraInfo;
/* set up the local pointers */
source=pArgs->source;
sourceLimit=pArgs->sourceLimit;
target=(uint8_t *)pArgs->target;
targetCapacity=(int32_t)(pArgs->targetLimit-pArgs->target);
/* get the state machine state */
isSingleByteMode=scsu->fromUIsSingleByteMode;
dynamicWindow=scsu->fromUDynamicWindow;
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow];
c=cnv->fromUChar32;
/* similar conversion "loop" as in toUnicode */
loop:
if(isSingleByteMode) {
if(c!=0 && targetCapacity>0) {
goto getTrailSingle;
}
/* state machine for single-byte mode */
/* singleByteMode: */
while(source<sourceLimit) {
if(targetCapacity<=0) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
c=*source++;
if((c-0x20)<=0x5f) {
/* pass US-ASCII graphic character through */
*target++=(uint8_t)c;
--targetCapacity;
} else if(c<0x20) {
if((1UL<<c)&0x2601 /* binary 0010 0110 0000 0001, check for b==0xd || b==0xa || b==9 || b==0 */) {
/* CR/LF/TAB/NUL */
*target++=(uint8_t)c;
--targetCapacity;
} else {
/* quote C0 control character */
c|=SQ0<<8;
length=2;
goto outputBytes;
}
} else if((delta=c-currentOffset)<=0x7f) {
/* use the current dynamic window */
*target++=(uint8_t)(delta|0x80);
--targetCapacity;
} else if(U16_IS_SURROGATE(c)) {
if(U16_IS_SURROGATE_LEAD(c)) {
getTrailSingle:
lead=(char16_t)c;
if(source<sourceLimit) {
/* test the following code unit */
trail=*source;
if(U16_IS_TRAIL(trail)) {
++source;
c=U16_GET_SUPPLEMENTARY(c, trail);
/* convert this surrogate code point */
/* exit this condition tree */
} else {
/* this is an unmatched lead code unit (1st surrogate) */
/* callback(illegal) */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
goto endloop;
}
} else {
/* no more input */
break;
}
} else {
/* this is an unmatched trail code unit (2nd surrogate) */
/* callback(illegal) */
*pErrorCode=U_ILLEGAL_CHAR_FOUND;
goto endloop;
}
/* compress supplementary character U+10000..U+10ffff */
if((delta=c-currentOffset)<=0x7f) {
/* use the current dynamic window */
*target++=(uint8_t)(delta|0x80);
--targetCapacity;
} else if((window=getWindow(scsu->fromUDynamicOffsets, c))>=0) {
/* there is a dynamic window that contains this character, change to it */
dynamicWindow=window;
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow];
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)(SC0+dynamicWindow)<<8)|(c-currentOffset)|0x80;
length=2;
goto outputBytes;
} else if((code=getDynamicOffset(c, &offset))>=0) {
/* might check if there are more characters in this window to come */
/* define an extended window with this character */
code-=0x200;
dynamicWindow=getNextDynamicWindow(scsu);
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow]=offset;
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)SDX<<24)|((uint32_t)dynamicWindow<<21)|((uint32_t)code<<8)|(c-currentOffset)|0x80;
length=4;
goto outputBytes;
} else {
/* change to Unicode mode and output this (lead, trail) pair */
isSingleByteMode=false;
*target++=(uint8_t)SCU;
--targetCapacity;
c=((uint32_t)lead<<16)|trail;
length=4;
goto outputBytes;
}
} else if(c<0xa0) {
/* quote C1 control character */
c=(c&0x7f)|(SQ0+1)<<8; /* SQ0+1==SQ1 */
length=2;
goto outputBytes;
} else if(c==0xfeff || c>=0xfff0) {
/* quote signature character=byte order mark and specials */
c|=SQU<<16;
length=3;
goto outputBytes;
} else {
/* compress all other BMP characters */
if((window=getWindow(scsu->fromUDynamicOffsets, c))>=0) {
/* there is a window defined that contains this character - switch to it or quote from it? */
if(source>=sourceLimit || isInOffsetWindowOrDirect(scsu->fromUDynamicOffsets[window], *source)) {
/* change to dynamic window */
dynamicWindow=window;
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow];
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)(SC0+dynamicWindow)<<8)|(c-currentOffset)|0x80;
length=2;
goto outputBytes;
} else {
/* quote from dynamic window */
c=((uint32_t)(SQ0+window)<<8)|(c-scsu->fromUDynamicOffsets[window])|0x80;
length=2;
goto outputBytes;
}
} else if((window=getWindow(staticOffsets, c))>=0) {
/* quote from static window */
c=((uint32_t)(SQ0+window)<<8)|(c-staticOffsets[window]);
length=2;
goto outputBytes;
} else if((code=getDynamicOffset(c, &offset))>=0) {
/* define a dynamic window with this character */
dynamicWindow=getNextDynamicWindow(scsu);
currentOffset=scsu->fromUDynamicOffsets[dynamicWindow]=offset;
useDynamicWindow(scsu, dynamicWindow);
c=((uint32_t)(SD0+dynamicWindow)<<16)|((uint32_t)code<<8)|(c-currentOffset)|0x80;
length=3;
goto outputBytes;
} else if (c - 0x3400 < 0xd800 - 0x3400 &&
(source >= sourceLimit || static_cast<uint32_t>(*source - 0x3400) < 0xd800 - 0x3400)
) {
/*
* this character is not compressible (a BMP ideograph or similar);
* switch to Unicode mode if this is the last character in the block
* or there is at least one more ideograph following immediately
*/
isSingleByteMode=false;
c|=SCU<<16;
length=3;
goto outputBytes;
} else {
/* quote Unicode */
c|=SQU<<16;
length=3;
goto outputBytes;
}
}
/* normal end of conversion: prepare for a new character */
c=0;
}
} else {
if(c!=0 && targetCapacity>0) {
goto getTrailUnicode;
}
/* state machine for Unicode mode */
/* unicodeByteMode: */
while(source<sourceLimit) {
if(targetCapacity<=0) {
/* target is full */
*pErrorCode=U_BUFFER_OVERFLOW_ERROR;
break;
}
c=*source++;
if (c - 0x3400 < 0xd800 - 0x3400) {
/* not compressible, write character directly */
if(targetCapacity>=2) {
--> --------------------
--> maximum size reached
--> --------------------
