scuffed-code/icu4c/source/common/ucnv_cnv.h
2002-06-11 04:43:45 +00:00

230 lines
8.8 KiB
C

/*
**********************************************************************
* Copyright (C) 1999-2001, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
*
* uconv_cnv.h:
* defines all the low level conversion functions
* T_UnicodeConverter_{to,from}Unicode_$ConversionType
*
* Modification History:
*
* Date Name Description
* 05/09/00 helena Added implementation to handle fallback mappings.
* 06/29/2000 helena Major rewrite of the callback APIs.
*/
#ifndef UCNV_CNV_H
#define UCNV_CNV_H
#include "unicode/utypes.h"
#include "unicode/ucnv_err.h"
#include "ucnv_bld.h"
#include "ucnvmbcs.h"
union UConverterTable
{
UConverterMBCSTable mbcs;
};
U_CDECL_BEGIN
/* this is used in fromUnicode DBCS tables as an "unassigned" marker */
#define missingCharMarker 0xFFFF
/*
* #define missingUCharMarker 0xfffe
*
* there are actually two values used in toUnicode tables:
* U+fffe "unassigned"
* U+ffff "illegal"
*/
typedef void (*UConverterLoad) (UConverterSharedData *sharedData, const uint8_t *raw, UErrorCode *pErrorCode);
typedef void (*UConverterUnload) (UConverterSharedData *sharedData);
typedef void (*UConverterOpen) (UConverter *cnv, const char *name, const char *locale,uint32_t options, UErrorCode *pErrorCode);
typedef void (*UConverterClose) (UConverter *cnv);
typedef enum UConverterResetChoice {
UCNV_RESET_BOTH,
UCNV_RESET_TO_UNICODE,
UCNV_RESET_FROM_UNICODE
} UConverterResetChoice;
typedef void (*UConverterReset) (UConverter *cnv, UConverterResetChoice choice);
typedef void (*T_ToUnicodeFunction) (UConverterToUnicodeArgs *, UErrorCode *);
typedef void (*T_FromUnicodeFunction) (UConverterFromUnicodeArgs *, UErrorCode *);
typedef UChar32 (*T_GetNextUCharFunction) (UConverterToUnicodeArgs *, UErrorCode *);
typedef void (*UConverterGetStarters)(const UConverter* converter,
UBool starters[256],
UErrorCode *pErrorCode);
/* If this function pointer is null or if the function returns null
* the name field in static data struct should be returned by
* ucnv_getName() API function
*/
typedef const char * (*UConverterGetName) (const UConverter *cnv);
/**
* Write the codepage substitution character.
* If this function is not set, then ucnv_cbFromUWriteSub() writes
* the substitution character from UConverter.
* For stateful converters, it is typically necessary to handle this
* specificially for the converter in order to properly maintain the state.
*/
typedef void (*UConverterWriteSub) (UConverterFromUnicodeArgs *pArgs, int32_t offsetIndex, UErrorCode *pErrorCode);
/**
* For converter-specific safeClone processing
* If this function is not set, then ucnv_safeClone assumes that the converter has no private data that changes
* after the converter is done opening.
*/
typedef UConverter * (*UConverterSafeClone) (const UConverter *cnv,
void *stackBuffer,
int32_t *pBufferSize,
UErrorCode *status);
UBool CONVERSION_U_SUCCESS (UErrorCode err);
void ucnv_flushInternalUnicodeBuffer (UConverter * _this,
UChar * myTarget,
int32_t * myTargetIndex,
int32_t targetLength,
int32_t** offsets,
UErrorCode * err);
void ucnv_flushInternalCharBuffer (UConverter * _this,
char *myTarget,
int32_t * myTargetIndex,
int32_t targetLength,
int32_t** offsets,
UErrorCode * err);
/**
* UConverterImpl contains all the data and functions for a converter type.
* Its function pointers work much like a C++ vtable.
* Many converter types need to define only a subset of the functions;
* when a function pointer is NULL, then a default action will be performed.
*
* Every converter type must implement toUnicode, fromUnicode, and getNextUChar,
* otherwise the converter may crash.
* Every converter type that has variable-length codepage sequences should
* also implement toUnicodeWithOffsets and fromUnicodeWithOffsets for
* correct offset handling.
* All other functions may or may not be implemented - it depends only on
* whether the converter type needs them.
*
* When open() fails, then close() will be called, if present.
*/
struct UConverterImpl {
UConverterType type;
UConverterLoad load;
UConverterUnload unload;
UConverterOpen open;
UConverterClose close;
UConverterReset reset;
T_ToUnicodeFunction toUnicode;
T_ToUnicodeFunction toUnicodeWithOffsets;
T_FromUnicodeFunction fromUnicode;
T_FromUnicodeFunction fromUnicodeWithOffsets;
T_GetNextUCharFunction getNextUChar;
UConverterGetStarters getStarters;
UConverterGetName getName;
UConverterWriteSub writeSub;
UConverterSafeClone safeClone;
};
extern const UConverterSharedData
_MBCSData, _Latin1Data,
_UTF8Data, _UTF16BEData, _UTF16LEData, _UTF32BEData, _UTF32LEData,
_ISO2022Data,
_LMBCSData1,_LMBCSData2, _LMBCSData3, _LMBCSData4, _LMBCSData5, _LMBCSData6,
_LMBCSData8,_LMBCSData11,_LMBCSData16,_LMBCSData17,_LMBCSData18,_LMBCSData19,
_HZData,_ISCIIData, _SCSUData, _ASCIIData, _UTF7Data, _Bocu1Data, _UTF16Data, _UTF32Data;
U_CDECL_END
/**
* This function is useful for implementations of getNextUChar().
* After a call to a callback function or to toUnicode(), an output buffer
* begins with a Unicode code point that needs to be returned as UChar32,
* and all following code units must be prepended to the - potentially
* prefilled - overflow buffer in the UConverter.
* The buffer should be at least of capacity UTF_MAX_CHAR_LENGTH so that a
* complete UChar32's UChars fit into it.
*
* @param cnv The converter that will get remaining UChars copied to its overflow area.
* @param buffer An array of UChars that was passed into a callback function
* or a toUnicode() function.
* @param length The number of code units (UChars) that are actually in the buffer.
* This must be >0.
* @return The code point from the first UChars in the buffer.
*/
U_CFUNC UChar32
ucnv_getUChar32KeepOverflow(UConverter *cnv, const UChar *buffer, int32_t length);
/**
* This helper function updates the offsets array after a callback function call.
* It adds the sourceIndex to each offsets item, or sets each of them to -1 if
* sourceIndex==-1.
*
* @param offsets The pointer to offsets entry that corresponds to the first target
* unit that the callback wrote.
* @param length The number of output units that the callback wrote.
* @param sourceIndex The sourceIndex of the input sequence that the callback
* function was called for.
* @return offsets+length if offsets!=NULL, otherwise NULL
*/
U_CFUNC int32_t *
ucnv_updateCallbackOffsets(int32_t *offsets, int32_t length, int32_t sourceIndex);
/** Always use fallbacks from codepage to Unicode */
#define TO_U_USE_FALLBACK(useFallback) TRUE
#define UCNV_TO_U_USE_FALLBACK(cnv) TRUE
/** Use fallbacks from Unicode to codepage when cnv->useFallback or for private-use code points */
#define IS_PRIVATE_USE(c) ((uint32_t)((c)-0xe000)<0x1900 || (uint32_t)((c)-0xf0000)<0x20000)
#define FROM_U_USE_FALLBACK(useFallback, c) ((useFallback) || IS_PRIVATE_USE(c))
#define UCNV_FROM_U_USE_FALLBACK(cnv, c) FROM_U_USE_FALLBACK((cnv)->useFallback, c)
/**
* This is a simple implementation of ucnv_getNextUChar() that uses the
* converter's toUnicode() function.
*
* \par
* A surrogate pair from a single byte sequence is always
* combined to a supplementary code point.
* A surrogate pair from consecutive byte sequences is only combined
* if collectPairs is set. This is necessary for SCSU
* but not allowed for most legacy codepages.
*
* @param pArgs The argument structure supplied by ucnv_getNextUChar()
* @param toU A function pointer to the converter's toUnicode() function
* @param collectPairs indicates whether separate surrogate results from
* consecutive byte sequences should be combined into
* a single code point
* @param pErrorCode An ICU error code parameter
* @return The Unicode code point as a result of a conversion of a minimal
* number of input bytes
*/
U_CFUNC UChar32
ucnv_getNextUCharFromToUImpl(UConverterToUnicodeArgs *pArgs,
T_ToUnicodeFunction toU,
UBool collectPairs,
UErrorCode *pErrorCode);
#endif /* UCNV_CNV */