CoreFoundation/CFStringEncodingConverterExt.h

/*
 * Copyright (c) 2008-2009 Brent Fulgham <bfulgham@gmail.org>.  All rights reserved.
 *
 * This source code is a modified version of the CoreFoundation sources released by Apple Inc. under
 * the terms of the APSL version 2.0 (see below).
 *
 * For information about changes from the original Apple source release can be found by reviewing the
 * source control system for the project at https://sourceforge.net/svn/?group_id=246198.
 *
 * The original license information is as follows:
 * 
 * Copyright (c) 2008 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*	CFStringEncodingConverterExt.h
	Copyright (c) 1998-2007, Apple Inc. All rights reserved.
*/

#if !defined(__COREFOUNDATION_CFSTRINGENCODINGCONVERETEREXT__)
#define __COREFOUNDATION_CFSTRINGENCODINGCONVERETEREXT__ 1

#include <CoreFoundation/CFStringEncodingConverter.h>

CF_EXTERN_C_BEGIN

#define MAX_DECOMPOSED_LENGTH (10)

enum {
    kCFStringEncodingConverterStandard = 0,
    kCFStringEncodingConverterCheapEightBit = 1,
    kCFStringEncodingConverterStandardEightBit = 2,
    kCFStringEncodingConverterCheapMultiByte = 3,
    kCFStringEncodingConverterPlatformSpecific = 4 // Other fields are ignored
};

/* kCFStringEncodingConverterStandard */
typedef CFIndex (*CFStringEncodingToBytesProc)(uint32_t flags, const UniChar *characters, CFIndex numChars, uint8_t *bytes, CFIndex maxByteLen, CFIndex *usedByteLen);
typedef CFIndex (*CFStringEncodingToUnicodeProc)(uint32_t flags, const uint8_t *bytes, CFIndex numBytes, UniChar *characters, CFIndex maxCharLen, CFIndex *usedCharLen);
/* kCFStringEncodingConverterCheapEightBit */
typedef bool (*CFStringEncodingCheapEightBitToBytesProc)(uint32_t flags, UniChar character, uint8_t *byte);
typedef bool (*CFStringEncodingCheapEightBitToUnicodeProc)(uint32_t flags, uint8_t byte, UniChar *character);
/* kCFStringEncodingConverterStandardEightBit */
typedef uint16_t (*CFStringEncodingStandardEightBitToBytesProc)(uint32_t flags, const UniChar *characters, CFIndex numChars, uint8_t *byte);
typedef uint16_t (*CFStringEncodingStandardEightBitToUnicodeProc)(uint32_t flags, uint8_t byte, UniChar *characters);
/* kCFStringEncodingConverterCheapMultiByte */
typedef uint16_t (*CFStringEncodingCheapMultiByteToBytesProc)(uint32_t flags, UniChar character, uint8_t *bytes);
typedef uint16_t (*CFStringEncodingCheapMultiByteToUnicodeProc)(uint32_t flags, const uint8_t *bytes, CFIndex numBytes, UniChar *character);

typedef CFIndex (*CFStringEncodingToBytesLenProc)(uint32_t flags, const UniChar *characters, CFIndex numChars);
typedef CFIndex (*CFStringEncodingToUnicodeLenProc)(uint32_t flags, const uint8_t *bytes, CFIndex numBytes);

typedef CFIndex (*CFStringEncodingToBytesPrecomposeProc)(uint32_t flags, const UniChar *character, CFIndex numChars, uint8_t *bytes, CFIndex maxByteLen, CFIndex *usedByteLen);
typedef bool (*CFStringEncodingIsValidCombiningCharacterProc)(UniChar character);

typedef struct {
    void *toBytes;
    void *toUnicode;
    uint16_t maxBytesPerChar;
    uint16_t maxDecomposedCharLen;
    uint8_t encodingClass;
    uint32_t :24;
    CFStringEncodingToBytesLenProc toBytesLen;
    CFStringEncodingToUnicodeLenProc toUnicodeLen;
    CFStringEncodingToBytesFallbackProc toBytesFallback;
    CFStringEncodingToUnicodeFallbackProc toUnicodeFallback;
    CFStringEncodingToBytesPrecomposeProc toBytesPrecompose;
    CFStringEncodingIsValidCombiningCharacterProc isValidCombiningChar;
} CFStringEncodingConverter;


extern const CFStringEncodingConverter *CFStringEncodingGetConverter(uint32_t encoding);

enum {
    kCFStringEncodingGetConverterSelector = 0,
    kCFStringEncodingIsDecomposableCharacterSelector = 1,
    kCFStringEncodingDecomposeCharacterSelector = 2,
    kCFStringEncodingIsValidLatin1CombiningCharacterSelector = 3,
    kCFStringEncodingPrecomposeLatin1CharacterSelector = 4
};

extern const void *CFStringEncodingGetAddressForSelector(uint32_t selector);

#define BOOTSTRAPFUNC_NAME	CFStringEncodingBootstrap
typedef const CFStringEncodingConverter* (*CFStringEncodingBootstrapProc)(uint32_t encoding, const void *getSelector);

extern uint32_t CFStringEncodingGetScriptCodeForEncoding(CFStringEncoding encoding);

/* Latin precomposition */
/* This function does not precompose recursively nor to U+01E0 and U+01E1.
*/
extern bool CFStringEncodingIsValidCombiningCharacterForLatin1(UniChar character);
extern UniChar CFStringEncodingPrecomposeLatinCharacter(const UniChar *character, CFIndex numChars, CFIndex *usedChars);

/* Convenience functions for converter development */
typedef struct _CFStringEncodingUnicodeTo8BitCharMap {
    UniChar _u;
    uint8_t _c;
    uint8_t :8;
} CFStringEncodingUnicodeTo8BitCharMap;

/* Binary searches CFStringEncodingUnicodeTo8BitCharMap */
CF_INLINE bool CFStringEncodingUnicodeTo8BitEncoding(const CFStringEncodingUnicodeTo8BitCharMap *theTable, CFIndex numElem, UniChar character, uint8_t *ch) {
    const CFStringEncodingUnicodeTo8BitCharMap *p, *q, *divider;

    if ((character < theTable[0]._u) || (character > theTable[numElem-1]._u)) {
        return 0;
    }
    p = theTable;
    q = p + (numElem-1);
    while (p <= q) {
        divider = p + ((q - p) >> 1);	/* divide by 2 */
        if (character < divider->_u) { q = divider - 1; }
        else if (character > divider->_u) { p = divider + 1; }
        else { *ch = divider->_c; return 1; }
    }
    return 0;
}


CF_EXTERN_C_END

#endif /* ! __COREFOUNDATION_CFSTRINGENCODINGCONVERETEREXT__ */