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      1 //  2016 and later: Unicode, Inc. and others.
      2 // License & terms of use: http://www.unicode.org/copyright.html
      3 /*
      4 *******************************************************************************
      5 *
      6 *   Copyright (C) 2003-2014, International Business Machines
      7 *   Corporation and others.  All Rights Reserved.
      8 *
      9 *******************************************************************************
     10 *   file name:  udataswp.h
     11 *   encoding:   UTF-8
     12 *   tab size:   8 (not used)
     13 *   indentation:4
     14 *
     15 *   created on: 2003jun05
     16 *   created by: Markus W. Scherer
     17 *
     18 *   Definitions for ICU data transformations for different platforms,
     19 *   changing between big- and little-endian data and/or between
     20 *   charset families (ASCII<->EBCDIC).
     21 */
     22 
     23 #ifndef __UDATASWP_H__
     24 #define __UDATASWP_H__
     25 
     26 #include <stdarg.h>
     27 #include "unicode/utypes.h"
     28 
     29 /* forward declaration */
     30 
     31 U_CDECL_BEGIN
     32 
     33 struct UDataSwapper;
     34 typedef struct UDataSwapper UDataSwapper;
     35 
     36 /**
     37  * Function type for data transformation.
     38  * Transforms data, or just returns the length of the data if
     39  * the input length is -1.
     40  * Swap functions assume that their data pointers are aligned properly.
     41  *
     42  * Quick implementation outline:
     43  * (best to copy and adapt and existing swapper implementation)
     44  * check that the data looks like the expected format
     45  * if(length<0) {
     46  *   preflight:
     47  *   never dereference outData
     48  *   read inData and determine the data size
     49  *   assume that inData is long enough for this
     50  * } else {
     51  *   outData can be NULL if length==0
     52  *   inData==outData (in-place swapping) possible but not required!
     53  *   verify that length>=(actual size)
     54  *   if there is a chance that not every byte up to size is reached
     55  *     due to padding etc.:
     56  *   if(inData!=outData) {
     57  *     memcpy(outData, inData, actual size);
     58  *   }
     59  *   swap contents
     60  * }
     61  * return actual size
     62  *
     63  * Further implementation notes:
     64  * - read integers from inData before swapping them
     65  *   because in-place swapping can make them unreadable
     66  * - compareInvChars compares a local Unicode string with already-swapped
     67  *   output charset strings
     68  *
     69  * @param ds Pointer to UDataSwapper containing global data about the
     70  *           transformation and function pointers for handling primitive
     71  *           types.
     72  * @param inData Pointer to the input data to be transformed or examined.
     73  * @param length Length of the data, counting bytes. May be -1 for preflighting.
     74  *               If length>=0, then transform the data.
     75  *               If length==-1, then only determine the length of the data.
     76  *               The length cannot be determined from the data itself for all
     77  *               types of data (e.g., not for simple arrays of integers).
     78  * @param outData Pointer to the output data buffer.
     79  *                If length>=0 (transformation), then the output buffer must
     80  *                have a capacity of at least length.
     81  *                If length==-1, then outData will not be used and can be NULL.
     82  * @param pErrorCode ICU UErrorCode parameter, must not be NULL and must
     83  *                   fulfill U_SUCCESS on input.
     84  * @return The actual length of the data.
     85  *
     86  * @see UDataSwapper
     87  * @internal ICU 2.8
     88  */
     89 typedef int32_t U_CALLCONV
     90 UDataSwapFn(const UDataSwapper *ds,
     91             const void *inData, int32_t length, void *outData,
     92             UErrorCode *pErrorCode);
     93 
     94 /**
     95  * Convert one uint16_t from input to platform endianness.
     96  * @internal ICU 2.8
     97  */
     98 typedef uint16_t U_CALLCONV
     99 UDataReadUInt16(uint16_t x);
    100 
    101 /**
    102  * Convert one uint32_t from input to platform endianness.
    103  * @internal ICU 2.8
    104  */
    105 typedef uint32_t U_CALLCONV
    106 UDataReadUInt32(uint32_t x);
    107 
    108 /**
    109  * Convert one uint16_t from platform to input endianness.
    110  * @internal ICU 2.8
    111  */
    112 typedef void U_CALLCONV
    113 UDataWriteUInt16(uint16_t *p, uint16_t x);
    114 
    115 /**
    116  * Convert one uint32_t from platform to input endianness.
    117  * @internal ICU 2.8
    118  */
    119 typedef void U_CALLCONV
    120 UDataWriteUInt32(uint32_t *p, uint32_t x);
    121 
    122 /**
    123  * Compare invariant-character strings, one in the output data and the
    124  * other one caller-provided in Unicode.
    125  * An output data string is compared because strings are usually swapped
    126  * before the rest of the data, to allow for sorting of string tables
    127  * according to the output charset.
    128  * You can use -1 for the length parameters of NUL-terminated strings as usual.
    129  * Returns Unicode code point order for invariant characters.
    130  * @internal ICU 2.8
    131  */
    132 typedef int32_t U_CALLCONV
    133 UDataCompareInvChars(const UDataSwapper *ds,
    134                      const char *outString, int32_t outLength,
    135                      const UChar *localString, int32_t localLength);
    136 
    137 /**
    138  * Function for message output when an error occurs during data swapping.
    139  * A format string and variable number of arguments are passed
    140  * like for vprintf().
    141  *
    142  * @param context A function-specific context pointer.
    143  * @param fmt The format string.
    144  * @param args The arguments for format string inserts.
    145  *
    146  * @internal ICU 2.8
    147  */
    148 typedef void U_CALLCONV
    149 UDataPrintError(void *context, const char *fmt, va_list args);
    150 
    151 struct UDataSwapper {
    152     /** Input endianness. @internal ICU 2.8 */
    153     UBool inIsBigEndian;
    154     /** Input charset family. @see U_CHARSET_FAMILY @internal ICU 2.8 */
    155     uint8_t inCharset;
    156     /** Output endianness. @internal ICU 2.8 */
    157     UBool outIsBigEndian;
    158     /** Output charset family. @see U_CHARSET_FAMILY @internal ICU 2.8 */
    159     uint8_t outCharset;
    160 
    161     /* basic functions for reading data values */
    162 
    163     /** Convert one uint16_t from input to platform endianness. @internal ICU 2.8 */
    164     UDataReadUInt16 *readUInt16;
    165     /** Convert one uint32_t from input to platform endianness. @internal ICU 2.8 */
    166     UDataReadUInt32 *readUInt32;
    167     /** Compare an invariant-character output string with a local one. @internal ICU 2.8 */
    168     UDataCompareInvChars *compareInvChars;
    169 
    170     /* basic functions for writing data values */
    171 
    172     /** Convert one uint16_t from platform to input endianness. @internal ICU 2.8 */
    173     UDataWriteUInt16 *writeUInt16;
    174     /** Convert one uint32_t from platform to input endianness. @internal ICU 2.8 */
    175     UDataWriteUInt32 *writeUInt32;
    176 
    177     /* basic functions for data transformations */
    178 
    179     /** Transform an array of 16-bit integers. @internal ICU 2.8 */
    180     UDataSwapFn *swapArray16;
    181     /** Transform an array of 32-bit integers. @internal ICU 2.8 */
    182     UDataSwapFn *swapArray32;
    183     /** Transform an array of 64-bit integers. @internal ICU 53 */
    184     UDataSwapFn *swapArray64;
    185     /** Transform an invariant-character string. @internal ICU 2.8 */
    186     UDataSwapFn *swapInvChars;
    187 
    188     /**
    189      * Function for message output when an error occurs during data swapping.
    190      * Can be NULL.
    191      * @internal ICU 2.8
    192      */
    193     UDataPrintError *printError;
    194     /** Context pointer for printError. @internal ICU 2.8 */
    195     void *printErrorContext;
    196 };
    197 
    198 U_CDECL_END
    199 
    200 U_CAPI UDataSwapper * U_EXPORT2
    201 udata_openSwapper(UBool inIsBigEndian, uint8_t inCharset,
    202                   UBool outIsBigEndian, uint8_t outCharset,
    203                   UErrorCode *pErrorCode);
    204 
    205 /**
    206  * Open a UDataSwapper for the given input data and the specified output
    207  * characteristics.
    208  * Values of -1 for any of the characteristics mean the local platform's
    209  * characteristics.
    210  *
    211  * @see udata_swap
    212  * @internal ICU 2.8
    213  */
    214 U_CAPI UDataSwapper * U_EXPORT2
    215 udata_openSwapperForInputData(const void *data, int32_t length,
    216                               UBool outIsBigEndian, uint8_t outCharset,
    217                               UErrorCode *pErrorCode);
    218 
    219 U_CAPI void U_EXPORT2
    220 udata_closeSwapper(UDataSwapper *ds);
    221 
    222 /**
    223  * Read the beginning of an ICU data piece, recognize magic bytes,
    224  * swap the structure.
    225  * Set a U_UNSUPPORTED_ERROR if it does not look like an ICU data piece.
    226  *
    227  * @return The size of the data header, in bytes.
    228  *
    229  * @internal ICU 2.8
    230  */
    231 U_CAPI int32_t U_EXPORT2
    232 udata_swapDataHeader(const UDataSwapper *ds,
    233                      const void *inData, int32_t length, void *outData,
    234                      UErrorCode *pErrorCode);
    235 
    236 /**
    237  * Convert one int16_t from input to platform endianness.
    238  * @internal ICU 2.8
    239  */
    240 U_CAPI int16_t U_EXPORT2
    241 udata_readInt16(const UDataSwapper *ds, int16_t x);
    242 
    243 /**
    244  * Convert one int32_t from input to platform endianness.
    245  * @internal ICU 2.8
    246  */
    247 U_CAPI int32_t U_EXPORT2
    248 udata_readInt32(const UDataSwapper *ds, int32_t x);
    249 
    250 /**
    251  * Swap a block of invariant, NUL-terminated strings, but not padding
    252  * bytes after the last string.
    253  * @internal
    254  */
    255 U_CAPI int32_t U_EXPORT2
    256 udata_swapInvStringBlock(const UDataSwapper *ds,
    257                          const void *inData, int32_t length, void *outData,
    258                          UErrorCode *pErrorCode);
    259 
    260 U_CAPI void U_EXPORT2
    261 udata_printError(const UDataSwapper *ds,
    262                  const char *fmt,
    263                  ...);
    264 
    265 /* internal exports from putil.c -------------------------------------------- */
    266 
    267 /* declared here to keep them out of the public putil.h */
    268 
    269 /**
    270  * Swap invariant char * strings ASCII->EBCDIC.
    271  * @internal
    272  */
    273 U_CAPI int32_t U_EXPORT2
    274 uprv_ebcdicFromAscii(const UDataSwapper *ds,
    275                      const void *inData, int32_t length, void *outData,
    276                      UErrorCode *pErrorCode);
    277 
    278 /**
    279  * Copy invariant ASCII char * strings and verify they are invariant.
    280  * @internal
    281  */
    282 U_CFUNC int32_t
    283 uprv_copyAscii(const UDataSwapper *ds,
    284                const void *inData, int32_t length, void *outData,
    285                UErrorCode *pErrorCode);
    286 
    287 /**
    288  * Swap invariant char * strings EBCDIC->ASCII.
    289  * @internal
    290  */
    291 U_CFUNC int32_t
    292 uprv_asciiFromEbcdic(const UDataSwapper *ds,
    293                      const void *inData, int32_t length, void *outData,
    294                      UErrorCode *pErrorCode);
    295 
    296 /**
    297  * Copy invariant EBCDIC char * strings and verify they are invariant.
    298  * @internal
    299  */
    300 U_CFUNC int32_t
    301 uprv_copyEbcdic(const UDataSwapper *ds,
    302                 const void *inData, int32_t length, void *outData,
    303                 UErrorCode *pErrorCode);
    304 
    305 /**
    306  * Compare ASCII invariant char * with Unicode invariant UChar *
    307  * @internal
    308  */
    309 U_CFUNC int32_t
    310 uprv_compareInvAscii(const UDataSwapper *ds,
    311                      const char *outString, int32_t outLength,
    312                      const UChar *localString, int32_t localLength);
    313 
    314 /**
    315  * Compare EBCDIC invariant char * with Unicode invariant UChar *
    316  * @internal
    317  */
    318 U_CFUNC int32_t
    319 uprv_compareInvEbcdic(const UDataSwapper *ds,
    320                       const char *outString, int32_t outLength,
    321                       const UChar *localString, int32_t localLength);
    322 
    323 /**
    324  * \def uprv_compareInvWithUChar
    325  * Compare an invariant-character strings with a UChar string
    326  * @internal
    327  */
    328 #if U_CHARSET_FAMILY==U_ASCII_FAMILY
    329 #   define uprv_compareInvWithUChar uprv_compareInvAscii
    330 #elif U_CHARSET_FAMILY==U_EBCDIC_FAMILY
    331 #   define uprv_compareInvWithUChar uprv_compareInvEbcdic
    332 #else
    333 #   error Unknown charset family!
    334 #endif
    335 
    336 
    337 /* material... -------------------------------------------------------------- */
    338 
    339 #if 0
    340 
    341 /* udata.h */
    342 
    343 /**
    344  * Public API function in udata.c
    345  *
    346  * Same as udata_openChoice() but automatically swaps the data.
    347  * isAcceptable, if not NULL, may accept data with endianness and charset family
    348  * different from the current platform's properties.
    349  * If the data is acceptable and the platform properties do not match, then
    350  * the swap function is called to swap an allocated version of the data.
    351  * Preflighting may or may not be performed depending on whether the size of
    352  * the loaded data item is known.
    353  *
    354  * @param isAcceptable Same as for udata_openChoice(). May be NULL.
    355  *
    356  * @internal ICU 2.8
    357  */
    358 U_CAPI UDataMemory * U_EXPORT2
    359 udata_openSwap(const char *path, const char *type, const char *name,
    360                UDataMemoryIsAcceptable *isAcceptable, void *isAcceptableContext,
    361                UDataSwapFn *swap,
    362                UDataPrintError *printError, void *printErrorContext,
    363                UErrorCode *pErrorCode);
    364 
    365 #endif
    366 
    367 #endif
    368