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      1 /*
      2 *******************************************************************************
      3 *
      4 *   Copyright (C) 2003-2005, International Business Machines
      5 *   Corporation and others.  All Rights Reserved.
      6 *
      7 *******************************************************************************
      8 *   file name:  udataswp.h
      9 *   encoding:   US-ASCII
     10 *   tab size:   8 (not used)
     11 *   indentation:4
     12 *
     13 *   created on: 2003jun05
     14 *   created by: Markus W. Scherer
     15 *
     16 *   Definitions for ICU data transformations for different platforms,
     17 *   changing between big- and little-endian data and/or between
     18 *   charset families (ASCII<->EBCDIC).
     19 */
     20 
     21 #ifndef __UDATASWP_H__
     22 #define __UDATASWP_H__
     23 
     24 #include <stdarg.h>
     25 #include "unicode/utypes.h"
     26 
     27 /* forward declaration */
     28 
     29 U_CDECL_BEGIN
     30 
     31 struct UDataSwapper;
     32 typedef struct UDataSwapper UDataSwapper;
     33 
     34 /**
     35  * Function type for data transformation.
     36  * Transforms data, or just returns the length of the data if
     37  * the input length is -1.
     38  * Swap functions assume that their data pointers are aligned properly.
     39  *
     40  * Quick implementation outline:
     41  * (best to copy and adapt and existing swapper implementation)
     42  * check that the data looks like the expected format
     43  * if(length<0) {
     44  *   preflight:
     45  *   never dereference outData
     46  *   read inData and determine the data size
     47  *   assume that inData is long enough for this
     48  * } else {
     49  *   outData can be NULL if length==0
     50  *   inData==outData (in-place swapping) possible but not required!
     51  *   verify that length>=(actual size)
     52  *   if there is a chance that not every byte up to size is reached
     53  *     due to padding etc.:
     54  *   if(inData!=outData) {
     55  *     memcpy(outData, inData, actual size);
     56  *   }
     57  *   swap contents
     58  * }
     59  * return actual size
     60  *
     61  * Further implementation notes:
     62  * - read integers from inData before swapping them
     63  *   because in-place swapping can make them unreadable
     64  * - compareInvChars compares a local Unicode string with already-swapped
     65  *   output charset strings
     66  *
     67  * @param ds Pointer to UDataSwapper containing global data about the
     68  *           transformation and function pointers for handling primitive
     69  *           types.
     70  * @param inData Pointer to the input data to be transformed or examined.
     71  * @param length Length of the data, counting bytes. May be -1 for preflighting.
     72  *               If length>=0, then transform the data.
     73  *               If length==-1, then only determine the length of the data.
     74  *               The length cannot be determined from the data itself for all
     75  *               types of data (e.g., not for simple arrays of integers).
     76  * @param outData Pointer to the output data buffer.
     77  *                If length>=0 (transformation), then the output buffer must
     78  *                have a capacity of at least length.
     79  *                If length==-1, then outData will not be used and can be NULL.
     80  * @param pErrorCode ICU UErrorCode parameter, must not be NULL and must
     81  *                   fulfill U_SUCCESS on input.
     82  * @return The actual length of the data.
     83  *
     84  * @see UDataSwapper
     85  * @internal ICU 2.8
     86  */
     87 typedef int32_t U_CALLCONV
     88 UDataSwapFn(const UDataSwapper *ds,
     89             const void *inData, int32_t length, void *outData,
     90             UErrorCode *pErrorCode);
     91 
     92 /**
     93  * Convert one uint16_t from input to platform endianness.
     94  * @internal ICU 2.8
     95  */
     96 typedef uint16_t U_CALLCONV
     97 UDataReadUInt16(uint16_t x);
     98 
     99 /**
    100  * Convert one uint32_t from input to platform endianness.
    101  * @internal ICU 2.8
    102  */
    103 typedef uint32_t U_CALLCONV
    104 UDataReadUInt32(uint32_t x);
    105 
    106 /**
    107  * Convert one uint16_t from platform to input endianness.
    108  * @internal ICU 2.8
    109  */
    110 typedef void U_CALLCONV
    111 UDataWriteUInt16(uint16_t *p, uint16_t x);
    112 
    113 /**
    114  * Convert one uint32_t from platform to input endianness.
    115  * @internal ICU 2.8
    116  */
    117 typedef void U_CALLCONV
    118 UDataWriteUInt32(uint32_t *p, uint32_t x);
    119 
    120 /**
    121  * Compare invariant-character strings, one in the output data and the
    122  * other one caller-provided in Unicode.
    123  * An output data string is compared because strings are usually swapped
    124  * before the rest of the data, to allow for sorting of string tables
    125  * according to the output charset.
    126  * You can use -1 for the length parameters of NUL-terminated strings as usual.
    127  * Returns Unicode code point order for invariant characters.
    128  * @internal ICU 2.8
    129  */
    130 typedef int32_t U_CALLCONV
    131 UDataCompareInvChars(const UDataSwapper *ds,
    132                      const char *outString, int32_t outLength,
    133                      const UChar *localString, int32_t localLength);
    134 
    135 /**
    136  * Function for message output when an error occurs during data swapping.
    137  * A format string and variable number of arguments are passed
    138  * like for vprintf().
    139  *
    140  * @param context A function-specific context pointer.
    141  * @param fmt The format string.
    142  * @param args The arguments for format string inserts.
    143  *
    144  * @internal ICU 2.8
    145  */
    146 typedef void U_CALLCONV
    147 UDataPrintError(void *context, const char *fmt, va_list args);
    148 
    149 struct UDataSwapper {
    150     /** Input endianness. @internal ICU 2.8 */
    151     UBool inIsBigEndian;
    152     /** Input charset family. @see U_CHARSET_FAMILY @internal ICU 2.8 */
    153     uint8_t inCharset;
    154     /** Output endianness. @internal ICU 2.8 */
    155     UBool outIsBigEndian;
    156     /** Output charset family. @see U_CHARSET_FAMILY @internal ICU 2.8 */
    157     uint8_t outCharset;
    158 
    159     /* basic functions for reading data values */
    160 
    161     /** Convert one uint16_t from input to platform endianness. @internal ICU 2.8 */
    162     UDataReadUInt16 *readUInt16;
    163     /** Convert one uint32_t from input to platform endianness. @internal ICU 2.8 */
    164     UDataReadUInt32 *readUInt32;
    165     /** Compare an invariant-character output string with a local one. @internal ICU 2.8 */
    166     UDataCompareInvChars *compareInvChars;
    167 
    168     /* basic functions for writing data values */
    169 
    170     /** Convert one uint16_t from platform to input endianness. @internal ICU 2.8 */
    171     UDataWriteUInt16 *writeUInt16;
    172     /** Convert one uint32_t from platform to input endianness. @internal ICU 2.8 */
    173     UDataWriteUInt32 *writeUInt32;
    174 
    175     /* basic functions for data transformations */
    176 
    177     /** Transform an array of 16-bit integers. @internal ICU 2.8 */
    178     UDataSwapFn *swapArray16;
    179     /** Transform an array of 32-bit integers. @internal ICU 2.8 */
    180     UDataSwapFn *swapArray32;
    181     /** Transform an invariant-character string. @internal ICU 2.8 */
    182     UDataSwapFn *swapInvChars;
    183 
    184     /**
    185      * Function for message output when an error occurs during data swapping.
    186      * Can be NULL.
    187      * @internal ICU 2.8
    188      */
    189     UDataPrintError *printError;
    190     /** Context pointer for printError. @internal ICU 2.8 */
    191     void *printErrorContext;
    192 };
    193 
    194 U_CDECL_END
    195 
    196 U_CAPI UDataSwapper * U_EXPORT2
    197 udata_openSwapper(UBool inIsBigEndian, uint8_t inCharset,
    198                   UBool outIsBigEndian, uint8_t outCharset,
    199                   UErrorCode *pErrorCode);
    200 
    201 /**
    202  * Open a UDataSwapper for the given input data and the specified output
    203  * characteristics.
    204  * Values of -1 for any of the characteristics mean the local platform's
    205  * characteristics.
    206  *
    207  * @see udata_swap
    208  * @internal ICU 2.8
    209  */
    210 U_CAPI UDataSwapper * U_EXPORT2
    211 udata_openSwapperForInputData(const void *data, int32_t length,
    212                               UBool outIsBigEndian, uint8_t outCharset,
    213                               UErrorCode *pErrorCode);
    214 
    215 U_CAPI void U_EXPORT2
    216 udata_closeSwapper(UDataSwapper *ds);
    217 
    218 /**
    219  * Read the beginning of an ICU data piece, recognize magic bytes,
    220  * swap the structure.
    221  * Set a U_UNSUPPORTED_ERROR if it does not look like an ICU data piece.
    222  *
    223  * @return The size of the data header, in bytes.
    224  *
    225  * @internal ICU 2.8
    226  */
    227 U_CAPI int32_t U_EXPORT2
    228 udata_swapDataHeader(const UDataSwapper *ds,
    229                      const void *inData, int32_t length, void *outData,
    230                      UErrorCode *pErrorCode);
    231 
    232 /**
    233  * Convert one int16_t from input to platform endianness.
    234  * @internal ICU 2.8
    235  */
    236 U_CAPI int16_t U_EXPORT2
    237 udata_readInt16(const UDataSwapper *ds, int16_t x);
    238 
    239 /**
    240  * Convert one int32_t from input to platform endianness.
    241  * @internal ICU 2.8
    242  */
    243 U_CAPI int32_t U_EXPORT2
    244 udata_readInt32(const UDataSwapper *ds, int32_t x);
    245 
    246 /**
    247  * Swap a block of invariant, NUL-terminated strings, but not padding
    248  * bytes after the last string.
    249  * @internal
    250  */
    251 U_CAPI int32_t U_EXPORT2
    252 udata_swapInvStringBlock(const UDataSwapper *ds,
    253                          const void *inData, int32_t length, void *outData,
    254                          UErrorCode *pErrorCode);
    255 
    256 U_CAPI void U_EXPORT2
    257 udata_printError(const UDataSwapper *ds,
    258                  const char *fmt,
    259                  ...);
    260 
    261 /* internal exports from putil.c -------------------------------------------- */
    262 
    263 /* declared here to keep them out of the public putil.h */
    264 
    265 /**
    266  * Swap invariant char * strings ASCII->EBCDIC.
    267  * @internal
    268  */
    269 U_CAPI int32_t U_EXPORT2
    270 uprv_ebcdicFromAscii(const UDataSwapper *ds,
    271                      const void *inData, int32_t length, void *outData,
    272                      UErrorCode *pErrorCode);
    273 
    274 /**
    275  * Copy invariant ASCII char * strings and verify they are invariant.
    276  * @internal
    277  */
    278 U_CFUNC int32_t
    279 uprv_copyAscii(const UDataSwapper *ds,
    280                const void *inData, int32_t length, void *outData,
    281                UErrorCode *pErrorCode);
    282 
    283 /**
    284  * Swap invariant char * strings EBCDIC->ASCII.
    285  * @internal
    286  */
    287 U_CFUNC int32_t
    288 uprv_asciiFromEbcdic(const UDataSwapper *ds,
    289                      const void *inData, int32_t length, void *outData,
    290                      UErrorCode *pErrorCode);
    291 
    292 /**
    293  * Copy invariant EBCDIC char * strings and verify they are invariant.
    294  * @internal
    295  */
    296 U_CFUNC int32_t
    297 uprv_copyEbcdic(const UDataSwapper *ds,
    298                 const void *inData, int32_t length, void *outData,
    299                 UErrorCode *pErrorCode);
    300 
    301 /**
    302  * Compare ASCII invariant char * with Unicode invariant UChar *
    303  * @internal
    304  */
    305 U_CFUNC int32_t
    306 uprv_compareInvAscii(const UDataSwapper *ds,
    307                      const char *outString, int32_t outLength,
    308                      const UChar *localString, int32_t localLength);
    309 
    310 /**
    311  * Compare EBCDIC invariant char * with Unicode invariant UChar *
    312  * @internal
    313  */
    314 U_CFUNC int32_t
    315 uprv_compareInvEbcdic(const UDataSwapper *ds,
    316                       const char *outString, int32_t outLength,
    317                       const UChar *localString, int32_t localLength);
    318 
    319 /* material... -------------------------------------------------------------- */
    320 
    321 #if 0
    322 
    323 /* udata.h */
    324 
    325 /**
    326  * Public API function in udata.c
    327  *
    328  * Same as udata_openChoice() but automatically swaps the data.
    329  * isAcceptable, if not NULL, may accept data with endianness and charset family
    330  * different from the current platform's properties.
    331  * If the data is acceptable and the platform properties do not match, then
    332  * the swap function is called to swap an allocated version of the data.
    333  * Preflighting may or may not be performed depending on whether the size of
    334  * the loaded data item is known.
    335  *
    336  * @param isAcceptable Same as for udata_openChoice(). May be NULL.
    337  *
    338  * @internal ICU 2.8
    339  */
    340 U_CAPI UDataMemory * U_EXPORT2
    341 udata_openSwap(const char *path, const char *type, const char *name,
    342                UDataMemoryIsAcceptable *isAcceptable, void *isAcceptableContext,
    343                UDataSwapFn *swap,
    344                UDataPrintError *printError, void *printErrorContext,
    345                UErrorCode *pErrorCode);
    346 
    347 #endif
    348 
    349 #endif
    350