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
29U_CDECL_BEGIN
30
31struct UDataSwapper;
32typedef 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 */
87typedef int32_t U_CALLCONV
88UDataSwapFn(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 */
96typedef uint16_t U_CALLCONV
97UDataReadUInt16(uint16_t x);
98
99/**
100 * Convert one uint32_t from input to platform endianness.
101 * @internal ICU 2.8
102 */
103typedef uint32_t U_CALLCONV
104UDataReadUInt32(uint32_t x);
105
106/**
107 * Convert one uint16_t from platform to input endianness.
108 * @internal ICU 2.8
109 */
110typedef void U_CALLCONV
111UDataWriteUInt16(uint16_t *p, uint16_t x);
112
113/**
114 * Convert one uint32_t from platform to input endianness.
115 * @internal ICU 2.8
116 */
117typedef void U_CALLCONV
118UDataWriteUInt32(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 */
130typedef int32_t U_CALLCONV
131UDataCompareInvChars(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 */
146typedef void U_CALLCONV
147UDataPrintError(void *context, const char *fmt, va_list args);
148
149struct 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
194U_CDECL_END
195
196U_CAPI UDataSwapper * U_EXPORT2
197udata_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 */
210U_CAPI UDataSwapper * U_EXPORT2
211udata_openSwapperForInputData(const void *data, int32_t length,
212                              UBool outIsBigEndian, uint8_t outCharset,
213                              UErrorCode *pErrorCode);
214
215U_CAPI void U_EXPORT2
216udata_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 */
227U_CAPI int32_t U_EXPORT2
228udata_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 */
236U_CAPI int16_t U_EXPORT2
237udata_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 */
243U_CAPI int32_t U_EXPORT2
244udata_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 */
251U_CAPI int32_t U_EXPORT2
252udata_swapInvStringBlock(const UDataSwapper *ds,
253                         const void *inData, int32_t length, void *outData,
254                         UErrorCode *pErrorCode);
255
256U_CAPI void U_EXPORT2
257udata_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 */
269U_CAPI int32_t U_EXPORT2
270uprv_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 */
278U_CFUNC int32_t
279uprv_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 */
287U_CFUNC int32_t
288uprv_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 */
296U_CFUNC int32_t
297uprv_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 */
305U_CFUNC int32_t
306uprv_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 */
314U_CFUNC int32_t
315uprv_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 */
340U_CAPI UDataMemory * U_EXPORT2
341udata_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