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1 /*
2 ******************************************************************************
3 *
4 *   Copyright (C) 2001-2011, International Business Machines
5 *   Corporation and others.  All Rights Reserved.
6 *
7 ******************************************************************************
8 *   file name:  utrie.h
9 *   encoding:   US-ASCII
10 *   tab size:   8 (not used)
11 *   indentation:4
12 *
13 *   created on: 2001nov08
14 *   created by: Markus W. Scherer
15 */
16 
17 #ifndef __UTRIE_H__
18 #define __UTRIE_H__
19 
20 #include "unicode/utypes.h"
21 #include "unicode/utf16.h"
22 #include "udataswp.h"
23 
24 U_CDECL_BEGIN
25 
26 /**
27  * \file
28  *
29  * This is a common implementation of a "folded" trie.
30  * It is a kind of compressed, serializable table of 16- or 32-bit values associated with
31  * Unicode code points (0..0x10ffff).
32  *
33  * This implementation is optimized for getting values while walking forward
34  * through a UTF-16 string.
35  * Therefore, the simplest and fastest access macros are the
36  * _FROM_LEAD() and _FROM_OFFSET_TRAIL() macros.
37  *
38  * The _FROM_BMP() macros are a little more complicated; they get values
39  * even for lead surrogate code _points_, while the _FROM_LEAD() macros
40  * get special "folded" values for lead surrogate code _units_ if
41  * there is relevant data associated with them.
42  * From such a folded value, an offset needs to be extracted to supply
43  * to the _FROM_OFFSET_TRAIL() macros.
44  *
45  * Most of the more complex (and more convenient) functions/macros call a callback function
46  * to get that offset from the folded value for a lead surrogate unit.
47  */
48 
49 /**
50  * Trie constants, defining shift widths, index array lengths, etc.
51  */
52 enum {
53     /** Shift size for shifting right the input index. 1..9 */
54     UTRIE_SHIFT=5,
55 
56     /** Number of data values in a stage 2 (data array) block. 2, 4, 8, .., 0x200 */
57     UTRIE_DATA_BLOCK_LENGTH=1<<UTRIE_SHIFT,
58 
59     /** Mask for getting the lower bits from the input index. */
60     UTRIE_MASK=UTRIE_DATA_BLOCK_LENGTH-1,
61 
62     /**
63      * Lead surrogate code points' index displacement in the index array.
64      * 0x10000-0xd800=0x2800
65      */
66     UTRIE_LEAD_INDEX_DISP=0x2800>>UTRIE_SHIFT,
67 
68     /**
69      * Shift size for shifting left the index array values.
70      * Increases possible data size with 16-bit index values at the cost
71      * of compactability.
72      * This requires blocks of stage 2 data to be aligned by UTRIE_DATA_GRANULARITY.
73      * 0..UTRIE_SHIFT
74      */
75     UTRIE_INDEX_SHIFT=2,
76 
77     /** The alignment size of a stage 2 data block. Also the granularity for compaction. */
78     UTRIE_DATA_GRANULARITY=1<<UTRIE_INDEX_SHIFT,
79 
80     /** Number of bits of a trail surrogate that are used in index table lookups. */
81     UTRIE_SURROGATE_BLOCK_BITS=10-UTRIE_SHIFT,
82 
83     /**
84      * Number of index (stage 1) entries per lead surrogate.
85      * Same as number of index entries for 1024 trail surrogates,
86      * ==0x400>>UTRIE_SHIFT
87      */
88     UTRIE_SURROGATE_BLOCK_COUNT=(1<<UTRIE_SURROGATE_BLOCK_BITS),
89 
90     /** Length of the BMP portion of the index (stage 1) array. */
91     UTRIE_BMP_INDEX_LENGTH=0x10000>>UTRIE_SHIFT
92 };
93 
94 /**
95  * Length of the index (stage 1) array before folding.
96  * Maximum number of Unicode code points (0x110000) shifted right by UTRIE_SHIFT.
97  */
98 #define UTRIE_MAX_INDEX_LENGTH (0x110000>>UTRIE_SHIFT)
99 
100 /**
101  * Maximum length of the runtime data (stage 2) array.
102  * Limited by 16-bit index values that are left-shifted by UTRIE_INDEX_SHIFT.
103  */
104 #define UTRIE_MAX_DATA_LENGTH (0x10000<<UTRIE_INDEX_SHIFT)
105 
106 /**
107  * Maximum length of the build-time data (stage 2) array.
108  * The maximum length is 0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400.
109  * (Number of Unicode code points + one all-initial-value block +
110  *  possible duplicate entries for 1024 lead surrogates.)
111  */
112 #define UTRIE_MAX_BUILD_TIME_DATA_LENGTH (0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400)
113 
114 /**
115  * Number of bytes for a dummy trie.
116  * A dummy trie is an empty runtime trie, used when a real data trie cannot
117  * be loaded.
118  * The number of bytes works for Latin-1-linear tries with 32-bit data
119  * (worst case).
120  *
121  * Calculation:
122  *   BMP index + 1 index block for lead surrogate code points +
123  *   Latin-1-linear array + 1 data block for lead surrogate code points
124  *
125  * Latin-1: if(UTRIE_SHIFT<=8) { 256 } else { included in first data block }
126  *
127  * @see utrie_unserializeDummy
128  */
129 #define UTRIE_DUMMY_SIZE ((UTRIE_BMP_INDEX_LENGTH+UTRIE_SURROGATE_BLOCK_COUNT)*2+(UTRIE_SHIFT<=8?256:UTRIE_DATA_BLOCK_LENGTH)*4+UTRIE_DATA_BLOCK_LENGTH*4)
130 
131 /**
132  * Runtime UTrie callback function.
133  * Extract from a lead surrogate's data the
134  * index array offset of the indexes for that lead surrogate.
135  *
136  * @param data data value for a surrogate from the trie, including the folding offset
137  * @return offset>=UTRIE_BMP_INDEX_LENGTH, or 0 if there is no data for the lead surrogate
138  */
139 typedef int32_t U_CALLCONV
140 UTrieGetFoldingOffset(uint32_t data);
141 
142 /**
143  * Run-time Trie structure.
144  *
145  * Either the data table is 16 bits wide and accessed via the index
146  * pointer, with each index item increased by indexLength;
147  * in this case, data32==NULL.
148  *
149  * Or the data table is 32 bits wide and accessed via the data32 pointer.
150  */
151 struct UTrie {
152     const uint16_t *index;
153     const uint32_t *data32; /* NULL if 16b data is used via index */
154 
155     /**
156      * This function is not used in _FROM_LEAD, _FROM_BMP, and _FROM_OFFSET_TRAIL macros.
157      * If convenience macros like _GET16 or _NEXT32 are used, this function must be set.
158      *
159      * utrie_unserialize() sets a default function which simply returns
160      * the lead surrogate's value itself - which is the inverse of the default
161      * folding function used by utrie_serialize().
162      *
163      * @see UTrieGetFoldingOffset
164      */
165     UTrieGetFoldingOffset *getFoldingOffset;
166 
167     int32_t indexLength, dataLength;
168     uint32_t initialValue;
169     UBool isLatin1Linear;
170 };
171 
172 #ifndef __UTRIE2_H__
173 typedef struct UTrie UTrie;
174 #endif
175 
176 /** Internal trie getter from an offset (0 if c16 is a BMP/lead units) and a 16-bit unit */
177 #define _UTRIE_GET_RAW(trie, data, offset, c16) \
178     (trie)->data[ \
179         ((int32_t)((trie)->index[(offset)+((c16)>>UTRIE_SHIFT)])<<UTRIE_INDEX_SHIFT)+ \
180         ((c16)&UTRIE_MASK) \
181     ]
182 
183 /** Internal trie getter from a pair of surrogates */
184 #define _UTRIE_GET_FROM_PAIR(trie, data, c, c2, result, resultType) { \
185     int32_t __offset; \
186 \
187     /* get data for lead surrogate */ \
188     (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
189     __offset=(trie)->getFoldingOffset(result); \
190 \
191     /* get the real data from the folded lead/trail units */ \
192     if(__offset>0) { \
193         (result)=_UTRIE_GET_RAW((trie), data, __offset, (c2)&0x3ff); \
194     } else { \
195         (result)=(resultType)((trie)->initialValue); \
196     } \
197 }
198 
199 /** Internal trie getter from a BMP code point, treating a lead surrogate as a normal code point */
200 #define _UTRIE_GET_FROM_BMP(trie, data, c16) \
201     _UTRIE_GET_RAW(trie, data, 0xd800<=(c16) && (c16)<=0xdbff ? UTRIE_LEAD_INDEX_DISP : 0, c16);
202 
203 /**
204  * Internal trie getter from a code point.
205  * Could be faster(?) but longer with
206  *   if((c32)<=0xd7ff) { (result)=_UTRIE_GET_RAW(trie, data, 0, c32); }
207  */
208 #define _UTRIE_GET(trie, data, c32, result, resultType) \
209     if((uint32_t)(c32)<=0xffff) { \
210         /* BMP code points */ \
211         (result)=_UTRIE_GET_FROM_BMP(trie, data, c32); \
212     } else if((uint32_t)(c32)<=0x10ffff) { \
213         /* supplementary code point */ \
214         UChar __lead16=U16_LEAD(c32); \
215         _UTRIE_GET_FROM_PAIR(trie, data, __lead16, c32, result, resultType); \
216     } else { \
217         /* out of range */ \
218         (result)=(resultType)((trie)->initialValue); \
219     }
220 
221 /** Internal next-post-increment: get the next code point (c, c2) and its data */
222 #define _UTRIE_NEXT(trie, data, src, limit, c, c2, result, resultType) { \
223     (c)=*(src)++; \
224     if(!U16_IS_LEAD(c)) { \
225         (c2)=0; \
226         (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
227     } else if((src)!=(limit) && U16_IS_TRAIL((c2)=*(src))) { \
228         ++(src); \
229         _UTRIE_GET_FROM_PAIR((trie), data, (c), (c2), (result), resultType); \
230     } else { \
231         /* unpaired lead surrogate code point */ \
232         (c2)=0; \
233         (result)=_UTRIE_GET_RAW((trie), data, UTRIE_LEAD_INDEX_DISP, (c)); \
234     } \
235 }
236 
237 /** Internal previous: get the previous code point (c, c2) and its data */
238 #define _UTRIE_PREVIOUS(trie, data, start, src, c, c2, result, resultType) { \
239     (c)=*--(src); \
240     if(!U16_IS_SURROGATE(c)) { \
241         (c2)=0; \
242         (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
243     } else if(!U16_IS_SURROGATE_LEAD(c)) { \
244         /* trail surrogate */ \
245         if((start)!=(src) && U16_IS_LEAD((c2)=*((src)-1))) { \
246             --(src); \
247             (result)=(c); (c)=(c2); (c2)=(UChar)(result); /* swap c, c2 */ \
248             _UTRIE_GET_FROM_PAIR((trie), data, (c), (c2), (result), resultType); \
249         } else { \
250             /* unpaired trail surrogate code point */ \
251             (c2)=0; \
252             (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
253         } \
254     } else { \
255         /* unpaired lead surrogate code point */ \
256         (c2)=0; \
257         (result)=_UTRIE_GET_RAW((trie), data, UTRIE_LEAD_INDEX_DISP, (c)); \
258     } \
259 }
260 
261 /* Public UTrie API ---------------------------------------------------------*/
262 
263 /**
264  * Get a pointer to the contiguous part of the data array
265  * for the Latin-1 range (U+0000..U+00ff).
266  * Must be used only if the Latin-1 range is in fact linear
267  * (trie->isLatin1Linear).
268  *
269  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
270  * @return (const uint16_t *) pointer to values for Latin-1 code points
271  */
272 #define UTRIE_GET16_LATIN1(trie) ((trie)->index+(trie)->indexLength+UTRIE_DATA_BLOCK_LENGTH)
273 
274 /**
275  * Get a pointer to the contiguous part of the data array
276  * for the Latin-1 range (U+0000..U+00ff).
277  * Must be used only if the Latin-1 range is in fact linear
278  * (trie->isLatin1Linear).
279  *
280  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
281  * @return (const uint32_t *) pointer to values for Latin-1 code points
282  */
283 #define UTRIE_GET32_LATIN1(trie) ((trie)->data32+UTRIE_DATA_BLOCK_LENGTH)
284 
285 /**
286  * Get a 16-bit trie value from a BMP code point (UChar, <=U+ffff).
287  * c16 may be a lead surrogate, which may have a value including a folding offset.
288  *
289  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
290  * @param c16 (UChar, in) the input BMP code point
291  * @return (uint16_t) trie lookup result
292  */
293 #define UTRIE_GET16_FROM_LEAD(trie, c16) _UTRIE_GET_RAW(trie, index, 0, c16)
294 
295 /**
296  * Get a 32-bit trie value from a BMP code point (UChar, <=U+ffff).
297  * c16 may be a lead surrogate, which may have a value including a folding offset.
298  *
299  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
300  * @param c16 (UChar, in) the input BMP code point
301  * @return (uint32_t) trie lookup result
302  */
303 #define UTRIE_GET32_FROM_LEAD(trie, c16) _UTRIE_GET_RAW(trie, data32, 0, c16)
304 
305 /**
306  * Get a 16-bit trie value from a BMP code point (UChar, <=U+ffff).
307  * Even lead surrogate code points are treated as normal code points,
308  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
309  *
310  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
311  * @param c16 (UChar, in) the input BMP code point
312  * @return (uint16_t) trie lookup result
313  */
314 #define UTRIE_GET16_FROM_BMP(trie, c16) _UTRIE_GET_FROM_BMP(trie, index, c16)
315 
316 /**
317  * Get a 32-bit trie value from a BMP code point (UChar, <=U+ffff).
318  * Even lead surrogate code points are treated as normal code points,
319  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
320  *
321  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
322  * @param c16 (UChar, in) the input BMP code point
323  * @return (uint32_t) trie lookup result
324  */
325 #define UTRIE_GET32_FROM_BMP(trie, c16) _UTRIE_GET_FROM_BMP(trie, data32, c16)
326 
327 /**
328  * Get a 16-bit trie value from a code point.
329  * Even lead surrogate code points are treated as normal code points,
330  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
331  *
332  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
333  * @param c32 (UChar32, in) the input code point
334  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
335  */
336 #define UTRIE_GET16(trie, c32, result) _UTRIE_GET(trie, index, c32, result, uint16_t)
337 
338 /**
339  * Get a 32-bit trie value from a code point.
340  * Even lead surrogate code points are treated as normal code points,
341  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
342  *
343  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
344  * @param c32 (UChar32, in) the input code point
345  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
346  */
347 #define UTRIE_GET32(trie, c32, result) _UTRIE_GET(trie, data32, c32, result, uint32_t)
348 
349 /**
350  * Get the next code point (c, c2), post-increment src,
351  * and get a 16-bit value from the trie.
352  *
353  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
354  * @param src (const UChar *, in/out) the source text pointer
355  * @param limit (const UChar *, in) the limit pointer for the text, or NULL
356  * @param c (UChar, out) variable for the BMP or lead code unit
357  * @param c2 (UChar, out) variable for 0 or the trail code unit
358  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
359  */
360 #define UTRIE_NEXT16(trie, src, limit, c, c2, result) _UTRIE_NEXT(trie, index, src, limit, c, c2, result, uint16_t)
361 
362 /**
363  * Get the next code point (c, c2), post-increment src,
364  * and get a 32-bit value from the trie.
365  *
366  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
367  * @param src (const UChar *, in/out) the source text pointer
368  * @param limit (const UChar *, in) the limit pointer for the text, or NULL
369  * @param c (UChar, out) variable for the BMP or lead code unit
370  * @param c2 (UChar, out) variable for 0 or the trail code unit
371  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
372  */
373 #define UTRIE_NEXT32(trie, src, limit, c, c2, result) _UTRIE_NEXT(trie, data32, src, limit, c, c2, result, uint32_t)
374 
375 /**
376  * Get the previous code point (c, c2), pre-decrement src,
377  * and get a 16-bit value from the trie.
378  *
379  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
380  * @param start (const UChar *, in) the start pointer for the text, or NULL
381  * @param src (const UChar *, in/out) the source text pointer
382  * @param c (UChar, out) variable for the BMP or lead code unit
383  * @param c2 (UChar, out) variable for 0 or the trail code unit
384  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
385  */
386 #define UTRIE_PREVIOUS16(trie, start, src, c, c2, result) _UTRIE_PREVIOUS(trie, index, start, src, c, c2, result, uint16_t)
387 
388 /**
389  * Get the previous code point (c, c2), pre-decrement src,
390  * and get a 32-bit value from the trie.
391  *
392  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
393  * @param start (const UChar *, in) the start pointer for the text, or NULL
394  * @param src (const UChar *, in/out) the source text pointer
395  * @param c (UChar, out) variable for the BMP or lead code unit
396  * @param c2 (UChar, out) variable for 0 or the trail code unit
397  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
398  */
399 #define UTRIE_PREVIOUS32(trie, start, src, c, c2, result) _UTRIE_PREVIOUS(trie, data32, start, src, c, c2, result, uint32_t)
400 
401 /**
402  * Get a 16-bit trie value from a pair of surrogates.
403  *
404  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
405  * @param c (UChar, in) a lead surrogate
406  * @param c2 (UChar, in) a trail surrogate
407  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
408  */
409 #define UTRIE_GET16_FROM_PAIR(trie, c, c2, result) _UTRIE_GET_FROM_PAIR(trie, index, c, c2, result, uint16_t)
410 
411 /**
412  * Get a 32-bit trie value from a pair of surrogates.
413  *
414  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
415  * @param c (UChar, in) a lead surrogate
416  * @param c2 (UChar, in) a trail surrogate
417  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
418  */
419 #define UTRIE_GET32_FROM_PAIR(trie, c, c2, result) _UTRIE_GET_FROM_PAIR(trie, data32, c, c2, result, uint32_t)
420 
421 /**
422  * Get a 16-bit trie value from a folding offset (from the value of a lead surrogate)
423  * and a trail surrogate.
424  *
425  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
426  * @param offset (int32_t, in) the folding offset from the value of a lead surrogate
427  * @param c2 (UChar, in) a trail surrogate (only the 10 low bits are significant)
428  * @return (uint16_t) trie lookup result
429  */
430 #define UTRIE_GET16_FROM_OFFSET_TRAIL(trie, offset, c2) _UTRIE_GET_RAW(trie, index, offset, (c2)&0x3ff)
431 
432 /**
433  * Get a 32-bit trie value from a folding offset (from the value of a lead surrogate)
434  * and a trail surrogate.
435  *
436  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
437  * @param offset (int32_t, in) the folding offset from the value of a lead surrogate
438  * @param c2 (UChar, in) a trail surrogate (only the 10 low bits are significant)
439  * @return (uint32_t) trie lookup result
440  */
441 #define UTRIE_GET32_FROM_OFFSET_TRAIL(trie, offset, c2) _UTRIE_GET_RAW(trie, data32, offset, (c2)&0x3ff)
442 
443 /* enumeration callback types */
444 
445 /**
446  * Callback from utrie_enum(), extracts a uint32_t value from a
447  * trie value. This value will be passed on to the UTrieEnumRange function.
448  *
449  * @param context an opaque pointer, as passed into utrie_enum()
450  * @param value a value from the trie
451  * @return the value that is to be passed on to the UTrieEnumRange function
452  */
453 typedef uint32_t U_CALLCONV
454 UTrieEnumValue(const void *context, uint32_t value);
455 
456 /**
457  * Callback from utrie_enum(), is called for each contiguous range
458  * of code points with the same value as retrieved from the trie and
459  * transformed by the UTrieEnumValue function.
460  *
461  * The callback function can stop the enumeration by returning FALSE.
462  *
463  * @param context an opaque pointer, as passed into utrie_enum()
464  * @param start the first code point in a contiguous range with value
465  * @param limit one past the last code point in a contiguous range with value
466  * @param value the value that is set for all code points in [start..limit[
467  * @return FALSE to stop the enumeration
468  */
469 typedef UBool U_CALLCONV
470 UTrieEnumRange(const void *context, UChar32 start, UChar32 limit, uint32_t value);
471 
472 /**
473  * Enumerate efficiently all values in a trie.
474  * For each entry in the trie, the value to be delivered is passed through
475  * the UTrieEnumValue function.
476  * The value is unchanged if that function pointer is NULL.
477  *
478  * For each contiguous range of code points with a given value,
479  * the UTrieEnumRange function is called.
480  *
481  * @param trie a pointer to the runtime trie structure
482  * @param enumValue a pointer to a function that may transform the trie entry value,
483  *                  or NULL if the values from the trie are to be used directly
484  * @param enumRange a pointer to a function that is called for each contiguous range
485  *                  of code points with the same value
486  * @param context an opaque pointer that is passed on to the callback functions
487  */
488 U_CAPI void U_EXPORT2
489 utrie_enum(const UTrie *trie,
490            UTrieEnumValue *enumValue, UTrieEnumRange *enumRange, const void *context);
491 
492 /**
493  * Unserialize a trie from 32-bit-aligned memory.
494  * Inverse of utrie_serialize().
495  * Fills the UTrie runtime trie structure with the settings for the trie data.
496  *
497  * @param trie a pointer to the runtime trie structure
498  * @param data a pointer to 32-bit-aligned memory containing trie data
499  * @param length the number of bytes available at data
500  * @param pErrorCode an in/out ICU UErrorCode
501  * @return the number of bytes at data taken up by the trie data
502  */
503 U_CAPI int32_t U_EXPORT2
504 utrie_unserialize(UTrie *trie, const void *data, int32_t length, UErrorCode *pErrorCode);
505 
506 /**
507  * "Unserialize" a dummy trie.
508  * A dummy trie is an empty runtime trie, used when a real data trie cannot
509  * be loaded.
510  *
511  * The input memory is filled so that the trie always returns the initialValue,
512  * or the leadUnitValue for lead surrogate code points.
513  * The Latin-1 part is always set up to be linear.
514  *
515  * @param trie a pointer to the runtime trie structure
516  * @param data a pointer to 32-bit-aligned memory to be filled with the dummy trie data
517  * @param length the number of bytes available at data (recommended to use UTRIE_DUMMY_SIZE)
518  * @param initialValue the initial value that is set for all code points
519  * @param leadUnitValue the value for lead surrogate code _units_ that do not
520  *                      have associated supplementary data
521  * @param pErrorCode an in/out ICU UErrorCode
522  *
523  * @see UTRIE_DUMMY_SIZE
524  * @see utrie_open
525  */
526 U_CAPI int32_t U_EXPORT2
527 utrie_unserializeDummy(UTrie *trie,
528                        void *data, int32_t length,
529                        uint32_t initialValue, uint32_t leadUnitValue,
530                        UBool make16BitTrie,
531                        UErrorCode *pErrorCode);
532 
533 /**
534  * Default implementation for UTrie.getFoldingOffset, set automatically by
535  * utrie_unserialize().
536  * Simply returns the lead surrogate's value itself - which is the inverse
537  * of the default folding function used by utrie_serialize().
538  * Exported for static const UTrie structures.
539  *
540  * @see UTrieGetFoldingOffset
541  */
542 U_CAPI int32_t U_EXPORT2
543 utrie_defaultGetFoldingOffset(uint32_t data);
544 
545 /* Building a trie ----------------------------------------------------------*/
546 
547 /**
548  * Build-time trie structure.
549  * Opaque definition, here only to make fillIn parameters possible
550  * for utrie_open() and utrie_clone().
551  */
552 struct UNewTrie {
553     /**
554      * Index values at build-time are 32 bits wide for easier processing.
555      * Bit 31 is set if the data block is used by multiple index values (from utrie_setRange()).
556      */
557     int32_t index[UTRIE_MAX_INDEX_LENGTH];
558     uint32_t *data;
559 
560     uint32_t leadUnitValue;
561     int32_t indexLength, dataCapacity, dataLength;
562     UBool isAllocated, isDataAllocated;
563     UBool isLatin1Linear, isCompacted;
564 
565     /**
566      * Map of adjusted indexes, used in utrie_compact().
567      * Maps from original indexes to new ones.
568      */
569     int32_t map[UTRIE_MAX_BUILD_TIME_DATA_LENGTH>>UTRIE_SHIFT];
570 };
571 
572 typedef struct UNewTrie UNewTrie;
573 
574 /**
575  * Build-time trie callback function, used with utrie_serialize().
576  * This function calculates a lead surrogate's value including a folding offset
577  * from the 1024 supplementary code points [start..start+1024[ .
578  * It is U+10000 <= start <= U+10fc00 and (start&0x3ff)==0.
579  *
580  * The folding offset is provided by the caller.
581  * It is offset=UTRIE_BMP_INDEX_LENGTH+n*UTRIE_SURROGATE_BLOCK_COUNT with n=0..1023.
582  * Instead of the offset itself, n can be stored in 10 bits -
583  * or fewer if it can be assumed that few lead surrogates have associated data.
584  *
585  * The returned value must be
586  * - not zero if and only if there is relevant data
587  *   for the corresponding 1024 supplementary code points
588  * - such that UTrie.getFoldingOffset(UNewTrieGetFoldedValue(..., offset))==offset
589  *
590  * @return a folded value, or 0 if there is no relevant data for the lead surrogate.
591  */
592 typedef uint32_t U_CALLCONV
593 UNewTrieGetFoldedValue(UNewTrie *trie, UChar32 start, int32_t offset);
594 
595 /**
596  * Open a build-time trie structure.
597  * The size of the build-time data array is specified to avoid allocating a large
598  * array in all cases. The array itself can also be passed in.
599  *
600  * Although the trie is never fully expanded to a linear array, especially when
601  * utrie_setRange32() is used, the data array could be large during build time.
602  * The maximum length is
603  * UTRIE_MAX_BUILD_TIME_DATA_LENGTH=0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400.
604  * (Number of Unicode code points + one all-initial-value block +
605  *  possible duplicate entries for 1024 lead surrogates.)
606  * (UTRIE_DATA_BLOCK_LENGTH<=0x200 in all cases.)
607  *
608  * @param fillIn a pointer to a UNewTrie structure to be initialized (will not be released), or
609  *               NULL if one is to be allocated
610  * @param aliasData a pointer to a data array to be used (will not be released), or
611  *                  NULL if one is to be allocated
612  * @param maxDataLength the capacity of aliasData (if not NULL) or
613  *                      the length of the data array to be allocated
614  * @param initialValue the initial value that is set for all code points
615  * @param leadUnitValue the value for lead surrogate code _units_ that do not
616  *                      have associated supplementary data
617  * @param latin1Linear a flag indicating whether the Latin-1 range is to be allocated and
618  *                     kept in a linear, contiguous part of the data array
619  * @return a pointer to the initialized fillIn or the allocated and initialized new UNewTrie
620  */
621 U_CAPI UNewTrie * U_EXPORT2
622 utrie_open(UNewTrie *fillIn,
623            uint32_t *aliasData, int32_t maxDataLength,
624            uint32_t initialValue, uint32_t leadUnitValue,
625            UBool latin1Linear);
626 
627 /**
628  * Clone a build-time trie structure with all entries.
629  *
630  * @param fillIn like in utrie_open()
631  * @param other the build-time trie structure to clone
632  * @param aliasData like in utrie_open(),
633  *                  used if aliasDataLength>=(capacity of other's data array)
634  * @param aliasDataLength the length of aliasData
635  * @return a pointer to the initialized fillIn or the allocated and initialized new UNewTrie
636  */
637 U_CAPI UNewTrie * U_EXPORT2
638 utrie_clone(UNewTrie *fillIn, const UNewTrie *other, uint32_t *aliasData, int32_t aliasDataLength);
639 
640 /**
641  * Close a build-time trie structure, and release memory
642  * that was allocated by utrie_open() or utrie_clone().
643  *
644  * @param trie the build-time trie
645  */
646 U_CAPI void U_EXPORT2
647 utrie_close(UNewTrie *trie);
648 
649 /**
650  * Get the data array of a build-time trie.
651  * The data may be modified, but entries that are equal before
652  * must still be equal after modification.
653  *
654  * @param trie the build-time trie
655  * @param pLength (out) a pointer to a variable that receives the number
656  *                of entries in the data array
657  * @return the data array
658  */
659 U_CAPI uint32_t * U_EXPORT2
660 utrie_getData(UNewTrie *trie, int32_t *pLength);
661 
662 /**
663  * Set a value for a code point.
664  *
665  * @param trie the build-time trie
666  * @param c the code point
667  * @param value the value
668  * @return FALSE if a failure occurred (illegal argument or data array overrun)
669  */
670 U_CAPI UBool U_EXPORT2
671 utrie_set32(UNewTrie *trie, UChar32 c, uint32_t value);
672 
673 /**
674  * Get a value from a code point as stored in the build-time trie.
675  *
676  * @param trie the build-time trie
677  * @param c the code point
678  * @param pInBlockZero if not NULL, then *pInBlockZero is set to TRUE
679  *                     iff the value is retrieved from block 0;
680  *                     block 0 is the all-initial-value initial block
681  * @return the value
682  */
683 U_CAPI uint32_t U_EXPORT2
684 utrie_get32(UNewTrie *trie, UChar32 c, UBool *pInBlockZero);
685 
686 /**
687  * Set a value in a range of code points [start..limit[.
688  * All code points c with start<=c<limit will get the value if
689  * overwrite is TRUE or if the old value is 0.
690  *
691  * @param trie the build-time trie
692  * @param start the first code point to get the value
693  * @param limit one past the last code point to get the value
694  * @param value the value
695  * @param overwrite flag for whether old non-initial values are to be overwritten
696  * @return FALSE if a failure occurred (illegal argument or data array overrun)
697  */
698 U_CAPI UBool U_EXPORT2
699 utrie_setRange32(UNewTrie *trie, UChar32 start, UChar32 limit, uint32_t value, UBool overwrite);
700 
701 /**
702  * Compact the build-time trie after all values are set, and then
703  * serialize it into 32-bit aligned memory.
704  *
705  * After this, the trie can only be serizalized again and/or closed;
706  * no further values can be added.
707  *
708  * @see utrie_unserialize()
709  *
710  * @param trie the build-time trie
711  * @param data a pointer to 32-bit-aligned memory for the trie data
712  * @param capacity the number of bytes available at data
713  * @param getFoldedValue a callback function that calculates the value for
714  *                       a lead surrogate from all of its supplementary code points
715  *                       and the folding offset;
716  *                       if NULL, then a default function is used which returns just
717  *                       the input offset when there are any non-initial-value entries
718  * @param reduceTo16Bits flag for whether the values are to be reduced to a
719  *                       width of 16 bits for serialization and runtime
720  * @param pErrorCode a UErrorCode argument; among other possible error codes:
721  * - U_BUFFER_OVERFLOW_ERROR if the data storage block is too small for serialization
722  * - U_MEMORY_ALLOCATION_ERROR if the trie data array is too small
723  * - U_INDEX_OUTOFBOUNDS_ERROR if the index or data arrays are too long after compaction for serialization
724  *
725  * @return the number of bytes written for the trie
726  */
727 U_CAPI int32_t U_EXPORT2
728 utrie_serialize(UNewTrie *trie, void *data, int32_t capacity,
729                 UNewTrieGetFoldedValue *getFoldedValue,
730                 UBool reduceTo16Bits,
731                 UErrorCode *pErrorCode);
732 
733 /**
734  * Swap a serialized UTrie.
735  * @internal
736  */
737 U_CAPI int32_t U_EXPORT2
738 utrie_swap(const UDataSwapper *ds,
739            const void *inData, int32_t length, void *outData,
740            UErrorCode *pErrorCode);
741 
742 /* serialization ------------------------------------------------------------ */
743 
744 /**
745  * Trie data structure in serialized form:
746  *
747  * UTrieHeader header;
748  * uint16_t index[header.indexLength];
749  * uint16_t data[header.dataLength];
750  * @internal
751  */
752 typedef struct UTrieHeader {
753     /** "Trie" in big-endian US-ASCII (0x54726965) */
754     uint32_t signature;
755 
756     /**
757      * options bit field:
758      *     9    1=Latin-1 data is stored linearly at data+UTRIE_DATA_BLOCK_LENGTH
759      *     8    0=16-bit data, 1=32-bit data
760      *  7..4    UTRIE_INDEX_SHIFT   // 0..UTRIE_SHIFT
761      *  3..0    UTRIE_SHIFT         // 1..9
762      */
763     uint32_t options;
764 
765     /** indexLength is a multiple of UTRIE_SURROGATE_BLOCK_COUNT */
766     int32_t indexLength;
767 
768     /** dataLength>=UTRIE_DATA_BLOCK_LENGTH */
769     int32_t dataLength;
770 } UTrieHeader;
771 
772 /**
773  * Constants for use with UTrieHeader.options.
774  * @internal
775  */
776 enum {
777     /** Mask to get the UTRIE_SHIFT value from options. */
778     UTRIE_OPTIONS_SHIFT_MASK=0xf,
779 
780     /** Shift options right this much to get the UTRIE_INDEX_SHIFT value. */
781     UTRIE_OPTIONS_INDEX_SHIFT=4,
782 
783     /** If set, then the data (stage 2) array is 32 bits wide. */
784     UTRIE_OPTIONS_DATA_IS_32_BIT=0x100,
785 
786     /**
787      * If set, then Latin-1 data (for U+0000..U+00ff) is stored in the data (stage 2) array
788      * as a simple, linear array at data+UTRIE_DATA_BLOCK_LENGTH.
789      */
790     UTRIE_OPTIONS_LATIN1_IS_LINEAR=0x200
791 };
792 
793 U_CDECL_END
794 
795 #endif
796