• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2 ******************************************************************************
3 *
4 *   Copyright (C) 2001-2008, 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 "udataswp.h"
22 
23 U_CDECL_BEGIN
24 
25 /**
26  * \file
27  *
28  * This is a common implementation of a "folded" trie.
29  * It is a kind of compressed, serializable table of 16- or 32-bit values associated with
30  * Unicode code points (0..0x10ffff).
31  *
32  * This implementation is optimized for getting values while walking forward
33  * through a UTF-16 string.
34  * Therefore, the simplest and fastest access macros are the
35  * _FROM_LEAD() and _FROM_OFFSET_TRAIL() macros.
36  *
37  * The _FROM_BMP() macros are a little more complicated; they get values
38  * even for lead surrogate code _points_, while the _FROM_LEAD() macros
39  * get special "folded" values for lead surrogate code _units_ if
40  * there is relevant data associated with them.
41  * From such a folded value, an offset needs to be extracted to supply
42  * to the _FROM_OFFSET_TRAIL() macros.
43  *
44  * Most of the more complex (and more convenient) functions/macros call a callback function
45  * to get that offset from the folded value for a lead surrogate unit.
46  */
47 
48 /**
49  * Trie constants, defining shift widths, index array lengths, etc.
50  */
51 enum {
52     /** Shift size for shifting right the input index. 1..9 */
53     UTRIE_SHIFT=5,
54 
55     /** Number of data values in a stage 2 (data array) block. 2, 4, 8, .., 0x200 */
56     UTRIE_DATA_BLOCK_LENGTH=1<<UTRIE_SHIFT,
57 
58     /** Mask for getting the lower bits from the input index. */
59     UTRIE_MASK=UTRIE_DATA_BLOCK_LENGTH-1,
60 
61     /**
62      * Lead surrogate code points' index displacement in the index array.
63      * 0x10000-0xd800=0x2800
64      */
65     UTRIE_LEAD_INDEX_DISP=0x2800>>UTRIE_SHIFT,
66 
67     /**
68      * Shift size for shifting left the index array values.
69      * Increases possible data size with 16-bit index values at the cost
70      * of compactability.
71      * This requires blocks of stage 2 data to be aligned by UTRIE_DATA_GRANULARITY.
72      * 0..UTRIE_SHIFT
73      */
74     UTRIE_INDEX_SHIFT=2,
75 
76     /** The alignment size of a stage 2 data block. Also the granularity for compaction. */
77     UTRIE_DATA_GRANULARITY=1<<UTRIE_INDEX_SHIFT,
78 
79     /** Number of bits of a trail surrogate that are used in index table lookups. */
80     UTRIE_SURROGATE_BLOCK_BITS=10-UTRIE_SHIFT,
81 
82     /**
83      * Number of index (stage 1) entries per lead surrogate.
84      * Same as number of index entries for 1024 trail surrogates,
85      * ==0x400>>UTRIE_SHIFT
86      */
87     UTRIE_SURROGATE_BLOCK_COUNT=(1<<UTRIE_SURROGATE_BLOCK_BITS),
88 
89     /** Length of the BMP portion of the index (stage 1) array. */
90     UTRIE_BMP_INDEX_LENGTH=0x10000>>UTRIE_SHIFT
91 };
92 
93 /**
94  * Length of the index (stage 1) array before folding.
95  * Maximum number of Unicode code points (0x110000) shifted right by UTRIE_SHIFT.
96  */
97 #define UTRIE_MAX_INDEX_LENGTH (0x110000>>UTRIE_SHIFT)
98 
99 /**
100  * Maximum length of the runtime data (stage 2) array.
101  * Limited by 16-bit index values that are left-shifted by UTRIE_INDEX_SHIFT.
102  */
103 #define UTRIE_MAX_DATA_LENGTH (0x10000<<UTRIE_INDEX_SHIFT)
104 
105 /**
106  * Maximum length of the build-time data (stage 2) array.
107  * The maximum length is 0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400.
108  * (Number of Unicode code points + one all-initial-value block +
109  *  possible duplicate entries for 1024 lead surrogates.)
110  */
111 #define UTRIE_MAX_BUILD_TIME_DATA_LENGTH (0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400)
112 
113 /**
114  * Number of bytes for a dummy trie.
115  * A dummy trie is an empty runtime trie, used when a real data trie cannot
116  * be loaded.
117  * The number of bytes works for Latin-1-linear tries with 32-bit data
118  * (worst case).
119  *
120  * Calculation:
121  *   BMP index + 1 index block for lead surrogate code points +
122  *   Latin-1-linear array + 1 data block for lead surrogate code points
123  *
124  * Latin-1: if(UTRIE_SHIFT<=8) { 256 } else { included in first data block }
125  *
126  * @see utrie_unserializeDummy
127  */
128 #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)
129 
130 /**
131  * Runtime UTrie callback function.
132  * Extract from a lead surrogate's data the
133  * index array offset of the indexes for that lead surrogate.
134  *
135  * @param data data value for a surrogate from the trie, including the folding offset
136  * @return offset>=UTRIE_BMP_INDEX_LENGTH, or 0 if there is no data for the lead surrogate
137  */
138 typedef int32_t U_CALLCONV
139 UTrieGetFoldingOffset(uint32_t data);
140 
141 /**
142  * Run-time Trie structure.
143  *
144  * Either the data table is 16 bits wide and accessed via the index
145  * pointer, with each index item increased by indexLength;
146  * in this case, data32==NULL.
147  *
148  * Or the data table is 32 bits wide and accessed via the data32 pointer.
149  */
150 struct UTrie {
151     const uint16_t *index;
152     const uint32_t *data32; /* NULL if 16b data is used via index */
153 
154     /**
155      * This function is not used in _FROM_LEAD, _FROM_BMP, and _FROM_OFFSET_TRAIL macros.
156      * If convenience macros like _GET16 or _NEXT32 are used, this function must be set.
157      *
158      * utrie_unserialize() sets a default function which simply returns
159      * the lead surrogate's value itself - which is the inverse of the default
160      * folding function used by utrie_serialize().
161      *
162      * @see UTrieGetFoldingOffset
163      */
164     UTrieGetFoldingOffset *getFoldingOffset;
165 
166     int32_t indexLength, dataLength;
167     uint32_t initialValue;
168     UBool isLatin1Linear;
169 };
170 
171 #ifndef __UTRIE2_H__
172 typedef struct UTrie UTrie;
173 #endif
174 
175 /** Internal trie getter from an offset (0 if c16 is a BMP/lead units) and a 16-bit unit */
176 #define _UTRIE_GET_RAW(trie, data, offset, c16) \
177     (trie)->data[ \
178         ((int32_t)((trie)->index[(offset)+((c16)>>UTRIE_SHIFT)])<<UTRIE_INDEX_SHIFT)+ \
179         ((c16)&UTRIE_MASK) \
180     ]
181 
182 /** Internal trie getter from a pair of surrogates */
183 #define _UTRIE_GET_FROM_PAIR(trie, data, c, c2, result, resultType) { \
184     int32_t __offset; \
185 \
186     /* get data for lead surrogate */ \
187     (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
188     __offset=(trie)->getFoldingOffset(result); \
189 \
190     /* get the real data from the folded lead/trail units */ \
191     if(__offset>0) { \
192         (result)=_UTRIE_GET_RAW((trie), data, __offset, (c2)&0x3ff); \
193     } else { \
194         (result)=(resultType)((trie)->initialValue); \
195     } \
196 }
197 
198 /** Internal trie getter from a BMP code point, treating a lead surrogate as a normal code point */
199 #define _UTRIE_GET_FROM_BMP(trie, data, c16) \
200     _UTRIE_GET_RAW(trie, data, 0xd800<=(c16) && (c16)<=0xdbff ? UTRIE_LEAD_INDEX_DISP : 0, c16);
201 
202 /**
203  * Internal trie getter from a code point.
204  * Could be faster(?) but longer with
205  *   if((c32)<=0xd7ff) { (result)=_UTRIE_GET_RAW(trie, data, 0, c32); }
206  */
207 #define _UTRIE_GET(trie, data, c32, result, resultType) \
208     if((uint32_t)(c32)<=0xffff) { \
209         /* BMP code points */ \
210         (result)=_UTRIE_GET_FROM_BMP(trie, data, c32); \
211     } else if((uint32_t)(c32)<=0x10ffff) { \
212         /* supplementary code point */ \
213         UChar __lead16=UTF16_LEAD(c32); \
214         _UTRIE_GET_FROM_PAIR(trie, data, __lead16, c32, result, resultType); \
215     } else { \
216         /* out of range */ \
217         (result)=(resultType)((trie)->initialValue); \
218     }
219 
220 /** Internal next-post-increment: get the next code point (c, c2) and its data */
221 #define _UTRIE_NEXT(trie, data, src, limit, c, c2, result, resultType) { \
222     (c)=*(src)++; \
223     if(!UTF_IS_LEAD(c)) { \
224         (c2)=0; \
225         (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
226     } else if((src)!=(limit) && UTF_IS_TRAIL((c2)=*(src))) { \
227         ++(src); \
228         _UTRIE_GET_FROM_PAIR((trie), data, (c), (c2), (result), resultType); \
229     } else { \
230         /* unpaired lead surrogate code point */ \
231         (c2)=0; \
232         (result)=_UTRIE_GET_RAW((trie), data, UTRIE_LEAD_INDEX_DISP, (c)); \
233     } \
234 }
235 
236 /** Internal previous: get the previous code point (c, c2) and its data */
237 #define _UTRIE_PREVIOUS(trie, data, start, src, c, c2, result, resultType) { \
238     (c)=*--(src); \
239     if(!UTF_IS_SURROGATE(c)) { \
240         (c2)=0; \
241         (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
242     } else if(!UTF_IS_SURROGATE_FIRST(c)) { \
243         /* trail surrogate */ \
244         if((start)!=(src) && UTF_IS_LEAD((c2)=*((src)-1))) { \
245             --(src); \
246             (result)=(c); (c)=(c2); (c2)=(UChar)(result); /* swap c, c2 */ \
247             _UTRIE_GET_FROM_PAIR((trie), data, (c), (c2), (result), resultType); \
248         } else { \
249             /* unpaired trail surrogate code point */ \
250             (c2)=0; \
251             (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
252         } \
253     } else { \
254         /* unpaired lead surrogate code point */ \
255         (c2)=0; \
256         (result)=_UTRIE_GET_RAW((trie), data, UTRIE_LEAD_INDEX_DISP, (c)); \
257     } \
258 }
259 
260 /* Public UTrie API ---------------------------------------------------------*/
261 
262 /**
263  * Get a pointer to the contiguous part of the data array
264  * for the Latin-1 range (U+0000..U+00ff).
265  * Must be used only if the Latin-1 range is in fact linear
266  * (trie->isLatin1Linear).
267  *
268  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
269  * @return (const uint16_t *) pointer to values for Latin-1 code points
270  */
271 #define UTRIE_GET16_LATIN1(trie) ((trie)->index+(trie)->indexLength+UTRIE_DATA_BLOCK_LENGTH)
272 
273 /**
274  * Get a pointer to the contiguous part of the data array
275  * for the Latin-1 range (U+0000..U+00ff).
276  * Must be used only if the Latin-1 range is in fact linear
277  * (trie->isLatin1Linear).
278  *
279  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
280  * @return (const uint32_t *) pointer to values for Latin-1 code points
281  */
282 #define UTRIE_GET32_LATIN1(trie) ((trie)->data32+UTRIE_DATA_BLOCK_LENGTH)
283 
284 /**
285  * Get a 16-bit trie value from a BMP code point (UChar, <=U+ffff).
286  * c16 may be a lead surrogate, which may have a value including a folding offset.
287  *
288  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
289  * @param c16 (UChar, in) the input BMP code point
290  * @return (uint16_t) trie lookup result
291  */
292 #define UTRIE_GET16_FROM_LEAD(trie, c16) _UTRIE_GET_RAW(trie, index, 0, c16)
293 
294 /**
295  * Get a 32-bit trie value from a BMP code point (UChar, <=U+ffff).
296  * c16 may be a lead surrogate, which may have a value including a folding offset.
297  *
298  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
299  * @param c16 (UChar, in) the input BMP code point
300  * @return (uint32_t) trie lookup result
301  */
302 #define UTRIE_GET32_FROM_LEAD(trie, c16) _UTRIE_GET_RAW(trie, data32, 0, c16)
303 
304 /**
305  * Get a 16-bit trie value from a BMP code point (UChar, <=U+ffff).
306  * Even lead surrogate code points are treated as normal code points,
307  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
308  *
309  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
310  * @param c16 (UChar, in) the input BMP code point
311  * @return (uint16_t) trie lookup result
312  */
313 #define UTRIE_GET16_FROM_BMP(trie, c16) _UTRIE_GET_FROM_BMP(trie, index, c16)
314 
315 /**
316  * Get a 32-bit trie value from a BMP code point (UChar, <=U+ffff).
317  * Even lead surrogate code points are treated as normal code points,
318  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
319  *
320  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
321  * @param c16 (UChar, in) the input BMP code point
322  * @return (uint32_t) trie lookup result
323  */
324 #define UTRIE_GET32_FROM_BMP(trie, c16) _UTRIE_GET_FROM_BMP(trie, data32, c16)
325 
326 /**
327  * Get a 16-bit trie value from a code point.
328  * Even lead surrogate code points are treated as normal code points,
329  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
330  *
331  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
332  * @param c32 (UChar32, in) the input code point
333  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
334  */
335 #define UTRIE_GET16(trie, c32, result) _UTRIE_GET(trie, index, c32, result, uint16_t)
336 
337 /**
338  * Get a 32-bit trie value from a code point.
339  * Even lead surrogate code points are treated as normal code points,
340  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
341  *
342  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
343  * @param c32 (UChar32, in) the input code point
344  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
345  */
346 #define UTRIE_GET32(trie, c32, result) _UTRIE_GET(trie, data32, c32, result, uint32_t)
347 
348 /**
349  * Get the next code point (c, c2), post-increment src,
350  * and get a 16-bit value from the trie.
351  *
352  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
353  * @param src (const UChar *, in/out) the source text pointer
354  * @param limit (const UChar *, in) the limit pointer for the text, or NULL
355  * @param c (UChar, out) variable for the BMP or lead code unit
356  * @param c2 (UChar, out) variable for 0 or the trail code unit
357  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
358  */
359 #define UTRIE_NEXT16(trie, src, limit, c, c2, result) _UTRIE_NEXT(trie, index, src, limit, c, c2, result, uint16_t)
360 
361 /**
362  * Get the next code point (c, c2), post-increment src,
363  * and get a 32-bit value from the trie.
364  *
365  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
366  * @param src (const UChar *, in/out) the source text pointer
367  * @param limit (const UChar *, in) the limit pointer for the text, or NULL
368  * @param c (UChar, out) variable for the BMP or lead code unit
369  * @param c2 (UChar, out) variable for 0 or the trail code unit
370  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
371  */
372 #define UTRIE_NEXT32(trie, src, limit, c, c2, result) _UTRIE_NEXT(trie, data32, src, limit, c, c2, result, uint32_t)
373 
374 /**
375  * Get the previous code point (c, c2), pre-decrement src,
376  * and get a 16-bit value from the trie.
377  *
378  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
379  * @param start (const UChar *, in) the start pointer for the text, or NULL
380  * @param src (const UChar *, in/out) the source text pointer
381  * @param c (UChar, out) variable for the BMP or lead code unit
382  * @param c2 (UChar, out) variable for 0 or the trail code unit
383  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
384  */
385 #define UTRIE_PREVIOUS16(trie, start, src, c, c2, result) _UTRIE_PREVIOUS(trie, index, start, src, c, c2, result, uint16_t)
386 
387 /**
388  * Get the previous code point (c, c2), pre-decrement src,
389  * and get a 32-bit value from the trie.
390  *
391  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
392  * @param start (const UChar *, in) the start pointer for the text, or NULL
393  * @param src (const UChar *, in/out) the source text pointer
394  * @param c (UChar, out) variable for the BMP or lead code unit
395  * @param c2 (UChar, out) variable for 0 or the trail code unit
396  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
397  */
398 #define UTRIE_PREVIOUS32(trie, start, src, c, c2, result) _UTRIE_PREVIOUS(trie, data32, start, src, c, c2, result, uint32_t)
399 
400 /**
401  * Get a 16-bit trie value from a pair of surrogates.
402  *
403  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
404  * @param c (UChar, in) a lead surrogate
405  * @param c2 (UChar, in) a trail surrogate
406  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
407  */
408 #define UTRIE_GET16_FROM_PAIR(trie, c, c2, result) _UTRIE_GET_FROM_PAIR(trie, index, c, c2, result, uint16_t)
409 
410 /**
411  * Get a 32-bit trie value from a pair of surrogates.
412  *
413  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
414  * @param c (UChar, in) a lead surrogate
415  * @param c2 (UChar, in) a trail surrogate
416  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
417  */
418 #define UTRIE_GET32_FROM_PAIR(trie, c, c2, result) _UTRIE_GET_FROM_PAIR(trie, data32, c, c2, result, uint32_t)
419 
420 /**
421  * Get a 16-bit trie value from a folding offset (from the value of a lead surrogate)
422  * and a trail surrogate.
423  *
424  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
425  * @param offset (int32_t, in) the folding offset from the value of a lead surrogate
426  * @param c2 (UChar, in) a trail surrogate (only the 10 low bits are significant)
427  * @return (uint16_t) trie lookup result
428  */
429 #define UTRIE_GET16_FROM_OFFSET_TRAIL(trie, offset, c2) _UTRIE_GET_RAW(trie, index, offset, (c2)&0x3ff)
430 
431 /**
432  * Get a 32-bit trie value from a folding offset (from the value of a lead surrogate)
433  * and a trail surrogate.
434  *
435  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
436  * @param offset (int32_t, in) the folding offset from the value of a lead surrogate
437  * @param c2 (UChar, in) a trail surrogate (only the 10 low bits are significant)
438  * @return (uint32_t) trie lookup result
439  */
440 #define UTRIE_GET32_FROM_OFFSET_TRAIL(trie, offset, c2) _UTRIE_GET_RAW(trie, data32, offset, (c2)&0x3ff)
441 
442 /* enumeration callback types */
443 
444 /**
445  * Callback from utrie_enum(), extracts a uint32_t value from a
446  * trie value. This value will be passed on to the UTrieEnumRange function.
447  *
448  * @param context an opaque pointer, as passed into utrie_enum()
449  * @param value a value from the trie
450  * @return the value that is to be passed on to the UTrieEnumRange function
451  */
452 typedef uint32_t U_CALLCONV
453 UTrieEnumValue(const void *context, uint32_t value);
454 
455 /**
456  * Callback from utrie_enum(), is called for each contiguous range
457  * of code points with the same value as retrieved from the trie and
458  * transformed by the UTrieEnumValue function.
459  *
460  * The callback function can stop the enumeration by returning FALSE.
461  *
462  * @param context an opaque pointer, as passed into utrie_enum()
463  * @param start the first code point in a contiguous range with value
464  * @param limit one past the last code point in a contiguous range with value
465  * @param value the value that is set for all code points in [start..limit[
466  * @return FALSE to stop the enumeration
467  */
468 typedef UBool U_CALLCONV
469 UTrieEnumRange(const void *context, UChar32 start, UChar32 limit, uint32_t value);
470 
471 /**
472  * Enumerate efficiently all values in a trie.
473  * For each entry in the trie, the value to be delivered is passed through
474  * the UTrieEnumValue function.
475  * The value is unchanged if that function pointer is NULL.
476  *
477  * For each contiguous range of code points with a given value,
478  * the UTrieEnumRange function is called.
479  *
480  * @param trie a pointer to the runtime trie structure
481  * @param enumValue a pointer to a function that may transform the trie entry value,
482  *                  or NULL if the values from the trie are to be used directly
483  * @param enumRange a pointer to a function that is called for each contiguous range
484  *                  of code points with the same value
485  * @param context an opaque pointer that is passed on to the callback functions
486  */
487 U_CAPI void U_EXPORT2
488 utrie_enum(const UTrie *trie,
489            UTrieEnumValue *enumValue, UTrieEnumRange *enumRange, const void *context);
490 
491 /**
492  * Unserialize a trie from 32-bit-aligned memory.
493  * Inverse of utrie_serialize().
494  * Fills the UTrie runtime trie structure with the settings for the trie data.
495  *
496  * @param trie a pointer to the runtime trie structure
497  * @param data a pointer to 32-bit-aligned memory containing trie data
498  * @param length the number of bytes available at data
499  * @param pErrorCode an in/out ICU UErrorCode
500  * @return the number of bytes at data taken up by the trie data
501  */
502 U_CAPI int32_t U_EXPORT2
503 utrie_unserialize(UTrie *trie, const void *data, int32_t length, UErrorCode *pErrorCode);
504 
505 /**
506  * "Unserialize" a dummy trie.
507  * A dummy trie is an empty runtime trie, used when a real data trie cannot
508  * be loaded.
509  *
510  * The input memory is filled so that the trie always returns the initialValue,
511  * or the leadUnitValue for lead surrogate code points.
512  * The Latin-1 part is always set up to be linear.
513  *
514  * @param trie a pointer to the runtime trie structure
515  * @param data a pointer to 32-bit-aligned memory to be filled with the dummy trie data
516  * @param length the number of bytes available at data (recommended to use UTRIE_DUMMY_SIZE)
517  * @param initialValue the initial value that is set for all code points
518  * @param leadUnitValue the value for lead surrogate code _units_ that do not
519  *                      have associated supplementary data
520  * @param pErrorCode an in/out ICU UErrorCode
521  *
522  * @see UTRIE_DUMMY_SIZE
523  * @see utrie_open
524  */
525 U_CAPI int32_t U_EXPORT2
526 utrie_unserializeDummy(UTrie *trie,
527                        void *data, int32_t length,
528                        uint32_t initialValue, uint32_t leadUnitValue,
529                        UBool make16BitTrie,
530                        UErrorCode *pErrorCode);
531 
532 /**
533  * Default implementation for UTrie.getFoldingOffset, set automatically by
534  * utrie_unserialize().
535  * Simply returns the lead surrogate's value itself - which is the inverse
536  * of the default folding function used by utrie_serialize().
537  * Exported for static const UTrie structures.
538  *
539  * @see UTrieGetFoldingOffset
540  */
541 U_CAPI int32_t U_EXPORT2
542 utrie_defaultGetFoldingOffset(uint32_t data);
543 
544 /* Building a trie ----------------------------------------------------------*/
545 
546 /**
547  * Build-time trie structure.
548  * Opaque definition, here only to make fillIn parameters possible
549  * for utrie_open() and utrie_clone().
550  */
551 struct UNewTrie {
552     /**
553      * Index values at build-time are 32 bits wide for easier processing.
554      * Bit 31 is set if the data block is used by multiple index values (from utrie_setRange()).
555      */
556     int32_t index[UTRIE_MAX_INDEX_LENGTH];
557     uint32_t *data;
558 
559     uint32_t leadUnitValue;
560     int32_t indexLength, dataCapacity, dataLength;
561     UBool isAllocated, isDataAllocated;
562     UBool isLatin1Linear, isCompacted;
563 
564     /**
565      * Map of adjusted indexes, used in utrie_compact().
566      * Maps from original indexes to new ones.
567      */
568     int32_t map[UTRIE_MAX_BUILD_TIME_DATA_LENGTH>>UTRIE_SHIFT];
569 };
570 
571 typedef struct UNewTrie UNewTrie;
572 
573 /**
574  * Build-time trie callback function, used with utrie_serialize().
575  * This function calculates a lead surrogate's value including a folding offset
576  * from the 1024 supplementary code points [start..start+1024[ .
577  * It is U+10000 <= start <= U+10fc00 and (start&0x3ff)==0.
578  *
579  * The folding offset is provided by the caller.
580  * It is offset=UTRIE_BMP_INDEX_LENGTH+n*UTRIE_SURROGATE_BLOCK_COUNT with n=0..1023.
581  * Instead of the offset itself, n can be stored in 10 bits -
582  * or fewer if it can be assumed that few lead surrogates have associated data.
583  *
584  * The returned value must be
585  * - not zero if and only if there is relevant data
586  *   for the corresponding 1024 supplementary code points
587  * - such that UTrie.getFoldingOffset(UNewTrieGetFoldedValue(..., offset))==offset
588  *
589  * @return a folded value, or 0 if there is no relevant data for the lead surrogate.
590  */
591 typedef uint32_t U_CALLCONV
592 UNewTrieGetFoldedValue(UNewTrie *trie, UChar32 start, int32_t offset);
593 
594 /**
595  * Open a build-time trie structure.
596  * The size of the build-time data array is specified to avoid allocating a large
597  * array in all cases. The array itself can also be passed in.
598  *
599  * Although the trie is never fully expanded to a linear array, especially when
600  * utrie_setRange32() is used, the data array could be large during build time.
601  * The maximum length is
602  * UTRIE_MAX_BUILD_TIME_DATA_LENGTH=0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400.
603  * (Number of Unicode code points + one all-initial-value block +
604  *  possible duplicate entries for 1024 lead surrogates.)
605  * (UTRIE_DATA_BLOCK_LENGTH<=0x200 in all cases.)
606  *
607  * @param fillIn a pointer to a UNewTrie structure to be initialized (will not be released), or
608  *               NULL if one is to be allocated
609  * @param aliasData a pointer to a data array to be used (will not be released), or
610  *                  NULL if one is to be allocated
611  * @param maxDataLength the capacity of aliasData (if not NULL) or
612  *                      the length of the data array to be allocated
613  * @param initialValue the initial value that is set for all code points
614  * @param leadUnitValue the value for lead surrogate code _units_ that do not
615  *                      have associated supplementary data
616  * @param latin1Linear a flag indicating whether the Latin-1 range is to be allocated and
617  *                     kept in a linear, contiguous part of the data array
618  * @return a pointer to the initialized fillIn or the allocated and initialized new UNewTrie
619  */
620 U_CAPI UNewTrie * U_EXPORT2
621 utrie_open(UNewTrie *fillIn,
622            uint32_t *aliasData, int32_t maxDataLength,
623            uint32_t initialValue, uint32_t leadUnitValue,
624            UBool latin1Linear);
625 
626 /**
627  * Clone a build-time trie structure with all entries.
628  *
629  * @param fillIn like in utrie_open()
630  * @param other the build-time trie structure to clone
631  * @param aliasData like in utrie_open(),
632  *                  used if aliasDataLength>=(capacity of other's data array)
633  * @param aliasDataLength the length of aliasData
634  * @return a pointer to the initialized fillIn or the allocated and initialized new UNewTrie
635  */
636 U_CAPI UNewTrie * U_EXPORT2
637 utrie_clone(UNewTrie *fillIn, const UNewTrie *other, uint32_t *aliasData, int32_t aliasDataLength);
638 
639 /**
640  * Close a build-time trie structure, and release memory
641  * that was allocated by utrie_open() or utrie_clone().
642  *
643  * @param trie the build-time trie
644  */
645 U_CAPI void U_EXPORT2
646 utrie_close(UNewTrie *trie);
647 
648 /**
649  * Get the data array of a build-time trie.
650  * The data may be modified, but entries that are equal before
651  * must still be equal after modification.
652  *
653  * @param trie the build-time trie
654  * @param pLength (out) a pointer to a variable that receives the number
655  *                of entries in the data array
656  * @return the data array
657  */
658 U_CAPI uint32_t * U_EXPORT2
659 utrie_getData(UNewTrie *trie, int32_t *pLength);
660 
661 /**
662  * Set a value for a code point.
663  *
664  * @param trie the build-time trie
665  * @param c the code point
666  * @param value the value
667  * @return FALSE if a failure occurred (illegal argument or data array overrun)
668  */
669 U_CAPI UBool U_EXPORT2
670 utrie_set32(UNewTrie *trie, UChar32 c, uint32_t value);
671 
672 /**
673  * Get a value from a code point as stored in the build-time trie.
674  *
675  * @param trie the build-time trie
676  * @param c the code point
677  * @param pInBlockZero if not NULL, then *pInBlockZero is set to TRUE
678  *                     iff the value is retrieved from block 0;
679  *                     block 0 is the all-initial-value initial block
680  * @return the value
681  */
682 U_CAPI uint32_t U_EXPORT2
683 utrie_get32(UNewTrie *trie, UChar32 c, UBool *pInBlockZero);
684 
685 /**
686  * Set a value in a range of code points [start..limit[.
687  * All code points c with start<=c<limit will get the value if
688  * overwrite is TRUE or if the old value is 0.
689  *
690  * @param trie the build-time trie
691  * @param start the first code point to get the value
692  * @param limit one past the last code point to get the value
693  * @param value the value
694  * @param overwrite flag for whether old non-initial values are to be overwritten
695  * @return FALSE if a failure occurred (illegal argument or data array overrun)
696  */
697 U_CAPI UBool U_EXPORT2
698 utrie_setRange32(UNewTrie *trie, UChar32 start, UChar32 limit, uint32_t value, UBool overwrite);
699 
700 /**
701  * Compact the build-time trie after all values are set, and then
702  * serialize it into 32-bit aligned memory.
703  *
704  * After this, the trie can only be serizalized again and/or closed;
705  * no further values can be added.
706  *
707  * @see utrie_unserialize()
708  *
709  * @param trie the build-time trie
710  * @param data a pointer to 32-bit-aligned memory for the trie data
711  * @param capacity the number of bytes available at data
712  * @param getFoldedValue a callback function that calculates the value for
713  *                       a lead surrogate from all of its supplementary code points
714  *                       and the folding offset;
715  *                       if NULL, then a default function is used which returns just
716  *                       the input offset when there are any non-initial-value entries
717  * @param reduceTo16Bits flag for whether the values are to be reduced to a
718  *                       width of 16 bits for serialization and runtime
719  * @param pErrorCode a UErrorCode argument; among other possible error codes:
720  * - U_BUFFER_OVERFLOW_ERROR if the data storage block is too small for serialization
721  * - U_MEMORY_ALLOCATION_ERROR if the trie data array is too small
722  * - U_INDEX_OUTOFBOUNDS_ERROR if the index or data arrays are too long after compaction for serialization
723  *
724  * @return the number of bytes written for the trie
725  */
726 U_CAPI int32_t U_EXPORT2
727 utrie_serialize(UNewTrie *trie, void *data, int32_t capacity,
728                 UNewTrieGetFoldedValue *getFoldedValue,
729                 UBool reduceTo16Bits,
730                 UErrorCode *pErrorCode);
731 
732 /**
733  * Swap a serialized UTrie.
734  * @internal
735  */
736 U_CAPI int32_t U_EXPORT2
737 utrie_swap(const UDataSwapper *ds,
738            const void *inData, int32_t length, void *outData,
739            UErrorCode *pErrorCode);
740 
741 /* serialization ------------------------------------------------------------ */
742 
743 /**
744  * Trie data structure in serialized form:
745  *
746  * UTrieHeader header;
747  * uint16_t index[header.indexLength];
748  * uint16_t data[header.dataLength];
749  * @internal
750  */
751 typedef struct UTrieHeader {
752     /** "Trie" in big-endian US-ASCII (0x54726965) */
753     uint32_t signature;
754 
755     /**
756      * options bit field:
757      *     9    1=Latin-1 data is stored linearly at data+UTRIE_DATA_BLOCK_LENGTH
758      *     8    0=16-bit data, 1=32-bit data
759      *  7..4    UTRIE_INDEX_SHIFT   // 0..UTRIE_SHIFT
760      *  3..0    UTRIE_SHIFT         // 1..9
761      */
762     uint32_t options;
763 
764     /** indexLength is a multiple of UTRIE_SURROGATE_BLOCK_COUNT */
765     int32_t indexLength;
766 
767     /** dataLength>=UTRIE_DATA_BLOCK_LENGTH */
768     int32_t dataLength;
769 } UTrieHeader;
770 
771 /**
772  * Constants for use with UTrieHeader.options.
773  * @internal
774  */
775 enum {
776     /** Mask to get the UTRIE_SHIFT value from options. */
777     UTRIE_OPTIONS_SHIFT_MASK=0xf,
778 
779     /** Shift options right this much to get the UTRIE_INDEX_SHIFT value. */
780     UTRIE_OPTIONS_INDEX_SHIFT=4,
781 
782     /** If set, then the data (stage 2) array is 32 bits wide. */
783     UTRIE_OPTIONS_DATA_IS_32_BIT=0x100,
784 
785     /**
786      * If set, then Latin-1 data (for U+0000..U+00ff) is stored in the data (stage 2) array
787      * as a simple, linear array at data+UTRIE_DATA_BLOCK_LENGTH.
788      */
789     UTRIE_OPTIONS_LATIN1_IS_LINEAR=0x200
790 };
791 
792 U_CDECL_END
793 
794 #endif
795