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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 ******************************************************************************
5 *
6 *   Copyright (C) 2001-2011, International Business Machines
7 *   Corporation and others.  All Rights Reserved.
8 *
9 ******************************************************************************
10 *   file name:  utrie.h
11 *   encoding:   UTF-8
12 *   tab size:   8 (not used)
13 *   indentation:4
14 *
15 *   created on: 2001nov08
16 *   created by: Markus W. Scherer
17 */
18 
19 #ifndef __UTRIE_H__
20 #define __UTRIE_H__
21 
22 #include "unicode/utypes.h"
23 #include "unicode/utf16.h"
24 
25 U_CDECL_BEGIN
26 
27 /**
28  * \file
29  *
30  * This is a common implementation of a "folded" trie.
31  * It is a kind of compressed, serializable table of 16- or 32-bit values associated with
32  * Unicode code points (0..0x10ffff).
33  *
34  * This implementation is optimized for getting values while walking forward
35  * through a UTF-16 string.
36  * Therefore, the simplest and fastest access macros are the
37  * _FROM_LEAD() and _FROM_OFFSET_TRAIL() macros.
38  *
39  * The _FROM_BMP() macros are a little more complicated; they get values
40  * even for lead surrogate code _points_, while the _FROM_LEAD() macros
41  * get special "folded" values for lead surrogate code _units_ if
42  * there is relevant data associated with them.
43  * From such a folded value, an offset needs to be extracted to supply
44  * to the _FROM_OFFSET_TRAIL() macros.
45  *
46  * Most of the more complex (and more convenient) functions/macros call a callback function
47  * to get that offset from the folded value for a lead surrogate unit.
48  */
49 
50 /**
51  * Trie constants, defining shift widths, index array lengths, etc.
52  */
53 enum {
54     /** Shift size for shifting right the input index. 1..9 */
55     UTRIE_SHIFT=5,
56 
57     /** Number of data values in a stage 2 (data array) block. 2, 4, 8, .., 0x200 */
58     UTRIE_DATA_BLOCK_LENGTH=1<<UTRIE_SHIFT,
59 
60     /** Mask for getting the lower bits from the input index. */
61     UTRIE_MASK=UTRIE_DATA_BLOCK_LENGTH-1,
62 
63     /**
64      * Lead surrogate code points' index displacement in the index array.
65      * 0x10000-0xd800=0x2800
66      */
67     UTRIE_LEAD_INDEX_DISP=0x2800>>UTRIE_SHIFT,
68 
69     /**
70      * Shift size for shifting left the index array values.
71      * Increases possible data size with 16-bit index values at the cost
72      * of compactability.
73      * This requires blocks of stage 2 data to be aligned by UTRIE_DATA_GRANULARITY.
74      * 0..UTRIE_SHIFT
75      */
76     UTRIE_INDEX_SHIFT=2,
77 
78     /** The alignment size of a stage 2 data block. Also the granularity for compaction. */
79     UTRIE_DATA_GRANULARITY=1<<UTRIE_INDEX_SHIFT,
80 
81     /** Number of bits of a trail surrogate that are used in index table lookups. */
82     UTRIE_SURROGATE_BLOCK_BITS=10-UTRIE_SHIFT,
83 
84     /**
85      * Number of index (stage 1) entries per lead surrogate.
86      * Same as number of index entries for 1024 trail surrogates,
87      * ==0x400>>UTRIE_SHIFT
88      */
89     UTRIE_SURROGATE_BLOCK_COUNT=(1<<UTRIE_SURROGATE_BLOCK_BITS),
90 
91     /** Length of the BMP portion of the index (stage 1) array. */
92     UTRIE_BMP_INDEX_LENGTH=0x10000>>UTRIE_SHIFT
93 };
94 
95 /**
96  * Length of the index (stage 1) array before folding.
97  * Maximum number of Unicode code points (0x110000) shifted right by UTRIE_SHIFT.
98  */
99 #define UTRIE_MAX_INDEX_LENGTH (0x110000>>UTRIE_SHIFT)
100 
101 /**
102  * Maximum length of the runtime data (stage 2) array.
103  * Limited by 16-bit index values that are left-shifted by UTRIE_INDEX_SHIFT.
104  */
105 #define UTRIE_MAX_DATA_LENGTH (0x10000<<UTRIE_INDEX_SHIFT)
106 
107 /**
108  * Maximum length of the build-time data (stage 2) array.
109  * The maximum length is 0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400.
110  * (Number of Unicode code points + one all-initial-value block +
111  *  possible duplicate entries for 1024 lead surrogates.)
112  */
113 #define UTRIE_MAX_BUILD_TIME_DATA_LENGTH (0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400)
114 
115 /**
116  * Number of bytes for a dummy trie.
117  * A dummy trie is an empty runtime trie, used when a real data trie cannot
118  * be loaded.
119  * The number of bytes works for Latin-1-linear tries with 32-bit data
120  * (worst case).
121  *
122  * Calculation:
123  *   BMP index + 1 index block for lead surrogate code points +
124  *   Latin-1-linear array + 1 data block for lead surrogate code points
125  *
126  * Latin-1: if(UTRIE_SHIFT<=8) { 256 } else { included in first data block }
127  *
128  * @see utrie_unserializeDummy
129  */
130 #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)
131 
132 /**
133  * Runtime UTrie callback function.
134  * Extract from a lead surrogate's data the
135  * index array offset of the indexes for that lead surrogate.
136  *
137  * @param data data value for a surrogate from the trie, including the folding offset
138  * @return offset>=UTRIE_BMP_INDEX_LENGTH, or 0 if there is no data for the lead surrogate
139  */
140 typedef int32_t U_CALLCONV
141 UTrieGetFoldingOffset(uint32_t data);
142 
143 /**
144  * Run-time Trie structure.
145  *
146  * Either the data table is 16 bits wide and accessed via the index
147  * pointer, with each index item increased by indexLength;
148  * in this case, data32==NULL.
149  *
150  * Or the data table is 32 bits wide and accessed via the data32 pointer.
151  */
152 struct UTrie {
153     const uint16_t *index;
154     const uint32_t *data32; /* NULL if 16b data is used via index */
155 
156     /**
157      * This function is not used in _FROM_LEAD, _FROM_BMP, and _FROM_OFFSET_TRAIL macros.
158      * If convenience macros like _GET16 or _NEXT32 are used, this function must be set.
159      *
160      * utrie_unserialize() sets a default function which simply returns
161      * the lead surrogate's value itself - which is the inverse of the default
162      * folding function used by utrie_serialize().
163      *
164      * @see UTrieGetFoldingOffset
165      */
166     UTrieGetFoldingOffset *getFoldingOffset;
167 
168     int32_t indexLength, dataLength;
169     uint32_t initialValue;
170     UBool isLatin1Linear;
171 };
172 
173 #ifndef __UTRIE2_H__
174 typedef struct UTrie UTrie;
175 #endif
176 
177 /** Internal trie getter from an offset (0 if c16 is a BMP/lead units) and a 16-bit unit */
178 #define _UTRIE_GET_RAW(trie, data, offset, c16) \
179     (trie)->data[ \
180         ((int32_t)((trie)->index[(offset)+((c16)>>UTRIE_SHIFT)])<<UTRIE_INDEX_SHIFT)+ \
181         ((c16)&UTRIE_MASK) \
182     ]
183 
184 /** Internal trie getter from a pair of surrogates */
185 #define _UTRIE_GET_FROM_PAIR(trie, data, c, c2, result, resultType) { \
186     int32_t __offset; \
187 \
188     /* get data for lead surrogate */ \
189     (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
190     __offset=(trie)->getFoldingOffset(result); \
191 \
192     /* get the real data from the folded lead/trail units */ \
193     if(__offset>0) { \
194         (result)=_UTRIE_GET_RAW((trie), data, __offset, (c2)&0x3ff); \
195     } else { \
196         (result)=(resultType)((trie)->initialValue); \
197     } \
198 }
199 
200 /** Internal trie getter from a BMP code point, treating a lead surrogate as a normal code point */
201 #define _UTRIE_GET_FROM_BMP(trie, data, c16) \
202     _UTRIE_GET_RAW(trie, data, 0xd800<=(c16) && (c16)<=0xdbff ? UTRIE_LEAD_INDEX_DISP : 0, c16);
203 
204 /**
205  * Internal trie getter from a code point.
206  * Could be faster(?) but longer with
207  *   if((c32)<=0xd7ff) { (result)=_UTRIE_GET_RAW(trie, data, 0, c32); }
208  */
209 #define _UTRIE_GET(trie, data, c32, result, resultType) \
210     if((uint32_t)(c32)<=0xffff) { \
211         /* BMP code points */ \
212         (result)=_UTRIE_GET_FROM_BMP(trie, data, c32); \
213     } else if((uint32_t)(c32)<=0x10ffff) { \
214         /* supplementary code point */ \
215         UChar __lead16=U16_LEAD(c32); \
216         _UTRIE_GET_FROM_PAIR(trie, data, __lead16, c32, result, resultType); \
217     } else { \
218         /* out of range */ \
219         (result)=(resultType)((trie)->initialValue); \
220     }
221 
222 /** Internal next-post-increment: get the next code point (c, c2) and its data */
223 #define _UTRIE_NEXT(trie, data, src, limit, c, c2, result, resultType) { \
224     (c)=*(src)++; \
225     if(!U16_IS_LEAD(c)) { \
226         (c2)=0; \
227         (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
228     } else if((src)!=(limit) && U16_IS_TRAIL((c2)=*(src))) { \
229         ++(src); \
230         _UTRIE_GET_FROM_PAIR((trie), data, (c), (c2), (result), resultType); \
231     } else { \
232         /* unpaired lead surrogate code point */ \
233         (c2)=0; \
234         (result)=_UTRIE_GET_RAW((trie), data, UTRIE_LEAD_INDEX_DISP, (c)); \
235     } \
236 }
237 
238 /** Internal previous: get the previous code point (c, c2) and its data */
239 #define _UTRIE_PREVIOUS(trie, data, start, src, c, c2, result, resultType) { \
240     (c)=*--(src); \
241     if(!U16_IS_SURROGATE(c)) { \
242         (c2)=0; \
243         (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
244     } else if(!U16_IS_SURROGATE_LEAD(c)) { \
245         /* trail surrogate */ \
246         if((start)!=(src) && U16_IS_LEAD((c2)=*((src)-1))) { \
247             --(src); \
248             (result)=(c); (c)=(c2); (c2)=(UChar)(result); /* swap c, c2 */ \
249             _UTRIE_GET_FROM_PAIR((trie), data, (c), (c2), (result), resultType); \
250         } else { \
251             /* unpaired trail surrogate code point */ \
252             (c2)=0; \
253             (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \
254         } \
255     } else { \
256         /* unpaired lead surrogate code point */ \
257         (c2)=0; \
258         (result)=_UTRIE_GET_RAW((trie), data, UTRIE_LEAD_INDEX_DISP, (c)); \
259     } \
260 }
261 
262 /* Public UTrie API ---------------------------------------------------------*/
263 
264 /**
265  * Get a pointer to the contiguous part of the data array
266  * for the Latin-1 range (U+0000..U+00ff).
267  * Must be used only if the Latin-1 range is in fact linear
268  * (trie->isLatin1Linear).
269  *
270  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
271  * @return (const uint16_t *) pointer to values for Latin-1 code points
272  */
273 #define UTRIE_GET16_LATIN1(trie) ((trie)->index+(trie)->indexLength+UTRIE_DATA_BLOCK_LENGTH)
274 
275 /**
276  * Get a pointer to the contiguous part of the data array
277  * for the Latin-1 range (U+0000..U+00ff).
278  * Must be used only if the Latin-1 range is in fact linear
279  * (trie->isLatin1Linear).
280  *
281  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
282  * @return (const uint32_t *) pointer to values for Latin-1 code points
283  */
284 #define UTRIE_GET32_LATIN1(trie) ((trie)->data32+UTRIE_DATA_BLOCK_LENGTH)
285 
286 /**
287  * Get a 16-bit trie value from a BMP code point (UChar, <=U+ffff).
288  * c16 may be a lead surrogate, which may have a value including a folding offset.
289  *
290  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
291  * @param c16 (UChar, in) the input BMP code point
292  * @return (uint16_t) trie lookup result
293  */
294 #define UTRIE_GET16_FROM_LEAD(trie, c16) _UTRIE_GET_RAW(trie, index, 0, c16)
295 
296 /**
297  * Get a 32-bit trie value from a BMP code point (UChar, <=U+ffff).
298  * c16 may be a lead surrogate, which may have a value including a folding offset.
299  *
300  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
301  * @param c16 (UChar, in) the input BMP code point
302  * @return (uint32_t) trie lookup result
303  */
304 #define UTRIE_GET32_FROM_LEAD(trie, c16) _UTRIE_GET_RAW(trie, data32, 0, c16)
305 
306 /**
307  * Get a 16-bit trie value from a BMP code point (UChar, <=U+ffff).
308  * Even lead surrogate code points are treated as normal code points,
309  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
310  *
311  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
312  * @param c16 (UChar, in) the input BMP code point
313  * @return (uint16_t) trie lookup result
314  */
315 #define UTRIE_GET16_FROM_BMP(trie, c16) _UTRIE_GET_FROM_BMP(trie, index, c16)
316 
317 /**
318  * Get a 32-bit trie value from a BMP code point (UChar, <=U+ffff).
319  * Even lead surrogate code points are treated as normal code points,
320  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
321  *
322  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
323  * @param c16 (UChar, in) the input BMP code point
324  * @return (uint32_t) trie lookup result
325  */
326 #define UTRIE_GET32_FROM_BMP(trie, c16) _UTRIE_GET_FROM_BMP(trie, data32, c16)
327 
328 /**
329  * Get a 16-bit trie value from a code point.
330  * Even lead surrogate code points are treated as normal code points,
331  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
332  *
333  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
334  * @param c32 (UChar32, in) the input code point
335  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
336  */
337 #define UTRIE_GET16(trie, c32, result) _UTRIE_GET(trie, index, c32, result, uint16_t)
338 
339 /**
340  * Get a 32-bit trie value from a code point.
341  * Even lead surrogate code points are treated as normal code points,
342  * with unfolded values that may differ from _FROM_LEAD() macro results for them.
343  *
344  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
345  * @param c32 (UChar32, in) the input code point
346  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
347  */
348 #define UTRIE_GET32(trie, c32, result) _UTRIE_GET(trie, data32, c32, result, uint32_t)
349 
350 /**
351  * Get the next code point (c, c2), post-increment src,
352  * and get a 16-bit value from the trie.
353  *
354  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
355  * @param src (const UChar *, in/out) the source text pointer
356  * @param limit (const UChar *, in) the limit pointer for the text, or NULL
357  * @param c (UChar, out) variable for the BMP or lead code unit
358  * @param c2 (UChar, out) variable for 0 or the trail code unit
359  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
360  */
361 #define UTRIE_NEXT16(trie, src, limit, c, c2, result) _UTRIE_NEXT(trie, index, src, limit, c, c2, result, uint16_t)
362 
363 /**
364  * Get the next code point (c, c2), post-increment src,
365  * and get a 32-bit value from the trie.
366  *
367  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
368  * @param src (const UChar *, in/out) the source text pointer
369  * @param limit (const UChar *, in) the limit pointer for the text, or NULL
370  * @param c (UChar, out) variable for the BMP or lead code unit
371  * @param c2 (UChar, out) variable for 0 or the trail code unit
372  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
373  */
374 #define UTRIE_NEXT32(trie, src, limit, c, c2, result) _UTRIE_NEXT(trie, data32, src, limit, c, c2, result, uint32_t)
375 
376 /**
377  * Get the previous code point (c, c2), pre-decrement src,
378  * and get a 16-bit value from the trie.
379  *
380  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
381  * @param start (const UChar *, in) the start pointer for the text, or NULL
382  * @param src (const UChar *, in/out) the source text pointer
383  * @param c (UChar, out) variable for the BMP or lead code unit
384  * @param c2 (UChar, out) variable for 0 or the trail code unit
385  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
386  */
387 #define UTRIE_PREVIOUS16(trie, start, src, c, c2, result) _UTRIE_PREVIOUS(trie, index, start, src, c, c2, result, uint16_t)
388 
389 /**
390  * Get the previous code point (c, c2), pre-decrement src,
391  * and get a 32-bit value from the trie.
392  *
393  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
394  * @param start (const UChar *, in) the start pointer for the text, or NULL
395  * @param src (const UChar *, in/out) the source text pointer
396  * @param c (UChar, out) variable for the BMP or lead code unit
397  * @param c2 (UChar, out) variable for 0 or the trail code unit
398  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
399  */
400 #define UTRIE_PREVIOUS32(trie, start, src, c, c2, result) _UTRIE_PREVIOUS(trie, data32, start, src, c, c2, result, uint32_t)
401 
402 /**
403  * Get a 16-bit trie value from a pair of surrogates.
404  *
405  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
406  * @param c (UChar, in) a lead surrogate
407  * @param c2 (UChar, in) a trail surrogate
408  * @param result (uint16_t, out) uint16_t variable for the trie lookup result
409  */
410 #define UTRIE_GET16_FROM_PAIR(trie, c, c2, result) _UTRIE_GET_FROM_PAIR(trie, index, c, c2, result, uint16_t)
411 
412 /**
413  * Get a 32-bit trie value from a pair of surrogates.
414  *
415  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
416  * @param c (UChar, in) a lead surrogate
417  * @param c2 (UChar, in) a trail surrogate
418  * @param result (uint32_t, out) uint32_t variable for the trie lookup result
419  */
420 #define UTRIE_GET32_FROM_PAIR(trie, c, c2, result) _UTRIE_GET_FROM_PAIR(trie, data32, c, c2, result, uint32_t)
421 
422 /**
423  * Get a 16-bit trie value from a folding offset (from the value of a lead surrogate)
424  * and a trail surrogate.
425  *
426  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
427  * @param offset (int32_t, in) the folding offset from the value of a lead surrogate
428  * @param c2 (UChar, in) a trail surrogate (only the 10 low bits are significant)
429  * @return (uint16_t) trie lookup result
430  */
431 #define UTRIE_GET16_FROM_OFFSET_TRAIL(trie, offset, c2) _UTRIE_GET_RAW(trie, index, offset, (c2)&0x3ff)
432 
433 /**
434  * Get a 32-bit trie value from a folding offset (from the value of a lead surrogate)
435  * and a trail surrogate.
436  *
437  * @param trie (const UTrie *, in) a pointer to the runtime trie structure
438  * @param offset (int32_t, in) the folding offset from the value of a lead surrogate
439  * @param c2 (UChar, in) a trail surrogate (only the 10 low bits are significant)
440  * @return (uint32_t) trie lookup result
441  */
442 #define UTRIE_GET32_FROM_OFFSET_TRAIL(trie, offset, c2) _UTRIE_GET_RAW(trie, data32, offset, (c2)&0x3ff)
443 
444 /* enumeration callback types */
445 
446 /**
447  * Callback from utrie_enum(), extracts a uint32_t value from a
448  * trie value. This value will be passed on to the UTrieEnumRange function.
449  *
450  * @param context an opaque pointer, as passed into utrie_enum()
451  * @param value a value from the trie
452  * @return the value that is to be passed on to the UTrieEnumRange function
453  */
454 typedef uint32_t U_CALLCONV
455 UTrieEnumValue(const void *context, uint32_t value);
456 
457 /**
458  * Callback from utrie_enum(), is called for each contiguous range
459  * of code points with the same value as retrieved from the trie and
460  * transformed by the UTrieEnumValue function.
461  *
462  * The callback function can stop the enumeration by returning FALSE.
463  *
464  * @param context an opaque pointer, as passed into utrie_enum()
465  * @param start the first code point in a contiguous range with value
466  * @param limit one past the last code point in a contiguous range with value
467  * @param value the value that is set for all code points in [start..limit[
468  * @return FALSE to stop the enumeration
469  */
470 typedef UBool U_CALLCONV
471 UTrieEnumRange(const void *context, UChar32 start, UChar32 limit, uint32_t value);
472 
473 /**
474  * Enumerate efficiently all values in a trie.
475  * For each entry in the trie, the value to be delivered is passed through
476  * the UTrieEnumValue function.
477  * The value is unchanged if that function pointer is NULL.
478  *
479  * For each contiguous range of code points with a given value,
480  * the UTrieEnumRange function is called.
481  *
482  * @param trie a pointer to the runtime trie structure
483  * @param enumValue a pointer to a function that may transform the trie entry value,
484  *                  or NULL if the values from the trie are to be used directly
485  * @param enumRange a pointer to a function that is called for each contiguous range
486  *                  of code points with the same value
487  * @param context an opaque pointer that is passed on to the callback functions
488  */
489 U_CAPI void U_EXPORT2
490 utrie_enum(const UTrie *trie,
491            UTrieEnumValue *enumValue, UTrieEnumRange *enumRange, const void *context);
492 
493 /**
494  * Unserialize a trie from 32-bit-aligned memory.
495  * Inverse of utrie_serialize().
496  * Fills the UTrie runtime trie structure with the settings for the trie data.
497  *
498  * @param trie a pointer to the runtime trie structure
499  * @param data a pointer to 32-bit-aligned memory containing trie data
500  * @param length the number of bytes available at data
501  * @param pErrorCode an in/out ICU UErrorCode
502  * @return the number of bytes at data taken up by the trie data
503  */
504 U_CAPI int32_t U_EXPORT2
505 utrie_unserialize(UTrie *trie, const void *data, int32_t length, UErrorCode *pErrorCode);
506 
507 /**
508  * "Unserialize" a dummy trie.
509  * A dummy trie is an empty runtime trie, used when a real data trie cannot
510  * be loaded.
511  *
512  * The input memory is filled so that the trie always returns the initialValue,
513  * or the leadUnitValue for lead surrogate code points.
514  * The Latin-1 part is always set up to be linear.
515  *
516  * @param trie a pointer to the runtime trie structure
517  * @param data a pointer to 32-bit-aligned memory to be filled with the dummy trie data
518  * @param length the number of bytes available at data (recommended to use UTRIE_DUMMY_SIZE)
519  * @param initialValue the initial value that is set for all code points
520  * @param leadUnitValue the value for lead surrogate code _units_ that do not
521  *                      have associated supplementary data
522  * @param pErrorCode an in/out ICU UErrorCode
523  *
524  * @see UTRIE_DUMMY_SIZE
525  * @see utrie_open
526  */
527 U_CAPI int32_t U_EXPORT2
528 utrie_unserializeDummy(UTrie *trie,
529                        void *data, int32_t length,
530                        uint32_t initialValue, uint32_t leadUnitValue,
531                        UBool make16BitTrie,
532                        UErrorCode *pErrorCode);
533 
534 /**
535  * Default implementation for UTrie.getFoldingOffset, set automatically by
536  * utrie_unserialize().
537  * Simply returns the lead surrogate's value itself - which is the inverse
538  * of the default folding function used by utrie_serialize().
539  * Exported for static const UTrie structures.
540  *
541  * @see UTrieGetFoldingOffset
542  */
543 U_CAPI int32_t U_EXPORT2
544 utrie_defaultGetFoldingOffset(uint32_t data);
545 
546 /* Building a trie ----------------------------------------------------------*/
547 
548 /**
549  * Build-time trie structure.
550  * Opaque definition, here only to make fillIn parameters possible
551  * for utrie_open() and utrie_clone().
552  */
553 struct UNewTrie {
554     /**
555      * Index values at build-time are 32 bits wide for easier processing.
556      * Bit 31 is set if the data block is used by multiple index values (from utrie_setRange()).
557      */
558     int32_t index[UTRIE_MAX_INDEX_LENGTH+UTRIE_SURROGATE_BLOCK_COUNT];
559     uint32_t *data;
560 
561     uint32_t leadUnitValue;
562     int32_t indexLength, dataCapacity, dataLength;
563     UBool isAllocated, isDataAllocated;
564     UBool isLatin1Linear, isCompacted;
565 
566     /**
567      * Map of adjusted indexes, used in utrie_compact().
568      * Maps from original indexes to new ones.
569      */
570     int32_t map[UTRIE_MAX_BUILD_TIME_DATA_LENGTH>>UTRIE_SHIFT];
571 };
572 
573 typedef struct UNewTrie UNewTrie;
574 
575 /**
576  * Build-time trie callback function, used with utrie_serialize().
577  * This function calculates a lead surrogate's value including a folding offset
578  * from the 1024 supplementary code points [start..start+1024[ .
579  * It is U+10000 <= start <= U+10fc00 and (start&0x3ff)==0.
580  *
581  * The folding offset is provided by the caller.
582  * It is offset=UTRIE_BMP_INDEX_LENGTH+n*UTRIE_SURROGATE_BLOCK_COUNT with n=0..1023.
583  * Instead of the offset itself, n can be stored in 10 bits -
584  * or fewer if it can be assumed that few lead surrogates have associated data.
585  *
586  * The returned value must be
587  * - not zero if and only if there is relevant data
588  *   for the corresponding 1024 supplementary code points
589  * - such that UTrie.getFoldingOffset(UNewTrieGetFoldedValue(..., offset))==offset
590  *
591  * @return a folded value, or 0 if there is no relevant data for the lead surrogate.
592  */
593 typedef uint32_t U_CALLCONV
594 UNewTrieGetFoldedValue(UNewTrie *trie, UChar32 start, int32_t offset);
595 
596 /**
597  * Open a build-time trie structure.
598  * The size of the build-time data array is specified to avoid allocating a large
599  * array in all cases. The array itself can also be passed in.
600  *
601  * Although the trie is never fully expanded to a linear array, especially when
602  * utrie_setRange32() is used, the data array could be large during build time.
603  * The maximum length is
604  * UTRIE_MAX_BUILD_TIME_DATA_LENGTH=0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400.
605  * (Number of Unicode code points + one all-initial-value block +
606  *  possible duplicate entries for 1024 lead surrogates.)
607  * (UTRIE_DATA_BLOCK_LENGTH<=0x200 in all cases.)
608  *
609  * @param fillIn a pointer to a UNewTrie structure to be initialized (will not be released), or
610  *               NULL if one is to be allocated
611  * @param aliasData a pointer to a data array to be used (will not be released), or
612  *                  NULL if one is to be allocated
613  * @param maxDataLength the capacity of aliasData (if not NULL) or
614  *                      the length of the data array to be allocated
615  * @param initialValue the initial value that is set for all code points
616  * @param leadUnitValue the value for lead surrogate code _units_ that do not
617  *                      have associated supplementary data
618  * @param latin1Linear a flag indicating whether the Latin-1 range is to be allocated and
619  *                     kept in a linear, contiguous part of the data array
620  * @return a pointer to the initialized fillIn or the allocated and initialized new UNewTrie
621  */
622 U_CAPI UNewTrie * U_EXPORT2
623 utrie_open(UNewTrie *fillIn,
624            uint32_t *aliasData, int32_t maxDataLength,
625            uint32_t initialValue, uint32_t leadUnitValue,
626            UBool latin1Linear);
627 
628 /**
629  * Clone a build-time trie structure with all entries.
630  *
631  * @param fillIn like in utrie_open()
632  * @param other the build-time trie structure to clone
633  * @param aliasData like in utrie_open(),
634  *                  used if aliasDataLength>=(capacity of other's data array)
635  * @param aliasDataLength the length of aliasData
636  * @return a pointer to the initialized fillIn or the allocated and initialized new UNewTrie
637  */
638 U_CAPI UNewTrie * U_EXPORT2
639 utrie_clone(UNewTrie *fillIn, const UNewTrie *other, uint32_t *aliasData, int32_t aliasDataLength);
640 
641 /**
642  * Close a build-time trie structure, and release memory
643  * that was allocated by utrie_open() or utrie_clone().
644  *
645  * @param trie the build-time trie
646  */
647 U_CAPI void U_EXPORT2
648 utrie_close(UNewTrie *trie);
649 
650 /**
651  * Get the data array of a build-time trie.
652  * The data may be modified, but entries that are equal before
653  * must still be equal after modification.
654  *
655  * @param trie the build-time trie
656  * @param pLength (out) a pointer to a variable that receives the number
657  *                of entries in the data array
658  * @return the data array
659  */
660 U_CAPI uint32_t * U_EXPORT2
661 utrie_getData(UNewTrie *trie, int32_t *pLength);
662 
663 /**
664  * Set a value for a code point.
665  *
666  * @param trie the build-time trie
667  * @param c the code point
668  * @param value the value
669  * @return FALSE if a failure occurred (illegal argument or data array overrun)
670  */
671 U_CAPI UBool U_EXPORT2
672 utrie_set32(UNewTrie *trie, UChar32 c, uint32_t value);
673 
674 /**
675  * Get a value from a code point as stored in the build-time trie.
676  *
677  * @param trie the build-time trie
678  * @param c the code point
679  * @param pInBlockZero if not NULL, then *pInBlockZero is set to TRUE
680  *                     iff the value is retrieved from block 0;
681  *                     block 0 is the all-initial-value initial block
682  * @return the value
683  */
684 U_CAPI uint32_t U_EXPORT2
685 utrie_get32(UNewTrie *trie, UChar32 c, UBool *pInBlockZero);
686 
687 /**
688  * Set a value in a range of code points [start..limit[.
689  * All code points c with start<=c<limit will get the value if
690  * overwrite is TRUE or if the old value is 0.
691  *
692  * @param trie the build-time trie
693  * @param start the first code point to get the value
694  * @param limit one past the last code point to get the value
695  * @param value the value
696  * @param overwrite flag for whether old non-initial values are to be overwritten
697  * @return FALSE if a failure occurred (illegal argument or data array overrun)
698  */
699 U_CAPI UBool U_EXPORT2
700 utrie_setRange32(UNewTrie *trie, UChar32 start, UChar32 limit, uint32_t value, UBool overwrite);
701 
702 /**
703  * Compact the build-time trie after all values are set, and then
704  * serialize it into 32-bit aligned memory.
705  *
706  * After this, the trie can only be serizalized again and/or closed;
707  * no further values can be added.
708  *
709  * @see utrie_unserialize()
710  *
711  * @param trie the build-time trie
712  * @param data a pointer to 32-bit-aligned memory for the trie data
713  * @param capacity the number of bytes available at data
714  * @param getFoldedValue a callback function that calculates the value for
715  *                       a lead surrogate from all of its supplementary code points
716  *                       and the folding offset;
717  *                       if NULL, then a default function is used which returns just
718  *                       the input offset when there are any non-initial-value entries
719  * @param reduceTo16Bits flag for whether the values are to be reduced to a
720  *                       width of 16 bits for serialization and runtime
721  * @param pErrorCode a UErrorCode argument; among other possible error codes:
722  * - U_BUFFER_OVERFLOW_ERROR if the data storage block is too small for serialization
723  * - U_MEMORY_ALLOCATION_ERROR if the trie data array is too small
724  * - U_INDEX_OUTOFBOUNDS_ERROR if the index or data arrays are too long after compaction for serialization
725  *
726  * @return the number of bytes written for the trie
727  */
728 U_CAPI int32_t U_EXPORT2
729 utrie_serialize(UNewTrie *trie, void *data, int32_t capacity,
730                 UNewTrieGetFoldedValue *getFoldedValue,
731                 UBool reduceTo16Bits,
732                 UErrorCode *pErrorCode);
733 
734 /* serialization ------------------------------------------------------------ */
735 
736 // UTrie signature values, in platform endianness and opposite endianness.
737 // The UTrie signature ASCII byte values spell "Trie".
738 #define UTRIE_SIG       0x54726965
739 #define UTRIE_OE_SIG    0x65697254
740 
741 /**
742  * Trie data structure in serialized form:
743  *
744  * UTrieHeader header;
745  * uint16_t index[header.indexLength];
746  * uint16_t data[header.dataLength];
747  * @internal
748  */
749 typedef struct UTrieHeader {
750     /** "Trie" in big-endian US-ASCII (0x54726965) */
751     uint32_t signature;
752 
753     /**
754      * options bit field:
755      *     9    1=Latin-1 data is stored linearly at data+UTRIE_DATA_BLOCK_LENGTH
756      *     8    0=16-bit data, 1=32-bit data
757      *  7..4    UTRIE_INDEX_SHIFT   // 0..UTRIE_SHIFT
758      *  3..0    UTRIE_SHIFT         // 1..9
759      */
760     uint32_t options;
761 
762     /** indexLength is a multiple of UTRIE_SURROGATE_BLOCK_COUNT */
763     int32_t indexLength;
764 
765     /** dataLength>=UTRIE_DATA_BLOCK_LENGTH */
766     int32_t dataLength;
767 } UTrieHeader;
768 
769 /**
770  * Constants for use with UTrieHeader.options.
771  * @internal
772  */
773 enum {
774     /** Mask to get the UTRIE_SHIFT value from options. */
775     UTRIE_OPTIONS_SHIFT_MASK=0xf,
776 
777     /** Shift options right this much to get the UTRIE_INDEX_SHIFT value. */
778     UTRIE_OPTIONS_INDEX_SHIFT=4,
779 
780     /** If set, then the data (stage 2) array is 32 bits wide. */
781     UTRIE_OPTIONS_DATA_IS_32_BIT=0x100,
782 
783     /**
784      * If set, then Latin-1 data (for U+0000..U+00ff) is stored in the data (stage 2) array
785      * as a simple, linear array at data+UTRIE_DATA_BLOCK_LENGTH.
786      */
787     UTRIE_OPTIONS_LATIN1_IS_LINEAR=0x200
788 };
789 
790 U_CDECL_END
791 
792 #endif
793