1/*
2*******************************************************************************
3* Copyright (C) 2010-2014, International Business Machines
4* Corporation and others.  All Rights Reserved.
5*******************************************************************************
6* collation.h
7*
8* created on: 2010oct27
9* created by: Markus W. Scherer
10*/
11
12#ifndef __COLLATION_H__
13#define __COLLATION_H__
14
15#include "unicode/utypes.h"
16
17#if !UCONFIG_NO_COLLATION
18
19U_NAMESPACE_BEGIN
20
21/**
22 * Collation v2 basic definitions and static helper functions.
23 *
24 * Data structures except for expansion tables store 32-bit CEs which are
25 * either specials (see tags below) or are compact forms of 64-bit CEs.
26 */
27class U_I18N_API Collation {
28public:
29    // Special sort key bytes for all levels.
30    static const uint8_t TERMINATOR_BYTE = 0;
31    static const uint8_t LEVEL_SEPARATOR_BYTE = 1;
32    /**
33     * Merge-sort-key separator.
34     * Must not be used as the lead byte of any CE weight,
35     * nor as primary compression low terminator.
36     * Otherwise usable.
37     */
38    static const uint8_t MERGE_SEPARATOR_BYTE = 2;
39    static const uint32_t MERGE_SEPARATOR_PRIMARY = 0x02000000;  // U+FFFE
40    static const uint32_t MERGE_SEPARATOR_WEIGHT16 = 0x0200;  // U+FFFE
41    static const uint32_t MERGE_SEPARATOR_LOWER32 = 0x02000200;  // U+FFFE
42    static const uint32_t MERGE_SEPARATOR_CE32 = 0x02000202;  // U+FFFE
43
44    /**
45     * Primary compression low terminator, must be greater than MERGE_SEPARATOR_BYTE.
46     * Reserved value in primary second byte if the lead byte is compressible.
47     * Otherwise usable in all CE weight bytes.
48     */
49    static const uint8_t PRIMARY_COMPRESSION_LOW_BYTE = 3;
50    /**
51     * Primary compression high terminator.
52     * Reserved value in primary second byte if the lead byte is compressible.
53     * Otherwise usable in all CE weight bytes.
54     */
55    static const uint8_t PRIMARY_COMPRESSION_HIGH_BYTE = 0xff;
56
57    /** Default secondary/tertiary weight lead byte. */
58    static const uint8_t COMMON_BYTE = 5;
59    static const uint32_t COMMON_WEIGHT16 = 0x0500;
60    /** Middle 16 bits of a CE with a common secondary weight. */
61    static const uint32_t COMMON_SECONDARY_CE = 0x05000000;
62    /** Lower 16 bits of a CE with a common tertiary weight. */
63    static const uint32_t COMMON_TERTIARY_CE = 0x0500;
64    /** Lower 32 bits of a CE with common secondary and tertiary weights. */
65    static const uint32_t COMMON_SEC_AND_TER_CE = 0x05000500;
66
67    static const uint32_t SECONDARY_MASK = 0xffff0000;
68    static const uint32_t CASE_MASK = 0xc000;
69    static const uint32_t SECONDARY_AND_CASE_MASK = SECONDARY_MASK | CASE_MASK;
70    /** Only the 2*6 bits for the pure tertiary weight. */
71    static const uint32_t ONLY_TERTIARY_MASK = 0x3f3f;
72    /** Only the secondary & tertiary bits; no case, no quaternary. */
73    static const uint32_t ONLY_SEC_TER_MASK = SECONDARY_MASK | ONLY_TERTIARY_MASK;
74    /** Case bits and tertiary bits. */
75    static const uint32_t CASE_AND_TERTIARY_MASK = CASE_MASK | ONLY_TERTIARY_MASK;
76    static const uint32_t QUATERNARY_MASK = 0xc0;
77    /** Case bits and quaternary bits. */
78    static const uint32_t CASE_AND_QUATERNARY_MASK = CASE_MASK | QUATERNARY_MASK;
79
80    static const uint8_t UNASSIGNED_IMPLICIT_BYTE = 0xfe;  // compressible
81    /**
82     * First unassigned: AlphabeticIndex overflow boundary.
83     * We want a 3-byte primary so that it fits into the root elements table.
84     *
85     * This 3-byte primary will not collide with
86     * any unassigned-implicit 4-byte primaries because
87     * the first few hundred Unicode code points all have real mappings.
88     */
89    static const uint32_t FIRST_UNASSIGNED_PRIMARY = 0xfe040200;
90
91    static const uint8_t TRAIL_WEIGHT_BYTE = 0xff;  // not compressible
92    static const uint32_t FIRST_TRAILING_PRIMARY = 0xff020200;  // [first trailing]
93    static const uint32_t MAX_PRIMARY = 0xffff0000;  // U+FFFF
94    static const uint32_t MAX_REGULAR_CE32 = 0xffff0505;  // U+FFFF
95
96    // CE32 value for U+FFFD as well as illegal UTF-8 byte sequences (which behave like U+FFFD).
97    // We use the third-highest primary weight for U+FFFD (as in UCA 6.3+).
98    static const uint32_t FFFD_PRIMARY = MAX_PRIMARY - 0x20000;
99    static const uint32_t FFFD_CE32 = MAX_REGULAR_CE32 - 0x20000;
100
101    /**
102     * A CE32 is special if its low byte is this or greater.
103     * Impossible case bits 11 mark special CE32s.
104     * This value itself is used to indicate a fallback to the base collator.
105     */
106    static const uint8_t SPECIAL_CE32_LOW_BYTE = 0xc0;
107    static const uint32_t FALLBACK_CE32 = SPECIAL_CE32_LOW_BYTE;
108    /**
109     * Low byte of a long-primary special CE32.
110     */
111    static const uint8_t LONG_PRIMARY_CE32_LOW_BYTE = 0xc1;  // SPECIAL_CE32_LOW_BYTE | LONG_PRIMARY_TAG
112
113    static const uint32_t UNASSIGNED_CE32 = 0xffffffff;  // Compute an unassigned-implicit CE.
114
115    static const uint32_t NO_CE32 = 1;
116
117    /** No CE: End of input. Only used in runtime code, not stored in data. */
118    static const uint32_t NO_CE_PRIMARY = 1;  // not a left-adjusted weight
119    static const uint32_t NO_CE_WEIGHT16 = 0x0100;  // weight of LEVEL_SEPARATOR_BYTE
120    static const int64_t NO_CE = INT64_C(0x101000100);  // NO_CE_PRIMARY, NO_CE_WEIGHT16, NO_CE_WEIGHT16
121
122    /** Sort key levels. */
123    enum Level {
124        /** Unspecified level. */
125        NO_LEVEL,
126        PRIMARY_LEVEL,
127        SECONDARY_LEVEL,
128        CASE_LEVEL,
129        TERTIARY_LEVEL,
130        QUATERNARY_LEVEL,
131        IDENTICAL_LEVEL,
132        /** Beyond sort key bytes. */
133        ZERO_LEVEL
134    };
135
136    /**
137     * Sort key level flags: xx_FLAG = 1 << xx_LEVEL.
138     * In Java, use enum Level with flag() getters, or use EnumSet rather than hand-made bit sets.
139     */
140    static const uint32_t NO_LEVEL_FLAG = 1;
141    static const uint32_t PRIMARY_LEVEL_FLAG = 2;
142    static const uint32_t SECONDARY_LEVEL_FLAG = 4;
143    static const uint32_t CASE_LEVEL_FLAG = 8;
144    static const uint32_t TERTIARY_LEVEL_FLAG = 0x10;
145    static const uint32_t QUATERNARY_LEVEL_FLAG = 0x20;
146    static const uint32_t IDENTICAL_LEVEL_FLAG = 0x40;
147    static const uint32_t ZERO_LEVEL_FLAG = 0x80;
148
149    /**
150     * Special-CE32 tags, from bits 3..0 of a special 32-bit CE.
151     * Bits 31..8 are available for tag-specific data.
152     * Bits  5..4: Reserved. May be used in the future to indicate lccc!=0 and tccc!=0.
153     */
154    enum {
155        /**
156         * Fall back to the base collator.
157         * This is the tag value in SPECIAL_CE32_LOW_BYTE and FALLBACK_CE32.
158         * Bits 31..8: Unused, 0.
159         */
160        FALLBACK_TAG = 0,
161        /**
162         * Long-primary CE with COMMON_SEC_AND_TER_CE.
163         * Bits 31..8: Three-byte primary.
164         */
165        LONG_PRIMARY_TAG = 1,
166        /**
167         * Long-secondary CE with zero primary.
168         * Bits 31..16: Secondary weight.
169         * Bits 15.. 8: Tertiary weight.
170         */
171        LONG_SECONDARY_TAG = 2,
172        /**
173         * Unused.
174         * May be used in the future for single-byte secondary CEs (SHORT_SECONDARY_TAG),
175         * storing the secondary in bits 31..24, the ccc in bits 23..16,
176         * and the tertiary in bits 15..8.
177         */
178        RESERVED_TAG_3 = 3,
179        /**
180         * Latin mini expansions of two simple CEs [pp, 05, tt] [00, ss, 05].
181         * Bits 31..24: Single-byte primary weight pp of the first CE.
182         * Bits 23..16: Tertiary weight tt of the first CE.
183         * Bits 15.. 8: Secondary weight ss of the second CE.
184         */
185        LATIN_EXPANSION_TAG = 4,
186        /**
187         * Points to one or more simple/long-primary/long-secondary 32-bit CE32s.
188         * Bits 31..13: Index into uint32_t table.
189         * Bits 12.. 8: Length=1..31.
190         */
191        EXPANSION32_TAG = 5,
192        /**
193         * Points to one or more 64-bit CEs.
194         * Bits 31..13: Index into CE table.
195         * Bits 12.. 8: Length=1..31.
196         */
197        EXPANSION_TAG = 6,
198        /**
199         * Builder data, used only in the CollationDataBuilder, not in runtime data.
200         *
201         * If bit 8 is 0: Builder context, points to a list of context-sensitive mappings.
202         * Bits 31..13: Index to the builder's list of ConditionalCE32 for this character.
203         * Bits 12.. 9: Unused, 0.
204         *
205         * If bit 8 is 1 (IS_BUILDER_JAMO_CE32): Builder-only jamoCE32 value.
206         * The builder fetches the Jamo CE32 from the trie.
207         * Bits 31..13: Jamo code point.
208         * Bits 12.. 9: Unused, 0.
209         */
210        BUILDER_DATA_TAG = 7,
211        /**
212         * Points to prefix trie.
213         * Bits 31..13: Index into prefix/contraction data.
214         * Bits 12.. 8: Unused, 0.
215         */
216        PREFIX_TAG = 8,
217        /**
218         * Points to contraction data.
219         * Bits 31..13: Index into prefix/contraction data.
220         * Bits 12..11: Unused, 0.
221         * Bit      10: CONTRACT_TRAILING_CCC flag.
222         * Bit       9: CONTRACT_NEXT_CCC flag.
223         * Bit       8: CONTRACT_SINGLE_CP_NO_MATCH flag.
224         */
225        CONTRACTION_TAG = 9,
226        /**
227         * Decimal digit.
228         * Bits 31..13: Index into uint32_t table for non-numeric-collation CE32.
229         * Bit      12: Unused, 0.
230         * Bits 11.. 8: Digit value 0..9.
231         */
232        DIGIT_TAG = 10,
233        /**
234         * Tag for U+0000, for moving the NUL-termination handling
235         * from the regular fastpath into specials-handling code.
236         * Bits 31..8: Unused, 0.
237         */
238        U0000_TAG = 11,
239        /**
240         * Tag for a Hangul syllable.
241         * Bits 31..9: Unused, 0.
242         * Bit      8: HANGUL_NO_SPECIAL_JAMO flag.
243         */
244        HANGUL_TAG = 12,
245        /**
246         * Tag for a lead surrogate code unit.
247         * Optional optimization for UTF-16 string processing.
248         * Bits 31..10: Unused, 0.
249         *       9.. 8: =0: All associated supplementary code points are unassigned-implict.
250         *              =1: All associated supplementary code points fall back to the base data.
251         *              else: (Normally 2) Look up the data for the supplementary code point.
252         */
253        LEAD_SURROGATE_TAG = 13,
254        /**
255         * Tag for CEs with primary weights in code point order.
256         * Bits 31..13: Index into CE table, for one data "CE".
257         * Bits 12.. 8: Unused, 0.
258         *
259         * This data "CE" has the following bit fields:
260         * Bits 63..32: Three-byte primary pppppp00.
261         *      31.. 8: Start/base code point of the in-order range.
262         *           7: Flag isCompressible primary.
263         *       6.. 0: Per-code point primary-weight increment.
264         */
265        OFFSET_TAG = 14,
266        /**
267         * Implicit CE tag. Compute an unassigned-implicit CE.
268         * All bits are set (UNASSIGNED_CE32=0xffffffff).
269         */
270        IMPLICIT_TAG = 15
271    };
272
273    static UBool isAssignedCE32(uint32_t ce32) {
274        return ce32 != FALLBACK_CE32 && ce32 != UNASSIGNED_CE32;
275    }
276
277    /**
278     * We limit the number of CEs in an expansion
279     * so that we can use a small number of length bits in the data structure,
280     * and so that an implementation can copy CEs at runtime without growing a destination buffer.
281     */
282    static const int32_t MAX_EXPANSION_LENGTH = 31;
283    static const int32_t MAX_INDEX = 0x7ffff;
284
285    /**
286     * Set if there is no match for the single (no-suffix) character itself.
287     * This is only possible if there is a prefix.
288     * In this case, discontiguous contraction matching cannot add combining marks
289     * starting from an empty suffix.
290     * The default CE32 is used anyway if there is no suffix match.
291     */
292    static const uint32_t CONTRACT_SINGLE_CP_NO_MATCH = 0x100;
293    /** Set if the first character of every contraction suffix has lccc!=0. */
294    static const uint32_t CONTRACT_NEXT_CCC = 0x200;
295    /** Set if any contraction suffix ends with lccc!=0. */
296    static const uint32_t CONTRACT_TRAILING_CCC = 0x400;
297
298    /** For HANGUL_TAG: None of its Jamo CE32s isSpecialCE32(). */
299    static const uint32_t HANGUL_NO_SPECIAL_JAMO = 0x100;
300
301    static const uint32_t LEAD_ALL_UNASSIGNED = 0;
302    static const uint32_t LEAD_ALL_FALLBACK = 0x100;
303    static const uint32_t LEAD_MIXED = 0x200;
304    static const uint32_t LEAD_TYPE_MASK = 0x300;
305
306    static uint32_t makeLongPrimaryCE32(uint32_t p) { return p | LONG_PRIMARY_CE32_LOW_BYTE; }
307
308    /** Turns the long-primary CE32 into a primary weight pppppp00. */
309    static inline uint32_t primaryFromLongPrimaryCE32(uint32_t ce32) {
310        return ce32 & 0xffffff00;
311    }
312    static inline int64_t ceFromLongPrimaryCE32(uint32_t ce32) {
313        return ((int64_t)(ce32 & 0xffffff00) << 32) | COMMON_SEC_AND_TER_CE;
314    }
315
316    static uint32_t makeLongSecondaryCE32(uint32_t lower32) {
317        return lower32 | SPECIAL_CE32_LOW_BYTE | LONG_SECONDARY_TAG;
318    }
319    static inline int64_t ceFromLongSecondaryCE32(uint32_t ce32) {
320        return ce32 & 0xffffff00;
321    }
322
323    /** Makes a special CE32 with tag, index and length. */
324    static uint32_t makeCE32FromTagIndexAndLength(int32_t tag, int32_t index, int32_t length) {
325        return (index << 13) | (length << 8) | SPECIAL_CE32_LOW_BYTE | tag;
326    }
327    /** Makes a special CE32 with only tag and index. */
328    static uint32_t makeCE32FromTagAndIndex(int32_t tag, int32_t index) {
329        return (index << 13) | SPECIAL_CE32_LOW_BYTE | tag;
330    }
331
332    static inline UBool isSpecialCE32(uint32_t ce32) {
333        return (ce32 & 0xff) >= SPECIAL_CE32_LOW_BYTE;
334    }
335
336    static inline int32_t tagFromCE32(uint32_t ce32) {
337        return (int32_t)(ce32 & 0xf);
338    }
339
340    static inline UBool hasCE32Tag(uint32_t ce32, int32_t tag) {
341        return isSpecialCE32(ce32) && tagFromCE32(ce32) == tag;
342    }
343
344    static inline UBool isLongPrimaryCE32(uint32_t ce32) {
345        return hasCE32Tag(ce32, LONG_PRIMARY_TAG);
346    }
347
348    static UBool isSimpleOrLongCE32(uint32_t ce32) {
349        return !isSpecialCE32(ce32) ||
350                tagFromCE32(ce32) == LONG_PRIMARY_TAG ||
351                tagFromCE32(ce32) == LONG_SECONDARY_TAG;
352    }
353
354    /**
355     * @return TRUE if the ce32 yields one or more CEs without further data lookups
356     */
357    static UBool isSelfContainedCE32(uint32_t ce32) {
358        return !isSpecialCE32(ce32) ||
359                tagFromCE32(ce32) == LONG_PRIMARY_TAG ||
360                tagFromCE32(ce32) == LONG_SECONDARY_TAG ||
361                tagFromCE32(ce32) == LATIN_EXPANSION_TAG;
362    }
363
364    static inline UBool isPrefixCE32(uint32_t ce32) {
365        return hasCE32Tag(ce32, PREFIX_TAG);
366    }
367
368    static inline UBool isContractionCE32(uint32_t ce32) {
369        return hasCE32Tag(ce32, CONTRACTION_TAG);
370    }
371
372    static inline UBool ce32HasContext(uint32_t ce32) {
373        return isSpecialCE32(ce32) &&
374                (tagFromCE32(ce32) == PREFIX_TAG ||
375                tagFromCE32(ce32) == CONTRACTION_TAG);
376    }
377
378    /**
379     * Get the first of the two Latin-expansion CEs encoded in ce32.
380     * @see LATIN_EXPANSION_TAG
381     */
382    static inline int64_t latinCE0FromCE32(uint32_t ce32) {
383        return ((int64_t)(ce32 & 0xff000000) << 32) | COMMON_SECONDARY_CE | ((ce32 & 0xff0000) >> 8);
384    }
385
386    /**
387     * Get the second of the two Latin-expansion CEs encoded in ce32.
388     * @see LATIN_EXPANSION_TAG
389     */
390    static inline int64_t latinCE1FromCE32(uint32_t ce32) {
391        return ((ce32 & 0xff00) << 16) | COMMON_TERTIARY_CE;
392    }
393
394    /**
395     * Returns the data index from a special CE32.
396     */
397    static inline int32_t indexFromCE32(uint32_t ce32) {
398        return (int32_t)(ce32 >> 13);
399    }
400
401    /**
402     * Returns the data length from a ce32.
403     */
404    static inline int32_t lengthFromCE32(uint32_t ce32) {
405        return (ce32 >> 8) & 31;
406    }
407
408    /**
409     * Returns the digit value from a DIGIT_TAG ce32.
410     */
411    static inline char digitFromCE32(uint32_t ce32) {
412        return (char)((ce32 >> 8) & 0xf);
413    }
414
415    /** Returns a 64-bit CE from a simple CE32 (not special). */
416    static inline int64_t ceFromSimpleCE32(uint32_t ce32) {
417        // normal form ppppsstt -> pppp0000ss00tt00
418        // assert (ce32 & 0xff) < SPECIAL_CE32_LOW_BYTE
419        return ((int64_t)(ce32 & 0xffff0000) << 32) | ((ce32 & 0xff00) << 16) | ((ce32 & 0xff) << 8);
420    }
421
422    /** Returns a 64-bit CE from a simple/long-primary/long-secondary CE32. */
423    static inline int64_t ceFromCE32(uint32_t ce32) {
424        uint32_t tertiary = ce32 & 0xff;
425        if(tertiary < SPECIAL_CE32_LOW_BYTE) {
426            // normal form ppppsstt -> pppp0000ss00tt00
427            return ((int64_t)(ce32 & 0xffff0000) << 32) | ((ce32 & 0xff00) << 16) | (tertiary << 8);
428        } else {
429            ce32 -= tertiary;
430            if((tertiary & 0xf) == LONG_PRIMARY_TAG) {
431                // long-primary form ppppppC1 -> pppppp00050000500
432                return ((int64_t)ce32 << 32) | COMMON_SEC_AND_TER_CE;
433            } else {
434                // long-secondary form ssssttC2 -> 00000000sssstt00
435                // assert (tertiary & 0xf) == LONG_SECONDARY_TAG
436                return ce32;
437            }
438        }
439    }
440
441    /** Creates a CE from a primary weight. */
442    static inline int64_t makeCE(uint32_t p) {
443        return ((int64_t)p << 32) | COMMON_SEC_AND_TER_CE;
444    }
445    /**
446     * Creates a CE from a primary weight,
447     * 16-bit secondary/tertiary weights, and a 2-bit quaternary.
448     */
449    static inline int64_t makeCE(uint32_t p, uint32_t s, uint32_t t, uint32_t q) {
450        return ((int64_t)p << 32) | (s << 16) | t | (q << 6);
451    }
452
453    /**
454     * Increments a 2-byte primary by a code point offset.
455     */
456    static uint32_t incTwoBytePrimaryByOffset(uint32_t basePrimary, UBool isCompressible,
457                                              int32_t offset);
458
459    /**
460     * Increments a 3-byte primary by a code point offset.
461     */
462    static uint32_t incThreeBytePrimaryByOffset(uint32_t basePrimary, UBool isCompressible,
463                                                int32_t offset);
464
465    /**
466     * Decrements a 2-byte primary by one range step (1..0x7f).
467     */
468    static uint32_t decTwoBytePrimaryByOneStep(uint32_t basePrimary, UBool isCompressible, int32_t step);
469
470    /**
471     * Decrements a 3-byte primary by one range step (1..0x7f).
472     */
473    static uint32_t decThreeBytePrimaryByOneStep(uint32_t basePrimary, UBool isCompressible, int32_t step);
474
475    /**
476     * Computes a 3-byte primary for c's OFFSET_TAG data "CE".
477     */
478    static uint32_t getThreeBytePrimaryForOffsetData(UChar32 c, int64_t dataCE);
479
480    /**
481     * Returns the unassigned-character implicit primary weight for any valid code point c.
482     */
483    static uint32_t unassignedPrimaryFromCodePoint(UChar32 c);
484
485    static inline int64_t unassignedCEFromCodePoint(UChar32 c) {
486        return makeCE(unassignedPrimaryFromCodePoint(c));
487    }
488
489    static inline uint32_t reorder(const uint8_t reorderTable[256], uint32_t primary) {
490        return ((uint32_t)reorderTable[primary >> 24] << 24) | (primary & 0xffffff);
491    }
492
493private:
494    Collation();  // No instantiation.
495};
496
497U_NAMESPACE_END
498
499#endif  // !UCONFIG_NO_COLLATION
500#endif  // __COLLATION_H__
501