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) 2007, International Business Machines
7* Corporation and others. All Rights Reserved.
8*
9******************************************************************************
10* file name: bmpset.h
11* encoding: UTF-8
12* tab size: 8 (not used)
13* indentation:4
14*
15* created on: 2007jan29
16* created by: Markus W. Scherer
17*/
18
19#ifndef __BMPSET_H__
20#define __BMPSET_H__
21
22#include "unicode/utypes.h"
23#include "unicode/uniset.h"
24
25U_NAMESPACE_BEGIN
26
27/*
28 * Helper class for frozen UnicodeSets, implements contains() and span()
29 * optimized for BMP code points. Structured to be UTF-8-friendly.
30 *
31 * Latin-1: Look up bytes.
32 * 2-byte characters: Bits organized vertically.
33 * 3-byte characters: Use zero/one/mixed data per 64-block in U+0000..U+FFFF,
34 * with mixed for illegal ranges.
35 * Supplementary characters: Binary search over
36 * the supplementary part of the parent set's inversion list.
37 */
38class BMPSet : public UMemory {
39public:
40 BMPSet(const int32_t *parentList, int32_t parentListLength);
41 BMPSet(const BMPSet &otherBMPSet, const int32_t *newParentList, int32_t newParentListLength);
42 virtual ~BMPSet();
43
44 virtual UBool contains(UChar32 c) const;
45
46 /*
47 * Span the initial substring for which each character c has spanCondition==contains(c).
48 * It must be s<limit and spanCondition==0 or 1.
49 * @return The string pointer which limits the span.
50 */
51 const char16_t *span(const char16_t *s, const char16_t *limit, USetSpanCondition spanCondition) const;
52
53 /*
54 * Span the trailing substring for which each character c has spanCondition==contains(c).
55 * It must be s<limit and spanCondition==0 or 1.
56 * @return The string pointer which starts the span.
57 */
58 const char16_t *spanBack(const char16_t *s, const char16_t *limit, USetSpanCondition spanCondition) const;
59
60 /*
61 * Span the initial substring for which each character c has spanCondition==contains(c).
62 * It must be length>0 and spanCondition==0 or 1.
63 * @return The string pointer which limits the span.
64 */
65 const uint8_t *spanUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const;
66
67 /*
68 * Span the trailing substring for which each character c has spanCondition==contains(c).
69 * It must be length>0 and spanCondition==0 or 1.
70 * @return The start of the span.
71 */
72 int32_t spanBackUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const;
73
74private:
75 void initBits();
76 void overrideIllegal();
77
78 /**
79 * Same as UnicodeSet::findCodePoint(UChar32 c) const except that the
80 * binary search is restricted for finding code points in a certain range.
81 *
82 * For restricting the search for finding in the range start..end,
83 * pass in
84 * lo=findCodePoint(start) and
85 * hi=findCodePoint(end)
86 * with 0<=lo<=hi<len.
87 * findCodePoint(c) defaults to lo=0 and hi=len-1.
88 *
89 * @param c a character in a subrange of MIN_VALUE..MAX_VALUE
90 * @param lo The lowest index to be returned.
91 * @param hi The highest index to be returned.
92 * @return the smallest integer i in the range lo..hi,
93 * inclusive, such that c < list[i]
94 */
95 int32_t findCodePoint(UChar32 c, int32_t lo, int32_t hi) const;
96
97 inline UBool containsSlow(UChar32 c, int32_t lo, int32_t hi) const;
98
99 /*
100 * One byte 0 or 1 per Latin-1 character.
101 */
102 UBool latin1Contains[0x100];
103
104 /* true if contains(U+FFFD). */
105 UBool containsFFFD;
106
107 /*
108 * One bit per code point from U+0000..U+07FF.
109 * The bits are organized vertically; consecutive code points
110 * correspond to the same bit positions in consecutive table words.
111 * With code point parts
112 * lead=c{10..6}
113 * trail=c{5..0}
114 * it is set.contains(c)==(table7FF[trail] bit lead)
115 *
116 * Bits for 0..7F (non-shortest forms) are set to the result of contains(FFFD)
117 * for faster validity checking at runtime.
118 */
119 uint32_t table7FF[64];
120
121 /*
122 * One bit per 64 BMP code points.
123 * The bits are organized vertically; consecutive 64-code point blocks
124 * correspond to the same bit position in consecutive table words.
125 * With code point parts
126 * lead=c{15..12}
127 * t1=c{11..6}
128 * test bits (lead+16) and lead in bmpBlockBits[t1].
129 * If the upper bit is 0, then the lower bit indicates if contains(c)
130 * for all code points in the 64-block.
131 * If the upper bit is 1, then the block is mixed and set.contains(c)
132 * must be called.
133 *
134 * Bits for 0..7FF (non-shortest forms) and D800..DFFF are set to
135 * the result of contains(FFFD) for faster validity checking at runtime.
136 */
137 uint32_t bmpBlockBits[64];
138
139 /*
140 * Inversion list indexes for restricted binary searches in
141 * findCodePoint(), from
142 * findCodePoint(U+0800, U+1000, U+2000, .., U+F000, U+10000).
143 * U+0800 is the first 3-byte-UTF-8 code point. Code points below U+0800 are
144 * always looked up in the bit tables.
145 * The last pair of indexes is for finding supplementary code points.
146 */
147 int32_t list4kStarts[18];
148
149 /*
150 * The inversion list of the parent set, for the slower contains() implementation
151 * for mixed BMP blocks and for supplementary code points.
152 * The list is terminated with list[listLength-1]=0x110000.
153 */
154 const int32_t *list;
155 int32_t listLength;
156};
157
158inline UBool BMPSet::containsSlow(UChar32 c, int32_t lo, int32_t hi) const {
159 return (UBool)(findCodePoint(c, lo, hi) & 1);
160}
161
162U_NAMESPACE_END
163
164#endif
165