Victor Chang | 7322950 | 2020-09-17 13:39:19 +0100 | [diff] [blame] | 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 | |
| 25 | U_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 | */ |
| 38 | class BMPSet : public UMemory { |
| 39 | public: |
| 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 UChar *span(const UChar *s, const UChar *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 UChar *spanBack(const UChar *s, const UChar *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 | |
| 74 | private: |
| 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 | |
Victor Chang | ce4bf3c | 2021-01-19 16:34:24 +0000 | [diff] [blame] | 104 | /* true if contains(U+FFFD). */ |
Victor Chang | 7322950 | 2020-09-17 13:39:19 +0100 | [diff] [blame] | 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 | |
| 158 | inline UBool BMPSet::containsSlow(UChar32 c, int32_t lo, int32_t hi) const { |
| 159 | return (UBool)(findCodePoint(c, lo, hi) & 1); |
| 160 | } |
| 161 | |
| 162 | U_NAMESPACE_END |
| 163 | |
| 164 | #endif |