1 // Copyright (C) 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: US-ASCII 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 * ASCII: 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: Call contains() on the parent set. 36 */ 37 class BMPSet : public UMemory { 38 public: 39 BMPSet(const int32_t *parentList, int32_t parentListLength); 40 BMPSet(const BMPSet &otherBMPSet, const int32_t *newParentList, int32_t newParentListLength); 41 virtual ~BMPSet(); 42 43 virtual UBool contains(UChar32 c) const; 44 45 /* 46 * Span the initial substring for which each character c has spanCondition==contains(c). 47 * It must be s<limit and spanCondition==0 or 1. 48 * @return The string pointer which limits the span. 49 */ 50 const UChar *span(const UChar *s, const UChar *limit, USetSpanCondition spanCondition) const; 51 52 /* 53 * Span the trailing substring for which each character c has spanCondition==contains(c). 54 * It must be s<limit and spanCondition==0 or 1. 55 * @return The string pointer which starts the span. 56 */ 57 const UChar *spanBack(const UChar *s, const UChar *limit, USetSpanCondition spanCondition) const; 58 59 /* 60 * Span the initial substring for which each character c has spanCondition==contains(c). 61 * It must be length>0 and spanCondition==0 or 1. 62 * @return The string pointer which limits the span. 63 */ 64 const uint8_t *spanUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const; 65 66 /* 67 * Span the trailing substring for which each character c has spanCondition==contains(c). 68 * It must be length>0 and spanCondition==0 or 1. 69 * @return The start of the span. 70 */ 71 int32_t spanBackUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const; 72 73 private: 74 void initBits(); 75 void overrideIllegal(); 76 77 /** 78 * Same as UnicodeSet::findCodePoint(UChar32 c) const except that the 79 * binary search is restricted for finding code points in a certain range. 80 * 81 * For restricting the search for finding in the range start..end, 82 * pass in 83 * lo=findCodePoint(start) and 84 * hi=findCodePoint(end) 85 * with 0<=lo<=hi<len. 86 * findCodePoint(c) defaults to lo=0 and hi=len-1. 87 * 88 * @param c a character in a subrange of MIN_VALUE..MAX_VALUE 89 * @param lo The lowest index to be returned. 90 * @param hi The highest index to be returned. 91 * @return the smallest integer i in the range lo..hi, 92 * inclusive, such that c < list[i] 93 */ 94 int32_t findCodePoint(UChar32 c, int32_t lo, int32_t hi) const; 95 96 inline UBool containsSlow(UChar32 c, int32_t lo, int32_t hi) const; 97 98 /* 99 * One byte per ASCII character, or trail byte in lead position. 100 * 0 or 1 for ASCII characters. 101 * The value for trail bytes is the result of contains(FFFD) 102 * for faster validity checking at runtime. 103 */ 104 UBool asciiBytes[0xc0]; 105 106 /* 107 * One bit per code point from U+0000..U+07FF. 108 * The bits are organized vertically; consecutive code points 109 * correspond to the same bit positions in consecutive table words. 110 * With code point parts 111 * lead=c{10..6} 112 * trail=c{5..0} 113 * it is set.contains(c)==(table7FF[trail] bit lead) 114 * 115 * Bits for 0..7F (non-shortest forms) are set to the result of contains(FFFD) 116 * for faster validity checking at runtime. 117 */ 118 uint32_t table7FF[64]; 119 120 /* 121 * One bit per 64 BMP code points. 122 * The bits are organized vertically; consecutive 64-code point blocks 123 * correspond to the same bit position in consecutive table words. 124 * With code point parts 125 * lead=c{15..12} 126 * t1=c{11..6} 127 * test bits (lead+16) and lead in bmpBlockBits[t1]. 128 * If the upper bit is 0, then the lower bit indicates if contains(c) 129 * for all code points in the 64-block. 130 * If the upper bit is 1, then the block is mixed and set.contains(c) 131 * must be called. 132 * 133 * Bits for 0..7FF (non-shortest forms) and D800..DFFF are set to 134 * the result of contains(FFFD) for faster validity checking at runtime. 135 */ 136 uint32_t bmpBlockBits[64]; 137 138 /* 139 * Inversion list indexes for restricted binary searches in 140 * findCodePoint(), from 141 * findCodePoint(U+0800, U+1000, U+2000, .., U+F000, U+10000). 142 * U+0800 is the first 3-byte-UTF-8 code point. Code points below U+0800 are 143 * always looked up in the bit tables. 144 * The last pair of indexes is for finding supplementary code points. 145 */ 146 int32_t list4kStarts[18]; 147 148 /* 149 * The inversion list of the parent set, for the slower contains() implementation 150 * for mixed BMP blocks and for supplementary code points. 151 * The list is terminated with list[listLength-1]=0x110000. 152 */ 153 const int32_t *list; 154 int32_t listLength; 155 }; 156 157 inline UBool BMPSet::containsSlow(UChar32 c, int32_t lo, int32_t hi) const { 158 return (UBool)(findCodePoint(c, lo, hi) & 1); 159 } 160 161 U_NAMESPACE_END 162 163 #endif 164
