1 /* 2 * Copyright 2012 Google, Inc. 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 * 24 * Google Author(s): Behdad Esfahbod 25 */ 26 27 #ifndef HB_SET_PRIVATE_HH 28 #define HB_SET_PRIVATE_HH 29 30 #include "hb-private.hh" 31 #include "hb-set.h" 32 #include "hb-object-private.hh" 33 34 35 struct hb_set_digest_common_bits_t 36 { 37 ASSERT_POD (); 38 39 typedef unsigned int mask_t; 40 41 inline void init (void) { 42 mask = ~0; 43 value = (mask_t) -1; 44 } 45 46 inline void add (hb_codepoint_t g) { 47 if (unlikely (value == (mask_t) -1)) { 48 value = g; 49 return; 50 } 51 52 mask ^= (g & mask) ^ value; 53 value &= mask; 54 } 55 56 inline void add_range (hb_codepoint_t a, hb_codepoint_t b) { 57 /* The negation here stands for ~(x-1). */ 58 mask &= -(1 << _hb_bit_storage (a ^ b)); 59 value &= mask; 60 } 61 62 inline bool may_have (hb_codepoint_t g) const { 63 return (g & mask) == value; 64 } 65 66 private: 67 mask_t mask; 68 mask_t value; 69 }; 70 71 struct hb_set_digest_lowest_bits_t 72 { 73 ASSERT_POD (); 74 75 typedef unsigned long mask_t; 76 77 inline void init (void) { 78 mask = 0; 79 } 80 81 inline void add (hb_codepoint_t g) { 82 mask |= mask_for (g); 83 } 84 85 inline void add_range (hb_codepoint_t a, hb_codepoint_t b) { 86 if (b - a >= sizeof (mask_t) * 8 - 1) 87 mask = (mask_t) -1; 88 else { 89 mask_t ma = mask_for (a); 90 mask_t mb = mask_for (b); 91 mask |= mb + (mb - ma) - (mb < ma); 92 } 93 } 94 95 inline bool may_have (hb_codepoint_t g) const { 96 return !!(mask & mask_for (g)); 97 } 98 99 private: 100 101 static inline mask_t mask_for (hb_codepoint_t g) { return ((mask_t) 1) << (g & (sizeof (mask_t) * 8 - 1)); } 102 mask_t mask; 103 }; 104 105 struct hb_set_digest_t 106 { 107 ASSERT_POD (); 108 109 inline void init (void) { 110 digest1.init (); 111 digest2.init (); 112 } 113 114 inline void add (hb_codepoint_t g) { 115 digest1.add (g); 116 digest2.add (g); 117 } 118 119 inline void add_range (hb_codepoint_t a, hb_codepoint_t b) { 120 digest1.add_range (a, b); 121 digest2.add_range (a, b); 122 } 123 124 inline bool may_have (hb_codepoint_t g) const { 125 return digest1.may_have (g) && digest2.may_have (g); 126 } 127 128 private: 129 hb_set_digest_common_bits_t digest1; 130 hb_set_digest_lowest_bits_t digest2; 131 }; 132 133 134 /* TODO Make this faster and memmory efficient. */ 135 136 struct hb_set_t 137 { 138 hb_object_header_t header; 139 ASSERT_POD (); 140 bool in_error; 141 142 inline void init (void) { 143 header.init (); 144 clear (); 145 } 146 inline void fini (void) { 147 } 148 inline void clear (void) { 149 if (unlikely (hb_object_is_inert (this))) 150 return; 151 in_error = false; 152 memset (elts, 0, sizeof elts); 153 } 154 inline bool is_empty (void) const { 155 for (unsigned int i = 0; i < ARRAY_LENGTH (elts); i++) 156 if (elts[i]) 157 return false; 158 return true; 159 } 160 inline void add (hb_codepoint_t g) 161 { 162 if (unlikely (in_error)) return; 163 if (unlikely (g == SENTINEL)) return; 164 if (unlikely (g > MAX_G)) return; 165 elt (g) |= mask (g); 166 } 167 inline void add_range (hb_codepoint_t a, hb_codepoint_t b) 168 { 169 if (unlikely (in_error)) return; 170 /* TODO Speedup */ 171 for (unsigned int i = a; i < b + 1; i++) 172 add (i); 173 } 174 inline void del (hb_codepoint_t g) 175 { 176 if (unlikely (in_error)) return; 177 if (unlikely (g > MAX_G)) return; 178 elt (g) &= ~mask (g); 179 } 180 inline void del_range (hb_codepoint_t a, hb_codepoint_t b) 181 { 182 if (unlikely (in_error)) return; 183 /* TODO Speedup */ 184 for (unsigned int i = a; i < b + 1; i++) 185 del (i); 186 } 187 inline bool has (hb_codepoint_t g) const 188 { 189 if (unlikely (g > MAX_G)) return false; 190 return !!(elt (g) & mask (g)); 191 } 192 inline bool intersects (hb_codepoint_t first, 193 hb_codepoint_t last) const 194 { 195 if (unlikely (first > MAX_G)) return false; 196 if (unlikely (last > MAX_G)) last = MAX_G; 197 unsigned int end = last + 1; 198 for (hb_codepoint_t i = first; i < end; i++) 199 if (has (i)) 200 return true; 201 return false; 202 } 203 inline bool is_equal (const hb_set_t *other) const 204 { 205 for (unsigned int i = 0; i < ELTS; i++) 206 if (elts[i] != other->elts[i]) 207 return false; 208 return true; 209 } 210 inline void set (const hb_set_t *other) 211 { 212 if (unlikely (in_error)) return; 213 for (unsigned int i = 0; i < ELTS; i++) 214 elts[i] = other->elts[i]; 215 } 216 inline void union_ (const hb_set_t *other) 217 { 218 if (unlikely (in_error)) return; 219 for (unsigned int i = 0; i < ELTS; i++) 220 elts[i] |= other->elts[i]; 221 } 222 inline void intersect (const hb_set_t *other) 223 { 224 if (unlikely (in_error)) return; 225 for (unsigned int i = 0; i < ELTS; i++) 226 elts[i] &= other->elts[i]; 227 } 228 inline void subtract (const hb_set_t *other) 229 { 230 if (unlikely (in_error)) return; 231 for (unsigned int i = 0; i < ELTS; i++) 232 elts[i] &= ~other->elts[i]; 233 } 234 inline void symmetric_difference (const hb_set_t *other) 235 { 236 if (unlikely (in_error)) return; 237 for (unsigned int i = 0; i < ELTS; i++) 238 elts[i] ^= other->elts[i]; 239 } 240 inline void invert (void) 241 { 242 if (unlikely (in_error)) return; 243 for (unsigned int i = 0; i < ELTS; i++) 244 elts[i] = ~elts[i]; 245 } 246 inline bool next (hb_codepoint_t *codepoint) const 247 { 248 if (unlikely (*codepoint == SENTINEL)) { 249 hb_codepoint_t i = get_min (); 250 if (i != SENTINEL) { 251 *codepoint = i; 252 return true; 253 } else 254 return false; 255 } 256 for (hb_codepoint_t i = *codepoint + 1; i < MAX_G + 1; i++) 257 if (has (i)) { 258 *codepoint = i; 259 return true; 260 } 261 return false; 262 } 263 inline bool next_range (hb_codepoint_t *first, hb_codepoint_t *last) const 264 { 265 hb_codepoint_t i; 266 267 i = *last; 268 if (!next (&i)) 269 return false; 270 271 *last = *first = i; 272 while (next (&i) && i == *last + 1) 273 (*last)++; 274 275 return true; 276 } 277 278 inline unsigned int get_population (void) const 279 { 280 unsigned int count = 0; 281 for (unsigned int i = 0; i < ELTS; i++) 282 count += _hb_popcount32 (elts[i]); 283 return count; 284 } 285 inline hb_codepoint_t get_min (void) const 286 { 287 for (unsigned int i = 0; i < ELTS; i++) 288 if (elts[i]) 289 for (unsigned int j = 0; i < BITS; j++) 290 if (elts[i] & (1 << j)) 291 return i * BITS + j; 292 return SENTINEL; 293 } 294 inline hb_codepoint_t get_max (void) const 295 { 296 for (unsigned int i = ELTS; i; i--) 297 if (elts[i - 1]) 298 for (unsigned int j = BITS; j; j--) 299 if (elts[i - 1] & (1 << (j - 1))) 300 return (i - 1) * BITS + (j - 1); 301 return SENTINEL; 302 } 303 304 typedef uint32_t elt_t; 305 static const unsigned int MAX_G = 65536 - 1; /* XXX Fix this... */ 306 static const unsigned int SHIFT = 5; 307 static const unsigned int BITS = (1 << SHIFT); 308 static const unsigned int MASK = BITS - 1; 309 static const unsigned int ELTS = (MAX_G + 1 + (BITS - 1)) / BITS; 310 static const hb_codepoint_t SENTINEL = (hb_codepoint_t) -1; 311 312 elt_t &elt (hb_codepoint_t g) { return elts[g >> SHIFT]; } 313 elt_t elt (hb_codepoint_t g) const { return elts[g >> SHIFT]; } 314 elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & MASK); } 315 316 elt_t elts[ELTS]; /* XXX 8kb */ 317 318 ASSERT_STATIC (sizeof (elt_t) * 8 == BITS); 319 ASSERT_STATIC (sizeof (elt_t) * 8 * ELTS > MAX_G); 320 }; 321 322 323 324 #endif /* HB_SET_PRIVATE_HH */ 325
