icuSources/i18n/collationcompare.cpp

   1 /*
   2 *******************************************************************************
   3 * Copyright (C) 1996-2015, International Business Machines
   4 * Corporation and others.  All Rights Reserved.
   5 *******************************************************************************
   6 * collationcompare.cpp
   7 *
   8 * created on: 2012feb14 with new and old collation code
   9 * created by: Markus W. Scherer
  10 */
  11
  12 #include "unicode/utypes.h"
  13
  14 #if !UCONFIG_NO_COLLATION
  15
  16 #include "unicode/ucol.h"
  17 #include "cmemory.h"
  18 #include "collation.h"
  19 #include "collationcompare.h"
  20 #include "collationiterator.h"
  21 #include "collationsettings.h"
  22 #include "uassert.h"
  23
  24 U_NAMESPACE_BEGIN
  25
  26 UCollationResult
  27 CollationCompare::compareUpToQuaternary(CollationIterator &left, CollationIterator &right,
  28                                         const CollationSettings &settings,
  29                                         UErrorCode &errorCode) {
  30     if(U_FAILURE(errorCode)) { return UCOL_EQUAL; }
  31
  32     int32_t options = settings.options;
  33     uint32_t variableTop;
  34     if((options & CollationSettings::ALTERNATE_MASK) == 0) {
  35         variableTop = 0;
  36     } else {
  37         // +1 so that we can use "<" and primary ignorables test out early.
  38         variableTop = settings.variableTop + 1;
  39     }
  40     UBool anyVariable = FALSE;
  41
  42     // Fetch CEs, compare primaries, store secondary & tertiary weights.
  43     U_ALIGN_CODE(16);
  44     for(;;) {
  45         // We fetch CEs until we get a non-ignorable primary or reach the end.
  46         uint32_t leftPrimary;
  47         do {
  48             int64_t ce = left.nextCE(errorCode);
  49             leftPrimary = (uint32_t)(ce >> 32);
  50             if(leftPrimary < variableTop && leftPrimary > Collation::MERGE_SEPARATOR_PRIMARY) {
  51                 // Variable CE, shift it to quaternary level.
  52                 // Ignore all following primary ignorables, and shift further variable CEs.
  53                 anyVariable = TRUE;
  54                 do {
  55                     // Store only the primary of the variable CE.
  56                     left.setCurrentCE(ce & INT64_C(0xffffffff00000000));
  57                     for(;;) {
  58                         ce = left.nextCE(errorCode);
  59                         leftPrimary = (uint32_t)(ce >> 32);
  60                         if(leftPrimary == 0) {
  61                             left.setCurrentCE(0);
  62                         } else {
  63                             break;
  64                         }
  65                     }
  66                 } while(leftPrimary < variableTop &&
  67                         leftPrimary > Collation::MERGE_SEPARATOR_PRIMARY);
  68             }
  69         } while(leftPrimary == 0);
  70
  71         uint32_t rightPrimary;
  72         do {
  73             int64_t ce = right.nextCE(errorCode);
  74             rightPrimary = (uint32_t)(ce >> 32);
  75             if(rightPrimary < variableTop && rightPrimary > Collation::MERGE_SEPARATOR_PRIMARY) {
  76                 // Variable CE, shift it to quaternary level.
  77                 // Ignore all following primary ignorables, and shift further variable CEs.
  78                 anyVariable = TRUE;
  79                 do {
  80                     // Store only the primary of the variable CE.
  81                     right.setCurrentCE(ce & INT64_C(0xffffffff00000000));
  82                     for(;;) {
  83                         ce = right.nextCE(errorCode);
  84                         rightPrimary = (uint32_t)(ce >> 32);
  85                         if(rightPrimary == 0) {
  86                             right.setCurrentCE(0);
  87                         } else {
  88                             break;
  89                         }
  90                     }
  91                 } while(rightPrimary < variableTop &&
  92                         rightPrimary > Collation::MERGE_SEPARATOR_PRIMARY);
  93             }
  94         } while(rightPrimary == 0);
  95
  96         if(leftPrimary != rightPrimary) {
  97             // Return the primary difference, with script reordering.
  98             if(settings.hasReordering()) {
  99                 leftPrimary = settings.reorder(leftPrimary);
 100                 rightPrimary = settings.reorder(rightPrimary);
 101             }
 102             return (leftPrimary < rightPrimary) ? UCOL_LESS : UCOL_GREATER;
 103         }
 104         if(leftPrimary == Collation::NO_CE_PRIMARY) { break; }
 105     }
 106     if(U_FAILURE(errorCode)) { return UCOL_EQUAL; }
 107
 108     // Compare the buffered secondary & tertiary weights.
 109     // We might skip the secondary level but continue with the case level
 110     // which is turned on separately.
 111     if(CollationSettings::getStrength(options) >= UCOL_SECONDARY) {
 112         if((options & CollationSettings::BACKWARD_SECONDARY) == 0) {
 113             int32_t leftIndex = 0;
 114             int32_t rightIndex = 0;
 115             for(;;) {
 116                 uint32_t leftSecondary;
 117                 do {
 118                     leftSecondary = ((uint32_t)left.getCE(leftIndex++)) >> 16;
 119                 } while(leftSecondary == 0);
 120
 121                 uint32_t rightSecondary;
 122                 do {
 123                     rightSecondary = ((uint32_t)right.getCE(rightIndex++)) >> 16;
 124                 } while(rightSecondary == 0);
 125
 126                 if(leftSecondary != rightSecondary) {
 127                     return (leftSecondary < rightSecondary) ? UCOL_LESS : UCOL_GREATER;
 128                 }
 129                 if(leftSecondary == Collation::NO_CE_WEIGHT16) { break; }
 130             }
 131         } else {
 132             // The backwards secondary level compares secondary weights backwards
 133             // within segments separated by the merge separator (U+FFFE, weight 02).
 134             int32_t leftStart = 0;
 135             int32_t rightStart = 0;
 136             for(;;) {
 137                 // Find the merge separator or the NO_CE terminator.
 138                 uint32_t p;
 139                 int32_t leftLimit = leftStart;
 140                 while((p = (uint32_t)(left.getCE(leftLimit) >> 32)) >
 141                             Collation::MERGE_SEPARATOR_PRIMARY ||
 142                         p == 0) {
 143                     ++leftLimit;
 144                 }
 145                 int32_t rightLimit = rightStart;
 146                 while((p = (uint32_t)(right.getCE(rightLimit) >> 32)) >
 147                             Collation::MERGE_SEPARATOR_PRIMARY ||
 148                         p == 0) {
 149                     ++rightLimit;
 150                 }
 151
 152                 // Compare the segments.
 153                 int32_t leftIndex = leftLimit;
 154                 int32_t rightIndex = rightLimit;
 155                 for(;;) {
 156                     int32_t leftSecondary = 0;
 157                     while(leftSecondary == 0 && leftIndex > leftStart) {
 158                         leftSecondary = ((uint32_t)left.getCE(--leftIndex)) >> 16;
 159                     }
 160
 161                     int32_t rightSecondary = 0;
 162                     while(rightSecondary == 0 && rightIndex > rightStart) {
 163                         rightSecondary = ((uint32_t)right.getCE(--rightIndex)) >> 16;
 164                     }
 165
 166                     if(leftSecondary != rightSecondary) {
 167                         return (leftSecondary < rightSecondary) ? UCOL_LESS : UCOL_GREATER;
 168                     }
 169                     if(leftSecondary == 0) { break; }
 170                 }
 171
 172                 // Did we reach the end of either string?
 173                 // Both strings have the same number of merge separators,
 174                 // or else there would have been a primary-level difference.
 175                 U_ASSERT(left.getCE(leftLimit) == right.getCE(rightLimit));
 176                 if(p == Collation::NO_CE_PRIMARY) { break; }
 177                 // Skip both merge separators and continue.
 178                 leftStart = leftLimit + 1;
 179                 rightStart = rightLimit + 1;
 180             }
 181         }
 182     }
 183
 184     if((options & CollationSettings::CASE_LEVEL) != 0) {
 185         int32_t strength = CollationSettings::getStrength(options);
 186         int32_t leftIndex = 0;
 187         int32_t rightIndex = 0;
 188         for(;;) {
 189             uint32_t leftCase, leftLower32, rightCase;
 190             if(strength == UCOL_PRIMARY) {
 191                 // Primary+caseLevel: Ignore case level weights of primary ignorables.
 192                 // Otherwise we would get a-umlaut > a
 193                 // which is not desirable for accent-insensitive sorting.
 194                 // Check for (lower 32 bits) == 0 as well because variable CEs are stored
 195                 // with only primary weights.
 196                 int64_t ce;
 197                 do {
 198                     ce = left.getCE(leftIndex++);
 199                     leftCase = (uint32_t)ce;
 200                 } while((uint32_t)(ce >> 32) == 0 || leftCase == 0);
 201                 leftLower32 = leftCase;
 202                 leftCase &= 0xc000;
 203
 204                 do {
 205                     ce = right.getCE(rightIndex++);
 206                     rightCase = (uint32_t)ce;
 207                 } while((uint32_t)(ce >> 32) == 0 || rightCase == 0);
 208                 rightCase &= 0xc000;
 209             } else {
 210                 // Secondary+caseLevel: By analogy with the above,
 211                 // ignore case level weights of secondary ignorables.
 212                 //
 213                 // Note: A tertiary CE has uppercase case bits (0.0.ut)
 214                 // to keep tertiary+caseFirst well-formed.
 215                 //
 216                 // Tertiary+caseLevel: Also ignore case level weights of secondary ignorables.
 217                 // Otherwise a tertiary CE's uppercase would be no greater than
 218                 // a primary/secondary CE's uppercase.
 219                 // (See UCA well-formedness condition 2.)
 220                 // We could construct a special case weight higher than uppercase,
 221                 // but it's simpler to always ignore case weights of secondary ignorables,
 222                 // turning 0.0.ut into 0.0.0.t.
 223                 // (See LDML Collation, Case Parameters.)
 224                 do {
 225                     leftCase = (uint32_t)left.getCE(leftIndex++);
 226                 } while(leftCase <= 0xffff);
 227                 leftLower32 = leftCase;
 228                 leftCase &= 0xc000;
 229
 230                 do {
 231                     rightCase = (uint32_t)right.getCE(rightIndex++);
 232                 } while(rightCase <= 0xffff);
 233                 rightCase &= 0xc000;
 234             }
 235
 236             // No need to handle NO_CE and MERGE_SEPARATOR specially:
 237             // There is one case weight for each previous-level weight,
 238             // so level length differences were handled there.
 239             if(leftCase != rightCase) {
 240                 if((options & CollationSettings::UPPER_FIRST) == 0) {
 241                     return (leftCase < rightCase) ? UCOL_LESS : UCOL_GREATER;
 242                 } else {
 243                     return (leftCase < rightCase) ? UCOL_GREATER : UCOL_LESS;
 244                 }
 245             }
 246             if((leftLower32 >> 16) == Collation::NO_CE_WEIGHT16) { break; }
 247         }
 248     }
 249     if(CollationSettings::getStrength(options) <= UCOL_SECONDARY) { return UCOL_EQUAL; }
 250
 251     uint32_t tertiaryMask = CollationSettings::getTertiaryMask(options);
 252
 253     int32_t leftIndex = 0;
 254     int32_t rightIndex = 0;
 255     uint32_t anyQuaternaries = 0;
 256     for(;;) {
 257         uint32_t leftLower32, leftTertiary;
 258         do {
 259             leftLower32 = (uint32_t)left.getCE(leftIndex++);
 260             anyQuaternaries |= leftLower32;
 261             U_ASSERT((leftLower32 & Collation::ONLY_TERTIARY_MASK) != 0 ||
 262                      (leftLower32 & 0xc0c0) == 0);
 263             leftTertiary = leftLower32 & tertiaryMask;
 264         } while(leftTertiary == 0);
 265
 266         uint32_t rightLower32, rightTertiary;
 267         do {
 268             rightLower32 = (uint32_t)right.getCE(rightIndex++);
 269             anyQuaternaries |= rightLower32;
 270             U_ASSERT((rightLower32 & Collation::ONLY_TERTIARY_MASK) != 0 ||
 271                      (rightLower32 & 0xc0c0) == 0);
 272             rightTertiary = rightLower32 & tertiaryMask;
 273         } while(rightTertiary == 0);
 274
 275         if(leftTertiary != rightTertiary) {
 276             if(CollationSettings::sortsTertiaryUpperCaseFirst(options)) {
 277                 // Pass through NO_CE and keep real tertiary weights larger than that.
 278                 // Do not change the artificial uppercase weight of a tertiary CE (0.0.ut),
 279                 // to keep tertiary CEs well-formed.
 280                 // Their case+tertiary weights must be greater than those of
 281                 // primary and secondary CEs.
 282                 if(leftTertiary > Collation::NO_CE_WEIGHT16) {
 283                     if(leftLower32 > 0xffff) {
 284                         leftTertiary ^= 0xc000;
 285                     } else {
 286                         leftTertiary += 0x4000;
 287                     }
 288                 }
 289                 if(rightTertiary > Collation::NO_CE_WEIGHT16) {
 290                     if(rightLower32 > 0xffff) {
 291                         rightTertiary ^= 0xc000;
 292                     } else {
 293                         rightTertiary += 0x4000;
 294                     }
 295                 }
 296             }
 297             return (leftTertiary < rightTertiary) ? UCOL_LESS : UCOL_GREATER;
 298         }
 299         if(leftTertiary == Collation::NO_CE_WEIGHT16) { break; }
 300     }
 301     if(CollationSettings::getStrength(options) <= UCOL_TERTIARY) { return UCOL_EQUAL; }
 302
 303     if(!anyVariable && (anyQuaternaries & 0xc0) == 0) {
 304         // If there are no "variable" CEs and no non-zero quaternary weights,
 305         // then there are no quaternary differences.
 306         return UCOL_EQUAL;
 307     }
 308
 309     leftIndex = 0;
 310     rightIndex = 0;
 311     for(;;) {
 312         uint32_t leftQuaternary;
 313         do {
 314             int64_t ce = left.getCE(leftIndex++);
 315             leftQuaternary = (uint32_t)ce & 0xffff;
 316             if(leftQuaternary <= Collation::NO_CE_WEIGHT16) {
 317                 // Variable primary or completely ignorable or NO_CE.
 318                 leftQuaternary = (uint32_t)(ce >> 32);
 319             } else {
 320                 // Regular CE, not tertiary ignorable.
 321                 // Preserve the quaternary weight in bits 7..6.
 322                 leftQuaternary |= 0xffffff3f;
 323             }
 324         } while(leftQuaternary == 0);
 325
 326         uint32_t rightQuaternary;
 327         do {
 328             int64_t ce = right.getCE(rightIndex++);
 329             rightQuaternary = (uint32_t)ce & 0xffff;
 330             if(rightQuaternary <= Collation::NO_CE_WEIGHT16) {
 331                 // Variable primary or completely ignorable or NO_CE.
 332                 rightQuaternary = (uint32_t)(ce >> 32);
 333             } else {
 334                 // Regular CE, not tertiary ignorable.
 335                 // Preserve the quaternary weight in bits 7..6.
 336                 rightQuaternary |= 0xffffff3f;
 337             }
 338         } while(rightQuaternary == 0);
 339
 340         if(leftQuaternary != rightQuaternary) {
 341             // Return the difference, with script reordering.
 342             if(settings.hasReordering()) {
 343                 leftQuaternary = settings.reorder(leftQuaternary);
 344                 rightQuaternary = settings.reorder(rightQuaternary);
 345             }
 346             return (leftQuaternary < rightQuaternary) ? UCOL_LESS : UCOL_GREATER;
 347         }
 348         if(leftQuaternary == Collation::NO_CE_PRIMARY) { break; }
 349     }
 350     return UCOL_EQUAL;
 351 }
 352
 353 U_NAMESPACE_END
 354
 355 #endif  // !UCONFIG_NO_COLLATION