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      1 //  2016 and later: Unicode, Inc. and others.
      2 // License & terms of use: http://www.unicode.org/copyright.html
      3 /*
      4 *******************************************************************************
      5 * Copyright (C) 1996-2015, International Business Machines
      6 * Corporation and others.  All Rights Reserved.
      7 *******************************************************************************
      8 * collationcompare.cpp
      9 *
     10 * created on: 2012feb14 with new and old collation code
     11 * created by: Markus W. Scherer
     12 */
     13 
     14 #include "unicode/utypes.h"
     15 
     16 #if !UCONFIG_NO_COLLATION
     17 
     18 #include "unicode/ucol.h"
     19 #include "cmemory.h"
     20 #include "collation.h"
     21 #include "collationcompare.h"
     22 #include "collationiterator.h"
     23 #include "collationsettings.h"
     24 #include "uassert.h"
     25 
     26 U_NAMESPACE_BEGIN
     27 
     28 UCollationResult
     29 CollationCompare::compareUpToQuaternary(CollationIterator &left, CollationIterator &right,
     30                                         const CollationSettings &settings,
     31                                         UErrorCode &errorCode) {
     32     if(U_FAILURE(errorCode)) { return UCOL_EQUAL; }
     33 
     34     int32_t options = settings.options;
     35     uint32_t variableTop;
     36     if((options & CollationSettings::ALTERNATE_MASK) == 0) {
     37         variableTop = 0;
     38     } else {
     39         // +1 so that we can use "<" and primary ignorables test out early.
     40         variableTop = settings.variableTop + 1;
     41     }
     42     UBool anyVariable = FALSE;
     43 
     44     // Fetch CEs, compare primaries, store secondary & tertiary weights.
     45     for(;;) {
     46         // We fetch CEs until we get a non-ignorable primary or reach the end.
     47         uint32_t leftPrimary;
     48         do {
     49             int64_t ce = left.nextCE(errorCode);
     50             leftPrimary = (uint32_t)(ce >> 32);
     51             if(leftPrimary < variableTop && leftPrimary > Collation::MERGE_SEPARATOR_PRIMARY) {
     52                 // Variable CE, shift it to quaternary level.
     53                 // Ignore all following primary ignorables, and shift further variable CEs.
     54                 anyVariable = TRUE;
     55                 do {
     56                     // Store only the primary of the variable CE.
     57                     left.setCurrentCE(ce & INT64_C(0xffffffff00000000));
     58                     for(;;) {
     59                         ce = left.nextCE(errorCode);
     60                         leftPrimary = (uint32_t)(ce >> 32);
     61                         if(leftPrimary == 0) {
     62                             left.setCurrentCE(0);
     63                         } else {
     64                             break;
     65                         }
     66                     }
     67                 } while(leftPrimary < variableTop &&
     68                         leftPrimary > Collation::MERGE_SEPARATOR_PRIMARY);
     69             }
     70         } while(leftPrimary == 0);
     71 
     72         uint32_t rightPrimary;
     73         do {
     74             int64_t ce = right.nextCE(errorCode);
     75             rightPrimary = (uint32_t)(ce >> 32);
     76             if(rightPrimary < variableTop && rightPrimary > Collation::MERGE_SEPARATOR_PRIMARY) {
     77                 // Variable CE, shift it to quaternary level.
     78                 // Ignore all following primary ignorables, and shift further variable CEs.
     79                 anyVariable = TRUE;
     80                 do {
     81                     // Store only the primary of the variable CE.
     82                     right.setCurrentCE(ce & INT64_C(0xffffffff00000000));
     83                     for(;;) {
     84                         ce = right.nextCE(errorCode);
     85                         rightPrimary = (uint32_t)(ce >> 32);
     86                         if(rightPrimary == 0) {
     87                             right.setCurrentCE(0);
     88                         } else {
     89                             break;
     90                         }
     91                     }
     92                 } while(rightPrimary < variableTop &&
     93                         rightPrimary > Collation::MERGE_SEPARATOR_PRIMARY);
     94             }
     95         } while(rightPrimary == 0);
     96 
     97         if(leftPrimary != rightPrimary) {
     98             // Return the primary difference, with script reordering.
     99             if(settings.hasReordering()) {
    100                 leftPrimary = settings.reorder(leftPrimary);
    101                 rightPrimary = settings.reorder(rightPrimary);
    102             }
    103             return (leftPrimary < rightPrimary) ? UCOL_LESS : UCOL_GREATER;
    104         }
    105         if(leftPrimary == Collation::NO_CE_PRIMARY) { break; }
    106     }
    107     if(U_FAILURE(errorCode)) { return UCOL_EQUAL; }
    108 
    109     // Compare the buffered secondary & tertiary weights.
    110     // We might skip the secondary level but continue with the case level
    111     // which is turned on separately.
    112     if(CollationSettings::getStrength(options) >= UCOL_SECONDARY) {
    113         if((options & CollationSettings::BACKWARD_SECONDARY) == 0) {
    114             int32_t leftIndex = 0;
    115             int32_t rightIndex = 0;
    116             for(;;) {
    117                 uint32_t leftSecondary;
    118                 do {
    119                     leftSecondary = ((uint32_t)left.getCE(leftIndex++)) >> 16;
    120                 } while(leftSecondary == 0);
    121 
    122                 uint32_t rightSecondary;
    123                 do {
    124                     rightSecondary = ((uint32_t)right.getCE(rightIndex++)) >> 16;
    125                 } while(rightSecondary == 0);
    126 
    127                 if(leftSecondary != rightSecondary) {
    128                     return (leftSecondary < rightSecondary) ? UCOL_LESS : UCOL_GREATER;
    129                 }
    130                 if(leftSecondary == Collation::NO_CE_WEIGHT16) { break; }
    131             }
    132         } else {
    133             // The backwards secondary level compares secondary weights backwards
    134             // within segments separated by the merge separator (U+FFFE, weight 02).
    135             int32_t leftStart = 0;
    136             int32_t rightStart = 0;
    137             for(;;) {
    138                 // Find the merge separator or the NO_CE terminator.
    139                 uint32_t p;
    140                 int32_t leftLimit = leftStart;
    141                 while((p = (uint32_t)(left.getCE(leftLimit) >> 32)) >
    142                             Collation::MERGE_SEPARATOR_PRIMARY ||
    143                         p == 0) {
    144                     ++leftLimit;
    145                 }
    146                 int32_t rightLimit = rightStart;
    147                 while((p = (uint32_t)(right.getCE(rightLimit) >> 32)) >
    148                             Collation::MERGE_SEPARATOR_PRIMARY ||
    149                         p == 0) {
    150                     ++rightLimit;
    151                 }
    152 
    153                 // Compare the segments.
    154                 int32_t leftIndex = leftLimit;
    155                 int32_t rightIndex = rightLimit;
    156                 for(;;) {
    157                     int32_t leftSecondary = 0;
    158                     while(leftSecondary == 0 && leftIndex > leftStart) {
    159                         leftSecondary = ((uint32_t)left.getCE(--leftIndex)) >> 16;
    160                     }
    161 
    162                     int32_t rightSecondary = 0;
    163                     while(rightSecondary == 0 && rightIndex > rightStart) {
    164                         rightSecondary = ((uint32_t)right.getCE(--rightIndex)) >> 16;
    165                     }
    166 
    167                     if(leftSecondary != rightSecondary) {
    168                         return (leftSecondary < rightSecondary) ? UCOL_LESS : UCOL_GREATER;
    169                     }
    170                     if(leftSecondary == 0) { break; }
    171                 }
    172 
    173                 // Did we reach the end of either string?
    174                 // Both strings have the same number of merge separators,
    175                 // or else there would have been a primary-level difference.
    176                 U_ASSERT(left.getCE(leftLimit) == right.getCE(rightLimit));
    177                 if(p == Collation::NO_CE_PRIMARY) { break; }
    178                 // Skip both merge separators and continue.
    179                 leftStart = leftLimit + 1;
    180                 rightStart = rightLimit + 1;
    181             }
    182         }
    183     }
    184 
    185     if((options & CollationSettings::CASE_LEVEL) != 0) {
    186         int32_t strength = CollationSettings::getStrength(options);
    187         int32_t leftIndex = 0;
    188         int32_t rightIndex = 0;
    189         for(;;) {
    190             uint32_t leftCase, leftLower32, rightCase;
    191             if(strength == UCOL_PRIMARY) {
    192                 // Primary+caseLevel: Ignore case level weights of primary ignorables.
    193                 // Otherwise we would get a-umlaut > a
    194                 // which is not desirable for accent-insensitive sorting.
    195                 // Check for (lower 32 bits) == 0 as well because variable CEs are stored
    196                 // with only primary weights.
    197                 int64_t ce;
    198                 do {
    199                     ce = left.getCE(leftIndex++);
    200                     leftCase = (uint32_t)ce;
    201                 } while((uint32_t)(ce >> 32) == 0 || leftCase == 0);
    202                 leftLower32 = leftCase;
    203                 leftCase &= 0xc000;
    204 
    205                 do {
    206                     ce = right.getCE(rightIndex++);
    207                     rightCase = (uint32_t)ce;
    208                 } while((uint32_t)(ce >> 32) == 0 || rightCase == 0);
    209                 rightCase &= 0xc000;
    210             } else {
    211                 // Secondary+caseLevel: By analogy with the above,
    212                 // ignore case level weights of secondary ignorables.
    213                 //
    214                 // Note: A tertiary CE has uppercase case bits (0.0.ut)
    215                 // to keep tertiary+caseFirst well-formed.
    216                 //
    217                 // Tertiary+caseLevel: Also ignore case level weights of secondary ignorables.
    218                 // Otherwise a tertiary CE's uppercase would be no greater than
    219                 // a primary/secondary CE's uppercase.
    220                 // (See UCA well-formedness condition 2.)
    221                 // We could construct a special case weight higher than uppercase,
    222                 // but it's simpler to always ignore case weights of secondary ignorables,
    223                 // turning 0.0.ut into 0.0.0.t.
    224                 // (See LDML Collation, Case Parameters.)
    225                 do {
    226                     leftCase = (uint32_t)left.getCE(leftIndex++);
    227                 } while(leftCase <= 0xffff);
    228                 leftLower32 = leftCase;
    229                 leftCase &= 0xc000;
    230 
    231                 do {
    232                     rightCase = (uint32_t)right.getCE(rightIndex++);
    233                 } while(rightCase <= 0xffff);
    234                 rightCase &= 0xc000;
    235             }
    236 
    237             // No need to handle NO_CE and MERGE_SEPARATOR specially:
    238             // There is one case weight for each previous-level weight,
    239             // so level length differences were handled there.
    240             if(leftCase != rightCase) {
    241                 if((options & CollationSettings::UPPER_FIRST) == 0) {
    242                     return (leftCase < rightCase) ? UCOL_LESS : UCOL_GREATER;
    243                 } else {
    244                     return (leftCase < rightCase) ? UCOL_GREATER : UCOL_LESS;
    245                 }
    246             }
    247             if((leftLower32 >> 16) == Collation::NO_CE_WEIGHT16) { break; }
    248         }
    249     }
    250     if(CollationSettings::getStrength(options) <= UCOL_SECONDARY) { return UCOL_EQUAL; }
    251 
    252     uint32_t tertiaryMask = CollationSettings::getTertiaryMask(options);
    253 
    254     int32_t leftIndex = 0;
    255     int32_t rightIndex = 0;
    256     uint32_t anyQuaternaries = 0;
    257     for(;;) {
    258         uint32_t leftLower32, leftTertiary;
    259         do {
    260             leftLower32 = (uint32_t)left.getCE(leftIndex++);
    261             anyQuaternaries |= leftLower32;
    262             U_ASSERT((leftLower32 & Collation::ONLY_TERTIARY_MASK) != 0 ||
    263                      (leftLower32 & 0xc0c0) == 0);
    264             leftTertiary = leftLower32 & tertiaryMask;
    265         } while(leftTertiary == 0);
    266 
    267         uint32_t rightLower32, rightTertiary;
    268         do {
    269             rightLower32 = (uint32_t)right.getCE(rightIndex++);
    270             anyQuaternaries |= rightLower32;
    271             U_ASSERT((rightLower32 & Collation::ONLY_TERTIARY_MASK) != 0 ||
    272                      (rightLower32 & 0xc0c0) == 0);
    273             rightTertiary = rightLower32 & tertiaryMask;
    274         } while(rightTertiary == 0);
    275 
    276         if(leftTertiary != rightTertiary) {
    277             if(CollationSettings::sortsTertiaryUpperCaseFirst(options)) {
    278                 // Pass through NO_CE and keep real tertiary weights larger than that.
    279                 // Do not change the artificial uppercase weight of a tertiary CE (0.0.ut),
    280                 // to keep tertiary CEs well-formed.
    281                 // Their case+tertiary weights must be greater than those of
    282                 // primary and secondary CEs.
    283                 if(leftTertiary > Collation::NO_CE_WEIGHT16) {
    284                     if(leftLower32 > 0xffff) {
    285                         leftTertiary ^= 0xc000;
    286                     } else {
    287                         leftTertiary += 0x4000;
    288                     }
    289                 }
    290                 if(rightTertiary > Collation::NO_CE_WEIGHT16) {
    291                     if(rightLower32 > 0xffff) {
    292                         rightTertiary ^= 0xc000;
    293                     } else {
    294                         rightTertiary += 0x4000;
    295                     }
    296                 }
    297             }
    298             return (leftTertiary < rightTertiary) ? UCOL_LESS : UCOL_GREATER;
    299         }
    300         if(leftTertiary == Collation::NO_CE_WEIGHT16) { break; }
    301     }
    302     if(CollationSettings::getStrength(options) <= UCOL_TERTIARY) { return UCOL_EQUAL; }
    303 
    304     if(!anyVariable && (anyQuaternaries & 0xc0) == 0) {
    305         // If there are no "variable" CEs and no non-zero quaternary weights,
    306         // then there are no quaternary differences.
    307         return UCOL_EQUAL;
    308     }
    309 
    310     leftIndex = 0;
    311     rightIndex = 0;
    312     for(;;) {
    313         uint32_t leftQuaternary;
    314         do {
    315             int64_t ce = left.getCE(leftIndex++);
    316             leftQuaternary = (uint32_t)ce & 0xffff;
    317             if(leftQuaternary <= Collation::NO_CE_WEIGHT16) {
    318                 // Variable primary or completely ignorable or NO_CE.
    319                 leftQuaternary = (uint32_t)(ce >> 32);
    320             } else {
    321                 // Regular CE, not tertiary ignorable.
    322                 // Preserve the quaternary weight in bits 7..6.
    323                 leftQuaternary |= 0xffffff3f;
    324             }
    325         } while(leftQuaternary == 0);
    326 
    327         uint32_t rightQuaternary;
    328         do {
    329             int64_t ce = right.getCE(rightIndex++);
    330             rightQuaternary = (uint32_t)ce & 0xffff;
    331             if(rightQuaternary <= Collation::NO_CE_WEIGHT16) {
    332                 // Variable primary or completely ignorable or NO_CE.
    333                 rightQuaternary = (uint32_t)(ce >> 32);
    334             } else {
    335                 // Regular CE, not tertiary ignorable.
    336                 // Preserve the quaternary weight in bits 7..6.
    337                 rightQuaternary |= 0xffffff3f;
    338             }
    339         } while(rightQuaternary == 0);
    340 
    341         if(leftQuaternary != rightQuaternary) {
    342             // Return the difference, with script reordering.
    343             if(settings.hasReordering()) {
    344                 leftQuaternary = settings.reorder(leftQuaternary);
    345                 rightQuaternary = settings.reorder(rightQuaternary);
    346             }
    347             return (leftQuaternary < rightQuaternary) ? UCOL_LESS : UCOL_GREATER;
    348         }
    349         if(leftQuaternary == Collation::NO_CE_PRIMARY) { break; }
    350     }
    351     return UCOL_EQUAL;
    352 }
    353 
    354 U_NAMESPACE_END
    355 
    356 #endif  // !UCONFIG_NO_COLLATION
    357