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      1 /*
      2 *******************************************************************************
      3 * Copyright (C) 2013-2014, International Business Machines
      4 * Corporation and others.  All Rights Reserved.
      5 *******************************************************************************
      6 * collationfastlatinbuilder.cpp
      7 *
      8 * created on: 2013aug09
      9 * created by: Markus W. Scherer
     10 */
     11 
     12 #define DEBUG_COLLATION_FAST_LATIN_BUILDER 0  // 0 or 1 or 2
     13 #if DEBUG_COLLATION_FAST_LATIN_BUILDER
     14 #include <stdio.h>
     15 #include <string>
     16 #endif
     17 
     18 #include "unicode/utypes.h"
     19 
     20 #if !UCONFIG_NO_COLLATION
     21 
     22 #include "unicode/ucol.h"
     23 #include "unicode/ucharstrie.h"
     24 #include "unicode/unistr.h"
     25 #include "unicode/uobject.h"
     26 #include "unicode/uscript.h"
     27 #include "cmemory.h"
     28 #include "collation.h"
     29 #include "collationdata.h"
     30 #include "collationfastlatin.h"
     31 #include "collationfastlatinbuilder.h"
     32 #include "uassert.h"
     33 #include "uvectr64.h"
     34 
     35 U_NAMESPACE_BEGIN
     36 
     37 struct CollationData;
     38 
     39 namespace {
     40 
     41 /**
     42  * Compare two signed int64_t values as if they were unsigned.
     43  */
     44 int32_t
     45 compareInt64AsUnsigned(int64_t a, int64_t b) {
     46     if((uint64_t)a < (uint64_t)b) {
     47         return -1;
     48     } else if((uint64_t)a > (uint64_t)b) {
     49         return 1;
     50     } else {
     51         return 0;
     52     }
     53 }
     54 
     55 // TODO: Merge this with the near-identical version in collationbasedatabuilder.cpp
     56 /**
     57  * Like Java Collections.binarySearch(List, String, Comparator).
     58  *
     59  * @return the index>=0 where the item was found,
     60  *         or the index<0 for inserting the string at ~index in sorted order
     61  */
     62 int32_t
     63 binarySearch(const int64_t list[], int32_t limit, int64_t ce) {
     64     if (limit == 0) { return ~0; }
     65     int32_t start = 0;
     66     for (;;) {
     67         int32_t i = (start + limit) / 2;
     68         int32_t cmp = compareInt64AsUnsigned(ce, list[i]);
     69         if (cmp == 0) {
     70             return i;
     71         } else if (cmp < 0) {
     72             if (i == start) {
     73                 return ~start;  // insert ce before i
     74             }
     75             limit = i;
     76         } else {
     77             if (i == start) {
     78                 return ~(start + 1);  // insert ce after i
     79             }
     80             start = i;
     81         }
     82     }
     83 }
     84 
     85 }  // namespace
     86 
     87 CollationFastLatinBuilder::CollationFastLatinBuilder(UErrorCode &errorCode)
     88         : ce0(0), ce1(0),
     89           contractionCEs(errorCode), uniqueCEs(errorCode),
     90           miniCEs(NULL),
     91           firstDigitPrimary(0), firstLatinPrimary(0), lastLatinPrimary(0),
     92           firstShortPrimary(0), shortPrimaryOverflow(FALSE),
     93           headerLength(0) {
     94 }
     95 
     96 CollationFastLatinBuilder::~CollationFastLatinBuilder() {
     97     uprv_free(miniCEs);
     98 }
     99 
    100 UBool
    101 CollationFastLatinBuilder::forData(const CollationData &data, UErrorCode &errorCode) {
    102     if(U_FAILURE(errorCode)) { return FALSE; }
    103     if(!result.isEmpty()) {  // This builder is not reusable.
    104         errorCode = U_INVALID_STATE_ERROR;
    105         return FALSE;
    106     }
    107     if(!loadGroups(data, errorCode)) { return FALSE; }
    108 
    109     // Fast handling of digits.
    110     firstShortPrimary = firstDigitPrimary;
    111     getCEs(data, errorCode);
    112     if(!encodeUniqueCEs(errorCode)) { return FALSE; }
    113     if(shortPrimaryOverflow) {
    114         // Give digits long mini primaries,
    115         // so that there are more short primaries for letters.
    116         firstShortPrimary = firstLatinPrimary;
    117         resetCEs();
    118         getCEs(data, errorCode);
    119         if(!encodeUniqueCEs(errorCode)) { return FALSE; }
    120     }
    121     // Note: If we still have a short-primary overflow but not a long-primary overflow,
    122     // then we could calculate how many more long primaries would fit,
    123     // and set the firstShortPrimary to that many after the current firstShortPrimary,
    124     // and try again.
    125     // However, this might only benefit the en_US_POSIX tailoring,
    126     // and it is simpler to suppress building fast Latin data for it in genrb,
    127     // or by returning FALSE here if shortPrimaryOverflow.
    128 
    129     UBool ok = !shortPrimaryOverflow &&
    130             encodeCharCEs(errorCode) && encodeContractions(errorCode);
    131     contractionCEs.removeAllElements();  // might reduce heap memory usage
    132     uniqueCEs.removeAllElements();
    133     return ok;
    134 }
    135 
    136 UBool
    137 CollationFastLatinBuilder::loadGroups(const CollationData &data, UErrorCode &errorCode) {
    138     if(U_FAILURE(errorCode)) { return FALSE; }
    139     result.append(0);  // reserved for version & headerLength
    140     // The first few reordering groups should be special groups
    141     // (space, punct, ..., digit) followed by Latn, then Grek and other scripts.
    142     for(int32_t i = 0;;) {
    143         if(i >= data.scriptsLength) {
    144             // no Latn script
    145             errorCode = U_INTERNAL_PROGRAM_ERROR;
    146             return FALSE;
    147         }
    148         uint32_t head = data.scripts[i];
    149         uint32_t lastByte = head & 0xff;  // last primary byte in the group
    150         int32_t group = data.scripts[i + 2];
    151         if(group == UCOL_REORDER_CODE_DIGIT) {
    152             firstDigitPrimary = (head & 0xff00) << 16;
    153             headerLength = result.length();
    154             uint32_t r0 = (CollationFastLatin::VERSION << 8) | headerLength;
    155             result.setCharAt(0, (UChar)r0);
    156         } else if(group == USCRIPT_LATIN) {
    157             if(firstDigitPrimary == 0) {
    158                 // no digit group
    159                 errorCode = U_INTERNAL_PROGRAM_ERROR;
    160                 return FALSE;
    161             }
    162             firstLatinPrimary = (head & 0xff00) << 16;
    163             lastLatinPrimary = (lastByte << 24) | 0xffffff;
    164             break;
    165         } else if(firstDigitPrimary == 0) {
    166             // a group below digits
    167             if(lastByte > 0x7f) {
    168                 // We only use 7 bits for the last byte of a below-digits group.
    169                 // This does not warrant an errorCode, but we do not build a fast Latin table.
    170                 return FALSE;
    171             }
    172             result.append((UChar)lastByte);
    173         }
    174         i = i + 2 + data.scripts[i + 1];
    175     }
    176     return TRUE;
    177 }
    178 
    179 UBool
    180 CollationFastLatinBuilder::inSameGroup(uint32_t p, uint32_t q) const {
    181     // Both or neither need to be encoded as short primaries,
    182     // so that we can test only one and use the same bit mask.
    183     if(p >= firstShortPrimary) {
    184         return q >= firstShortPrimary;
    185     } else if(q >= firstShortPrimary) {
    186         return FALSE;
    187     }
    188     // Both or neither must be potentially-variable,
    189     // so that we can test only one and determine if both are variable.
    190     if(p >= firstDigitPrimary) {
    191         return q >= firstDigitPrimary;
    192     } else if(q >= firstDigitPrimary) {
    193         return FALSE;
    194     }
    195     // Both will be encoded with long mini primaries.
    196     // They must be in the same special reordering group,
    197     // so that we can test only one and determine if both are variable.
    198     p >>= 24;  // first primary byte
    199     q >>= 24;
    200     U_ASSERT(p != 0 && q != 0);
    201     U_ASSERT(p <= result[headerLength - 1]);  // the loop will terminate
    202     for(int32_t i = 1;; ++i) {
    203         uint32_t lastByte = result[i];
    204         if(p <= lastByte) {
    205             return q <= lastByte;
    206         } else if(q <= lastByte) {
    207             return FALSE;
    208         }
    209     }
    210 }
    211 
    212 void
    213 CollationFastLatinBuilder::resetCEs() {
    214     contractionCEs.removeAllElements();
    215     uniqueCEs.removeAllElements();
    216     shortPrimaryOverflow = FALSE;
    217     result.truncate(headerLength);
    218 }
    219 
    220 void
    221 CollationFastLatinBuilder::getCEs(const CollationData &data, UErrorCode &errorCode) {
    222     if(U_FAILURE(errorCode)) { return; }
    223     int32_t i = 0;
    224     for(UChar c = 0;; ++i, ++c) {
    225         if(c == CollationFastLatin::LATIN_LIMIT) {
    226             c = CollationFastLatin::PUNCT_START;
    227         } else if(c == CollationFastLatin::PUNCT_LIMIT) {
    228             break;
    229         }
    230         const CollationData *d;
    231         uint32_t ce32 = data.getCE32(c);
    232         if(ce32 == Collation::FALLBACK_CE32) {
    233             d = data.base;
    234             ce32 = d->getCE32(c);
    235         } else {
    236             d = &data;
    237         }
    238         if(getCEsFromCE32(*d, c, ce32, errorCode)) {
    239             charCEs[i][0] = ce0;
    240             charCEs[i][1] = ce1;
    241             addUniqueCE(ce0, errorCode);
    242             addUniqueCE(ce1, errorCode);
    243         } else {
    244             // bail out for c
    245             charCEs[i][0] = ce0 = Collation::NO_CE;
    246             charCEs[i][1] = ce1 = 0;
    247         }
    248         if(c == 0 && !isContractionCharCE(ce0)) {
    249             // Always map U+0000 to a contraction.
    250             // Write a contraction list with only a default value if there is no real contraction.
    251             U_ASSERT(contractionCEs.isEmpty());
    252             addContractionEntry(CollationFastLatin::CONTR_CHAR_MASK, ce0, ce1, errorCode);
    253             charCEs[0][0] = ((int64_t)Collation::NO_CE_PRIMARY << 32) | CONTRACTION_FLAG;
    254             charCEs[0][1] = 0;
    255         }
    256     }
    257     // Terminate the last contraction list.
    258     contractionCEs.addElement(CollationFastLatin::CONTR_CHAR_MASK, errorCode);
    259 }
    260 
    261 UBool
    262 CollationFastLatinBuilder::getCEsFromCE32(const CollationData &data, UChar32 c, uint32_t ce32,
    263                                           UErrorCode &errorCode) {
    264     if(U_FAILURE(errorCode)) { return FALSE; }
    265     ce32 = data.getFinalCE32(ce32);
    266     ce1 = 0;
    267     if(Collation::isSimpleOrLongCE32(ce32)) {
    268         ce0 = Collation::ceFromCE32(ce32);
    269     } else {
    270         switch(Collation::tagFromCE32(ce32)) {
    271         case Collation::LATIN_EXPANSION_TAG:
    272             ce0 = Collation::latinCE0FromCE32(ce32);
    273             ce1 = Collation::latinCE1FromCE32(ce32);
    274             break;
    275         case Collation::EXPANSION32_TAG: {
    276             const uint32_t *ce32s = data.ce32s + Collation::indexFromCE32(ce32);
    277             int32_t length = Collation::lengthFromCE32(ce32);
    278             if(length <= 2) {
    279                 ce0 = Collation::ceFromCE32(ce32s[0]);
    280                 if(length == 2) {
    281                     ce1 = Collation::ceFromCE32(ce32s[1]);
    282                 }
    283                 break;
    284             } else {
    285                 return FALSE;
    286             }
    287         }
    288         case Collation::EXPANSION_TAG: {
    289             const int64_t *ces = data.ces + Collation::indexFromCE32(ce32);
    290             int32_t length = Collation::lengthFromCE32(ce32);
    291             if(length <= 2) {
    292                 ce0 = ces[0];
    293                 if(length == 2) {
    294                     ce1 = ces[1];
    295                 }
    296                 break;
    297             } else {
    298                 return FALSE;
    299             }
    300         }
    301         // Note: We could support PREFIX_TAG (assert c>=0)
    302         // by recursing on its default CE32 and checking that none of the prefixes starts
    303         // with a fast Latin character.
    304         // However, currently (2013) there are only the L-before-middle-dot
    305         // prefix mappings in the Latin range, and those would be rejected anyway.
    306         case Collation::CONTRACTION_TAG:
    307             U_ASSERT(c >= 0);
    308             return getCEsFromContractionCE32(data, ce32, errorCode);
    309         case Collation::OFFSET_TAG:
    310             U_ASSERT(c >= 0);
    311             ce0 = data.getCEFromOffsetCE32(c, ce32);
    312             break;
    313         default:
    314             return FALSE;
    315         }
    316     }
    317     // A mapping can be completely ignorable.
    318     if(ce0 == 0) { return ce1 == 0; }
    319     // We do not support an ignorable ce0 unless it is completely ignorable.
    320     uint32_t p0 = (uint32_t)(ce0 >> 32);
    321     if(p0 == 0) { return FALSE; }
    322     // We only support primaries up to the Latin script.
    323     if(p0 > lastLatinPrimary) { return FALSE; }
    324     // We support non-common secondary and case weights only together with short primaries.
    325     uint32_t lower32_0 = (uint32_t)ce0;
    326     if(p0 < firstShortPrimary) {
    327         uint32_t sc0 = lower32_0 & Collation::SECONDARY_AND_CASE_MASK;
    328         if(sc0 != Collation::COMMON_SECONDARY_CE) { return FALSE; }
    329     }
    330     // No below-common tertiary weights.
    331     if((lower32_0 & Collation::ONLY_TERTIARY_MASK) < Collation::COMMON_WEIGHT16) { return FALSE; }
    332     if(ce1 != 0) {
    333         // Both primaries must be in the same group,
    334         // or both must get short mini primaries,
    335         // or a short-primary CE is followed by a secondary CE.
    336         // This is so that we can test the first primary and use the same mask for both,
    337         // and determine for both whether they are variable.
    338         uint32_t p1 = (uint32_t)(ce1 >> 32);
    339         if(p1 == 0 ? p0 < firstShortPrimary : !inSameGroup(p0, p1)) { return FALSE; }
    340         uint32_t lower32_1 = (uint32_t)ce1;
    341         // No tertiary CEs.
    342         if((lower32_1 >> 16) == 0) { return FALSE; }
    343         // We support non-common secondary and case weights
    344         // only for secondary CEs or together with short primaries.
    345         if(p1 != 0 && p1 < firstShortPrimary) {
    346             uint32_t sc1 = lower32_1 & Collation::SECONDARY_AND_CASE_MASK;
    347             if(sc1 != Collation::COMMON_SECONDARY_CE) { return FALSE; }
    348         }
    349         // No below-common tertiary weights.
    350         if((lower32_1 & Collation::ONLY_TERTIARY_MASK) < Collation::COMMON_WEIGHT16) { return FALSE; }
    351     }
    352     // No quaternary weights.
    353     if(((ce0 | ce1) & Collation::QUATERNARY_MASK) != 0) { return FALSE; }
    354     return TRUE;
    355 }
    356 
    357 UBool
    358 CollationFastLatinBuilder::getCEsFromContractionCE32(const CollationData &data, uint32_t ce32,
    359                                                      UErrorCode &errorCode) {
    360     if(U_FAILURE(errorCode)) { return FALSE; }
    361     const UChar *p = data.contexts + Collation::indexFromCE32(ce32);
    362     ce32 = CollationData::readCE32(p);  // Default if no suffix match.
    363     // Since the original ce32 is not a prefix mapping,
    364     // the default ce32 must not be another contraction.
    365     U_ASSERT(!Collation::isContractionCE32(ce32));
    366     int32_t contractionIndex = contractionCEs.size();
    367     if(getCEsFromCE32(data, U_SENTINEL, ce32, errorCode)) {
    368         addContractionEntry(CollationFastLatin::CONTR_CHAR_MASK, ce0, ce1, errorCode);
    369     } else {
    370         // Bail out for c-without-contraction.
    371         addContractionEntry(CollationFastLatin::CONTR_CHAR_MASK, Collation::NO_CE, 0, errorCode);
    372     }
    373     // Handle an encodable contraction unless the next contraction is too long
    374     // and starts with the same character.
    375     int32_t prevX = -1;
    376     UBool addContraction = FALSE;
    377     UCharsTrie::Iterator suffixes(p + 2, 0, errorCode);
    378     while(suffixes.next(errorCode)) {
    379         const UnicodeString &suffix = suffixes.getString();
    380         int32_t x = CollationFastLatin::getCharIndex(suffix.charAt(0));
    381         if(x < 0) { continue; }  // ignore anything but fast Latin text
    382         if(x == prevX) {
    383             if(addContraction) {
    384                 // Bail out for all contractions starting with this character.
    385                 addContractionEntry(x, Collation::NO_CE, 0, errorCode);
    386                 addContraction = FALSE;
    387             }
    388             continue;
    389         }
    390         if(addContraction) {
    391             addContractionEntry(prevX, ce0, ce1, errorCode);
    392         }
    393         ce32 = (uint32_t)suffixes.getValue();
    394         if(suffix.length() == 1 && getCEsFromCE32(data, U_SENTINEL, ce32, errorCode)) {
    395             addContraction = TRUE;
    396         } else {
    397             addContractionEntry(x, Collation::NO_CE, 0, errorCode);
    398             addContraction = FALSE;
    399         }
    400         prevX = x;
    401     }
    402     if(addContraction) {
    403         addContractionEntry(prevX, ce0, ce1, errorCode);
    404     }
    405     if(U_FAILURE(errorCode)) { return FALSE; }
    406     // Note: There might not be any fast Latin contractions, but
    407     // we need to enter contraction handling anyway so that we can bail out
    408     // when there is a non-fast-Latin character following.
    409     // For example: Danish &Y<<u+umlaut, when we compare Y vs. u\u0308 we need to see the
    410     // following umlaut and bail out, rather than return the difference of Y vs. u.
    411     ce0 = ((int64_t)Collation::NO_CE_PRIMARY << 32) | CONTRACTION_FLAG | contractionIndex;
    412     ce1 = 0;
    413     return TRUE;
    414 }
    415 
    416 void
    417 CollationFastLatinBuilder::addContractionEntry(int32_t x, int64_t cce0, int64_t cce1,
    418                                                UErrorCode &errorCode) {
    419     contractionCEs.addElement(x, errorCode);
    420     contractionCEs.addElement(cce0, errorCode);
    421     contractionCEs.addElement(cce1, errorCode);
    422     addUniqueCE(cce0, errorCode);
    423     addUniqueCE(cce1, errorCode);
    424 }
    425 
    426 void
    427 CollationFastLatinBuilder::addUniqueCE(int64_t ce, UErrorCode &errorCode) {
    428     if(U_FAILURE(errorCode)) { return; }
    429     if(ce == 0 || (uint32_t)(ce >> 32) == Collation::NO_CE_PRIMARY) { return; }
    430     ce &= ~(int64_t)Collation::CASE_MASK;  // blank out case bits
    431     int32_t i = binarySearch(uniqueCEs.getBuffer(), uniqueCEs.size(), ce);
    432     if(i < 0) {
    433         uniqueCEs.insertElementAt(ce, ~i, errorCode);
    434     }
    435 }
    436 
    437 uint32_t
    438 CollationFastLatinBuilder::getMiniCE(int64_t ce) const {
    439     ce &= ~(int64_t)Collation::CASE_MASK;  // blank out case bits
    440     int32_t index = binarySearch(uniqueCEs.getBuffer(), uniqueCEs.size(), ce);
    441     U_ASSERT(index >= 0);
    442     return miniCEs[index];
    443 }
    444 
    445 UBool
    446 CollationFastLatinBuilder::encodeUniqueCEs(UErrorCode &errorCode) {
    447     if(U_FAILURE(errorCode)) { return FALSE; }
    448     uprv_free(miniCEs);
    449     miniCEs = (uint16_t *)uprv_malloc(uniqueCEs.size() * 2);
    450     if(miniCEs == NULL) {
    451         errorCode = U_MEMORY_ALLOCATION_ERROR;
    452         return FALSE;
    453     }
    454     int32_t group = 1;
    455     uint32_t lastGroupByte = result[group];
    456     // The lowest unique CE must be at least a secondary CE.
    457     U_ASSERT(((uint32_t)uniqueCEs.elementAti(0) >> 16) != 0);
    458     uint32_t prevPrimary = 0;
    459     uint32_t prevSecondary = 0;
    460     uint32_t pri = 0;
    461     uint32_t sec = 0;
    462     uint32_t ter = CollationFastLatin::COMMON_TER;
    463     for(int32_t i = 0; i < uniqueCEs.size(); ++i) {
    464         int64_t ce = uniqueCEs.elementAti(i);
    465         // Note: At least one of the p/s/t weights changes from one unique CE to the next.
    466         // (uniqueCEs does not store case bits.)
    467         uint32_t p = (uint32_t)(ce >> 32);
    468         if(p != prevPrimary) {
    469             uint32_t p1 = p >> 24;
    470             while(p1 > lastGroupByte) {
    471                 U_ASSERT(pri <= CollationFastLatin::MAX_LONG);
    472                 // Add the last "long primary" in or before the group
    473                 // into the upper 9 bits of the group entry.
    474                 result.setCharAt(group, (UChar)((pri << 4) | lastGroupByte));
    475                 if(++group < headerLength) {  // group is 1-based
    476                     lastGroupByte = result[group];
    477                 } else {
    478                     lastGroupByte = 0xff;
    479                     break;
    480                 }
    481             }
    482             if(p < firstShortPrimary) {
    483                 if(pri == 0) {
    484                     pri = CollationFastLatin::MIN_LONG;
    485                 } else if(pri < CollationFastLatin::MAX_LONG) {
    486                     pri += CollationFastLatin::LONG_INC;
    487                 } else {
    488 #if DEBUG_COLLATION_FAST_LATIN_BUILDER
    489                     printf("long-primary overflow for %08x\n", p);
    490 #endif
    491                     miniCEs[i] = CollationFastLatin::BAIL_OUT;
    492                     continue;
    493                 }
    494             } else {
    495                 if(pri < CollationFastLatin::MIN_SHORT) {
    496                     pri = CollationFastLatin::MIN_SHORT;
    497                 } else if(pri < (CollationFastLatin::MAX_SHORT - CollationFastLatin::SHORT_INC)) {
    498                     // Reserve the highest primary weight for U+FFFF.
    499                     pri += CollationFastLatin::SHORT_INC;
    500                 } else {
    501 #if DEBUG_COLLATION_FAST_LATIN_BUILDER
    502                     printf("short-primary overflow for %08x\n", p);
    503 #endif
    504                     shortPrimaryOverflow = TRUE;
    505                     miniCEs[i] = CollationFastLatin::BAIL_OUT;
    506                     continue;
    507                 }
    508             }
    509             prevPrimary = p;
    510             prevSecondary = Collation::COMMON_WEIGHT16;
    511             sec = CollationFastLatin::COMMON_SEC;
    512             ter = CollationFastLatin::COMMON_TER;
    513         }
    514         uint32_t lower32 = (uint32_t)ce;
    515         uint32_t s = lower32 >> 16;
    516         if(s != prevSecondary) {
    517             if(pri == 0) {
    518                 if(sec == 0) {
    519                     sec = CollationFastLatin::MIN_SEC_HIGH;
    520                 } else if(sec < CollationFastLatin::MAX_SEC_HIGH) {
    521                     sec += CollationFastLatin::SEC_INC;
    522                 } else {
    523                     miniCEs[i] = CollationFastLatin::BAIL_OUT;
    524                     continue;
    525                 }
    526                 prevSecondary = s;
    527                 ter = CollationFastLatin::COMMON_TER;
    528             } else if(s < Collation::COMMON_WEIGHT16) {
    529                 if(sec == CollationFastLatin::COMMON_SEC) {
    530                     sec = CollationFastLatin::MIN_SEC_BEFORE;
    531                 } else if(sec < CollationFastLatin::MAX_SEC_BEFORE) {
    532                     sec += CollationFastLatin::SEC_INC;
    533                 } else {
    534                     miniCEs[i] = CollationFastLatin::BAIL_OUT;
    535                     continue;
    536                 }
    537             } else if(s == Collation::COMMON_WEIGHT16) {
    538                 sec = CollationFastLatin::COMMON_SEC;
    539             } else {
    540                 if(sec < CollationFastLatin::MIN_SEC_AFTER) {
    541                     sec = CollationFastLatin::MIN_SEC_AFTER;
    542                 } else if(sec < CollationFastLatin::MAX_SEC_AFTER) {
    543                     sec += CollationFastLatin::SEC_INC;
    544                 } else {
    545                     miniCEs[i] = CollationFastLatin::BAIL_OUT;
    546                     continue;
    547                 }
    548             }
    549             prevSecondary = s;
    550             ter = CollationFastLatin::COMMON_TER;
    551         }
    552         U_ASSERT((lower32 & Collation::CASE_MASK) == 0);  // blanked out in uniqueCEs
    553         uint32_t t = lower32 & Collation::ONLY_TERTIARY_MASK;
    554         if(t > Collation::COMMON_WEIGHT16) {
    555             if(ter < CollationFastLatin::MAX_TER_AFTER) {
    556                 ++ter;
    557             } else {
    558                 miniCEs[i] = CollationFastLatin::BAIL_OUT;
    559                 continue;
    560             }
    561         }
    562         if(CollationFastLatin::MIN_LONG <= pri && pri <= CollationFastLatin::MAX_LONG) {
    563             U_ASSERT(sec == CollationFastLatin::COMMON_SEC);
    564             miniCEs[i] = (uint16_t)(pri | ter);
    565         } else {
    566             miniCEs[i] = (uint16_t)(pri | sec | ter);
    567         }
    568     }
    569 #if DEBUG_COLLATION_FAST_LATIN_BUILDER
    570     printf("last mini primary: %04x\n", pri);
    571 #endif
    572 #if DEBUG_COLLATION_FAST_LATIN_BUILDER >= 2
    573     for(int32_t i = 0; i < uniqueCEs.size(); ++i) {
    574         int64_t ce = uniqueCEs.elementAti(i);
    575         printf("unique CE 0x%016lx -> 0x%04x\n", ce, miniCEs[i]);
    576     }
    577 #endif
    578     return U_SUCCESS(errorCode);
    579 }
    580 
    581 UBool
    582 CollationFastLatinBuilder::encodeCharCEs(UErrorCode &errorCode) {
    583     if(U_FAILURE(errorCode)) { return FALSE; }
    584     int32_t miniCEsStart = result.length();
    585     for(int32_t i = 0; i < CollationFastLatin::NUM_FAST_CHARS; ++i) {
    586         result.append(0);  // initialize to completely ignorable
    587     }
    588     int32_t indexBase = result.length();
    589     for(int32_t i = 0; i < CollationFastLatin::NUM_FAST_CHARS; ++i) {
    590         int64_t ce = charCEs[i][0];
    591         if(isContractionCharCE(ce)) { continue; }  // defer contraction
    592         uint32_t miniCE = encodeTwoCEs(ce, charCEs[i][1]);
    593         if(miniCE > 0xffff) {
    594             // Note: There is a chance that this new expansion is the same as a previous one,
    595             // and if so, then we could reuse the other expansion.
    596             // However, that seems unlikely.
    597             int32_t expansionIndex = result.length() - indexBase;
    598             if(expansionIndex > (int32_t)CollationFastLatin::INDEX_MASK) {
    599                 miniCE = CollationFastLatin::BAIL_OUT;
    600             } else {
    601                 result.append((UChar)(miniCE >> 16)).append((UChar)miniCE);
    602                 miniCE = CollationFastLatin::EXPANSION | expansionIndex;
    603             }
    604         }
    605         result.setCharAt(miniCEsStart + i, (UChar)miniCE);
    606     }
    607     return U_SUCCESS(errorCode);
    608 }
    609 
    610 UBool
    611 CollationFastLatinBuilder::encodeContractions(UErrorCode &errorCode) {
    612     // We encode all contraction lists so that the first word of a list
    613     // terminates the previous list, and we only need one additional terminator at the end.
    614     if(U_FAILURE(errorCode)) { return FALSE; }
    615     int32_t indexBase = headerLength + CollationFastLatin::NUM_FAST_CHARS;
    616     int32_t firstContractionIndex = result.length();
    617     for(int32_t i = 0; i < CollationFastLatin::NUM_FAST_CHARS; ++i) {
    618         int64_t ce = charCEs[i][0];
    619         if(!isContractionCharCE(ce)) { continue; }
    620         int32_t contractionIndex = result.length() - indexBase;
    621         if(contractionIndex > (int32_t)CollationFastLatin::INDEX_MASK) {
    622             result.setCharAt(headerLength + i, CollationFastLatin::BAIL_OUT);
    623             continue;
    624         }
    625         UBool firstTriple = TRUE;
    626         for(int32_t index = (int32_t)ce & 0x7fffffff;; index += 3) {
    627             int32_t x = contractionCEs.elementAti(index);
    628             if((uint32_t)x == CollationFastLatin::CONTR_CHAR_MASK && !firstTriple) { break; }
    629             int64_t cce0 = contractionCEs.elementAti(index + 1);
    630             int64_t cce1 = contractionCEs.elementAti(index + 2);
    631             uint32_t miniCE = encodeTwoCEs(cce0, cce1);
    632             if(miniCE == CollationFastLatin::BAIL_OUT) {
    633                 result.append((UChar)(x | (1 << CollationFastLatin::CONTR_LENGTH_SHIFT)));
    634             } else if(miniCE <= 0xffff) {
    635                 result.append((UChar)(x | (2 << CollationFastLatin::CONTR_LENGTH_SHIFT)));
    636                 result.append((UChar)miniCE);
    637             } else {
    638                 result.append((UChar)(x | (3 << CollationFastLatin::CONTR_LENGTH_SHIFT)));
    639                 result.append((UChar)(miniCE >> 16)).append((UChar)miniCE);
    640             }
    641             firstTriple = FALSE;
    642         }
    643         // Note: There is a chance that this new contraction list is the same as a previous one,
    644         // and if so, then we could truncate the result and reuse the other list.
    645         // However, that seems unlikely.
    646         result.setCharAt(headerLength + i,
    647                          (UChar)(CollationFastLatin::CONTRACTION | contractionIndex));
    648     }
    649     if(result.length() > firstContractionIndex) {
    650         // Terminate the last contraction list.
    651         result.append((UChar)CollationFastLatin::CONTR_CHAR_MASK);
    652     }
    653     if(result.isBogus()) {
    654         errorCode = U_MEMORY_ALLOCATION_ERROR;
    655         return FALSE;
    656     }
    657 #if DEBUG_COLLATION_FAST_LATIN_BUILDER
    658     printf("** fast Latin %d * 2 = %d bytes\n", result.length(), result.length() * 2);
    659     puts("   header & below-digit groups map");
    660     int32_t i = 0;
    661     for(; i < headerLength; ++i) {
    662         printf(" %04x", result[i]);
    663     }
    664     printf("\n   char mini CEs");
    665     U_ASSERT(CollationFastLatin::NUM_FAST_CHARS % 16 == 0);
    666     for(; i < indexBase; i += 16) {
    667         UChar32 c = i - headerLength;
    668         if(c >= CollationFastLatin::LATIN_LIMIT) {
    669             c = CollationFastLatin::PUNCT_START + c - CollationFastLatin::LATIN_LIMIT;
    670         }
    671         printf("\n %04x:", c);
    672         for(int32_t j = 0; j < 16; ++j) {
    673             printf(" %04x", result[i + j]);
    674         }
    675     }
    676     printf("\n   expansions & contractions");
    677     for(; i < result.length(); ++i) {
    678         if((i - indexBase) % 16 == 0) { puts(""); }
    679         printf(" %04x", result[i]);
    680     }
    681     puts("");
    682 #endif
    683     return TRUE;
    684 }
    685 
    686 uint32_t
    687 CollationFastLatinBuilder::encodeTwoCEs(int64_t first, int64_t second) const {
    688     if(first == 0) {
    689         return 0;  // completely ignorable
    690     }
    691     if(first == Collation::NO_CE) {
    692         return CollationFastLatin::BAIL_OUT;
    693     }
    694     U_ASSERT((uint32_t)(first >> 32) != Collation::NO_CE_PRIMARY);
    695 
    696     uint32_t miniCE = getMiniCE(first);
    697     if(miniCE == CollationFastLatin::BAIL_OUT) { return miniCE; }
    698     if(miniCE >= CollationFastLatin::MIN_SHORT) {
    699         // Extract & copy the case bits.
    700         // Shift them from normal CE bits 15..14 to mini CE bits 4..3.
    701         uint32_t c = (((uint32_t)first & Collation::CASE_MASK) >> (14 - 3));
    702         // Only in mini CEs: Ignorable case bits = 0, lowercase = 1.
    703         c += CollationFastLatin::LOWER_CASE;
    704         miniCE |= c;
    705     }
    706     if(second == 0) { return miniCE; }
    707 
    708     uint32_t miniCE1 = getMiniCE(second);
    709     if(miniCE1 == CollationFastLatin::BAIL_OUT) { return miniCE1; }
    710 
    711     uint32_t case1 = (uint32_t)second & Collation::CASE_MASK;
    712     if(miniCE >= CollationFastLatin::MIN_SHORT &&
    713             (miniCE & CollationFastLatin::SECONDARY_MASK) == CollationFastLatin::COMMON_SEC) {
    714         // Try to combine the two mini CEs into one.
    715         uint32_t sec1 = miniCE1 & CollationFastLatin::SECONDARY_MASK;
    716         uint32_t ter1 = miniCE1 & CollationFastLatin::TERTIARY_MASK;
    717         if(sec1 >= CollationFastLatin::MIN_SEC_HIGH && case1 == 0 &&
    718                 ter1 == CollationFastLatin::COMMON_TER) {
    719             // sec1>=sec_high implies pri1==0.
    720             return (miniCE & ~CollationFastLatin::SECONDARY_MASK) | sec1;
    721         }
    722     }
    723 
    724     if(miniCE1 <= CollationFastLatin::SECONDARY_MASK || CollationFastLatin::MIN_SHORT <= miniCE1) {
    725         // Secondary CE, or a CE with a short primary, copy the case bits.
    726         case1 = (case1 >> (14 - 3)) + CollationFastLatin::LOWER_CASE;
    727         miniCE1 |= case1;
    728     }
    729     return (miniCE << 16) | miniCE1;
    730 }
    731 
    732 U_NAMESPACE_END
    733 
    734 #endif  // !UCONFIG_NO_COLLATION
    735