1/*
2*******************************************************************************
3* Copyright (C) 2013-2015, 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
35U_NAMESPACE_BEGIN
36
37struct CollationData;
38
39namespace {
40
41/**
42 * Compare two signed int64_t values as if they were unsigned.
43 */
44int32_t
45compareInt64AsUnsigned(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 */
62int32_t
63binarySearch(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
87CollationFastLatinBuilder::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
96CollationFastLatinBuilder::~CollationFastLatinBuilder() {
97    uprv_free(miniCEs);
98}
99
100UBool
101CollationFastLatinBuilder::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
136UBool
137CollationFastLatinBuilder::loadGroups(const CollationData &data, UErrorCode &errorCode) {
138    if(U_FAILURE(errorCode)) { return FALSE; }
139    headerLength = 1 + NUM_SPECIAL_GROUPS;
140    uint32_t r0 = (CollationFastLatin::VERSION << 8) | headerLength;
141    result.append((UChar)r0);
142    // The first few reordering groups should be special groups
143    // (space, punct, ..., digit) followed by Latn, then Grek and other scripts.
144    for(int32_t i = 0; i < NUM_SPECIAL_GROUPS; ++i) {
145        lastSpecialPrimaries[i] = data.getLastPrimaryForGroup(UCOL_REORDER_CODE_FIRST + i);
146        if(lastSpecialPrimaries[i] == 0) {
147            // missing data
148            return FALSE;
149        }
150        result.append(0);  // reserve a slot for this group
151    }
152
153    firstDigitPrimary = data.getFirstPrimaryForGroup(UCOL_REORDER_CODE_DIGIT);
154    firstLatinPrimary = data.getFirstPrimaryForGroup(USCRIPT_LATIN);
155    lastLatinPrimary = data.getLastPrimaryForGroup(USCRIPT_LATIN);
156    if(firstDigitPrimary == 0 || firstLatinPrimary == 0) {
157        // missing data
158        return FALSE;
159    }
160    return TRUE;
161}
162
163UBool
164CollationFastLatinBuilder::inSameGroup(uint32_t p, uint32_t q) const {
165    // Both or neither need to be encoded as short primaries,
166    // so that we can test only one and use the same bit mask.
167    if(p >= firstShortPrimary) {
168        return q >= firstShortPrimary;
169    } else if(q >= firstShortPrimary) {
170        return FALSE;
171    }
172    // Both or neither must be potentially-variable,
173    // so that we can test only one and determine if both are variable.
174    uint32_t lastVariablePrimary = lastSpecialPrimaries[NUM_SPECIAL_GROUPS - 1];
175    if(p > lastVariablePrimary) {
176        return q > lastVariablePrimary;
177    } else if(q > lastVariablePrimary) {
178        return FALSE;
179    }
180    // Both will be encoded with long mini primaries.
181    // They must be in the same special reordering group,
182    // so that we can test only one and determine if both are variable.
183    U_ASSERT(p != 0 && q != 0);
184    for(int32_t i = 0;; ++i) {  // will terminate
185        uint32_t lastPrimary = lastSpecialPrimaries[i];
186        if(p <= lastPrimary) {
187            return q <= lastPrimary;
188        } else if(q <= lastPrimary) {
189            return FALSE;
190        }
191    }
192}
193
194void
195CollationFastLatinBuilder::resetCEs() {
196    contractionCEs.removeAllElements();
197    uniqueCEs.removeAllElements();
198    shortPrimaryOverflow = FALSE;
199    result.truncate(headerLength);
200}
201
202void
203CollationFastLatinBuilder::getCEs(const CollationData &data, UErrorCode &errorCode) {
204    if(U_FAILURE(errorCode)) { return; }
205    int32_t i = 0;
206    for(UChar c = 0;; ++i, ++c) {
207        if(c == CollationFastLatin::LATIN_LIMIT) {
208            c = CollationFastLatin::PUNCT_START;
209        } else if(c == CollationFastLatin::PUNCT_LIMIT) {
210            break;
211        }
212        const CollationData *d;
213        uint32_t ce32 = data.getCE32(c);
214        if(ce32 == Collation::FALLBACK_CE32) {
215            d = data.base;
216            ce32 = d->getCE32(c);
217        } else {
218            d = &data;
219        }
220        if(getCEsFromCE32(*d, c, ce32, errorCode)) {
221            charCEs[i][0] = ce0;
222            charCEs[i][1] = ce1;
223            addUniqueCE(ce0, errorCode);
224            addUniqueCE(ce1, errorCode);
225        } else {
226            // bail out for c
227            charCEs[i][0] = ce0 = Collation::NO_CE;
228            charCEs[i][1] = ce1 = 0;
229        }
230        if(c == 0 && !isContractionCharCE(ce0)) {
231            // Always map U+0000 to a contraction.
232            // Write a contraction list with only a default value if there is no real contraction.
233            U_ASSERT(contractionCEs.isEmpty());
234            addContractionEntry(CollationFastLatin::CONTR_CHAR_MASK, ce0, ce1, errorCode);
235            charCEs[0][0] = ((int64_t)Collation::NO_CE_PRIMARY << 32) | CONTRACTION_FLAG;
236            charCEs[0][1] = 0;
237        }
238    }
239    // Terminate the last contraction list.
240    contractionCEs.addElement(CollationFastLatin::CONTR_CHAR_MASK, errorCode);
241}
242
243UBool
244CollationFastLatinBuilder::getCEsFromCE32(const CollationData &data, UChar32 c, uint32_t ce32,
245                                          UErrorCode &errorCode) {
246    if(U_FAILURE(errorCode)) { return FALSE; }
247    ce32 = data.getFinalCE32(ce32);
248    ce1 = 0;
249    if(Collation::isSimpleOrLongCE32(ce32)) {
250        ce0 = Collation::ceFromCE32(ce32);
251    } else {
252        switch(Collation::tagFromCE32(ce32)) {
253        case Collation::LATIN_EXPANSION_TAG:
254            ce0 = Collation::latinCE0FromCE32(ce32);
255            ce1 = Collation::latinCE1FromCE32(ce32);
256            break;
257        case Collation::EXPANSION32_TAG: {
258            const uint32_t *ce32s = data.ce32s + Collation::indexFromCE32(ce32);
259            int32_t length = Collation::lengthFromCE32(ce32);
260            if(length <= 2) {
261                ce0 = Collation::ceFromCE32(ce32s[0]);
262                if(length == 2) {
263                    ce1 = Collation::ceFromCE32(ce32s[1]);
264                }
265                break;
266            } else {
267                return FALSE;
268            }
269        }
270        case Collation::EXPANSION_TAG: {
271            const int64_t *ces = data.ces + Collation::indexFromCE32(ce32);
272            int32_t length = Collation::lengthFromCE32(ce32);
273            if(length <= 2) {
274                ce0 = ces[0];
275                if(length == 2) {
276                    ce1 = ces[1];
277                }
278                break;
279            } else {
280                return FALSE;
281            }
282        }
283        // Note: We could support PREFIX_TAG (assert c>=0)
284        // by recursing on its default CE32 and checking that none of the prefixes starts
285        // with a fast Latin character.
286        // However, currently (2013) there are only the L-before-middle-dot
287        // prefix mappings in the Latin range, and those would be rejected anyway.
288        case Collation::CONTRACTION_TAG:
289            U_ASSERT(c >= 0);
290            return getCEsFromContractionCE32(data, ce32, errorCode);
291        case Collation::OFFSET_TAG:
292            U_ASSERT(c >= 0);
293            ce0 = data.getCEFromOffsetCE32(c, ce32);
294            break;
295        default:
296            return FALSE;
297        }
298    }
299    // A mapping can be completely ignorable.
300    if(ce0 == 0) { return ce1 == 0; }
301    // We do not support an ignorable ce0 unless it is completely ignorable.
302    uint32_t p0 = (uint32_t)(ce0 >> 32);
303    if(p0 == 0) { return FALSE; }
304    // We only support primaries up to the Latin script.
305    if(p0 > lastLatinPrimary) { return FALSE; }
306    // We support non-common secondary and case weights only together with short primaries.
307    uint32_t lower32_0 = (uint32_t)ce0;
308    if(p0 < firstShortPrimary) {
309        uint32_t sc0 = lower32_0 & Collation::SECONDARY_AND_CASE_MASK;
310        if(sc0 != Collation::COMMON_SECONDARY_CE) { return FALSE; }
311    }
312    // No below-common tertiary weights.
313    if((lower32_0 & Collation::ONLY_TERTIARY_MASK) < Collation::COMMON_WEIGHT16) { return FALSE; }
314    if(ce1 != 0) {
315        // Both primaries must be in the same group,
316        // or both must get short mini primaries,
317        // or a short-primary CE is followed by a secondary CE.
318        // This is so that we can test the first primary and use the same mask for both,
319        // and determine for both whether they are variable.
320        uint32_t p1 = (uint32_t)(ce1 >> 32);
321        if(p1 == 0 ? p0 < firstShortPrimary : !inSameGroup(p0, p1)) { return FALSE; }
322        uint32_t lower32_1 = (uint32_t)ce1;
323        // No tertiary CEs.
324        if((lower32_1 >> 16) == 0) { return FALSE; }
325        // We support non-common secondary and case weights
326        // only for secondary CEs or together with short primaries.
327        if(p1 != 0 && p1 < firstShortPrimary) {
328            uint32_t sc1 = lower32_1 & Collation::SECONDARY_AND_CASE_MASK;
329            if(sc1 != Collation::COMMON_SECONDARY_CE) { return FALSE; }
330        }
331        // No below-common tertiary weights.
332        if((lower32_1 & Collation::ONLY_TERTIARY_MASK) < Collation::COMMON_WEIGHT16) { return FALSE; }
333    }
334    // No quaternary weights.
335    if(((ce0 | ce1) & Collation::QUATERNARY_MASK) != 0) { return FALSE; }
336    return TRUE;
337}
338
339UBool
340CollationFastLatinBuilder::getCEsFromContractionCE32(const CollationData &data, uint32_t ce32,
341                                                     UErrorCode &errorCode) {
342    if(U_FAILURE(errorCode)) { return FALSE; }
343    const UChar *p = data.contexts + Collation::indexFromCE32(ce32);
344    ce32 = CollationData::readCE32(p);  // Default if no suffix match.
345    // Since the original ce32 is not a prefix mapping,
346    // the default ce32 must not be another contraction.
347    U_ASSERT(!Collation::isContractionCE32(ce32));
348    int32_t contractionIndex = contractionCEs.size();
349    if(getCEsFromCE32(data, U_SENTINEL, ce32, errorCode)) {
350        addContractionEntry(CollationFastLatin::CONTR_CHAR_MASK, ce0, ce1, errorCode);
351    } else {
352        // Bail out for c-without-contraction.
353        addContractionEntry(CollationFastLatin::CONTR_CHAR_MASK, Collation::NO_CE, 0, errorCode);
354    }
355    // Handle an encodable contraction unless the next contraction is too long
356    // and starts with the same character.
357    int32_t prevX = -1;
358    UBool addContraction = FALSE;
359    UCharsTrie::Iterator suffixes(p + 2, 0, errorCode);
360    while(suffixes.next(errorCode)) {
361        const UnicodeString &suffix = suffixes.getString();
362        int32_t x = CollationFastLatin::getCharIndex(suffix.charAt(0));
363        if(x < 0) { continue; }  // ignore anything but fast Latin text
364        if(x == prevX) {
365            if(addContraction) {
366                // Bail out for all contractions starting with this character.
367                addContractionEntry(x, Collation::NO_CE, 0, errorCode);
368                addContraction = FALSE;
369            }
370            continue;
371        }
372        if(addContraction) {
373            addContractionEntry(prevX, ce0, ce1, errorCode);
374        }
375        ce32 = (uint32_t)suffixes.getValue();
376        if(suffix.length() == 1 && getCEsFromCE32(data, U_SENTINEL, ce32, errorCode)) {
377            addContraction = TRUE;
378        } else {
379            addContractionEntry(x, Collation::NO_CE, 0, errorCode);
380            addContraction = FALSE;
381        }
382        prevX = x;
383    }
384    if(addContraction) {
385        addContractionEntry(prevX, ce0, ce1, errorCode);
386    }
387    if(U_FAILURE(errorCode)) { return FALSE; }
388    // Note: There might not be any fast Latin contractions, but
389    // we need to enter contraction handling anyway so that we can bail out
390    // when there is a non-fast-Latin character following.
391    // For example: Danish &Y<<u+umlaut, when we compare Y vs. u\u0308 we need to see the
392    // following umlaut and bail out, rather than return the difference of Y vs. u.
393    ce0 = ((int64_t)Collation::NO_CE_PRIMARY << 32) | CONTRACTION_FLAG | contractionIndex;
394    ce1 = 0;
395    return TRUE;
396}
397
398void
399CollationFastLatinBuilder::addContractionEntry(int32_t x, int64_t cce0, int64_t cce1,
400                                               UErrorCode &errorCode) {
401    contractionCEs.addElement(x, errorCode);
402    contractionCEs.addElement(cce0, errorCode);
403    contractionCEs.addElement(cce1, errorCode);
404    addUniqueCE(cce0, errorCode);
405    addUniqueCE(cce1, errorCode);
406}
407
408void
409CollationFastLatinBuilder::addUniqueCE(int64_t ce, UErrorCode &errorCode) {
410    if(U_FAILURE(errorCode)) { return; }
411    if(ce == 0 || (uint32_t)(ce >> 32) == Collation::NO_CE_PRIMARY) { return; }
412    ce &= ~(int64_t)Collation::CASE_MASK;  // blank out case bits
413    int32_t i = binarySearch(uniqueCEs.getBuffer(), uniqueCEs.size(), ce);
414    if(i < 0) {
415        uniqueCEs.insertElementAt(ce, ~i, errorCode);
416    }
417}
418
419uint32_t
420CollationFastLatinBuilder::getMiniCE(int64_t ce) const {
421    ce &= ~(int64_t)Collation::CASE_MASK;  // blank out case bits
422    int32_t index = binarySearch(uniqueCEs.getBuffer(), uniqueCEs.size(), ce);
423    U_ASSERT(index >= 0);
424    return miniCEs[index];
425}
426
427UBool
428CollationFastLatinBuilder::encodeUniqueCEs(UErrorCode &errorCode) {
429    if(U_FAILURE(errorCode)) { return FALSE; }
430    uprv_free(miniCEs);
431    miniCEs = (uint16_t *)uprv_malloc(uniqueCEs.size() * 2);
432    if(miniCEs == NULL) {
433        errorCode = U_MEMORY_ALLOCATION_ERROR;
434        return FALSE;
435    }
436    int32_t group = 0;
437    uint32_t lastGroupPrimary = lastSpecialPrimaries[group];
438    // The lowest unique CE must be at least a secondary CE.
439    U_ASSERT(((uint32_t)uniqueCEs.elementAti(0) >> 16) != 0);
440    uint32_t prevPrimary = 0;
441    uint32_t prevSecondary = 0;
442    uint32_t pri = 0;
443    uint32_t sec = 0;
444    uint32_t ter = CollationFastLatin::COMMON_TER;
445    for(int32_t i = 0; i < uniqueCEs.size(); ++i) {
446        int64_t ce = uniqueCEs.elementAti(i);
447        // Note: At least one of the p/s/t weights changes from one unique CE to the next.
448        // (uniqueCEs does not store case bits.)
449        uint32_t p = (uint32_t)(ce >> 32);
450        if(p != prevPrimary) {
451            while(p > lastGroupPrimary) {
452                U_ASSERT(pri <= CollationFastLatin::MAX_LONG);
453                // Set the group's header entry to the
454                // last "long primary" in or before the group.
455                result.setCharAt(1 + group, (UChar)pri);
456                if(++group < NUM_SPECIAL_GROUPS) {
457                    lastGroupPrimary = lastSpecialPrimaries[group];
458                } else {
459                    lastGroupPrimary = 0xffffffff;
460                    break;
461                }
462            }
463            if(p < firstShortPrimary) {
464                if(pri == 0) {
465                    pri = CollationFastLatin::MIN_LONG;
466                } else if(pri < CollationFastLatin::MAX_LONG) {
467                    pri += CollationFastLatin::LONG_INC;
468                } else {
469#if DEBUG_COLLATION_FAST_LATIN_BUILDER
470                    printf("long-primary overflow for %08x\n", p);
471#endif
472                    miniCEs[i] = CollationFastLatin::BAIL_OUT;
473                    continue;
474                }
475            } else {
476                if(pri < CollationFastLatin::MIN_SHORT) {
477                    pri = CollationFastLatin::MIN_SHORT;
478                } else if(pri < (CollationFastLatin::MAX_SHORT - CollationFastLatin::SHORT_INC)) {
479                    // Reserve the highest primary weight for U+FFFF.
480                    pri += CollationFastLatin::SHORT_INC;
481                } else {
482#if DEBUG_COLLATION_FAST_LATIN_BUILDER
483                    printf("short-primary overflow for %08x\n", p);
484#endif
485                    shortPrimaryOverflow = TRUE;
486                    miniCEs[i] = CollationFastLatin::BAIL_OUT;
487                    continue;
488                }
489            }
490            prevPrimary = p;
491            prevSecondary = Collation::COMMON_WEIGHT16;
492            sec = CollationFastLatin::COMMON_SEC;
493            ter = CollationFastLatin::COMMON_TER;
494        }
495        uint32_t lower32 = (uint32_t)ce;
496        uint32_t s = lower32 >> 16;
497        if(s != prevSecondary) {
498            if(pri == 0) {
499                if(sec == 0) {
500                    sec = CollationFastLatin::MIN_SEC_HIGH;
501                } else if(sec < CollationFastLatin::MAX_SEC_HIGH) {
502                    sec += CollationFastLatin::SEC_INC;
503                } else {
504                    miniCEs[i] = CollationFastLatin::BAIL_OUT;
505                    continue;
506                }
507                prevSecondary = s;
508                ter = CollationFastLatin::COMMON_TER;
509            } else if(s < Collation::COMMON_WEIGHT16) {
510                if(sec == CollationFastLatin::COMMON_SEC) {
511                    sec = CollationFastLatin::MIN_SEC_BEFORE;
512                } else if(sec < CollationFastLatin::MAX_SEC_BEFORE) {
513                    sec += CollationFastLatin::SEC_INC;
514                } else {
515                    miniCEs[i] = CollationFastLatin::BAIL_OUT;
516                    continue;
517                }
518            } else if(s == Collation::COMMON_WEIGHT16) {
519                sec = CollationFastLatin::COMMON_SEC;
520            } else {
521                if(sec < CollationFastLatin::MIN_SEC_AFTER) {
522                    sec = CollationFastLatin::MIN_SEC_AFTER;
523                } else if(sec < CollationFastLatin::MAX_SEC_AFTER) {
524                    sec += CollationFastLatin::SEC_INC;
525                } else {
526                    miniCEs[i] = CollationFastLatin::BAIL_OUT;
527                    continue;
528                }
529            }
530            prevSecondary = s;
531            ter = CollationFastLatin::COMMON_TER;
532        }
533        U_ASSERT((lower32 & Collation::CASE_MASK) == 0);  // blanked out in uniqueCEs
534        uint32_t t = lower32 & Collation::ONLY_TERTIARY_MASK;
535        if(t > Collation::COMMON_WEIGHT16) {
536            if(ter < CollationFastLatin::MAX_TER_AFTER) {
537                ++ter;
538            } else {
539                miniCEs[i] = CollationFastLatin::BAIL_OUT;
540                continue;
541            }
542        }
543        if(CollationFastLatin::MIN_LONG <= pri && pri <= CollationFastLatin::MAX_LONG) {
544            U_ASSERT(sec == CollationFastLatin::COMMON_SEC);
545            miniCEs[i] = (uint16_t)(pri | ter);
546        } else {
547            miniCEs[i] = (uint16_t)(pri | sec | ter);
548        }
549    }
550#if DEBUG_COLLATION_FAST_LATIN_BUILDER
551    printf("last mini primary: %04x\n", pri);
552#endif
553#if DEBUG_COLLATION_FAST_LATIN_BUILDER >= 2
554    for(int32_t i = 0; i < uniqueCEs.size(); ++i) {
555        int64_t ce = uniqueCEs.elementAti(i);
556        printf("unique CE 0x%016lx -> 0x%04x\n", ce, miniCEs[i]);
557    }
558#endif
559    return U_SUCCESS(errorCode);
560}
561
562UBool
563CollationFastLatinBuilder::encodeCharCEs(UErrorCode &errorCode) {
564    if(U_FAILURE(errorCode)) { return FALSE; }
565    int32_t miniCEsStart = result.length();
566    for(int32_t i = 0; i < CollationFastLatin::NUM_FAST_CHARS; ++i) {
567        result.append(0);  // initialize to completely ignorable
568    }
569    int32_t indexBase = result.length();
570    for(int32_t i = 0; i < CollationFastLatin::NUM_FAST_CHARS; ++i) {
571        int64_t ce = charCEs[i][0];
572        if(isContractionCharCE(ce)) { continue; }  // defer contraction
573        uint32_t miniCE = encodeTwoCEs(ce, charCEs[i][1]);
574        if(miniCE > 0xffff) {
575            // Note: There is a chance that this new expansion is the same as a previous one,
576            // and if so, then we could reuse the other expansion.
577            // However, that seems unlikely.
578            int32_t expansionIndex = result.length() - indexBase;
579            if(expansionIndex > (int32_t)CollationFastLatin::INDEX_MASK) {
580                miniCE = CollationFastLatin::BAIL_OUT;
581            } else {
582                result.append((UChar)(miniCE >> 16)).append((UChar)miniCE);
583                miniCE = CollationFastLatin::EXPANSION | expansionIndex;
584            }
585        }
586        result.setCharAt(miniCEsStart + i, (UChar)miniCE);
587    }
588    return U_SUCCESS(errorCode);
589}
590
591UBool
592CollationFastLatinBuilder::encodeContractions(UErrorCode &errorCode) {
593    // We encode all contraction lists so that the first word of a list
594    // terminates the previous list, and we only need one additional terminator at the end.
595    if(U_FAILURE(errorCode)) { return FALSE; }
596    int32_t indexBase = headerLength + CollationFastLatin::NUM_FAST_CHARS;
597    int32_t firstContractionIndex = result.length();
598    for(int32_t i = 0; i < CollationFastLatin::NUM_FAST_CHARS; ++i) {
599        int64_t ce = charCEs[i][0];
600        if(!isContractionCharCE(ce)) { continue; }
601        int32_t contractionIndex = result.length() - indexBase;
602        if(contractionIndex > (int32_t)CollationFastLatin::INDEX_MASK) {
603            result.setCharAt(headerLength + i, CollationFastLatin::BAIL_OUT);
604            continue;
605        }
606        UBool firstTriple = TRUE;
607        for(int32_t index = (int32_t)ce & 0x7fffffff;; index += 3) {
608            int32_t x = contractionCEs.elementAti(index);
609            if((uint32_t)x == CollationFastLatin::CONTR_CHAR_MASK && !firstTriple) { break; }
610            int64_t cce0 = contractionCEs.elementAti(index + 1);
611            int64_t cce1 = contractionCEs.elementAti(index + 2);
612            uint32_t miniCE = encodeTwoCEs(cce0, cce1);
613            if(miniCE == CollationFastLatin::BAIL_OUT) {
614                result.append((UChar)(x | (1 << CollationFastLatin::CONTR_LENGTH_SHIFT)));
615            } else if(miniCE <= 0xffff) {
616                result.append((UChar)(x | (2 << CollationFastLatin::CONTR_LENGTH_SHIFT)));
617                result.append((UChar)miniCE);
618            } else {
619                result.append((UChar)(x | (3 << CollationFastLatin::CONTR_LENGTH_SHIFT)));
620                result.append((UChar)(miniCE >> 16)).append((UChar)miniCE);
621            }
622            firstTriple = FALSE;
623        }
624        // Note: There is a chance that this new contraction list is the same as a previous one,
625        // and if so, then we could truncate the result and reuse the other list.
626        // However, that seems unlikely.
627        result.setCharAt(headerLength + i,
628                         (UChar)(CollationFastLatin::CONTRACTION | contractionIndex));
629    }
630    if(result.length() > firstContractionIndex) {
631        // Terminate the last contraction list.
632        result.append((UChar)CollationFastLatin::CONTR_CHAR_MASK);
633    }
634    if(result.isBogus()) {
635        errorCode = U_MEMORY_ALLOCATION_ERROR;
636        return FALSE;
637    }
638#if DEBUG_COLLATION_FAST_LATIN_BUILDER
639    printf("** fast Latin %d * 2 = %d bytes\n", result.length(), result.length() * 2);
640    puts("   header & below-digit groups map");
641    int32_t i = 0;
642    for(; i < headerLength; ++i) {
643        printf(" %04x", result[i]);
644    }
645    printf("\n   char mini CEs");
646    U_ASSERT(CollationFastLatin::NUM_FAST_CHARS % 16 == 0);
647    for(; i < indexBase; i += 16) {
648        UChar32 c = i - headerLength;
649        if(c >= CollationFastLatin::LATIN_LIMIT) {
650            c = CollationFastLatin::PUNCT_START + c - CollationFastLatin::LATIN_LIMIT;
651        }
652        printf("\n %04x:", c);
653        for(int32_t j = 0; j < 16; ++j) {
654            printf(" %04x", result[i + j]);
655        }
656    }
657    printf("\n   expansions & contractions");
658    for(; i < result.length(); ++i) {
659        if((i - indexBase) % 16 == 0) { puts(""); }
660        printf(" %04x", result[i]);
661    }
662    puts("");
663#endif
664    return TRUE;
665}
666
667uint32_t
668CollationFastLatinBuilder::encodeTwoCEs(int64_t first, int64_t second) const {
669    if(first == 0) {
670        return 0;  // completely ignorable
671    }
672    if(first == Collation::NO_CE) {
673        return CollationFastLatin::BAIL_OUT;
674    }
675    U_ASSERT((uint32_t)(first >> 32) != Collation::NO_CE_PRIMARY);
676
677    uint32_t miniCE = getMiniCE(first);
678    if(miniCE == CollationFastLatin::BAIL_OUT) { return miniCE; }
679    if(miniCE >= CollationFastLatin::MIN_SHORT) {
680        // Extract & copy the case bits.
681        // Shift them from normal CE bits 15..14 to mini CE bits 4..3.
682        uint32_t c = (((uint32_t)first & Collation::CASE_MASK) >> (14 - 3));
683        // Only in mini CEs: Ignorable case bits = 0, lowercase = 1.
684        c += CollationFastLatin::LOWER_CASE;
685        miniCE |= c;
686    }
687    if(second == 0) { return miniCE; }
688
689    uint32_t miniCE1 = getMiniCE(second);
690    if(miniCE1 == CollationFastLatin::BAIL_OUT) { return miniCE1; }
691
692    uint32_t case1 = (uint32_t)second & Collation::CASE_MASK;
693    if(miniCE >= CollationFastLatin::MIN_SHORT &&
694            (miniCE & CollationFastLatin::SECONDARY_MASK) == CollationFastLatin::COMMON_SEC) {
695        // Try to combine the two mini CEs into one.
696        uint32_t sec1 = miniCE1 & CollationFastLatin::SECONDARY_MASK;
697        uint32_t ter1 = miniCE1 & CollationFastLatin::TERTIARY_MASK;
698        if(sec1 >= CollationFastLatin::MIN_SEC_HIGH && case1 == 0 &&
699                ter1 == CollationFastLatin::COMMON_TER) {
700            // sec1>=sec_high implies pri1==0.
701            return (miniCE & ~CollationFastLatin::SECONDARY_MASK) | sec1;
702        }
703    }
704
705    if(miniCE1 <= CollationFastLatin::SECONDARY_MASK || CollationFastLatin::MIN_SHORT <= miniCE1) {
706        // Secondary CE, or a CE with a short primary, copy the case bits.
707        case1 = (case1 >> (14 - 3)) + CollationFastLatin::LOWER_CASE;
708        miniCE1 |= case1;
709    }
710    return (miniCE << 16) | miniCE1;
711}
712
713U_NAMESPACE_END
714
715#endif  // !UCONFIG_NO_COLLATION
716