| // © 2016 and later: Unicode, Inc. and others. |
| // License & terms of use: http://www.unicode.org/copyright.html |
| /* |
| ******************************************************************************* |
| * Copyright (C) 2013-2015, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| ******************************************************************************* |
| * collationfastlatin.h |
| * |
| * created on: 2013aug09 |
| * created by: Markus W. Scherer |
| */ |
| |
| #ifndef __COLLATIONFASTLATIN_H__ |
| #define __COLLATIONFASTLATIN_H__ |
| |
| #include "unicode/utypes.h" |
| |
| #if !UCONFIG_NO_COLLATION |
| |
| U_NAMESPACE_BEGIN |
| |
| struct CollationData; |
| struct CollationSettings; |
| |
| class U_I18N_API CollationFastLatin /* all static */ { |
| public: |
| /** |
| * Fast Latin format version (one byte 1..FF). |
| * Must be incremented for any runtime-incompatible changes, |
| * in particular, for changes to any of the following constants. |
| * |
| * When the major version number of the main data format changes, |
| * we can reset this fast Latin version to 1. |
| */ |
| static const uint16_t VERSION = 2; |
| |
| static const int32_t LATIN_MAX = 0x17f; |
| static const int32_t LATIN_LIMIT = LATIN_MAX + 1; |
| |
| static const int32_t LATIN_MAX_UTF8_LEAD = 0xc5; // UTF-8 lead byte of LATIN_MAX |
| |
| static const int32_t PUNCT_START = 0x2000; |
| static const int32_t PUNCT_LIMIT = 0x2040; |
| |
| // excludes U+FFFE & U+FFFF |
| static const int32_t NUM_FAST_CHARS = LATIN_LIMIT + (PUNCT_LIMIT - PUNCT_START); |
| |
| // Note on the supported weight ranges: |
| // Analysis of UCA 6.3 and CLDR 23 non-search tailorings shows that |
| // the CEs for characters in the above ranges, excluding expansions with length >2, |
| // excluding contractions of >2 characters, and other restrictions |
| // (see the builder's getCEsFromCE32()), |
| // use at most about 150 primary weights, |
| // where about 94 primary weights are possibly-variable (space/punct/symbol/currency), |
| // at most 4 secondary before-common weights, |
| // at most 4 secondary after-common weights, |
| // at most 16 secondary high weights (in secondary CEs), and |
| // at most 4 tertiary after-common weights. |
| // The following ranges are designed to support slightly more weights than that. |
| // (en_US_POSIX is unusual: It creates about 64 variable + 116 Latin primaries.) |
| |
| // Digits may use long primaries (preserving more short ones) |
| // or short primaries (faster) without changing this data structure. |
| // (If we supported numeric collation, then digits would have to have long primaries |
| // so that special handling does not affect the fast path.) |
| |
| static const uint32_t SHORT_PRIMARY_MASK = 0xfc00; // bits 15..10 |
| static const uint32_t INDEX_MASK = 0x3ff; // bits 9..0 for expansions & contractions |
| static const uint32_t SECONDARY_MASK = 0x3e0; // bits 9..5 |
| static const uint32_t CASE_MASK = 0x18; // bits 4..3 |
| static const uint32_t LONG_PRIMARY_MASK = 0xfff8; // bits 15..3 |
| static const uint32_t TERTIARY_MASK = 7; // bits 2..0 |
| static const uint32_t CASE_AND_TERTIARY_MASK = CASE_MASK | TERTIARY_MASK; |
| |
| static const uint32_t TWO_SHORT_PRIMARIES_MASK = |
| (SHORT_PRIMARY_MASK << 16) | SHORT_PRIMARY_MASK; // 0xfc00fc00 |
| static const uint32_t TWO_LONG_PRIMARIES_MASK = |
| (LONG_PRIMARY_MASK << 16) | LONG_PRIMARY_MASK; // 0xfff8fff8 |
| static const uint32_t TWO_SECONDARIES_MASK = |
| (SECONDARY_MASK << 16) | SECONDARY_MASK; // 0x3e003e0 |
| static const uint32_t TWO_CASES_MASK = |
| (CASE_MASK << 16) | CASE_MASK; // 0x180018 |
| static const uint32_t TWO_TERTIARIES_MASK = |
| (TERTIARY_MASK << 16) | TERTIARY_MASK; // 0x70007 |
| |
| /** |
| * Contraction with one fast Latin character. |
| * Use INDEX_MASK to find the start of the contraction list after the fixed table. |
| * The first entry contains the default mapping. |
| * Otherwise use CONTR_CHAR_MASK for the contraction character index |
| * (in ascending order). |
| * Use CONTR_LENGTH_SHIFT for the length of the entry |
| * (1=BAIL_OUT, 2=one CE, 3=two CEs). |
| * |
| * Also, U+0000 maps to a contraction entry, so that the fast path need not |
| * check for NUL termination. |
| * It usually maps to a contraction list with only the completely ignorable default value. |
| */ |
| static const uint32_t CONTRACTION = 0x400; |
| /** |
| * An expansion encodes two CEs. |
| * Use INDEX_MASK to find the pair of CEs after the fixed table. |
| * |
| * The higher a mini CE value, the easier it is to process. |
| * For expansions and higher, no context needs to be considered. |
| */ |
| static const uint32_t EXPANSION = 0x800; |
| /** |
| * Encodes one CE with a long/low mini primary (there are 128). |
| * All potentially-variable primaries must be in this range, |
| * to make the short-primary path as fast as possible. |
| */ |
| static const uint32_t MIN_LONG = 0xc00; |
| static const uint32_t LONG_INC = 8; |
| static const uint32_t MAX_LONG = 0xff8; |
| /** |
| * Encodes one CE with a short/high primary (there are 60), |
| * plus a secondary CE if the secondary weight is high. |
| * Fast handling: At least all letter primaries should be in this range. |
| */ |
| static const uint32_t MIN_SHORT = 0x1000; |
| static const uint32_t SHORT_INC = 0x400; |
| /** The highest primary weight is reserved for U+FFFF. */ |
| static const uint32_t MAX_SHORT = SHORT_PRIMARY_MASK; |
| |
| static const uint32_t MIN_SEC_BEFORE = 0; // must add SEC_OFFSET |
| static const uint32_t SEC_INC = 0x20; |
| static const uint32_t MAX_SEC_BEFORE = MIN_SEC_BEFORE + 4 * SEC_INC; // 5 before common |
| static const uint32_t COMMON_SEC = MAX_SEC_BEFORE + SEC_INC; |
| static const uint32_t MIN_SEC_AFTER = COMMON_SEC + SEC_INC; |
| static const uint32_t MAX_SEC_AFTER = MIN_SEC_AFTER + 5 * SEC_INC; // 6 after common |
| static const uint32_t MIN_SEC_HIGH = MAX_SEC_AFTER + SEC_INC; // 20 high secondaries |
| static const uint32_t MAX_SEC_HIGH = SECONDARY_MASK; |
| |
| /** |
| * Lookup: Add this offset to secondary weights, except for completely ignorable CEs. |
| * Must be greater than any special value, e.g., MERGE_WEIGHT. |
| * The exact value is not relevant for the format version. |
| */ |
| static const uint32_t SEC_OFFSET = SEC_INC; |
| static const uint32_t COMMON_SEC_PLUS_OFFSET = COMMON_SEC + SEC_OFFSET; |
| |
| static const uint32_t TWO_SEC_OFFSETS = |
| (SEC_OFFSET << 16) | SEC_OFFSET; // 0x200020 |
| static const uint32_t TWO_COMMON_SEC_PLUS_OFFSET = |
| (COMMON_SEC_PLUS_OFFSET << 16) | COMMON_SEC_PLUS_OFFSET; |
| |
| static const uint32_t LOWER_CASE = 8; // case bits include this offset |
| static const uint32_t TWO_LOWER_CASES = (LOWER_CASE << 16) | LOWER_CASE; // 0x80008 |
| |
| static const uint32_t COMMON_TER = 0; // must add TER_OFFSET |
| static const uint32_t MAX_TER_AFTER = 7; // 7 after common |
| |
| /** |
| * Lookup: Add this offset to tertiary weights, except for completely ignorable CEs. |
| * Must be greater than any special value, e.g., MERGE_WEIGHT. |
| * Must be greater than case bits as well, so that with combined case+tertiary weights |
| * plus the offset the tertiary bits does not spill over into the case bits. |
| * The exact value is not relevant for the format version. |
| */ |
| static const uint32_t TER_OFFSET = SEC_OFFSET; |
| static const uint32_t COMMON_TER_PLUS_OFFSET = COMMON_TER + TER_OFFSET; |
| |
| static const uint32_t TWO_TER_OFFSETS = (TER_OFFSET << 16) | TER_OFFSET; |
| static const uint32_t TWO_COMMON_TER_PLUS_OFFSET = |
| (COMMON_TER_PLUS_OFFSET << 16) | COMMON_TER_PLUS_OFFSET; |
| |
| static const uint32_t MERGE_WEIGHT = 3; |
| static const uint32_t EOS = 2; // end of string |
| static const uint32_t BAIL_OUT = 1; |
| |
| /** |
| * Contraction result first word bits 8..0 contain the |
| * second contraction character, as a char index 0..NUM_FAST_CHARS-1. |
| * Each contraction list is terminated with a word containing CONTR_CHAR_MASK. |
| */ |
| static const uint32_t CONTR_CHAR_MASK = 0x1ff; |
| /** |
| * Contraction result first word bits 10..9 contain the result length: |
| * 1=bail out, 2=one mini CE, 3=two mini CEs |
| */ |
| static const uint32_t CONTR_LENGTH_SHIFT = 9; |
| |
| /** |
| * Comparison return value when the regular comparison must be used. |
| * The exact value is not relevant for the format version. |
| */ |
| static const int32_t BAIL_OUT_RESULT = -2; |
| |
| static inline int32_t getCharIndex(UChar c) { |
| if(c <= LATIN_MAX) { |
| return c; |
| } else if(PUNCT_START <= c && c < PUNCT_LIMIT) { |
| return c - (PUNCT_START - LATIN_LIMIT); |
| } else { |
| // Not a fast Latin character. |
| // Note: U+FFFE & U+FFFF are forbidden in tailorings |
| // and thus do not occur in any contractions. |
| return -1; |
| } |
| } |
| |
| /** |
| * Computes the options value for the compare functions |
| * and writes the precomputed primary weights. |
| * Returns -1 if the Latin fastpath is not supported for the data and settings. |
| * The capacity must be LATIN_LIMIT. |
| */ |
| static int32_t getOptions(const CollationData *data, const CollationSettings &settings, |
| uint16_t *primaries, int32_t capacity); |
| |
| static int32_t compareUTF16(const uint16_t *table, const uint16_t *primaries, int32_t options, |
| const UChar *left, int32_t leftLength, |
| const UChar *right, int32_t rightLength); |
| |
| static int32_t compareUTF8(const uint16_t *table, const uint16_t *primaries, int32_t options, |
| const uint8_t *left, int32_t leftLength, |
| const uint8_t *right, int32_t rightLength); |
| |
| private: |
| static uint32_t lookup(const uint16_t *table, UChar32 c); |
| static uint32_t lookupUTF8(const uint16_t *table, UChar32 c, |
| const uint8_t *s8, int32_t &sIndex, int32_t sLength); |
| static uint32_t lookupUTF8Unsafe(const uint16_t *table, UChar32 c, |
| const uint8_t *s8, int32_t &sIndex); |
| |
| static uint32_t nextPair(const uint16_t *table, UChar32 c, uint32_t ce, |
| const UChar *s16, const uint8_t *s8, int32_t &sIndex, int32_t &sLength); |
| |
| static inline uint32_t getPrimaries(uint32_t variableTop, uint32_t pair) { |
| uint32_t ce = pair & 0xffff; |
| if(ce >= MIN_SHORT) { return pair & TWO_SHORT_PRIMARIES_MASK; } |
| if(ce > variableTop) { return pair & TWO_LONG_PRIMARIES_MASK; } |
| if(ce >= MIN_LONG) { return 0; } // variable |
| return pair; // special mini CE |
| } |
| static inline uint32_t getSecondariesFromOneShortCE(uint32_t ce) { |
| ce &= SECONDARY_MASK; |
| if(ce < MIN_SEC_HIGH) { |
| return ce + SEC_OFFSET; |
| } else { |
| return ((ce + SEC_OFFSET) << 16) | COMMON_SEC_PLUS_OFFSET; |
| } |
| } |
| static uint32_t getSecondaries(uint32_t variableTop, uint32_t pair); |
| static uint32_t getCases(uint32_t variableTop, UBool strengthIsPrimary, uint32_t pair); |
| static uint32_t getTertiaries(uint32_t variableTop, UBool withCaseBits, uint32_t pair); |
| static uint32_t getQuaternaries(uint32_t variableTop, uint32_t pair); |
| |
| private: |
| CollationFastLatin(); // no constructor |
| }; |
| |
| /* |
| * Format of the CollationFastLatin data table. |
| * CollationFastLatin::VERSION = 2. |
| * |
| * This table contains data for a Latin-text collation fastpath. |
| * The data is stored as an array of uint16_t which contains the following parts. |
| * |
| * uint16_t -- version & header length |
| * Bits 15..8: version, must match the VERSION |
| * 7..0: length of the header |
| * |
| * uint16_t varTops[header length - 1] |
| * Version 2: |
| * varTops[m] is the highest CollationFastLatin long-primary weight |
| * of supported maxVariable group m |
| * (special reorder group space, punct, symbol, currency). |
| * |
| * Version 1: |
| * Each of these values maps the variable top lead byte of a supported maxVariable group |
| * to the highest CollationFastLatin long-primary weight. |
| * The values are stored in ascending order. |
| * Bits 15..7: max fast-Latin long-primary weight (bits 11..3 shifted left by 4 bits) |
| * 6..0: regular primary lead byte |
| * |
| * uint16_t miniCEs[0x1c0] |
| * A mini collation element for each character U+0000..U+017F and U+2000..U+203F. |
| * Each value encodes one or two mini CEs (two are possible if the first one |
| * has a short mini primary and the second one is a secondary CE, i.e., primary == 0), |
| * or points to an expansion or to a contraction table. |
| * U+0000 always has a contraction entry, |
| * so that NUL-termination need not be tested in the fastpath. |
| * If the collation elements for a character or contraction cannot be encoded in this format, |
| * then the BAIL_OUT value is stored. |
| * For details see the comments for the class constants. |
| * |
| * uint16_t expansions[variable length]; |
| * Expansion mini CEs contain an offset relative to just after the miniCEs table. |
| * An expansions contains exactly 2 mini CEs. |
| * |
| * uint16_t contractions[variable length]; |
| * Contraction mini CEs contain an offset relative to just after the miniCEs table. |
| * It points to a list of tuples which map from a contraction suffix character to a result. |
| * First uint16_t of each tuple: |
| * Bits 10..9: Length of the result (1..3), see comments on CONTR_LENGTH_SHIFT. |
| * Bits 8..0: Contraction character, see comments on CONTR_CHAR_MASK. |
| * This is followed by 0, 1, or 2 uint16_t according to the length. |
| * Each list is terminated by an entry with CONTR_CHAR_MASK. |
| * Each list starts with such an entry which also contains the default result |
| * for when there is no contraction match. |
| * |
| * ----------------- |
| * Changes for version 2 (ICU 55) |
| * |
| * Special reorder groups do not necessarily start on whole primary lead bytes any more. |
| * Therefore, the varTops data has a new format: |
| * Version 1 stored the lead bytes of the highest root primaries for |
| * the maxVariable-supported special reorder groups. |
| * Now the top 16 bits would need to be stored, |
| * and it is simpler to store only the fast-Latin weights. |
| */ |
| |
| U_NAMESPACE_END |
| |
| #endif // !UCONFIG_NO_COLLATION |
| #endif // __COLLATIONFASTLATIN_H__ |
