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Diffstat (limited to 'deps/icu-small/source/i18n/collationfastlatin.h')
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diff --git a/deps/icu-small/source/i18n/collationfastlatin.h b/deps/icu-small/source/i18n/collationfastlatin.h new file mode 100644 index 0000000000..6a25c6692c --- /dev/null +++ b/deps/icu-small/source/i18n/collationfastlatin.h @@ -0,0 +1,317 @@ +/* +******************************************************************************* +* 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__ |