[apple/icu.git] / icuSources / i18n / collationfastlatin.h

/*
*******************************************************************************
* Copyright (C) 2013-2014, 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 = 1;

    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 = 1.
 *
 * 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]
 *   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.
 */

U_NAMESPACE_END

#endif  // !UCONFIG_NO_COLLATION
#endif  // __COLLATIONFASTLATIN_H__
Commit	Line	Data
57a6839d A	1	/*
	2	*******************************************************************************
	3	* Copyright (C) 2013-2014, International Business Machines
	4	* Corporation and others. All Rights Reserved.
	5	*******************************************************************************
	6	* collationfastlatin.h
	7	*
	8	* created on: 2013aug09
	9	* created by: Markus W. Scherer
	10	*/
	11
	12	#ifndef __COLLATIONFASTLATIN_H__
	13	#define __COLLATIONFASTLATIN_H__
	14
	15	#include "unicode/utypes.h"
	16
	17	#if !UCONFIG_NO_COLLATION
	18
	19	U_NAMESPACE_BEGIN
	20
	21	struct CollationData;
	22	struct CollationSettings;
	23
	24	class U_I18N_API CollationFastLatin /* all static */ {
	25	public:
	26	/**
	27	* Fast Latin format version (one byte 1..FF).
	28	* Must be incremented for any runtime-incompatible changes,
	29	* in particular, for changes to any of the following constants.
	30	*
	31	* When the major version number of the main data format changes,
	32	* we can reset this fast Latin version to 1.
	33	*/
	34	static const uint16_t VERSION = 1;
	35
	36	static const int32_t LATIN_MAX = 0x17f;
	37	static const int32_t LATIN_LIMIT = LATIN_MAX + 1;
	38
	39	static const int32_t LATIN_MAX_UTF8_LEAD = 0xc5; // UTF-8 lead byte of LATIN_MAX
	40
	41	static const int32_t PUNCT_START = 0x2000;
	42	static const int32_t PUNCT_LIMIT = 0x2040;
	43
	44	// excludes U+FFFE & U+FFFF
	45	static const int32_t NUM_FAST_CHARS = LATIN_LIMIT + (PUNCT_LIMIT - PUNCT_START);
	46
	47	// Note on the supported weight ranges:
	48	// Analysis of UCA 6.3 and CLDR 23 non-search tailorings shows that
	49	// the CEs for characters in the above ranges, excluding expansions with length >2,
	50	// excluding contractions of >2 characters, and other restrictions
	51	// (see the builder's getCEsFromCE32()),
	52	// use at most about 150 primary weights,
	53	// where about 94 primary weights are possibly-variable (space/punct/symbol/currency),
	54	// at most 4 secondary before-common weights,
	55	// at most 4 secondary after-common weights,
	56	// at most 16 secondary high weights (in secondary CEs), and
	57	// at most 4 tertiary after-common weights.
	58	// The following ranges are designed to support slightly more weights than that.
	59	// (en_US_POSIX is unusual: It creates about 64 variable + 116 Latin primaries.)
	60
	61	// Digits may use long primaries (preserving more short ones)
	62	// or short primaries (faster) without changing this data structure.
	63	// (If we supported numeric collation, then digits would have to have long primaries
	64	// so that special handling does not affect the fast path.)
65
66	static const uint32_t SHORT_PRIMARY_MASK = 0xfc00; // bits 15..10
67	static const uint32_t INDEX_MASK = 0x3ff; // bits 9..0 for expansions & contractions
68	static const uint32_t SECONDARY_MASK = 0x3e0; // bits 9..5
69	static const uint32_t CASE_MASK = 0x18; // bits 4..3
70	static const uint32_t LONG_PRIMARY_MASK = 0xfff8; // bits 15..3
71	static const uint32_t TERTIARY_MASK = 7; // bits 2..0
72	static const uint32_t CASE_AND_TERTIARY_MASK = CASE_MASK \| TERTIARY_MASK;
73
74	static const uint32_t TWO_SHORT_PRIMARIES_MASK =
75	(SHORT_PRIMARY_MASK << 16) \| SHORT_PRIMARY_MASK; // 0xfc00fc00
76	static const uint32_t TWO_LONG_PRIMARIES_MASK =
77	(LONG_PRIMARY_MASK << 16) \| LONG_PRIMARY_MASK; // 0xfff8fff8
78	static const uint32_t TWO_SECONDARIES_MASK =
79	(SECONDARY_MASK << 16) \| SECONDARY_MASK; // 0x3e003e0
80	static const uint32_t TWO_CASES_MASK =
81	(CASE_MASK << 16) \| CASE_MASK; // 0x180018
82	static const uint32_t TWO_TERTIARIES_MASK =
83	(TERTIARY_MASK << 16) \| TERTIARY_MASK; // 0x70007
84
85	/**
86	* Contraction with one fast Latin character.
87	* Use INDEX_MASK to find the start of the contraction list after the fixed table.
88	* The first entry contains the default mapping.
89	* Otherwise use CONTR_CHAR_MASK for the contraction character index
90	* (in ascending order).
91	* Use CONTR_LENGTH_SHIFT for the length of the entry
92	* (1=BAIL_OUT, 2=one CE, 3=two CEs).
93	*
94	* Also, U+0000 maps to a contraction entry, so that the fast path need not
95	* check for NUL termination.
96	* It usually maps to a contraction list with only the completely ignorable default value.
97	*/
98	static const uint32_t CONTRACTION = 0x400;
99	/**
100	* An expansion encodes two CEs.
101	* Use INDEX_MASK to find the pair of CEs after the fixed table.
102	*
103	* The higher a mini CE value, the easier it is to process.
104	* For expansions and higher, no context needs to be considered.
105	*/
106	static const uint32_t EXPANSION = 0x800;
107	/**
108	* Encodes one CE with a long/low mini primary (there are 128).
109	* All potentially-variable primaries must be in this range,
110	* to make the short-primary path as fast as possible.
111	*/
112	static const uint32_t MIN_LONG = 0xc00;
113	static const uint32_t LONG_INC = 8;
114	static const uint32_t MAX_LONG = 0xff8;
115	/**
116	* Encodes one CE with a short/high primary (there are 60),
117	* plus a secondary CE if the secondary weight is high.
118	* Fast handling: At least all letter primaries should be in this range.
119	*/
120	static const uint32_t MIN_SHORT = 0x1000;
121	static const uint32_t SHORT_INC = 0x400;
122	/** The highest primary weight is reserved for U+FFFF. */
123	static const uint32_t MAX_SHORT = SHORT_PRIMARY_MASK;
124
125	static const uint32_t MIN_SEC_BEFORE = 0; // must add SEC_OFFSET
126	static const uint32_t SEC_INC = 0x20;
127	static const uint32_t MAX_SEC_BEFORE = MIN_SEC_BEFORE + 4 * SEC_INC; // 5 before common
128	static const uint32_t COMMON_SEC = MAX_SEC_BEFORE + SEC_INC;
129	static const uint32_t MIN_SEC_AFTER = COMMON_SEC + SEC_INC;
130	static const uint32_t MAX_SEC_AFTER = MIN_SEC_AFTER + 5 * SEC_INC; // 6 after common
131	static const uint32_t MIN_SEC_HIGH = MAX_SEC_AFTER + SEC_INC; // 20 high secondaries
132	static const uint32_t MAX_SEC_HIGH = SECONDARY_MASK;
133
134	/**
135	* Lookup: Add this offset to secondary weights, except for completely ignorable CEs.
136	* Must be greater than any special value, e.g., MERGE_WEIGHT.
137	* The exact value is not relevant for the format version.
138	*/
139	static const uint32_t SEC_OFFSET = SEC_INC;
140	static const uint32_t COMMON_SEC_PLUS_OFFSET = COMMON_SEC + SEC_OFFSET;
141
142	static const uint32_t TWO_SEC_OFFSETS =
143	(SEC_OFFSET << 16) \| SEC_OFFSET; // 0x200020
144	static const uint32_t TWO_COMMON_SEC_PLUS_OFFSET =
145	(COMMON_SEC_PLUS_OFFSET << 16) \| COMMON_SEC_PLUS_OFFSET;
146
147	static const uint32_t LOWER_CASE = 8; // case bits include this offset
148	static const uint32_t TWO_LOWER_CASES = (LOWER_CASE << 16) \| LOWER_CASE; // 0x80008
149
150	static const uint32_t COMMON_TER = 0; // must add TER_OFFSET
151	static const uint32_t MAX_TER_AFTER = 7; // 7 after common
152
153	/**
154	* Lookup: Add this offset to tertiary weights, except for completely ignorable CEs.
155	* Must be greater than any special value, e.g., MERGE_WEIGHT.
156	* Must be greater than case bits as well, so that with combined case+tertiary weights
157	* plus the offset the tertiary bits does not spill over into the case bits.
158	* The exact value is not relevant for the format version.
159	*/
160	static const uint32_t TER_OFFSET = SEC_OFFSET;
161	static const uint32_t COMMON_TER_PLUS_OFFSET = COMMON_TER + TER_OFFSET;
162
163	static const uint32_t TWO_TER_OFFSETS = (TER_OFFSET << 16) \| TER_OFFSET;
164	static const uint32_t TWO_COMMON_TER_PLUS_OFFSET =
165	(COMMON_TER_PLUS_OFFSET << 16) \| COMMON_TER_PLUS_OFFSET;
166
167	static const uint32_t MERGE_WEIGHT = 3;
168	static const uint32_t EOS = 2; // end of string
169	static const uint32_t BAIL_OUT = 1;
170
171	/**
172	* Contraction result first word bits 8..0 contain the
173	* second contraction character, as a char index 0..NUM_FAST_CHARS-1.
174	* Each contraction list is terminated with a word containing CONTR_CHAR_MASK.
175	*/
176	static const uint32_t CONTR_CHAR_MASK = 0x1ff;
177	/**
178	* Contraction result first word bits 10..9 contain the result length:
179	* 1=bail out, 2=one mini CE, 3=two mini CEs
180	*/
181	static const uint32_t CONTR_LENGTH_SHIFT = 9;
182
183	/**
184	* Comparison return value when the regular comparison must be used.
185	* The exact value is not relevant for the format version.
186	*/
187	static const int32_t BAIL_OUT_RESULT = -2;
188
189	static inline int32_t getCharIndex(UChar c) {
190	if(c <= LATIN_MAX) {
191	return c;
192	} else if(PUNCT_START <= c && c < PUNCT_LIMIT) {
193	return c - (PUNCT_START - LATIN_LIMIT);
194	} else {
195	// Not a fast Latin character.
196	// Note: U+FFFE & U+FFFF are forbidden in tailorings
197	// and thus do not occur in any contractions.
198	return -1;
199	}
200	}
201
202	/**
203	* Computes the options value for the compare functions
204	* and writes the precomputed primary weights.
205	* Returns -1 if the Latin fastpath is not supported for the data and settings.
206	* The capacity must be LATIN_LIMIT.
207	*/
208	static int32_t getOptions(const CollationData *data, const CollationSettings &settings,
209	uint16_t *primaries, int32_t capacity);
210
211	static int32_t compareUTF16(const uint16_t table, const uint16_t primaries, int32_t options,
212	const UChar *left, int32_t leftLength,
213	const UChar *right, int32_t rightLength);
214
215	static int32_t compareUTF8(const uint16_t table, const uint16_t primaries, int32_t options,
216	const uint8_t *left, int32_t leftLength,
217	const uint8_t *right, int32_t rightLength);
218
219	private:
220	static uint32_t lookup(const uint16_t *table, UChar32 c);
221	static uint32_t lookupUTF8(const uint16_t *table, UChar32 c,
222	const uint8_t *s8, int32_t &sIndex, int32_t sLength);
223	static uint32_t lookupUTF8Unsafe(const uint16_t *table, UChar32 c,
224	const uint8_t *s8, int32_t &sIndex);
225
226	static uint32_t nextPair(const uint16_t *table, UChar32 c, uint32_t ce,
227	const UChar s16, const uint8_t s8, int32_t &sIndex, int32_t &sLength);
228
229	static inline uint32_t getPrimaries(uint32_t variableTop, uint32_t pair) {
230	uint32_t ce = pair & 0xffff;
231	if(ce >= MIN_SHORT) { return pair & TWO_SHORT_PRIMARIES_MASK; }
232	if(ce > variableTop) { return pair & TWO_LONG_PRIMARIES_MASK; }
233	if(ce >= MIN_LONG) { return 0; } // variable
234	return pair; // special mini CE
235	}
236	static inline uint32_t getSecondariesFromOneShortCE(uint32_t ce) {
237	ce &= SECONDARY_MASK;
238	if(ce < MIN_SEC_HIGH) {
239	return ce + SEC_OFFSET;
240	} else {
241	return ((ce + SEC_OFFSET) << 16) \| COMMON_SEC_PLUS_OFFSET;
242	}
243	}
244	static uint32_t getSecondaries(uint32_t variableTop, uint32_t pair);
245	static uint32_t getCases(uint32_t variableTop, UBool strengthIsPrimary, uint32_t pair);
246	static uint32_t getTertiaries(uint32_t variableTop, UBool withCaseBits, uint32_t pair);
247	static uint32_t getQuaternaries(uint32_t variableTop, uint32_t pair);
248
249	private:
250	CollationFastLatin(); // no constructor
251	};
252
253	/*
254	* Format of the CollationFastLatin data table.
255	* CollationFastLatin::VERSION = 1.
256	*
257	* This table contains data for a Latin-text collation fastpath.
258	* The data is stored as an array of uint16_t which contains the following parts.
259	*
260	* uint16_t -- version & header length
261	* Bits 15..8: version, must match the VERSION
262	* 7..0: length of the header
263	*
264	* uint16_t varTops[header length - 1]
265	* Each of these values maps the variable top lead byte of a supported maxVariable group
266	* to the highest CollationFastLatin long-primary weight.
267	* The values are stored in ascending order.
268	* Bits 15..7: max fast-Latin long-primary weight (bits 11..3 shifted left by 4 bits)
269	* 6..0: regular primary lead byte
270	*
271	* uint16_t miniCEs[0x1c0]
272	* A mini collation element for each character U+0000..U+017F and U+2000..U+203F.
273	* Each value encodes one or two mini CEs (two are possible if the first one
274	* has a short mini primary and the second one is a secondary CE, i.e., primary == 0),
275	* or points to an expansion or to a contraction table.
276	* U+0000 always has a contraction entry,
277	* so that NUL-termination need not be tested in the fastpath.
278	* If the collation elements for a character or contraction cannot be encoded in this format,
279	* then the BAIL_OUT value is stored.
280	* For details see the comments for the class constants.
281	*
282	* uint16_t expansions[variable length];
283	* Expansion mini CEs contain an offset relative to just after the miniCEs table.
284	* An expansions contains exactly 2 mini CEs.
285	*
286	* uint16_t contractions[variable length];
287	* Contraction mini CEs contain an offset relative to just after the miniCEs table.
288	* It points to a list of tuples which map from a contraction suffix character to a result.
289	* First uint16_t of each tuple:
290	* Bits 10..9: Length of the result (1..3), see comments on CONTR_LENGTH_SHIFT.
291	* Bits 8..0: Contraction character, see comments on CONTR_CHAR_MASK.
292	* This is followed by 0, 1, or 2 uint16_t according to the length.
293	* Each list is terminated by an entry with CONTR_CHAR_MASK.
294	* Each list starts with such an entry which also contains the default result
295	* for when there is no contraction match.
296	*/
297
298	U_NAMESPACE_END
299
300	#endif // !UCONFIG_NO_COLLATION
301	#endif // __COLLATIONFASTLATIN_H__