Victor Chang | 7322950 | 2020-09-17 13:39:19 +0100 | [diff] [blame] | 1 | // © 2016 and later: Unicode, Inc. and others. |
| 2 | // License & terms of use: http://www.unicode.org/copyright.html |
| 3 | /* |
| 4 | ******************************************************************************* |
| 5 | * Copyright (C) 2013-2014, International Business Machines |
| 6 | * Corporation and others. All Rights Reserved. |
| 7 | ******************************************************************************* |
| 8 | * collationrootelements.h |
| 9 | * |
| 10 | * created on: 2013mar01 |
| 11 | * created by: Markus W. Scherer |
| 12 | */ |
| 13 | |
| 14 | #ifndef __COLLATIONROOTELEMENTS_H__ |
| 15 | #define __COLLATIONROOTELEMENTS_H__ |
| 16 | |
| 17 | #include "unicode/utypes.h" |
| 18 | |
| 19 | #if !UCONFIG_NO_COLLATION |
| 20 | |
| 21 | #include "unicode/uobject.h" |
| 22 | #include "collation.h" |
| 23 | |
| 24 | U_NAMESPACE_BEGIN |
| 25 | |
| 26 | /** |
| 27 | * Container and access methods for collation elements and weights |
| 28 | * that occur in the root collator. |
| 29 | * Needed for finding boundaries for building a tailoring. |
| 30 | * |
| 31 | * This class takes and returns 16-bit secondary and tertiary weights. |
| 32 | */ |
| 33 | class U_I18N_API CollationRootElements : public UMemory { |
| 34 | public: |
| 35 | CollationRootElements(const uint32_t *rootElements, int32_t rootElementsLength) |
| 36 | : elements(rootElements), length(rootElementsLength) {} |
| 37 | |
| 38 | /** |
| 39 | * Higher than any root primary. |
| 40 | */ |
| 41 | static const uint32_t PRIMARY_SENTINEL = 0xffffff00; |
| 42 | |
| 43 | /** |
| 44 | * Flag in a root element, set if the element contains secondary & tertiary weights, |
| 45 | * rather than a primary. |
| 46 | */ |
| 47 | static const uint32_t SEC_TER_DELTA_FLAG = 0x80; |
| 48 | /** |
| 49 | * Mask for getting the primary range step value from a primary-range-end element. |
| 50 | */ |
| 51 | static const uint8_t PRIMARY_STEP_MASK = 0x7f; |
| 52 | |
| 53 | enum { |
| 54 | /** |
| 55 | * Index of the first CE with a non-zero tertiary weight. |
| 56 | * Same as the start of the compact root elements table. |
| 57 | */ |
| 58 | IX_FIRST_TERTIARY_INDEX, |
| 59 | /** |
| 60 | * Index of the first CE with a non-zero secondary weight. |
| 61 | */ |
| 62 | IX_FIRST_SECONDARY_INDEX, |
| 63 | /** |
| 64 | * Index of the first CE with a non-zero primary weight. |
| 65 | */ |
| 66 | IX_FIRST_PRIMARY_INDEX, |
| 67 | /** |
| 68 | * Must match Collation::COMMON_SEC_AND_TER_CE. |
| 69 | */ |
| 70 | IX_COMMON_SEC_AND_TER_CE, |
| 71 | /** |
| 72 | * Secondary & tertiary boundaries. |
| 73 | * Bits 31..24: [fixed last secondary common byte 45] |
| 74 | * Bits 23..16: [fixed first ignorable secondary byte 80] |
| 75 | * Bits 15.. 8: reserved, 0 |
| 76 | * Bits 7.. 0: [fixed first ignorable tertiary byte 3C] |
| 77 | */ |
| 78 | IX_SEC_TER_BOUNDARIES, |
| 79 | /** |
| 80 | * The current number of indexes. |
| 81 | * Currently the same as elements[IX_FIRST_TERTIARY_INDEX]. |
| 82 | */ |
| 83 | IX_COUNT |
| 84 | }; |
| 85 | |
| 86 | /** |
| 87 | * Returns the boundary between tertiary weights of primary/secondary CEs |
| 88 | * and those of tertiary CEs. |
| 89 | * This is the upper limit for tertiaries of primary/secondary CEs. |
| 90 | * This minus one is the lower limit for tertiaries of tertiary CEs. |
| 91 | */ |
| 92 | uint32_t getTertiaryBoundary() const { |
| 93 | return (elements[IX_SEC_TER_BOUNDARIES] << 8) & 0xff00; |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * Returns the first assigned tertiary CE. |
| 98 | */ |
| 99 | uint32_t getFirstTertiaryCE() const { |
| 100 | return elements[elements[IX_FIRST_TERTIARY_INDEX]] & ~SEC_TER_DELTA_FLAG; |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Returns the last assigned tertiary CE. |
| 105 | */ |
| 106 | uint32_t getLastTertiaryCE() const { |
| 107 | return elements[elements[IX_FIRST_SECONDARY_INDEX] - 1] & ~SEC_TER_DELTA_FLAG; |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * Returns the last common secondary weight. |
| 112 | * This is the lower limit for secondaries of primary CEs. |
| 113 | */ |
| 114 | uint32_t getLastCommonSecondary() const { |
| 115 | return (elements[IX_SEC_TER_BOUNDARIES] >> 16) & 0xff00; |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * Returns the boundary between secondary weights of primary CEs |
| 120 | * and those of secondary CEs. |
| 121 | * This is the upper limit for secondaries of primary CEs. |
| 122 | * This minus one is the lower limit for secondaries of secondary CEs. |
| 123 | */ |
| 124 | uint32_t getSecondaryBoundary() const { |
| 125 | return (elements[IX_SEC_TER_BOUNDARIES] >> 8) & 0xff00; |
| 126 | } |
| 127 | |
| 128 | /** |
| 129 | * Returns the first assigned secondary CE. |
| 130 | */ |
| 131 | uint32_t getFirstSecondaryCE() const { |
| 132 | return elements[elements[IX_FIRST_SECONDARY_INDEX]] & ~SEC_TER_DELTA_FLAG; |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * Returns the last assigned secondary CE. |
| 137 | */ |
| 138 | uint32_t getLastSecondaryCE() const { |
| 139 | return elements[elements[IX_FIRST_PRIMARY_INDEX] - 1] & ~SEC_TER_DELTA_FLAG; |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * Returns the first assigned primary weight. |
| 144 | */ |
| 145 | uint32_t getFirstPrimary() const { |
| 146 | return elements[elements[IX_FIRST_PRIMARY_INDEX]]; // step=0: cannot be a range end |
| 147 | } |
| 148 | |
| 149 | /** |
| 150 | * Returns the first assigned primary CE. |
| 151 | */ |
| 152 | int64_t getFirstPrimaryCE() const { |
| 153 | return Collation::makeCE(getFirstPrimary()); |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * Returns the last root CE with a primary weight before p. |
| 158 | * Intended only for reordering group boundaries. |
| 159 | */ |
| 160 | int64_t lastCEWithPrimaryBefore(uint32_t p) const; |
| 161 | |
| 162 | /** |
| 163 | * Returns the first root CE with a primary weight of at least p. |
| 164 | * Intended only for reordering group boundaries. |
| 165 | */ |
| 166 | int64_t firstCEWithPrimaryAtLeast(uint32_t p) const; |
| 167 | |
| 168 | /** |
| 169 | * Returns the primary weight before p. |
| 170 | * p must be greater than the first root primary. |
| 171 | */ |
| 172 | uint32_t getPrimaryBefore(uint32_t p, UBool isCompressible) const; |
| 173 | |
| 174 | /** Returns the secondary weight before [p, s]. */ |
| 175 | uint32_t getSecondaryBefore(uint32_t p, uint32_t s) const; |
| 176 | |
| 177 | /** Returns the tertiary weight before [p, s, t]. */ |
| 178 | uint32_t getTertiaryBefore(uint32_t p, uint32_t s, uint32_t t) const; |
| 179 | |
| 180 | /** |
| 181 | * Finds the index of the input primary. |
| 182 | * p must occur as a root primary, and must not be 0. |
| 183 | */ |
| 184 | int32_t findPrimary(uint32_t p) const; |
| 185 | |
| 186 | /** |
| 187 | * Returns the primary weight after p where index=findPrimary(p). |
| 188 | * p must be at least the first root primary. |
| 189 | */ |
| 190 | uint32_t getPrimaryAfter(uint32_t p, int32_t index, UBool isCompressible) const; |
| 191 | /** |
| 192 | * Returns the secondary weight after [p, s] where index=findPrimary(p) |
| 193 | * except use index=0 for p=0. |
| 194 | * |
| 195 | * Must return a weight for every root [p, s] as well as for every weight |
| 196 | * returned by getSecondaryBefore(). If p!=0 then s can be BEFORE_WEIGHT16. |
| 197 | * |
| 198 | * Exception: [0, 0] is handled by the CollationBuilder: |
| 199 | * Both its lower and upper boundaries are special. |
| 200 | */ |
| 201 | uint32_t getSecondaryAfter(int32_t index, uint32_t s) const; |
| 202 | /** |
| 203 | * Returns the tertiary weight after [p, s, t] where index=findPrimary(p) |
| 204 | * except use index=0 for p=0. |
| 205 | * |
| 206 | * Must return a weight for every root [p, s, t] as well as for every weight |
| 207 | * returned by getTertiaryBefore(). If s!=0 then t can be BEFORE_WEIGHT16. |
| 208 | * |
| 209 | * Exception: [0, 0, 0] is handled by the CollationBuilder: |
| 210 | * Both its lower and upper boundaries are special. |
| 211 | */ |
| 212 | uint32_t getTertiaryAfter(int32_t index, uint32_t s, uint32_t t) const; |
| 213 | |
| 214 | private: |
| 215 | /** |
| 216 | * Returns the first secondary & tertiary weights for p where index=findPrimary(p)+1. |
| 217 | */ |
| 218 | uint32_t getFirstSecTerForPrimary(int32_t index) const; |
| 219 | |
| 220 | /** |
| 221 | * Finds the largest index i where elements[i]<=p. |
| 222 | * Requires first primary<=p<0xffffff00 (PRIMARY_SENTINEL). |
| 223 | * Does not require that p is a root collator primary. |
| 224 | */ |
| 225 | int32_t findP(uint32_t p) const; |
| 226 | |
| 227 | static inline UBool isEndOfPrimaryRange(uint32_t q) { |
| 228 | return (q & SEC_TER_DELTA_FLAG) == 0 && (q & PRIMARY_STEP_MASK) != 0; |
| 229 | } |
| 230 | |
| 231 | /** |
| 232 | * Data structure: |
| 233 | * |
| 234 | * The first few entries are indexes, up to elements[IX_FIRST_TERTIARY_INDEX]. |
| 235 | * See the comments on the IX_ constants. |
| 236 | * |
| 237 | * All other elements are a compact form of the root collator CEs |
| 238 | * in mostly collation order. |
| 239 | * |
| 240 | * A sequence of one or more root CEs with the same primary weight is stored as |
| 241 | * one element with the primary weight, with the SEC_TER_DELTA_FLAG flag not set, |
| 242 | * followed by elements with only the secondary/tertiary weights, |
| 243 | * each with that flag set. |
| 244 | * If the lowest secondary/tertiary combination is Collation::COMMON_SEC_AND_TER_CE, |
| 245 | * then the element for that combination is omitted. |
| 246 | * |
| 247 | * Note: If the first actual secondary/tertiary combination is higher than |
| 248 | * Collation::COMMON_SEC_AND_TER_CE (which is unusual), |
| 249 | * the runtime code will assume anyway that Collation::COMMON_SEC_AND_TER_CE is present. |
| 250 | * |
| 251 | * A range of only-primary CEs with a consistent "step" increment |
| 252 | * from each primary to the next may be stored as a range. |
| 253 | * Only the first and last primary are stored, and the last has the step |
| 254 | * value in the low bits (PRIMARY_STEP_MASK). |
| 255 | * |
| 256 | * An range-end element may also either start a new range or be followed by |
| 257 | * elements with secondary/tertiary deltas. |
| 258 | * |
| 259 | * A primary element that is not a range end has zero step bits. |
| 260 | * |
| 261 | * There is no element for the completely ignorable CE (all weights 0). |
| 262 | * |
| 263 | * Before elements[IX_FIRST_PRIMARY_INDEX], all elements are secondary/tertiary deltas, |
| 264 | * for all of the ignorable root CEs. |
| 265 | * |
| 266 | * There are no elements for unassigned-implicit primary CEs. |
| 267 | * All primaries stored here are at most 3 bytes long. |
| 268 | */ |
| 269 | const uint32_t *elements; |
| 270 | int32_t length; |
| 271 | }; |
| 272 | |
| 273 | U_NAMESPACE_END |
| 274 | |
| 275 | #endif // !UCONFIG_NO_COLLATION |
| 276 | #endif // __COLLATIONROOTELEMENTS_H__ |