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| 1 /* |
| 2 ******************************************************************************* |
| 3 * |
| 4 * Copyright (C) 1999-2014, International Business Machines |
| 5 * Corporation and others. All Rights Reserved. |
| 6 * |
| 7 ******************************************************************************* |
| 8 * file name: collationweights.h |
| 9 * encoding: US-ASCII |
| 10 * tab size: 8 (not used) |
| 11 * indentation:4 |
| 12 * |
| 13 * created on: 2001mar08 as ucol_wgt.h |
| 14 * created by: Markus W. Scherer |
| 15 */ |
| 16 |
| 17 #ifndef __COLLATIONWEIGHTS_H__ |
| 18 #define __COLLATIONWEIGHTS_H__ |
| 19 |
| 20 #include "unicode/utypes.h" |
| 21 |
| 22 #if !UCONFIG_NO_COLLATION |
| 23 |
| 24 #include "unicode/uobject.h" |
| 25 |
| 26 U_NAMESPACE_BEGIN |
| 27 |
| 28 /** |
| 29 * Allocates n collation element weights between two exclusive limits. |
| 30 * Used only internally by the collation tailoring builder. |
| 31 */ |
| 32 class U_I18N_API CollationWeights : public UMemory { |
| 33 public: |
| 34 CollationWeights(); |
| 35 |
| 36 static inline int32_t lengthOfWeight(uint32_t weight) { |
| 37 if((weight&0xffffff)==0) { |
| 38 return 1; |
| 39 } else if((weight&0xffff)==0) { |
| 40 return 2; |
| 41 } else if((weight&0xff)==0) { |
| 42 return 3; |
| 43 } else { |
| 44 return 4; |
| 45 } |
| 46 } |
| 47 |
| 48 void initForPrimary(UBool compressible); |
| 49 void initForSecondary(); |
| 50 void initForTertiary(); |
| 51 |
| 52 /** |
| 53 * Determine heuristically |
| 54 * what ranges to use for a given number of weights between (excluding) |
| 55 * two limits. |
| 56 * |
| 57 * @param lowerLimit A collation element weight; the ranges will be filled t
o cover |
| 58 * weights greater than this one. |
| 59 * @param upperLimit A collation element weight; the ranges will be filled t
o cover |
| 60 * weights less than this one. |
| 61 * @param n The number of collation element weights w necessary suc
h that |
| 62 * lowerLimit<w<upperLimit in lexical order. |
| 63 * @return TRUE if it is possible to fit n elements between the limits |
| 64 */ |
| 65 UBool allocWeights(uint32_t lowerLimit, uint32_t upperLimit, int32_t n); |
| 66 |
| 67 /** |
| 68 * Given a set of ranges calculated by allocWeights(), |
| 69 * iterate through the weights. |
| 70 * The ranges are modified to keep the current iteration state. |
| 71 * |
| 72 * @return The next weight in the ranges, or 0xffffffff if there is none lef
t. |
| 73 */ |
| 74 uint32_t nextWeight(); |
| 75 |
| 76 /** @internal */ |
| 77 struct WeightRange { |
| 78 uint32_t start, end; |
| 79 int32_t length, count; |
| 80 }; |
| 81 |
| 82 private: |
| 83 /** @return number of usable byte values for byte idx */ |
| 84 inline int32_t countBytes(int32_t idx) const { |
| 85 return (int32_t)(maxBytes[idx] - minBytes[idx] + 1); |
| 86 } |
| 87 |
| 88 uint32_t incWeight(uint32_t weight, int32_t length) const; |
| 89 uint32_t incWeightByOffset(uint32_t weight, int32_t length, int32_t offset)
const; |
| 90 void lengthenRange(WeightRange &range) const; |
| 91 /** |
| 92 * Takes two CE weights and calculates the |
| 93 * possible ranges of weights between the two limits, excluding them. |
| 94 * For weights with up to 4 bytes there are up to 2*4-1=7 ranges. |
| 95 */ |
| 96 UBool getWeightRanges(uint32_t lowerLimit, uint32_t upperLimit); |
| 97 UBool allocWeightsInShortRanges(int32_t n, int32_t minLength); |
| 98 UBool allocWeightsInMinLengthRanges(int32_t n, int32_t minLength); |
| 99 |
| 100 int32_t middleLength; |
| 101 uint32_t minBytes[5]; // for byte 1, 2, 3, 4 |
| 102 uint32_t maxBytes[5]; |
| 103 WeightRange ranges[7]; |
| 104 int32_t rangeIndex; |
| 105 int32_t rangeCount; |
| 106 }; |
| 107 |
| 108 U_NAMESPACE_END |
| 109 |
| 110 #endif // !UCONFIG_NO_COLLATION |
| 111 #endif // __COLLATIONWEIGHTS_H__ |
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