// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
*
* Copyright (C) 1999-2014, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
* file name: collationweights.h
* encoding: UTF-8
* tab size: 8 (not used)
* indentation:4
*
* created on: 2001mar08 as ucol_wgt.h
* created by: Markus W. Scherer
*/
#ifndef __COLLATIONWEIGHTS_H__
#define __COLLATIONWEIGHTS_H__
#include "unicode/utypes.h"
#if !UCONFIG_NO_COLLATION
#include "unicode/uobject.h"
U_NAMESPACE_BEGIN
/**
* Allocates n collation element weights between two exclusive limits.
* Used only internally by the collation tailoring builder.
*/
class U_I18N_API CollationWeights :
public UMemory {
public:
CollationWeights();
static inline int32_t lengthOfWeight(uint32_t weight) {
if((weight&0xffffff)==0) {
return 1;
}
else if((weight&0xffff)==0) {
return 2;
}
else if((weight&0xff)==0) {
return 3;
}
else {
return 4;
}
}
void initForPrimary(UBool compressible);
void initForSecondary();
void initForTertiary();
/**
* Determine heuristically
* what ranges to use for a given number of weights between (excluding)
* two limits.
*
* @param lowerLimit A collation element weight; the ranges will be filled to cover
* weights greater than this one.
* @param upperLimit A collation element weight; the ranges will be filled to cover
* weights less than this one.
* @param n The number of collation element weights w necessary such that
* lowerLimit<w<upperLimit in lexical order.
* @return true if it is possible to fit n elements between the limits
*/
UBool allocWeights(uint32_t lowerLimit, uint32_t upperLimit, int32_t n);
/**
* Given a set of ranges calculated by allocWeights(),
* iterate through the weights.
* The ranges are modified to keep the current iteration state.
*
* @return The next weight in the ranges, or 0xffffffff if there is none left.
*/
uint32_t nextWeight();
/** @internal */
struct WeightRange {
uint32_t start, end;
int32_t length, count;
};
private:
/** @return number of usable byte values for byte idx */
inline int32_t countBytes(int32_t idx)
const {
return static_cast<int32_t>(maxBytes[idx] - minBytes[idx] + 1);
}
uint32_t incWeight(uint32_t weight, int32_t length)
const;
uint32_t incWeightByOffset(uint32_t weight, int32_t length, int32_t offset)
const;
void lengthenRange(WeightRange &range)
const;
/**
* Takes two CE weights and calculates the
* possible ranges of weights between the two limits, excluding them.
* For weights with up to 4 bytes there are up to 2*4-1=7 ranges.
*/
UBool getWeightRanges(uint32_t lowerLimit, uint32_t upperLimit);
UBool allocWeightsInShortRanges(int32_t n, int32_t minLength);
UBool allocWeightsInMinLengthRanges(int32_t n, int32_t minLength);
int32_t middleLength;
uint32_t minBytes[5];
// for byte 1, 2, 3, 4
uint32_t maxBytes[5];
WeightRange ranges[7];
int32_t rangeIndex;
int32_t rangeCount;
};
U_NAMESPACE_END
#endif // !UCONFIG_NO_COLLATION
#endif // __COLLATIONWEIGHTS_H__
