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// © 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 (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__