sortkey.h

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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
 *****************************************************************************
 * Copyright (C) 1996-2014, International Business Machines Corporation and others.
 * All Rights Reserved.
 *****************************************************************************
 *
 * File sortkey.h
 *
 * Created by: Helena Shih
 *
 * Modification History:
 *
 *  Date         Name          Description
 *
 *  6/20/97     helena      Java class name change.
 *  8/18/97     helena      Added internal API documentation.
 *  6/26/98     erm         Changed to use byte arrays and memcmp.
 *****************************************************************************
 */

#ifndef SORTKEY_H
#define SORTKEY_H

#include "unicode/utypes.h"

#if !UCONFIG_NO_COLLATION

#include "unicode/uobject.h"
#include "unicode/unistr.h"
#include "unicode/coll.h"

U_NAMESPACE_BEGIN

/* forward declaration */
class RuleBasedCollator;
class CollationKeyByteSink;

class U_I18N_API CollationKey : public UObject {
public:
    CollationKey();


    CollationKey(const  uint8_t*    values,
                int32_t     count);

    CollationKey(const CollationKey& other);

    virtual ~CollationKey();

    const   CollationKey&   operator=(const CollationKey& other);

    UBool                   operator==(const CollationKey& source) const;

    UBool                   operator!=(const CollationKey& source) const;


    UBool                   isBogus(void) const;

    const    uint8_t*       getByteArray(int32_t& count) const;

#ifdef U_USE_COLLATION_KEY_DEPRECATES

    uint8_t*                toByteArray(int32_t& count) const;
#endif

#ifndef U_HIDE_DEPRECATED_API 

    Collator::EComparisonResult compareTo(const CollationKey& target) const;
#endif  /* U_HIDE_DEPRECATED_API */

    UCollationResult compareTo(const CollationKey& target, UErrorCode &status) const;

    int32_t                 hashCode(void) const;

    virtual UClassID getDynamicClassID() const;

    static UClassID U_EXPORT2 getStaticClassID();

private:
    uint8_t *reallocate(int32_t newCapacity, int32_t length);
    void setLength(int32_t newLength);

    uint8_t *getBytes() {
        return (fFlagAndLength >= 0) ? fUnion.fStackBuffer : fUnion.fFields.fBytes;
    }
    const uint8_t *getBytes() const {
        return (fFlagAndLength >= 0) ? fUnion.fStackBuffer : fUnion.fFields.fBytes;
    }
    int32_t getCapacity() const {
        return (fFlagAndLength >= 0) ? (int32_t)sizeof(fUnion) : fUnion.fFields.fCapacity;
    }
    int32_t getLength() const { return fFlagAndLength & 0x7fffffff; }

    CollationKey&           setToBogus(void);
    CollationKey&           reset(void);

    friend  class           RuleBasedCollator;
    friend  class           CollationKeyByteSink;

    // Class fields. sizeof(CollationKey) is intended to be 48 bytes
    // on a machine with 64-bit pointers.
    // We use a union to maximize the size of the internal buffer,
    // similar to UnicodeString but not as tight and complex.

    // (implicit) *vtable;
    int32_t fFlagAndLength;
    mutable int32_t fHashCode;
    union StackBufferOrFields {
        uint8_t fStackBuffer[32];
        struct {
            uint8_t *fBytes;
            int32_t fCapacity;
        } fFields;
    } fUnion;
};

inline UBool
CollationKey::operator!=(const CollationKey& other) const
{
    return !(*this == other);
}

inline UBool
CollationKey::isBogus() const
{
    return fHashCode == 2;  // kBogusHashCode
}

inline const uint8_t*
CollationKey::getByteArray(int32_t &count) const
{
    count = getLength();
    return getBytes();
}

U_NAMESPACE_END

#endif /* #if !UCONFIG_NO_COLLATION */

#endif

---