/*
 * Copyright 2011, Ingo Weinhold, ingo_weinhold@gmx.de.
 * Distributed under the terms of the MIT License.
 */
#ifndef _SUPPORT_BSTRING_PRIVATE_H_
#define _SUPPORT_BSTRING_PRIVATE_H_


#include <stdlib.h>

#include <String.h>


class BString::Private {
public:
        static const uint32 kPrivateDataOffset = 2 * sizeof(int32);

public:
        Private(const BString& string)
                :
                fString(string)
        {
        }

        char* Data()
        {
                return fString.fPrivateData;
        }

        bool IsShareable() const
        {
                return fString._IsShareable();
        }

        static int32& DataRefCount(char* data)
        {
                return *(((int32 *)data) - 2);
        }

        int32& DataRefCount()
        {
                return DataRefCount(Data());
        }

        static int32& DataLength(char* data)
        {
                return *(((int32*)data) - 1);
        }

        int32& DataLength()
        {
                return DataLength(Data());
        }

        static void IncrementDataRefCount(char* data)
        {
                if (data != NULL)
                        atomic_add(&DataRefCount(data), 1);
        }

        static void DecrementDataRefCount(char* data)
        {
                if (data != NULL) {
                        if (atomic_add(&DataRefCount(data), -1) == 1)
                                free(data - kPrivateDataOffset);
                }
        }

        static BString StringFromData(char* data)
        {
                return BString(data, BString::PRIVATE_DATA);
        }

private:
        const BString&  fString;
};


#endif  // _SUPPORT_BSTRING_PRIVATE_H_