XMLBigInteger.hpp

/*
 * The Apache Software License, Version 1.1
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 * Copyright (c) 2001 The Apache Software Foundation.  All rights
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 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation, and was
 * originally based on software copyright (c) 2001 International
 * Business Machines, Inc., http://www.ibm.com .  For more information
 * on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
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/*
 * $Id$
 */

#ifndef XML_BIGINTEGER_HPP
#define XML_BIGINTEGER_HPP

#include <xercesc/util/XercesDefs.hpp>
#include <xercesc/util/XMLString.hpp>

class XMLUTIL_EXPORT XMLBigInteger
{
public:

	/**
	 * Constructs a newly allocated <code>XMLBigInteger</code> object that
	 * represents the value represented by the string. The string is
	 * converted to an int value as if by the <code>valueOf</code> method.
	 *
	 * @param      strValue   the <code>String</code> to be converted to an
	 *                       <code>XMLBigInteger</code>.
	 * @exception  NumberFormatException  if the <code>String</code> does not
	 *               contain a parsable XMLBigInteger.
	 */

	XMLBigInteger(const XMLCh* const strValue);

	~XMLBigInteger();

	XMLBigInteger(const XMLBigInteger& toCopy);

    static void parseBigInteger(const XMLCh* const toConvert
                              , XMLCh* const       retBuffer
                              , int&   signValue);

    static int  compareValues(const XMLBigInteger* const lValue
                             ,const XMLBigInteger* const rValue);


    void        multiply(const unsigned int byteToShift);

    void        divide(const unsigned int byteToShift);

    int         getTotalDigit() const;

	/**
	 *  Return a copy of the fMagnitue.
     *  A leading sign is ALWAYS in place and the caller of this method
     *  is responsible for the de-allocation of the memory.
	 */
    XMLCh*      toString() const;

	/**
	 * Compares this object to the specified object.
	 * The result is <code>true</code> if and only if the argument is not
	 * <code>null</code> and is an <code>XMLBigInteger</code> object that contains
	 * the same <code>int</code> value as this object.
	 *
	 * @param   toCompare   the object to compare with.
	 * @return  <code>true</code> if the objects are the same;
	 *          <code>false</code> otherwise.
	 */
	bool operator==(const XMLBigInteger& toCompare) const;

	/**
	 * Returns the signum function of this number (i.e., -1, 0 or 1 as
	 * the value of this number is negative, zero or positive).
	 */
	int getSign() const;

    int intValue() const;

private:

	void setSign(int);

	/*
	 * The number is internally stored in "minimal" sign-fMagnitude format
	 * (i.e., no BigIntegers have a leading zero byte in their magnitudes).
	 * Zero is represented with a signum of 0 (and a zero-length fMagnitude).
	 * Thus, there is exactly one representation for each value.
	 */
    // -----------------------------------------------------------------------
    //  Private data members
    //
    //  fSign
    //     to represent the sign of the number.
    //
	//  fMagnitude
    //     the buffer holding the number.
    //
    // -----------------------------------------------------------------------

    int         fSign;
	XMLCh*      fMagnitude;  //null terminated

};

inline int XMLBigInteger::getSign() const
{	
    return fSign;
}

inline int XMLBigInteger::getTotalDigit() const
{
    return ((getSign() ==0) ? 0 : XMLString::stringLen(fMagnitude));
}

inline bool XMLBigInteger::operator==(const XMLBigInteger& toCompare) const
{
    return ( compareValues(this, &toCompare) ==0 ? true : false);
}

inline void XMLBigInteger::setSign(int newSign)
{
    fSign = newSign;
}

#endif