sqlinteger.java

derby database source code.good for you.

			throw outOfRange();

		float floorValue = (float)Math.floor(theValue);

		value = (int)floorValue;
		isnull = false;
	}

	/**
	 * @see NumberDataValue#setValue
	 *
	 * @exception StandardException		Thrown on error
	 */
	public void setValue(double theValue) throws StandardException
	{
		theValue = NumberDataType.normalizeDOUBLE(theValue);

		if (theValue > Integer.MAX_VALUE || theValue < Integer.MIN_VALUE)
			throw outOfRange();

		double floorValue = Math.floor(theValue);

		value = (int)floorValue;
		isnull = false;
	}

	public void setValue(boolean theValue)
	{
		value = theValue?1:0;
		isnull = false;
	}


	/**
	 * @see DataValueDescriptor#setValue
	 *
	 * @exception StandardException on failure of intValue on Number
	 *
	 */	
	public void setValue(Object theValue) 
		throws StandardException
	{
		if (theValue == null)
		{
			setToNull();
		}
		else if (theValue instanceof Number)
		{
			this.setValue(((Number)theValue).intValue());
		}
		else
		{
			genericSetObject(theValue);
		}
	}

	protected void setFrom(DataValueDescriptor theValue) throws StandardException {

		setValue(theValue.getInt());
	}

	/*
	 * DataValueDescriptor interface
	 */

	/** @see DataValueDescriptor#typePrecedence */
	public int typePrecedence()
	{
		return TypeId.INT_PRECEDENCE;
	}

	/*
	** SQL Operators
	*/

	/**
	 * The = operator as called from the language module, as opposed to
	 * the storage module.
	 *
	 * @param left			The value on the left side of the =
	 * @param right			The value on the right side of the =
	 *
	 * @return	A SQL boolean value telling whether the two parameters are equal
	 *
	 * @exception StandardException		Thrown on error
	 */

	public BooleanDataValue equals(DataValueDescriptor left,
							DataValueDescriptor right)
			throws StandardException
	{
		return SQLBoolean.truthValue(left,
									 right,
									 left.getInt() == right.getInt());
	}

	/**
	 * The <> operator as called from the language module, as opposed to
	 * the storage module.
	 *
	 * @param left			The value on the left side of the <>
	 * @param right			The value on the right side of the <>
	 *
	 * @return	A SQL boolean value telling whether the two parameters
	 *			are not equal
	 *
	 * @exception StandardException		Thrown on error
	 */

	public BooleanDataValue notEquals(DataValueDescriptor left,
							DataValueDescriptor right)
			throws StandardException
	{
		return SQLBoolean.truthValue(left,
									 right,
									 left.getInt() != right.getInt());
	}

	/**
	 * The < operator as called from the language module, as opposed to
	 * the storage module.
	 *
	 * @param left			The value on the left side of the <
	 * @param right			The value on the right side of the <
	 *
	 * @return	A SQL boolean value telling whether the first operand is less
	 *			than the second operand
	 *
	 * @exception StandardException		Thrown on error
	 */

	public BooleanDataValue lessThan(DataValueDescriptor left,
							DataValueDescriptor right)
			throws StandardException
	{
		return SQLBoolean.truthValue(left,
									 right,
									 left.getInt() < right.getInt());
	}

	/**
	 * The > operator as called from the language module, as opposed to
	 * the storage module.
	 *
	 * @param left			The value on the left side of the >
	 * @param right			The value on the right side of the >
	 *
	 * @return	A SQL boolean value telling whether the first operand is greater
	 *			than the second operand
	 *
	 * @exception StandardException		Thrown on error
	 */

	public BooleanDataValue greaterThan(DataValueDescriptor left,
							DataValueDescriptor right)
			throws StandardException
	{
		return SQLBoolean.truthValue(left,
									 right,
									 left.getInt() > right.getInt());
	}

	/**
	 * The <= operator as called from the language module, as opposed to
	 * the storage module.
	 *
	 * @param left			The value on the left side of the <=
	 * @param right			The value on the right side of the <=
	 *
	 * @return	A SQL boolean value telling whether the first operand is less
	 *			than or equal to the second operand
	 *
	 * @exception StandardException		Thrown on error
	 */

	public BooleanDataValue lessOrEquals(DataValueDescriptor left,
							DataValueDescriptor right)
			throws StandardException
	{
		return SQLBoolean.truthValue(left,
									 right,
									 left.getInt() <= right.getInt());
	}

	/**
	 * The >= operator as called from the language module, as opposed to
	 * the storage module.
	 *
	 * @param left			The value on the left side of the >=
	 * @param right			The value on the right side of the >=
	 *
	 * @return	A SQL boolean value telling whether the first operand is greater
	 *			than or equal to the second operand
	 *
	 * @exception StandardException		Thrown on error
	 */

	public BooleanDataValue greaterOrEquals(DataValueDescriptor left,
							DataValueDescriptor right)
			throws StandardException
	{
		return SQLBoolean.truthValue(left,
									 right,
									 left.getInt() >= right.getInt());
	}

	/**
	 * This method implements the * operator for "int * int".
	 *
	 * @param left	The first value to be multiplied
	 * @param right	The second value to be multiplied
	 * @param result	The result of a previous call to this method, null
	 *					if not called yet
	 *
	 * @return	A SQLInteger containing the result of the multiplication
	 *
	 * @exception StandardException		Thrown on error
	 */

	public NumberDataValue times(NumberDataValue left,
							NumberDataValue right,
							NumberDataValue result)
				throws StandardException
	{
		if (result == null)
		{
			result = new SQLInteger();
		}

		if (left.isNull() || right.isNull())
		{
			result.setToNull();
			return result;
		}

		/*
		** Java does not check for overflow with integral types. We have to
		** check the result ourselves.
		**
		** We can't use sign checking tricks like we do for '+' and '-' since
		** the product of 2 integers can wrap around multiple times.  So, we
		** do long arithmetic and then verify that the result is within the 
		** range of an int, throwing an error if it isn't.
		*/
		long tempResult = left.getLong() * right.getLong();

		result.setValue(tempResult);
		return result;
	}


	/**
		mod(int, int)
	*/
	public NumberDataValue mod(NumberDataValue dividend,
								NumberDataValue divisor,
								NumberDataValue result)
								throws StandardException {
		if (result == null)
		{
			result = new SQLInteger();
		}

		if (dividend.isNull() || divisor.isNull())
		{
			result.setToNull();
			return result;
		}

		/* Catch divide by 0 */
		int intDivisor = divisor.getInt();
		if (intDivisor == 0)
		{
			throw StandardException.newException(SQLState.LANG_DIVIDE_BY_ZERO);
		}

		result.setValue(dividend.getInt() % intDivisor);
		return result;
	}
	/**
	 * This method implements the unary minus operator for int.
	 *
	 * @param result	The result of a previous call to this method, null
	 *					if not called yet
	 *
	 * @return	A SQLInteger containing the result of the division
	 *
	 * @exception StandardException		Thrown on error
	 */

	public NumberDataValue minus(NumberDataValue result)
									throws StandardException
	{
		int		operandValue;

		if (result == null)
		{
			result = new SQLInteger();
		}

		if (this.isNull())
		{
			result.setToNull();
			return result;
		}

		operandValue = this.getInt();

		/*
		** In two's complement arithmetic, the minimum value for a number
		** can't be negated, since there is no representation for its
		** positive value.  For integers, the minimum value is -2147483648,
		** and the maximum value is 2147483647.
		*/
		if (operandValue == Integer.MIN_VALUE)
		{
			throw outOfRange();
		}

		result.setValue(-operandValue);
		return result;
	}

    /**
     * This method implements the isNegative method.
     *
     * @return  A boolean.  If this.value is negative, return true.
     *          For positive values or null, return false.
     */

    protected boolean isNegative()
    {
        return !isNull() && value < 0;
    }

	/*
	 * String display of value
	 */

	public String toString()
	{
		if (isNull())
			return "NULL";
		else
			return Integer.toString(value);
	}

	/*
	 * Hash code
	 */
	public int hashCode()
	{
		return value;
	}

	/*
	 * useful constants...
	 */
	static final int INTEGER_LENGTH		= 4; // must match the number of bytes written by DataOutput.writeInt()

    private static final int BASE_MEMORY_USAGE = ClassSize.estimateBaseFromCatalog( SQLInteger.class);

    public int estimateMemoryUsage()
    {
        return BASE_MEMORY_USAGE;
    }

	/*
	 * object state
	 */
	private int		value;
	private boolean	isnull;
}