/*
* @(#)DivideFunction.java
*
* Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
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package com.sun.xacml.cond;
import com.sun.xacml.EvaluationCtx;
import com.sun.xacml.attr.AttributeValue;
import com.sun.xacml.attr.DoubleAttribute;
import com.sun.xacml.attr.IntegerAttribute;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* A class that implements all the *-divide functions. It takes two
* operands of the appropriate type and returns the quotient of the
* operands. If either of the operands is indeterminate, an indeterminate
* result is returned.
*
* @since 1.0
* @author Steve Hanna
* @author Seth Proctor
*/
public class DivideFunction extends FunctionBase
{
/**
* Standard identifier for the integer-divide function.
*/
public static final String NAME_INTEGER_DIVIDE =
FUNCTION_NS + "integer-divide";
/**
* Standard identifier for the double-divide function.
*/
public static final String NAME_DOUBLE_DIVIDE =
FUNCTION_NS + "double-divide";
// inernal identifiers for each of the supported functions
private static final int ID_INTEGER_DIVIDE = 0;
private static final int ID_DOUBLE_DIVIDE = 1;
/**
* Creates a new <code>DivideFunction</code> object.
*
* @param functionName the standard XACML name of the function to be
* handled by this object, including the full namespace
*
* @throws IllegalArgumentException if the function is unknown
*/
public DivideFunction(String functionName) {
super(functionName, getId(functionName), getArgumentType(functionName),
false, 2, getArgumentType(functionName), false);
}
/**
* Private helper that returns the internal identifier used for the
* given standard function.
*/
private static int getId(String functionName) {
if (functionName.equals(NAME_INTEGER_DIVIDE)) {
return ID_INTEGER_DIVIDE;
} else if (functionName.equals(NAME_DOUBLE_DIVIDE)) {
return ID_DOUBLE_DIVIDE;
} else {
throw new IllegalArgumentException("unknown divide function "
+ functionName);
}
}
/**
* Private helper that returns the type used for the given standard
* function. Note that this doesn't check on the return value since the
* method always is called after getId, so we assume that the function
* is present.
*/
private static String getArgumentType(String functionName) {
if (functionName.equals(NAME_INTEGER_DIVIDE)) {
return IntegerAttribute.identifier;
}
return DoubleAttribute.identifier;
}
/**
* Returns a <code>Set</code> containing all the function identifiers
* supported by this class.
*
* @return a <code>Set</code> of <code>String</code>s
*/
public static Set<String> getSupportedIdentifiers() {
Set<String> set = new HashSet<String>();
set.add(NAME_INTEGER_DIVIDE);
set.add(NAME_DOUBLE_DIVIDE);
return set;
}
/**
* Evaluate the function, using the specified parameters.
*
* @param inputs a <code>List</code> of <code>Evaluatable</code>
* objects representing the arguments passed to the function
* @param context an <code>EvaluationCtx</code> so that the
* <code>Evaluatable</code> objects can be evaluated
* @return an <code>EvaluationResult</code> representing the
* function's result
*/
public EvaluationResult evaluate(List<Expression> inputs, EvaluationCtx context) {
// Evaluate the arguments
AttributeValue [] argValues = new AttributeValue[inputs.size()];
EvaluationResult result = evalArgs(inputs, context, argValues);
if (result != null) {
return result;
}
// Now that we have real values, perform the divide operation
// in the manner appropriate for the type of the arguments.
if (getFunctionId() == ID_INTEGER_DIVIDE) {
long dividend = ((IntegerAttribute) argValues[0]).getValue();
long divisor = ((IntegerAttribute) argValues[1]).getValue();
if (divisor == 0) {
result = makeProcessingError("divide by zero");
} else {
long quotient = dividend / divisor;
result = new EvaluationResult(new IntegerAttribute(quotient));
}
} else if (getFunctionId() == ID_DOUBLE_DIVIDE) {
double dividend = ((DoubleAttribute) argValues[0]).getValue();
double divisor = ((DoubleAttribute) argValues[1]).getValue();
if (divisor == 0) {
result = makeProcessingError("divide by zero");
} else {
double quotient = dividend / divisor;
result = new EvaluationResult(new DoubleAttribute(quotient));
}
}
return result;
}
}