/*
* @(#)ConditionSetFunction.java
*
* Copyright 2004-2006 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.BagAttribute;
import com.sun.xacml.attr.BooleanAttribute;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
/**
* Specific <code>SetFunction</code> class that supports all of the
* condition set functions: type-at-least-one-member-of, type-subset, and
* type-set-equals.
*
* @since 1.2
* @author Seth Proctor
*/
public class ConditionSetFunction extends SetFunction
{
// private identifiers for the supported functions
private static final int ID_BASE_AT_LEAST_ONE_MEMBER_OF = 0;
private static final int ID_BASE_SUBSET = 1;
private static final int ID_BASE_SET_EQUALS = 2;
// mapping of function name to its associated id and parameter type
private static HashMap<String, Integer> idMap;
private static HashMap<String, String> typeMap;
// the actual supported ids
private static Set<String> supportedIds;
/**
* Static initializer that sets up the paramater info for all the
* supported functions.
*/
static {
idMap = new HashMap<String, Integer>();
typeMap = new HashMap<String, String>();
for (int i = 0; i < baseTypes.length; i++) {
String baseName = FUNCTION_NS + simpleTypes[i];
String baseType = baseTypes[i];
idMap.put(baseName + NAME_BASE_AT_LEAST_ONE_MEMBER_OF,
Integer.valueOf(ID_BASE_AT_LEAST_ONE_MEMBER_OF));
idMap.put(baseName + NAME_BASE_SUBSET,
Integer.valueOf(ID_BASE_SUBSET));
idMap.put(baseName + NAME_BASE_SET_EQUALS,
Integer.valueOf(ID_BASE_SET_EQUALS));
typeMap.put(baseName + NAME_BASE_AT_LEAST_ONE_MEMBER_OF, baseType);
typeMap.put(baseName + NAME_BASE_SUBSET, baseType);
typeMap.put(baseName + NAME_BASE_SET_EQUALS, baseType);
}
for (int i = 0; i < baseTypes2.length; i++) {
String baseName = FUNCTION_NS_2 + simpleTypes2[i];
String baseType = baseTypes2[i];
idMap.put(baseName + NAME_BASE_AT_LEAST_ONE_MEMBER_OF,
Integer.valueOf(ID_BASE_AT_LEAST_ONE_MEMBER_OF));
idMap.put(baseName + NAME_BASE_SUBSET,
Integer.valueOf(ID_BASE_SUBSET));
idMap.put(baseName + NAME_BASE_SET_EQUALS,
Integer.valueOf(ID_BASE_SET_EQUALS));
typeMap.put(baseName + NAME_BASE_AT_LEAST_ONE_MEMBER_OF, baseType);
typeMap.put(baseName + NAME_BASE_SUBSET, baseType);
typeMap.put(baseName + NAME_BASE_SET_EQUALS, baseType);
}
supportedIds = Collections.
unmodifiableSet(new HashSet<String>(idMap.keySet()));
idMap.put(NAME_BASE_AT_LEAST_ONE_MEMBER_OF,
Integer.valueOf(ID_BASE_AT_LEAST_ONE_MEMBER_OF));
idMap.put(NAME_BASE_SUBSET, Integer.valueOf(ID_BASE_SUBSET));
idMap.put(NAME_BASE_SET_EQUALS, Integer.valueOf(ID_BASE_SET_EQUALS));
}
/**
* Constructor that is used to create one of the condition standard
* set functions. The name supplied must be one of the standard XACML
* functions supported by this class, including the full namespace,
* otherwise an exception is thrown. Look in <code>SetFunction</code>
* for details about the supported names.
*
* @param functionName the name of the function to create
*
* @throws IllegalArgumentException if the function is unknown
*/
public ConditionSetFunction(String functionName) {
super(functionName, getId(functionName), getArgumentType(functionName),
BooleanAttribute.identifier, false);
}
/**
* Constructor that is used to create instances of condition set
* functions for new (non-standard) datatypes. This is equivalent to
* using the <code>getInstance</code> methods in <code>SetFunction</code>
* and is generally only used by the run-time configuration code.
*
* @param functionName the name of the new function
* @param datatype the full identifier for the supported datatype
* @param functionType which kind of Set function, based on the
* <code>NAME_BASE_*</code> fields
*/
public ConditionSetFunction(String functionName, String datatype,
String functionType) {
super(functionName, getId(functionName), datatype,
BooleanAttribute.identifier, false);
}
/**
* Private helper that returns the internal identifier used for the
* given standard function.
*/
private static int getId(String functionName) {
Integer id = (Integer)(idMap.get(functionName));
if (id == null) {
throw new IllegalArgumentException("unknown set function " +
functionName);
}
return id.intValue();
}
/**
* Private helper that returns the argument type 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) {
return (String)(typeMap.get(functionName));
}
/**
* 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() {
return supportedIds;
}
/**
* Evaluates 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 evalResult = evalArgs(inputs, context, argValues);
if (evalResult != null) {
return evalResult;
}
// setup the two bags we'll be using
BagAttribute [] bags = new BagAttribute[2];
bags[0] = (BagAttribute)(argValues[0]);
bags[1] = (BagAttribute)(argValues[1]);
AttributeValue result = null;
switch(getFunctionId()) {
// *-at-least-one-member-of takes two bags of the same type and
// returns a boolean
case ID_BASE_AT_LEAST_ONE_MEMBER_OF:
// true if at least one element in the first argument is in the
// second argument (using the *-is-in semantics)
result = BooleanAttribute.getFalseInstance();
Iterator<AttributeValue> it = bags[0].iterator();
while (it.hasNext()) {
if (bags[1].contains((AttributeValue)(it.next()))) {
result = BooleanAttribute.getTrueInstance();
break;
}
}
break;
// *-set-equals takes two bags of the same type and returns
// a boolean
case ID_BASE_SUBSET:
// returns true if the first argument is a subset of the second
// argument (ie, all the elements in the first bag appear in
// the second bag) ... ignore all duplicate values in both
// input bags
boolean subset = bags[1].containsAll(bags[0]);
result = BooleanAttribute.getInstance(subset);
break;
// *-set-equals takes two bags of the same type and returns
// a boolean
case ID_BASE_SET_EQUALS:
// returns true if the two inputs contain the same elements
// discounting any duplicates in either input ... this is the same
// as applying the and function on the subset function with
// the two inputs, and then the two inputs reversed (ie, are the
// two inputs subsets of each other)
boolean equals = (bags[1].containsAll(bags[0]) &&
bags[0].containsAll(bags[1]));
result = BooleanAttribute.getInstance(equals);
break;
}
return new EvaluationResult(result);
}
}