/*
* @(#)GeneralBagFunction.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.IntegerAttribute;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* Specific <code>BagFunction</code> class that supports all of the
* general-purpose bag functions: type-one-and-only, type-bag-size, and
* type-bag.
*
* @since 1.2
* @author Seth Proctor
*/
public class GeneralBagFunction extends BagFunction
{
// private identifiers for the supported functions
private static final int ID_BASE_ONE_AND_ONLY = 0;
private static final int ID_BASE_BAG_SIZE = 1;
private static final int ID_BASE_BAG = 2;
// mapping of function name to its associated parameters
private static HashMap<String, BagParameters> paramMap;
private static Set<String> supportedIds;
/**
* Static initializer that sets up the parameter info for all the
* supported functions.
*/
static {
paramMap = new HashMap<String, BagParameters>();
for (int i = 0; i < baseTypes.length; i++) {
String baseType = baseTypes[i];
String functionBaseName = FUNCTION_NS + simpleTypes[i];
paramMap.put(functionBaseName + NAME_BASE_ONE_AND_ONLY,
new BagParameters(ID_BASE_ONE_AND_ONLY, baseType,
true, 1, baseType, false));
paramMap.put(functionBaseName + NAME_BASE_BAG_SIZE,
new BagParameters(ID_BASE_BAG_SIZE, baseType, true,
1, IntegerAttribute.identifier,
false));
paramMap.put(functionBaseName + NAME_BASE_BAG,
new BagParameters(ID_BASE_BAG, baseType, false, -1,
baseType, true));
}
for (int i = 0; i < baseTypes2.length; i++) {
String baseType = baseTypes2[i];
String functionBaseName = FUNCTION_NS_2 + simpleTypes2[i];
paramMap.put(functionBaseName + NAME_BASE_ONE_AND_ONLY,
new BagParameters(ID_BASE_ONE_AND_ONLY, baseType,
true, 1, baseType, false));
paramMap.put(functionBaseName + NAME_BASE_BAG_SIZE,
new BagParameters(ID_BASE_BAG_SIZE, baseType, true,
1, IntegerAttribute.identifier,
false));
paramMap.put(functionBaseName + NAME_BASE_BAG,
new BagParameters(ID_BASE_BAG, baseType, false, -1,
baseType, true));
}
supportedIds = Collections.
unmodifiableSet(new HashSet<String>(paramMap.keySet()));
paramMap.put(NAME_BASE_ONE_AND_ONLY,
new BagParameters(ID_BASE_ONE_AND_ONLY, null, true, 1,
null, false));
paramMap.put(NAME_BASE_BAG_SIZE,
new BagParameters(ID_BASE_BAG_SIZE, null, true, 1,
IntegerAttribute.identifier, false));
paramMap.put(NAME_BASE_BAG,
new BagParameters(ID_BASE_BAG, null, false, -1, null,
true));
}
/**
* Constructor that is used to create one of the general-purpose standard
* bag 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>BagFunction</code>
* for details about the supported names.
*
* @param functionName the name of the function to create
*
* @throws IllegalArgumentException if the function is unknown
*/
public GeneralBagFunction(String functionName) {
super(functionName, getId(functionName), getArgumentType(functionName),
getIsBag(functionName), getNumArgs(functionName),
getReturnType(functionName), getReturnsBag(functionName));
}
/**
* Constructor that is used to create instances of general-purpose bag
* functions for new (non-standard) datatypes. This is equivalent to
* using the <code>getInstance</code> methods in <code>BagFunction</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 Bag function, based on the
* <code>NAME_BASE_*</code> fields
*/
public GeneralBagFunction(String functionName, String datatype,
String functionType) {
super(functionName, getId(functionType), datatype,
getIsBag(functionType), getNumArgs(functionType),
getCustomReturnType(functionType, datatype),
getReturnsBag(functionType));
}
/**
* Private helper that returns the internal identifier used for the
* given standard function.
*/
private static int getId(String functionName) {
BagParameters params = (BagParameters)(paramMap.get(functionName));
if (params == null) {
throw new IllegalArgumentException("unknown bag function: " +
functionName);
}
return params.id;
}
/**
* 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 ((BagParameters)(paramMap.get(functionName))).arg;
}
/**
* Private helper that returns if the given standard function takes
* a bag. 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 boolean getIsBag(String functionName) {
return ((BagParameters)(paramMap.get(functionName))).argIsBag;
}
/**
* Private helper that returns the argument count 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 int getNumArgs(String functionName) {
return ((BagParameters)(paramMap.get(functionName))).params;
}
/**
* Private helper that returns the return 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 getReturnType(String functionName) {
return ((BagParameters)(paramMap.get(functionName))).returnType;
}
/**
* Private helper that returns if the return type is a bag 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 boolean getReturnsBag(String functionName) {
return ((BagParameters)(paramMap.get(functionName))).returnsBag;
}
/**
* Private helper used by the custom datatype constructor to figure out
* what the return type is. 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 getCustomReturnType(String functionType,
String datatype) {
String ret = ((BagParameters)(paramMap.get(functionType))).returnType;
if (ret == null) {
return datatype;
}
return ret;
}
/**
* 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;
}
/**
* 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 requested operation.
AttributeValue attrResult = null;
switch (getFunctionId()) {
// *-one-and-only takes a single bag and returns a
// single value of baseType
case ID_BASE_ONE_AND_ONLY: {
BagAttribute bag = (BagAttribute)(argValues[0]);
if (bag.size() != 1) {
//return new EvaluationResult(Status)
return makeProcessingError(getFunctionName() + " expects "
+ "a bag that contains a single element,"
+ "got a bag with " + bag.size() + " elements");
}
attrResult = (AttributeValue)(bag.iterator().next());
break;
}
// *-size takes a single bag and returns an integer
case ID_BASE_BAG_SIZE: {
BagAttribute bag = (BagAttribute)(argValues[0]);
attrResult = new IntegerAttribute(bag.size());
break;
}
// *-bag takes any number of elements of baseType and
// returns a bag containing those elements
case ID_BASE_BAG: {
List<AttributeValue> argsList = Arrays.asList(argValues);
attrResult = new BagAttribute(getReturnType(), argsList);
break;
}
}
return new EvaluationResult(attrResult);
}
/**
* Private class that is used for mapping each function to it set of
* parameters.
*/
private static class BagParameters {
/**
*
*/
public int id;
/**
*
*/
public String arg;
/**
*
*/
public boolean argIsBag;
/**
*
*/
public int params;
/**
*
*/
public String returnType;
/**
*
*/
public boolean returnsBag;
/**
* @param id
* @param arg
* @param argIsBag
* @param params
* @param returnType
* @param returnsBag
*/
public BagParameters(int id, String arg, boolean argIsBag, int params,
String returnType, boolean returnsBag) {
this.id = id;
this.arg = arg;
this.argIsBag = argIsBag;
this.params = params;
this.returnType = returnType;
this.returnsBag = returnsBag;
}
}
}