/*
* $Header$
* $Revision: 982 $
* $Date: 2006-12-08 18:42:51 +1000 (Fri, 08 Dec 2006) $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2003-2009 The JRDF Project. 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. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions 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.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* the JRDF Project (http://jrdf.sf.net/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The JRDF Project" and "JRDF" must not be used to endorse
* or promote products derived from this software without prior written
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* newmana@users.sourceforge.net.
*
* 5. Products derived from this software may not be called "JRDF"
* nor may "JRDF" appear in their names without prior written
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*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the JRDF Project. For more
* information on JRDF, please see <http://jrdf.sourceforge.net/>.
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*/
package org.jrdf.sparql.analysis;
import org.jrdf.graph.Graph;
import org.jrdf.graph.Node;
import org.jrdf.query.expression.Conjunction;
import org.jrdf.query.expression.Constraint;
import static org.jrdf.query.expression.EmptyConstraint.EMPTY_CONSTRAINT;
import org.jrdf.query.expression.Expression;
import org.jrdf.query.expression.Filter;
import org.jrdf.query.expression.Optional;
import org.jrdf.query.expression.SingleConstraint;
import org.jrdf.query.expression.Union;
import org.jrdf.query.expression.logic.LogicExpression;
import org.jrdf.query.relation.Attribute;
import org.jrdf.sparql.builder.LiteralBuilder;
import org.jrdf.sparql.builder.LiteralBuilderImpl;
import org.jrdf.sparql.builder.TripleBuilder;
import org.jrdf.sparql.builder.URIReferenceBuilder;
import org.jrdf.sparql.builder.URIReferenceBuilderImpl;
import org.jrdf.sparql.parser.analysis.DepthFirstAdapter;
import org.jrdf.sparql.parser.node.ABlockOfTriples;
import org.jrdf.sparql.parser.node.AFilterPatternGraphPatternOrFilter;
import org.jrdf.sparql.parser.node.AFilteredBasicGraphPatternGraphPattern;
import org.jrdf.sparql.parser.node.AGraphPatternOrFilterGraphPatternOperationPattern;
import org.jrdf.sparql.parser.node.AGroupOrUnionGraphPattern;
import org.jrdf.sparql.parser.node.AOptionalGraphPattern;
import org.jrdf.sparql.parser.node.ATriple;
import org.jrdf.sparql.parser.node.PGroupGraphPattern;
import org.jrdf.sparql.parser.node.PMoreTriples;
import org.jrdf.sparql.parser.node.POperationPattern;
import org.jrdf.sparql.parser.node.PUnionGraphPattern;
import org.jrdf.sparql.parser.parser.ParserException;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
/**
* Default implementation of {@link SparqlAnalyser}.
*/
//TODO This is a mess fix me please!!!!
public final class WhereAnalyserImpl extends DepthFirstAdapter implements WhereAnalyser {
private TripleBuilder tripleBuilder;
private Graph graph;
private VariableCollector collector;
private Expression expression;
private ParserException exception;
public WhereAnalyserImpl(TripleBuilder newTripleBuilder, Graph newGraph, VariableCollector newCollector) {
this.tripleBuilder = newTripleBuilder;
this.graph = newGraph;
this.collector = newCollector;
}
public Expression getExpression() throws ParserException {
if (exception != null) {
throw exception;
}
return expression;
}
@Override
public void caseAFilteredBasicGraphPatternGraphPattern(AFilteredBasicGraphPatternGraphPattern node) {
Expression lhs = getExpression((org.jrdf.sparql.parser.node.Node) node.getFilteredBasicGraphPattern().clone());
if (node.getOperationPattern() != null) {
expression = lhs;
LinkedList<POperationPattern> list = node.getOperationPattern();
for (POperationPattern pOperationPattern : list) {
Expression rhs = getExpression((org.jrdf.sparql.parser.node.Node) pOperationPattern.clone());
handleExpressions(expression, rhs);
}
} else {
super.caseAFilteredBasicGraphPatternGraphPattern(node);
}
}
private void handleExpressions(Expression lhs, Expression rhs) {
if (lhs != null) {
if (Optional.class.isAssignableFrom(rhs.getClass())) {
handleOptional(lhs, rhs);
} else if (Conjunction.class.isAssignableFrom(rhs.getClass())) {
Conjunction conjunction = (Conjunction) rhs;
if (conjunction.getLhs() != null) {
expression = new Conjunction(lhs, rhs);
} else {
conjunction.setLhs(lhs);
expression = rhs;
}
} else if (Constraint.class.isAssignableFrom(rhs.getClass()) &&
(Constraint.class.isAssignableFrom(lhs.getClass()))) {
expression = new Conjunction(lhs, rhs);
} else if (LogicExpression.class.isAssignableFrom(rhs.getClass())) {
expression = new Filter(lhs, (LogicExpression) rhs);
} else if (LogicExpression.class.isAssignableFrom(lhs.getClass())) {
expression = new Filter(rhs, (LogicExpression) lhs);
} else {
expression = new Conjunction(lhs, rhs);
}
} else {
expression = rhs;
}
}
@Override
public void caseATriple(ATriple node) {
try {
node.apply(tripleBuilder);
LinkedHashMap<Attribute, Node> map = tripleBuilder.getTriples();
collector.addConstraints(map);
expression = new SingleConstraint(map);
} catch (ParserException e) {
exception = e;
}
}
@Override
public void caseABlockOfTriples(ABlockOfTriples node) {
if (!node.getMoreTriples().isEmpty()) {
Expression lhs = getExpression((org.jrdf.sparql.parser.node.Node) node.getTriple().clone());
LinkedList<PMoreTriples> moreTriples = node.getMoreTriples();
List<Expression> expressions = new ArrayList<Expression>();
for (PMoreTriples pMoreTriples : moreTriples) {
Expression rhs = getExpression((org.jrdf.sparql.parser.node.Node) pMoreTriples.clone());
expressions.add(rhs);
}
Expression lhsSide = lhs;
for (Expression currentExpression : expressions) {
lhsSide = new Conjunction(lhsSide, currentExpression);
}
expression = lhsSide;
} else {
super.caseABlockOfTriples(node);
}
}
@Override
public void caseAGraphPatternOrFilterGraphPatternOperationPattern(
AGraphPatternOrFilterGraphPatternOperationPattern node) {
Expression lhs = getExpression((org.jrdf.sparql.parser.node.Node) node.getGraphPatternOrFilter().clone());
Expression rhs = getExpression((org.jrdf.sparql.parser.node.Node) node.getFilteredBasicGraphPattern().clone());
if (lhs != null && rhs != null) {
handleExpressions(rhs, lhs);
} else if (lhs != null) {
expression = lhs;
} else if (rhs != null) {
expression = rhs;
}
}
@Override
public void caseAFilterPatternGraphPatternOrFilter(AFilterPatternGraphPatternOrFilter node) {
try {
final LiteralBuilder builder = new LiteralBuilderImpl(graph.getElementFactory(),
tripleBuilder.getPrefixMap());
final URIReferenceBuilder uriReferenceBuilder = new URIReferenceBuilderImpl(graph.getElementFactory(),
tripleBuilder.getPrefixMap());
FilterAnalyser analyser = new FilterAnalyserImpl(builder, collector, uriReferenceBuilder);
node.apply(analyser);
expression = analyser.getExpression();
} catch (ParserException e) {
exception = e;
}
}
@Override
public void caseAGroupOrUnionGraphPattern(AGroupOrUnionGraphPattern node) {
if (node.getUnionGraphPattern() != null) {
Expression lhs = getExpressionWithEmptyConstraint(
(org.jrdf.sparql.parser.node.Node) node.getGroupGraphPattern().clone());
LinkedList<PUnionGraphPattern> unionGraphPattern = node.getUnionGraphPattern();
List<Expression> expressions = new ArrayList<Expression>();
for (PUnionGraphPattern pUnionGraphPattern : unionGraphPattern) {
Expression rhs = getExpressionWithEmptyConstraint(
(org.jrdf.sparql.parser.node.Node) pUnionGraphPattern.clone());
expressions.add(rhs);
}
Expression lhsSide = lhs;
for (Expression currentExpression : expressions) {
lhsSide = new Union(lhsSide, currentExpression);
}
expression = lhsSide;
} else {
super.caseAGroupOrUnionGraphPattern(node);
}
}
@Override
public void caseAOptionalGraphPattern(AOptionalGraphPattern node) {
Expression rhs = getExpression((PGroupGraphPattern) node.getGroupGraphPattern().clone());
expression = new Optional(rhs);
}
private void handleOptional(Expression lhs, Expression rhs) {
Optional rhsOptional = (Optional) rhs;
if (rhsOptional.getLhs() != null) {
expression = new Conjunction(lhs, rhsOptional);
} else {
rhsOptional.setLhs(lhs);
expression = rhsOptional;
}
}
private Expression getExpressionWithEmptyConstraint(org.jrdf.sparql.parser.node.Node node) {
Expression result = getExpression(node);
if (result == null) {
return EMPTY_CONSTRAINT;
} else {
return result;
}
}
private Expression getExpression(org.jrdf.sparql.parser.node.Node node) {
try {
WhereAnalyser analyser = new WhereAnalyserImpl(tripleBuilder, graph, collector);
node.apply(analyser);
return analyser.getExpression();
} catch (ParserException e) {
exception = e;
return null;
}
}
}