/*
* Hibernate OGM, Domain model persistence for NoSQL datastores
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later
* See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
*/
package org.hibernate.ogm.datastore.neo4j.query.impl;
import org.hibernate.engine.query.spi.ParameterParser.Recognizer;
import org.parboiled.BaseParser;
import org.parboiled.Rule;
import org.parboiled.annotations.SkipNode;
import org.parboiled.annotations.SuppressSubnodes;
import org.parboiled.support.StringVar;
/**
* Simple parser for Neo4j queries which recognizes named parameters.
*
* @author Gunnar Morling
*/
// Use @BuildParseTree together with ParseTreeUtils#printNodeTree() for debugging purposes
//@BuildParseTree
public class QueryParser extends BaseParser<Recognizer> {
final Recognizer journaler;
final RecognizerAdapter adapter;
public QueryParser(Recognizer journaler) {
this.journaler = journaler;
this.adapter = new RecognizerAdapter( journaler );
}
public Rule Query() {
return Sequence( QueryParts(), EOI, push( journaler ) );
}
@SkipNode
public Rule QueryParts() {
return ZeroOrMore( QueryPart() );
}
@SkipNode
public Rule QueryPart() {
return FirstOf( Quoted(), Escaped(), NamedParameter(), Other() );
}
@SuppressSubnodes
public Rule NamedParameter() {
StringVar name = new StringVar( "" );
return Sequence(
ParameterBeginDelimiter(),
ZeroOrMore( WhiteSpace() ),
OneOrMore( Alphanumeric() ),
name.set( match() ),
ZeroOrMore( WhiteSpace() ),
ParameterEndDelimiter(),
adapter.addNamedParameter( name.get(), currentIndex() )
);
}
@SuppressSubnodes
public Rule Quoted() {
return Sequence(
QuoteDelimiter(),
ZeroOrMore(
FirstOf(
EscapedQuoteDelimiter(),
Sequence( TestNot( QuoteDelimiter() ), ANY )
)
),
QuoteDelimiter()
);
}
@SuppressSubnodes
public Rule Escaped() {
return Sequence(
EscapeDelimiter(),
ZeroOrMore(
FirstOf(
EscapedEscapeDelimiter(),
Sequence( TestNot( EscapeDelimiter() ), ANY )
)
),
EscapeDelimiter()
);
}
@SuppressSubnodes
public Rule Other() {
return OneOrMore( TestNot( NamedParameter() ), TestNot( Quoted() ), TestNot( Escaped() ), ANY );
}
public Rule QuoteDelimiter() {
return Ch( '\'' );
}
public Rule EscapedQuoteDelimiter() {
return Sequence( Ch( '\\' ), Ch( '\'' ) );
}
public Rule EscapeDelimiter() {
return Ch( '`' );
}
public Rule EscapedEscapeDelimiter() {
return Sequence( Ch( '\\' ), Ch( '`' ) );
}
public Rule ParameterBeginDelimiter() {
return Ch( '{' );
}
public Rule ParameterEndDelimiter() {
return Ch( '}' );
}
public Rule Alphanumeric() {
return FirstOf( Letter(), Digit() );
}
public Rule Letter() {
return FirstOf( CharRange( 'a', 'z' ), CharRange( 'A', 'Z' ) );
}
public Rule Digit() {
return CharRange( '0', '9' );
}
Rule WhiteSpace() {
return OneOrMore( AnyOf( " \t\f" ) );
}
/**
* Wraps a {@link Recognizer} so it can be invoked by the parser (which requires the methods to return a
* {@code boolean}).
*
* @author Gunnar Morling
*/
private static class RecognizerAdapter {
private final Recognizer recognizer;
private RecognizerAdapter(Recognizer recognizer) {
this.recognizer = recognizer;
}
private boolean addNamedParameter(String name, int position) {
recognizer.namedParameter( name, position );
return true;
}
}
}