/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Nov 27, 2011
*/
package com.bigdata.rdf.sparql.ast.hints;
import java.util.Properties;
import java.util.UUID;
import com.bigdata.rdf.sail.sparql.Bigdata2ASTSPARQLParser;
import com.bigdata.rdf.sparql.ast.ASTBase;
import com.bigdata.rdf.sparql.ast.ASTContainer;
import com.bigdata.rdf.sparql.ast.QueryHints;
import com.bigdata.rdf.sparql.ast.QueryRoot;
import com.bigdata.rdf.sparql.ast.eval.AST2BOpContext;
import com.bigdata.rdf.sparql.ast.optimizers.ASTQueryHintOptimizer;
/**
* This just strips the {@link QueryHints#QUERYID} out of the AST. The
* {@link Bigdata2ASTSPARQLParser} is responsible for traversing the AST and, if
* it finds the {@link QueryHints#QUERYID}, attaching it to the
* {@link ASTContainer}'s query hints {@link Properties} object.
* <P>
* Note: The timing for interpreting this query hint is critical, which is why
* it is handled by the {@link Bigdata2ASTSPARQLParser}. We need to know if the
* QueryID was set long before the {@link ASTQueryHintOptimizer} runs.
*/
final class QueryIdHint extends AbstractQueryHint<UUID> {
protected QueryIdHint() {
super(QueryHints.QUERYID, null/* defaultValue */);
}
@Override
public UUID validate(final String value) {
return UUID.fromString(value);
}
@Override
public void handle(final AST2BOpContext context,
final QueryRoot queryRoot,
final QueryHintScope scope, final ASTBase op, final UUID value) {
/*
* NOP.
*/
}
}