/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hp.hpl.jena.sdb.compiler;
import com.hp.hpl.jena.sdb.shared.SDBInternalError;
import com.hp.hpl.jena.sparql.algebra.Op;
import com.hp.hpl.jena.sparql.core.Substitute;
import com.hp.hpl.jena.sparql.engine.ExecutionContext;
import com.hp.hpl.jena.sparql.engine.QueryIterator;
import com.hp.hpl.jena.sparql.engine.binding.Binding;
import com.hp.hpl.jena.sparql.engine.iterator.QueryIterRepeatApply;
import org.apache.jena.atlas.io.IndentedWriter;
public class QueryIterOpSQL extends QueryIterRepeatApply
{
private OpSQL opSQL ;
public QueryIterOpSQL(OpSQL op,
QueryIterator input ,
ExecutionContext context)
{
super(input, context) ;
this.opSQL = op ;
}
@Override
protected QueryIterator nextStage(Binding binding)
{
OpSQL execSQL = this.opSQL ;
if ( binding != null && ! isRoot(binding) )
{
QueryCompiler qc = opSQL.getRequest().getStore().getQueryCompilerFactory().createQueryCompiler(opSQL.getRequest()) ;
Op op2 = Substitute.substitute(opSQL.getOriginal(), binding) ;
Op op = qc.compile(op2) ;
if ( op instanceof OpSQL )
execSQL = (OpSQL)op ;
else
throw new SDBInternalError("Failed to recompile the OpSQL to an OpSQL") ;
}
return execSQL.exec(binding, getExecContext()) ;
}
private static boolean isRoot(Binding binding)
{
return ! binding.vars().hasNext() ;
}
@Override
public void output(IndentedWriter out)
{
opSQL.output(out) ;
}
}