/*
* 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.core;
import java.util.HashMap;
import java.util.Map;
import com.hp.hpl.jena.query.Query;
import com.hp.hpl.jena.sdb.SDB;
import com.hp.hpl.jena.sdb.Store;
import com.hp.hpl.jena.sdb.store.StoreHolder;
import com.hp.hpl.jena.shared.PrefixMapping;
import com.hp.hpl.jena.sparql.core.Var;
import com.hp.hpl.jena.sparql.core.VarAlloc;
import com.hp.hpl.jena.sparql.util.Context;
/** A collection of things to track during query compilation
* and execution from SPARQL to SQL.
*
* @author Andy Seaborne
*/
public class SDBRequest extends StoreHolder
{
private PrefixMapping prefixMapping ;
private Query query ;
// Per request unique variables.
private VarAlloc varAlloc = new VarAlloc(AliasesSparql.VarBase) ;
// Set in SDBCompile.compile
public boolean LeftJoinTranslation = true ; // Does the DB support general join expressions?
public boolean LimitOffsetTranslation = false ; // Does the DB grok the Limit/Offset SQL?
public boolean DistinctTranslation = true ; // Some DBs can't do DISTINCt on CLOBS.
private Context context ;
public SDBRequest(Store store, Query query, Context context)
{
super(store) ;
this.query = query ;
this.prefixMapping = null ;
if ( query != null )
prefixMapping = query.getPrefixMapping() ;
if ( context == null )
context = SDB.getContext() ;
this.context = new Context(context) ;
}
public SDBRequest(Store store, Query query)
{
this(store, query, null) ;
}
public Context getContext() { return context ; }
public PrefixMapping getPrefixMapping() { return prefixMapping ; }
public Query getQuery() { return query ; }
public Store getStore() { return store() ; }
// Per request allocations
private Map<String, Generator> generators = new HashMap<String, Generator>() ;
public Generator generator(String base)
{
Generator g = generators.get(base) ;
if ( g == null )
{
g = Gensym.create(base) ;
generators.put(base, g) ;
}
return g ;
}
public String genId(String base)
{
Generator gen = generator(base) ;
return gen.next() ;
}
public Var genVar() { return varAlloc.allocVar() ; }
}