/*
* 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.graph.Node;
import com.hp.hpl.jena.sparql.core.Var;
import com.hp.hpl.jena.sdb.core.SDBRequest;
import com.hp.hpl.jena.sdb.core.ScopeEntry;
import com.hp.hpl.jena.sdb.core.sqlexpr.S_Equal;
import com.hp.hpl.jena.sdb.core.sqlexpr.SqlColumn;
import com.hp.hpl.jena.sdb.core.sqlexpr.SqlExpr;
import com.hp.hpl.jena.sdb.core.sqlexpr.SqlExprList;
import com.hp.hpl.jena.sdb.core.sqlnode.SqlNode;
import com.hp.hpl.jena.sdb.core.sqlnode.SqlTable;
public abstract class SlotCompiler
{
private SDBRequest request ;
public abstract SqlNode start(QuadBlock quads) ;
public abstract SqlNode finish(SqlNode sqlNode, QuadBlock quads) ;
public SlotCompiler(SDBRequest request)
{
this.request = request ;
}
protected SDBRequest getRequest() { return request ; }
public final void processSlot(SDBRequest request,
SqlTable table, SqlExprList conditions,
Node node, String colName)
{
SqlColumn thisCol = new SqlColumn(table, colName) ;
if ( ! node.isVariable() )
{
constantSlot(request, node, thisCol, conditions) ;
return ;
}
Var var = Var.alloc(node) ;
if ( table.getIdScope().hasColumnForVar(var) )
{
ScopeEntry e = table.getIdScope().findScopeForVar(var) ;
SqlColumn otherCol = e.getColumn() ;
SqlExpr c = new S_Equal(otherCol, thisCol) ;
conditions.add(c) ;
c.addNote("processVar: "+node) ;
return ;
}
table.setIdColumnForVar(var, thisCol) ;
}
protected abstract void constantSlot(SDBRequest request, Node node, SqlColumn thisCol, SqlExprList conditions) ;
}