ExecStagingTableInstruction.java

/*
 * JBoss, Home of Professional Open Source.
 * See the COPYRIGHT.txt file distributed with this work for information
 * regarding copyright ownership.  Some portions may be licensed
 * to Red Hat, Inc. under one or more contributor license agreements.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA.
 */

package org.teiid.query.processor.xml;

import static org.teiid.query.analysis.AnalysisRecord.*;

import org.teiid.client.plan.PlanNode;
import org.teiid.common.buffer.BlockedException;
import org.teiid.core.TeiidComponentException;
import org.teiid.core.TeiidProcessingException;
import org.teiid.query.mapping.xml.ResultSetInfo;
import org.teiid.query.metadata.TempMetadataAdapter;
import org.teiid.query.optimizer.xml.XMLQueryPlanner;
import org.teiid.query.processor.RegisterRequestParameter;
import org.teiid.query.sql.lang.Insert;
import org.teiid.query.tempdata.AlterTempTable;



/** 
 * This instruction is to start loading a staging table. The difference between the loading the 
 * staging table and execute sql node is that sql node will capture the results and save them in
 * the context object, where as staging does not care about the results, because they are actually
 * stored in the temp table store, will be accessed by required query directly from there, as these
 * results are nothing do with producing the document directly.
 */
public class ExecStagingTableInstruction extends ExecSqlInstruction {
    
    public ExecStagingTableInstruction(String resultName, ResultSetInfo info) {
    	super(resultName, info);
    }
    
    /** 
     * @see org.teiid.query.processor.xml.ProcessorInstruction#process(org.teiid.query.processor.xml.XMLProcessorEnvironment, org.teiid.query.processor.xml.XMLContext)
     */
    public XMLContext process(XMLProcessorEnvironment env, XMLContext context) 
        throws BlockedException, TeiidComponentException, TeiidProcessingException {
        
        if (!env.isStagingTableLoaded(this.resultSetName)) {
        	super.execute(env, context);
            
            env.markStagingTableAsLoaded(this.resultSetName);
            
            if (!info.isAutoStaged() && info.getTempTable() == null && info.getCommand() instanceof Insert) {
	            //TODO: should consolidate with the other temp logic in RelationalPlanExecutor
	            AlterTempTable att = new AlterTempTable(XMLQueryPlanner.getTempTableName(this.resultSetName));
				att.setIndexColumns(this.info.getFkColumns());
				//mark the temp table as non-updatable
				env.getDataManager().registerRequest(env.getProcessorContext(), att, TempMetadataAdapter.TEMP_MODEL.getName(), new RegisterRequestParameter());
            }
            
            // now that we done executing the plan; remove the plan from context
            context.removeResultExecutor(resultSetName);
        }
        
        env.incrementCurrentProgramCounter();
        return context;
    }
    
    public String toString() {
        return "STAGING:"+resultSetName; //$NON-NLS-1$
    }

    public PlanNode getDescriptionProperties() {
    	PlanNode props = new PlanNode("Staging Table"); //$NON-NLS-1$
        props.addProperty(PROP_RESULT_SET, this.resultSetName);
        props.addProperty(PROP_IS_STAGING, "true"); //$NON-NLS-1$    
        props.addProperty(PROP_SQL, this.info.getPlan().getDescriptionProperties());
        return props;
    }    
    
}