/*
* 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.proc;
import static org.teiid.query.analysis.AnalysisRecord.*;
import java.util.Arrays;
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.logging.LogConstants;
import org.teiid.logging.LogManager;
import org.teiid.query.analysis.AnalysisRecord;
import org.teiid.query.sql.symbol.ElementSymbol;
import org.teiid.query.sql.symbol.Expression;
import org.teiid.query.sql.util.VariableContext;
/**
* <p> This instruction updates the current variable context with a value for the Variable
* defined using a DeclareInstruction, the variable value is obtained by either processing
* a expression or a command(stored as a processplan). The Processing of the command is
* expected to result in 1 column, 1 row tuple.</p>
*/
public class AssignmentInstruction extends ProgramInstruction {
// variable whose value is updated in the context
private ElementSymbol variable;
// expression to be processed
private Expression expression;
public AssignmentInstruction() {
}
/**
* <p> Updates the current variable context with a value for the Variable
* defined using a DeclareInstruction, the variable value is obtained by either processing
* a expression or a command(stored as a processplan). The Processing of the command is
* expected to result in 1 column, 1 row tuple, if more than a row is returned an exception
* is thrown. Also updates the program counter.</p>
* @throws BlockedException
* @throws TeiidComponentException if error processing command or expression on this instruction
*/
public void process(ProcedurePlan procEnv) throws BlockedException,
TeiidComponentException, TeiidProcessingException {
VariableContext varContext = procEnv.getCurrentVariableContext();
Object value = null;
if (this.expression != null) {
value = procEnv.evaluateExpression(this.expression);
}
varContext.setValue(getVariable(), value);
LogManager.logTrace(LogConstants.CTX_DQP,
new Object[] {this.toString() + " The variable " //$NON-NLS-1$
+ getVariable() + " in the variablecontext is updated with the value :", value}); //$NON-NLS-1$
}
public PlanNode getDescriptionProperties() {
PlanNode props = new PlanNode("ASSIGNMENT"); //$NON-NLS-1$
props.addProperty(PROP_VARIABLE, this.variable.toString());
if (this.expression != null) {
AnalysisRecord.addLanaguageObjects(props, PROP_EXPRESSION, Arrays.asList(this.expression));
}
return props;
}
/**
* @return Returns the expression.
*/
public Expression getExpression() {
return this.expression;
}
/**
* @param expression The expression to set.
*/
public void setExpression(Expression expression) {
this.expression = expression;
}
/**
* @return Returns the variable.
*/
public ElementSymbol getVariable() {
return this.variable;
}
/**
* @param variable The variable to set.
*/
public void setVariable(ElementSymbol variable) {
this.variable = variable;
}
public String toString() {
return "ASSIGNMENT INSTRUCTION: " + variable; //$NON-NLS-1$
}
/**
* @see org.teiid.query.processor.proc.ProgramInstruction#clone()
*/
public AssignmentInstruction clone() {
AssignmentInstruction clone = new AssignmentInstruction();
clone.setVariable(this.variable);
clone.setExpression(this.expression);
return clone;
}
}