/**************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package com.espertech.esper.core.start;
import com.espertech.esper.core.context.util.AgentInstanceContext;
import com.espertech.esper.core.context.util.EPStatementAgentInstanceHandle;
import com.espertech.esper.core.service.EPServicesContext;
import com.espertech.esper.core.service.StatementAgentInstanceFilterVersion;
import com.espertech.esper.core.service.StatementContext;
import com.espertech.esper.epl.expression.ExprValidationException;
import com.espertech.esper.epl.spec.StatementSpecCompiled;
import com.espertech.esper.util.AuditPath;
import com.espertech.esper.view.ViewProcessingException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Starts and provides the stop method for EPL statements.
*/
public abstract class EPStatementStartMethodBase implements EPStatementStartMethod
{
private static final Log log = LogFactory.getLog(EPStatementStartMethodBase.class);
private static final Log queryPlanLog = LogFactory.getLog(AuditPath.QUERYPLAN_LOG);
protected final StatementSpecCompiled statementSpec;
protected final EPServicesContext services;
protected final StatementContext statementContext;
protected final boolean queryPlanLogging;
protected EPStatementStartMethodBase(StatementSpecCompiled statementSpec, EPServicesContext services, StatementContext statementContext) {
this.statementSpec = statementSpec;
this.services = services;
this.statementContext = statementContext;
this.queryPlanLogging = services.getConfigSnapshot().getEngineDefaults().getLogging().isEnableQueryPlan();
}
public abstract EPStatementStartResult startInternal(boolean isNewStatement, boolean isRecoveringStatement, boolean isRecoveringResilient)
throws ExprValidationException, ViewProcessingException;
public EPStatementStartResult start(boolean isNewStatement, boolean isRecoveringStatement, boolean isRecoveringResilient) throws ExprValidationException, ViewProcessingException {
statementContext.getVariableService().setLocalVersion(); // get current version of variables
boolean queryPlanLogging = services.getConfigSnapshot().getEngineDefaults().getLogging().isEnableQueryPlan();
if (queryPlanLogging && queryPlanLog.isInfoEnabled()) {
queryPlanLog.info("Query plans for statement '" + statementContext.getStatementName() + "' expression '" + statementContext.getExpression() + "'");
}
// validate context - may not exist
if (statementSpec.getOptionalContextName() != null && statementContext.getContextDescriptor() == null) {
throw new ExprValidationException("Context by name '" + statementSpec.getOptionalContextName() + "' has not been declared");
}
return startInternal(isNewStatement, isRecoveringStatement, isRecoveringResilient);
}
protected EPStatementAgentInstanceHandle getDefaultAgentInstanceHandle() {
return new EPStatementAgentInstanceHandle(statementContext.getEpStatementHandle(), statementContext.getDefaultAgentInstanceLock(), -1, new StatementAgentInstanceFilterVersion());
}
protected AgentInstanceContext getDefaultAgentInstanceContext() {
EPStatementAgentInstanceHandle handle = getDefaultAgentInstanceHandle();
return new AgentInstanceContext(statementContext, handle, -1, null, null, statementContext.getDefaultAgentInstanceScriptContext());
}
}