/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* 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.view.window;
import com.espertech.esper.client.EventType;
import com.espertech.esper.collection.ViewUpdatedCollection;
import com.espertech.esper.core.context.util.AgentInstanceContext;
import com.espertech.esper.core.context.util.AgentInstanceViewFactoryChainContext;
import com.espertech.esper.core.service.StatementContext;
import com.espertech.esper.epl.expression.core.ExprNode;
import com.espertech.esper.epl.expression.time.ExprTimePeriodEvalDeltaConst;
import com.espertech.esper.epl.expression.time.ExprTimePeriodEvalDeltaConstFactory;
import com.espertech.esper.view.*;
import java.util.List;
/**
* Factory for {@link TimeWindowView}.
*/
public class TimeWindowViewFactory implements DataWindowViewFactory, DataWindowViewWithPrevious {
protected ExprTimePeriodEvalDeltaConstFactory timeDeltaComputationFactory;
private EventType eventType;
public void setViewParameters(ViewFactoryContext viewFactoryContext, List<ExprNode> expressionParameters) throws ViewParameterException {
if (expressionParameters.size() != 1) {
throw new ViewParameterException(getViewParamMessage());
}
timeDeltaComputationFactory = ViewFactoryTimePeriodHelper.validateAndEvaluateTimeDeltaFactory(getViewName(), viewFactoryContext.getStatementContext(), expressionParameters.get(0), getViewParamMessage(), 0);
}
public void attach(EventType parentEventType, StatementContext statementContext, ViewFactory optionalParentFactory, List<ViewFactory> parentViewFactories) throws ViewParameterException {
this.eventType = parentEventType;
}
public Object makePreviousGetter() {
return new RandomAccessByIndexGetter();
}
public View makeView(AgentInstanceViewFactoryChainContext agentInstanceViewFactoryContext) {
ExprTimePeriodEvalDeltaConst timeDeltaComputation = timeDeltaComputationFactory.make(getViewName(), "view", agentInstanceViewFactoryContext.getAgentInstanceContext());
ViewUpdatedCollection randomAccess = agentInstanceViewFactoryContext.getStatementContext().getViewServicePreviousFactory().getOptPreviousExprRandomAccess(agentInstanceViewFactoryContext);
return new TimeWindowView(agentInstanceViewFactoryContext, this, timeDeltaComputation, randomAccess);
}
public EventType getEventType() {
return eventType;
}
public boolean canReuse(View view, AgentInstanceContext agentInstanceContext) {
if (!(view instanceof TimeWindowView)) {
return false;
}
TimeWindowView myView = (TimeWindowView) view;
ExprTimePeriodEvalDeltaConst delta = timeDeltaComputationFactory.make(getViewName(), "view", agentInstanceContext);
if (!delta.equalsTimePeriod(myView.getTimeDeltaComputation())) {
return false;
}
// For reuse of the time window it doesn't matter if it provides random access or not
return myView.isEmpty();
}
public String getViewName() {
return "Time";
}
public ExprTimePeriodEvalDeltaConstFactory getTimeDeltaComputationFactory() {
return timeDeltaComputationFactory;
}
private String getViewParamMessage() {
return getViewName() + " view requires a single numeric or time period parameter";
}
}