/*
***************************************************************************************
* 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.ExprEvaluator;
import com.espertech.esper.epl.expression.core.ExprNode;
import com.espertech.esper.epl.expression.core.ExprNodeUtility;
import com.espertech.esper.epl.expression.time.ExprTimePeriodEvalDeltaConst;
import com.espertech.esper.epl.expression.time.ExprTimePeriodEvalDeltaConstFactory;
import com.espertech.esper.util.JavaClassHelper;
import com.espertech.esper.view.*;
import java.util.List;
/**
* Factory for {@link com.espertech.esper.view.window.ExternallyTimedBatchView}.
*/
public class ExternallyTimedBatchViewFactory implements DataWindowBatchingViewFactory, DataWindowViewFactory, DataWindowViewWithPrevious {
private List<ExprNode> viewParameters;
private EventType eventType;
/**
* The timestamp property name.
*/
protected ExprNode timestampExpression;
protected ExprEvaluator timestampExpressionEval;
protected Long optionalReferencePoint;
/**
* The number of msec to expire.
*/
protected ExprTimePeriodEvalDeltaConstFactory timeDeltaComputationFactory;
public void setViewParameters(ViewFactoryContext viewFactoryContext, List<ExprNode> expressionParameters) throws ViewParameterException {
this.viewParameters = expressionParameters;
}
public void attach(EventType parentEventType, StatementContext statementContext, ViewFactory optionalParentFactory, List<ViewFactory> parentViewFactories) throws ViewParameterException {
final String windowName = getViewName();
ExprNode[] validated = ViewFactorySupport.validate(windowName, parentEventType, statementContext, viewParameters, true);
if (viewParameters.size() < 2 || viewParameters.size() > 3) {
throw new ViewParameterException(getViewParamMessage());
}
// validate first parameter: timestamp expression
if (!JavaClassHelper.isNumeric(validated[0].getExprEvaluator().getType())) {
throw new ViewParameterException(getViewParamMessage());
}
timestampExpression = validated[0];
timestampExpressionEval = timestampExpression.getExprEvaluator();
ViewFactorySupport.assertReturnsNonConstant(windowName, validated[0], 0);
timeDeltaComputationFactory = ViewFactoryTimePeriodHelper.validateAndEvaluateTimeDeltaFactory(getViewName(), statementContext, viewParameters.get(1), getViewParamMessage(), 1);
// validate optional parameters
if (validated.length == 3) {
Object constant = ViewFactorySupport.validateAndEvaluate(windowName, statementContext, validated[2]);
if ((!(constant instanceof Number)) || (JavaClassHelper.isFloatingPointNumber((Number) constant))) {
throw new ViewParameterException("Externally-timed batch view requires a Long-typed reference point in msec as a third parameter");
}
optionalReferencePoint = ((Number) constant).longValue();
}
this.eventType = parentEventType;
}
public Object makePreviousGetter() {
return new RelativeAccessByEventNIndexGetterImpl();
}
public View makeView(AgentInstanceViewFactoryChainContext agentInstanceViewFactoryContext) {
ExprTimePeriodEvalDeltaConst timeDeltaComputation = timeDeltaComputationFactory.make(getViewName(), "view", agentInstanceViewFactoryContext.getAgentInstanceContext());
ViewUpdatedCollection viewUpdatedCollection = agentInstanceViewFactoryContext.getStatementContext().getViewServicePreviousFactory().getOptPreviousExprRelativeAccess(agentInstanceViewFactoryContext);
return new ExternallyTimedBatchView(this, timestampExpression, timestampExpressionEval, timeDeltaComputation, optionalReferencePoint, viewUpdatedCollection, agentInstanceViewFactoryContext);
}
public EventType getEventType() {
return eventType;
}
public boolean canReuse(View view, AgentInstanceContext agentInstanceContext) {
if (!(view instanceof ExternallyTimedBatchView)) {
return false;
}
ExternallyTimedBatchView myView = (ExternallyTimedBatchView) view;
ExprTimePeriodEvalDeltaConst delta = timeDeltaComputationFactory.make(getViewName(), "view", agentInstanceContext);
if ((!delta.equalsTimePeriod(myView.getTimeDeltaComputation())) ||
(!ExprNodeUtility.deepEquals(myView.getTimestampExpression(), timestampExpression, false))) {
return false;
}
return myView.isEmpty();
}
public String getViewName() {
return "Externally-timed-batch";
}
public ExprEvaluator getTimestampExpressionEval() {
return timestampExpressionEval;
}
public Long getOptionalReferencePoint() {
return optionalReferencePoint;
}
private String getViewParamMessage() {
return getViewName() + " view requires a timestamp expression and a numeric or time period parameter for window size and an optional long-typed reference point in msec, and an optional list of control keywords as a string parameter (please see the documentation)";
}
}