/************************************************************************************** * 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.view.window; import com.espertech.esper.client.EventType; import com.espertech.esper.core.context.util.AgentInstanceViewFactoryChainContext; import com.espertech.esper.core.service.StatementContext; import com.espertech.esper.epl.expression.ExprNode; import com.espertech.esper.util.JavaClassHelper; import com.espertech.esper.view.*; import java.util.List; /** * Factory for {@link com.espertech.esper.view.window.TimeBatchView}. */ public class LengthBatchViewFactory implements DataWindowViewFactory, DataWindowViewWithPrevious, DataWindowBatchingViewFactory { /** * The length window size. */ protected int size; private EventType eventType; public void setViewParameters(ViewFactoryContext viewFactoryContext, List<ExprNode> expressionParameters) throws ViewParameterException { List<Object> viewParameters = ViewFactorySupport.validateAndEvaluate("Length window view", viewFactoryContext.getStatementContext(), expressionParameters); String errorMessage = "Length window view requires a single integer-type parameter"; if (viewParameters.size() != 1) { throw new ViewParameterException(errorMessage); } Object parameter = viewParameters.get(0); if (!(parameter instanceof Number)) { throw new ViewParameterException(errorMessage); } Number numParam = (Number) parameter; if ( (JavaClassHelper.isFloatingPointNumber(numParam)) || (numParam instanceof Long)) { throw new ViewParameterException(errorMessage); } size = numParam.intValue(); if (size <= 0) { throw new ViewParameterException("Length window requires a positive number"); } } public void attach(EventType parentEventType, StatementContext statementContext, ViewFactory optionalParentFactory, List<ViewFactory> parentViewFactories) throws ViewParameterException { this.eventType = parentEventType; } public Object makePreviousGetter() { return new RelativeAccessByEventNIndexMap(); } public View makeView(AgentInstanceViewFactoryChainContext agentInstanceViewFactoryContext) { IStreamRelativeAccess relativeAccessByEvent = ViewServiceHelper.getOptPreviousExprRelativeAccess(agentInstanceViewFactoryContext); if (agentInstanceViewFactoryContext.isRemoveStream()) { return new LengthBatchViewRStream(agentInstanceViewFactoryContext, this, size); } else { return new LengthBatchView(agentInstanceViewFactoryContext, this, size, relativeAccessByEvent); } } public EventType getEventType() { return eventType; } public boolean canReuse(View view) { if (!(view instanceof LengthBatchView)) { return false; } LengthBatchView myView = (LengthBatchView) view; if (myView.getSize() != size) { return false; } return myView.isEmpty(); } }