/* *************************************************************************************** * 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.ext; import com.espertech.esper.client.EventType; 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 com.espertech.esper.view.window.RandomAccessByIndexGetter; import java.util.List; /** * Factory for views for time-ordering events. */ public class TimeOrderViewFactory implements DataWindowViewFactory, DataWindowViewWithPrevious { private List<ExprNode> viewParameters; /** * The timestamp expression. */ protected ExprNode timestampExpression; protected ExprEvaluator timestampExpressionEvaluator; /** * The interval to wait for newer events to arrive. */ protected ExprTimePeriodEvalDeltaConstFactory timeDeltaComputationFactory; private EventType eventType; public void setViewParameters(ViewFactoryContext viewFactoryContext, List<ExprNode> expressionParameters) throws ViewParameterException { viewParameters = expressionParameters; } public void attach(EventType parentEventType, StatementContext statementContext, ViewFactory optionalParentFactory, List<ViewFactory> parentViewFactories) throws ViewParameterException { ExprNode[] validated = ViewFactorySupport.validate(getViewName(), parentEventType, statementContext, viewParameters, true); if (viewParameters.size() != 2) { throw new ViewParameterException(getViewParamMessage()); } if (!JavaClassHelper.isNumeric(validated[0].getExprEvaluator().getType())) { throw new ViewParameterException(getViewParamMessage()); } timestampExpression = validated[0]; timeDeltaComputationFactory = ViewFactoryTimePeriodHelper.validateAndEvaluateTimeDeltaFactory(getViewName(), statementContext, viewParameters.get(1), getViewParamMessage(), 1); timestampExpressionEvaluator = timestampExpression.getExprEvaluator(); eventType = parentEventType; } public Object makePreviousGetter() { return new RandomAccessByIndexGetter(); } public View makeView(AgentInstanceViewFactoryChainContext agentInstanceViewFactoryContext) { ExprTimePeriodEvalDeltaConst timeDeltaComputation = timeDeltaComputationFactory.make(getViewName(), "view", agentInstanceViewFactoryContext.getAgentInstanceContext()); IStreamSortRankRandomAccess sortedRandomAccess = agentInstanceViewFactoryContext.getStatementContext().getViewServicePreviousFactory().getOptPreviousExprSortedRankedAccess(agentInstanceViewFactoryContext); return new TimeOrderView(agentInstanceViewFactoryContext, this, timestampExpression, timestampExpression.getExprEvaluator(), timeDeltaComputation, sortedRandomAccess); } public EventType getEventType() { return eventType; } public boolean canReuse(View view, AgentInstanceContext agentInstanceContext) { if (!(view instanceof TimeOrderView)) { return false; } TimeOrderView other = (TimeOrderView) view; ExprTimePeriodEvalDeltaConst timeDeltaComputation = timeDeltaComputationFactory.make(getViewName(), "view", agentInstanceContext); if ((!timeDeltaComputation.equalsTimePeriod(other.getTimeDeltaComputation())) || (!ExprNodeUtility.deepEquals(other.getTimestampExpression(), timestampExpression, false))) { return false; } return other.isEmpty(); } public String getViewName() { return "Time-Order"; } public ExprEvaluator getTimestampExpressionEvaluator() { return timestampExpressionEvaluator; } private String getViewParamMessage() { return getViewName() + " view requires the expression supplying timestamp values, and a numeric or time period parameter for interval size"; } }