/*
***************************************************************************************
* 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";
}
}