/**************************************************************************************
* 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.epl.join.base;
import com.espertech.esper.collection.MultiKey;
import com.espertech.esper.collection.UniformPair;
import com.espertech.esper.epl.join.table.EventTable;
import com.espertech.esper.epl.db.DataCacheClearableMap;
import com.espertech.esper.epl.expression.ExprEvaluatorContext;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.view.Viewable;
import com.espertech.esper.view.HistoricalEventViewable;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
/**
* Implements the function to determine a join result set using tables/indexes and query strategy
* instances for each stream.
*/
public class JoinSetComposerHistoricalImpl implements JoinSetComposer
{
private final EventTable[][] repositories;
private final QueryStrategy[] queryStrategies;
// Set semantic eliminates duplicates in result set, use Linked set to preserve order
private Set<MultiKey<EventBean>> oldResults = new LinkedHashSet<MultiKey<EventBean>>();
private Set<MultiKey<EventBean>> newResults = new LinkedHashSet<MultiKey<EventBean>>();
private EventTable[][] tables = new EventTable[0][];
private Viewable[] streamViews;
private ExprEvaluatorContext staticEvalExprEvaluatorContext;
/**
* Ctor.
* @param repositories indexes for non-historical streams
* @param queryStrategies for each stream a strategy to execute the join
* @param streamViews the viewable representing each stream
* @param staticEvalExprEvaluatorContext expression evaluation context for static (not runtime) evaluation
*/
public JoinSetComposerHistoricalImpl(Map<String, EventTable>[] repositories, QueryStrategy[] queryStrategies, Viewable[] streamViews,
ExprEvaluatorContext staticEvalExprEvaluatorContext)
{
this.repositories = JoinSetComposerUtil.toArray(repositories, streamViews.length);
this.queryStrategies = queryStrategies;
this.streamViews = streamViews;
this.staticEvalExprEvaluatorContext = staticEvalExprEvaluatorContext;
}
public void init(EventBean[][] eventsPerStream)
{
if (repositories == null)
{
return;
}
for (int i = 0; i < eventsPerStream.length; i++)
{
if ((eventsPerStream[i] != null) && (repositories[i] != null))
{
for (int j = 0; j < repositories[i].length; j++)
{
repositories[i][j].add((eventsPerStream[i]));
}
}
}
}
public void destroy()
{
if (repositories == null)
{
return;
}
for (int i = 0; i < repositories.length; i++)
{
if (repositories[i] != null)
{
for (EventTable table : repositories[i])
{
table.clear();
}
}
}
}
public UniformPair<Set<MultiKey<EventBean>>> join(EventBean[][] newDataPerStream, EventBean[][] oldDataPerStream, ExprEvaluatorContext exprEvaluatorContext)
{
oldResults.clear();
newResults.clear();
// join old data
for (int i = 0; i < oldDataPerStream.length; i++)
{
if (oldDataPerStream[i] != null)
{
queryStrategies[i].lookup(oldDataPerStream[i], oldResults, exprEvaluatorContext);
}
}
// add new data to indexes
if (repositories != null)
{
for (int i = 0; i < newDataPerStream.length; i++)
{
if (newDataPerStream[i] != null)
{
for (int j = 0; j < repositories[i].length; j++)
{
repositories[i][j].add((newDataPerStream[i]));
}
}
}
// remove old data from indexes
// adding first and then removing as the events added may be remove right away
for (int i = 0; i < oldDataPerStream.length; i++)
{
if (oldDataPerStream[i] != null)
{
for (int j = 0; j < repositories[i].length; j++)
{
repositories[i][j].remove(oldDataPerStream[i]);
}
}
}
}
// join new data
for (int i = 0; i < newDataPerStream.length; i++)
{
if (newDataPerStream[i] != null)
{
queryStrategies[i].lookup(newDataPerStream[i], newResults, exprEvaluatorContext);
}
}
return new UniformPair<Set<MultiKey<EventBean>>>(newResults, oldResults);
}
/**
* Returns tables.
* @return tables for stream.
*/
protected EventTable[][] getTables()
{
return tables;
}
/**
* Returns query strategies.
* @return query strategies
*/
protected QueryStrategy[] getQueryStrategies()
{
return queryStrategies;
}
public Set<MultiKey<EventBean>> staticJoin()
{
Set<MultiKey<EventBean>> result = new LinkedHashSet<MultiKey<EventBean>>();
EventBean[] lookupEvents = new EventBean[1];
// Assign a local cache for the thread's evaluation of the join
// This ensures that if a SQL/method generates a row for a result set based on an input parameter, the event instance is the same
// in the join, and thus the same row does not appear twice.
DataCacheClearableMap caches[] = new DataCacheClearableMap[queryStrategies.length];
assignThreadLocalCache(streamViews, caches);
// perform join
try
{
// for each stream, perform query strategy
for (int stream = 0; stream < queryStrategies.length; stream++)
{
if (streamViews[stream] instanceof HistoricalEventViewable)
{
HistoricalEventViewable historicalViewable = (HistoricalEventViewable) streamViews[stream];
if (historicalViewable.hasRequiredStreams())
{
continue;
}
// there may not be a query strategy since only a full outer join may need to consider all rows
if (queryStrategies[stream] != null)
{
Iterator<EventBean> streamEvents = historicalViewable.iterator();
for (;streamEvents.hasNext();)
{
lookupEvents[0] = streamEvents.next();
queryStrategies[stream].lookup(lookupEvents, result, staticEvalExprEvaluatorContext);
}
}
}
else
{
Iterator<EventBean> streamEvents = streamViews[stream].iterator();
for (;streamEvents.hasNext();)
{
lookupEvents[0] = streamEvents.next();
queryStrategies[stream].lookup(lookupEvents, result,staticEvalExprEvaluatorContext);
}
}
}
}
finally
{
deassignThreadLocalCache(streamViews, caches);
}
return result;
}
private void assignThreadLocalCache(Viewable[] streamViews, DataCacheClearableMap[] caches)
{
for (int stream = 0; stream < streamViews.length; stream++)
{
if (streamViews[stream] instanceof HistoricalEventViewable)
{
HistoricalEventViewable historicalViewable = (HistoricalEventViewable) streamViews[stream];
caches[stream] = new DataCacheClearableMap();
historicalViewable.getDataCacheThreadLocal().set(caches[stream]);
}
}
}
private void deassignThreadLocalCache(Viewable[] streamViews, DataCacheClearableMap[] caches)
{
for (int stream = 0; stream < streamViews.length; stream++)
{
if (streamViews[stream] instanceof HistoricalEventViewable)
{
HistoricalEventViewable historicalViewable = (HistoricalEventViewable) streamViews[stream];
historicalViewable.getDataCacheThreadLocal().set(null);
caches[stream].clear();
}
}
}
}