/**************************************************************************************
* 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.exec.base;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.epl.expression.ExprEvaluatorContext;
import com.espertech.esper.epl.expression.ExprNode;
import com.espertech.esper.epl.expression.ExprNodeUtility;
import com.espertech.esper.epl.join.exec.composite.CompositeIndexQuery;
import com.espertech.esper.epl.join.exec.composite.CompositeIndexQueryFactory;
import com.espertech.esper.epl.join.plan.QueryGraphValueEntryHashKeyed;
import com.espertech.esper.epl.join.plan.QueryGraphValueEntryRange;
import com.espertech.esper.epl.join.rep.Cursor;
import com.espertech.esper.epl.join.table.PropertyCompositeEventTable;
import com.espertech.esper.epl.lookup.LookupStrategyDesc;
import com.espertech.esper.epl.lookup.LookupStrategyType;
import com.espertech.esper.metrics.instrumentation.InstrumentationHelper;
import java.util.*;
/**
* Lookup on an nested map structure that represents an index for use with at least one range and possibly multiple ranges
* and optionally keyed by one or more unique keys.
* <p>
* Use the sorted strategy instead if supporting a single range only and no other unique keys are part of the index.
*/
public class CompositeTableLookupStrategy implements JoinExecTableLookupStrategy
{
private final EventType eventType;
private final PropertyCompositeEventTable index;
private final CompositeIndexQuery chain;
private final List<QueryGraphValueEntryRange> rangeKeyPairs;
private final LookupStrategyDesc lookupStrategyDesc;
/**
* Ctor.
* @param eventType - event type to expect for lookup
* @param index - index to look up in
*/
public CompositeTableLookupStrategy(EventType eventType, int lookupStream, List<QueryGraphValueEntryHashKeyed> hashKeys, List<QueryGraphValueEntryRange> rangeKeyPairs, PropertyCompositeEventTable index)
{
this.eventType = eventType;
this.index = index;
this.rangeKeyPairs = rangeKeyPairs;
chain = CompositeIndexQueryFactory.makeJoinSingleLookupStream(false, lookupStream, hashKeys, index.getOptKeyCoercedTypes(), rangeKeyPairs, index.getOptRangeCoercedTypes());
Deque<String> expressionTexts = new ArrayDeque<String>();
for (QueryGraphValueEntryRange pair : rangeKeyPairs) {
ExprNode[] expressions = pair.getExpressions();
for (ExprNode node : expressions) {
expressionTexts.add(ExprNodeUtility.toExpressionStringMinPrecedence(node));
}
}
lookupStrategyDesc = new LookupStrategyDesc(LookupStrategyType.COMPOSITE, expressionTexts.toArray(new String[expressionTexts.size()]));
}
/**
* Returns event type of the lookup event.
* @return event type of the lookup event
*/
public EventType getEventType()
{
return eventType;
}
/**
* Returns index to look up in.
* @return index to use
*/
public PropertyCompositeEventTable getIndex()
{
return index;
}
public Set<EventBean> lookup(EventBean theEvent, Cursor cursor, ExprEvaluatorContext context)
{
if (InstrumentationHelper.ENABLED) {
InstrumentationHelper.get().qIndexJoinLookup(this, index);
ArrayList<Object> keys = new ArrayList<Object>(2);
Set<EventBean> result = chain.getCollectKeys(theEvent, index.getIndex(), context, keys);
InstrumentationHelper.get().aIndexJoinLookup(result, keys.size() > 1 ? keys.toArray() : keys.get(0));
return result;
}
Set<EventBean> result = chain.get(theEvent, index.getIndex(), context);
if (result != null && result.isEmpty()) {
return null;
}
return result;
}
public LookupStrategyDesc getStrategyDesc() {
return lookupStrategyDesc;
}
public String toString()
{
return "CompositeTableLookupStrategy indexProps=" + Arrays.toString(rangeKeyPairs.toArray()) +
" index=(" + index + ')';
}
}