package com.espertech.esper.epl.virtualdw;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.hook.VirtualDataWindowLookup;
import com.espertech.esper.client.hook.VirtualDataWindowKeyRange;
import com.espertech.esper.epl.expression.ExprEvaluator;
import com.espertech.esper.epl.expression.ExprEvaluatorContext;
import com.espertech.esper.epl.join.exec.base.JoinExecTableLookupStrategy;
import com.espertech.esper.epl.join.plan.*;
import com.espertech.esper.epl.join.rep.Cursor;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.Set;
public class JoinExecTableLookupStrategyVirtualDW implements JoinExecTableLookupStrategy {
private static final Log log = LogFactory.getLog(JoinExecTableLookupStrategyVirtualDW.class);
private final String namedWindowName;
private final VirtualDataWindowLookup externalIndex;
private final ExternalEvaluator[] evaluators;
private final EventBean[] eventsPerStream;
private final int lookupStream;
public JoinExecTableLookupStrategyVirtualDW(String namedWindowName, VirtualDataWindowLookup externalIndex, TableLookupKeyDesc keyDescriptor, int lookupStream) {
this.namedWindowName = namedWindowName;
this.externalIndex = externalIndex;
this.evaluators = new ExternalEvaluator[keyDescriptor.getHashes().size() + keyDescriptor.getRanges().size()];
this.eventsPerStream = new EventBean[lookupStream + 1];
this.lookupStream = lookupStream;
int count = 0;
for (QueryGraphValueEntryHashKeyed hashKey : keyDescriptor.getHashes()) {
ExprEvaluator evaluator = hashKey.getKeyExpr().getExprEvaluator();
evaluators[count] = new ExternalEvaluatorHashRelOp(evaluator);
count++;
}
for (QueryGraphValueEntryRange rangeKey : keyDescriptor.getRanges()) {
if (rangeKey.getType().isRange()) {
QueryGraphValueEntryRangeIn range = (QueryGraphValueEntryRangeIn) rangeKey;
ExprEvaluator evaluatorStart = range.getExprStart().getExprEvaluator();
ExprEvaluator evaluatorEnd = range.getExprEnd().getExprEvaluator();
evaluators[count] = new ExternalEvaluatorBtreeRange(evaluatorStart, evaluatorEnd);
}
else {
QueryGraphValueEntryRangeRelOp relOp = (QueryGraphValueEntryRangeRelOp) rangeKey;
ExprEvaluator evaluator = relOp.getExpression().getExprEvaluator();
evaluators[count] = new ExternalEvaluatorHashRelOp(evaluator);
}
count++;
}
}
public Set<EventBean> lookup(EventBean event, Cursor cursor, ExprEvaluatorContext context) {
eventsPerStream[lookupStream] = event;
Object[] keys = new Object[evaluators.length];
for (int i = 0; i < evaluators.length; i++) {
keys[i] = evaluators[i].evaluate(eventsPerStream, context);
}
Set<EventBean> events = null;
try {
events = externalIndex.lookup(keys);
}
catch (RuntimeException ex) {
log.warn("Exception encountered invoking virtual data window external index for window '" + namedWindowName + "': " + ex.getMessage(), ex);
}
return events;
}
public String toQueryPlan() {
return this.getClass().getSimpleName() + " external index " + externalIndex;
}
private interface ExternalEvaluator
{
public Object evaluate(EventBean[] events, ExprEvaluatorContext context);
}
private static class ExternalEvaluatorHashRelOp implements ExternalEvaluator {
private final ExprEvaluator hashKeysEval;
private ExternalEvaluatorHashRelOp(ExprEvaluator hashKeysEval) {
this.hashKeysEval = hashKeysEval;
}
public Object evaluate(EventBean[] events, ExprEvaluatorContext context) {
return hashKeysEval.evaluate(events, true, context);
}
}
private static class ExternalEvaluatorBtreeRange implements ExternalEvaluator {
private final ExprEvaluator startEval;
private final ExprEvaluator endEval;
private ExternalEvaluatorBtreeRange(ExprEvaluator startEval, ExprEvaluator endEval) {
this.startEval = startEval;
this.endEval = endEval;
}
public Object evaluate(EventBean[] events, ExprEvaluatorContext context) {
Object start = startEval.evaluate(events, true, context);
Object end = endEval.evaluate(events, true, context);
return new VirtualDataWindowKeyRange(start, end);
}
}
}