/*
***************************************************************************************
* 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.filter;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.metrics.instrumentation.InstrumentationHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Collection;
import java.util.Map;
import java.util.TreeMap;
import java.util.concurrent.locks.ReadWriteLock;
/**
* Index for filter parameter constants for the comparison operators (less, greater, etc).
* The implementation is based on the SortedMap implementation of TreeMap.
* The index only accepts numeric constants. It keeps a lower and upper bounds of all constants in the index
* for fast range checking, since the assumption is that frequently values fall within a range.
*/
public final class FilterParamIndexCompare extends FilterParamIndexLookupableBase {
private final TreeMap<Object, EventEvaluator> constantsMap;
private final ReadWriteLock constantsMapRWLock;
private Double lowerBounds;
private Double upperBounds;
public FilterParamIndexCompare(FilterSpecLookupable lookupable, ReadWriteLock readWriteLock, FilterOperator filterOperator) {
super(filterOperator, lookupable);
constantsMap = new TreeMap<Object, EventEvaluator>();
constantsMapRWLock = readWriteLock;
if ((filterOperator != FilterOperator.GREATER) &&
(filterOperator != FilterOperator.GREATER_OR_EQUAL) &&
(filterOperator != FilterOperator.LESS) &&
(filterOperator != FilterOperator.LESS_OR_EQUAL)) {
throw new IllegalArgumentException("Invalid filter operator for index of " + filterOperator);
}
}
public final EventEvaluator get(Object filterConstant) {
return constantsMap.get(filterConstant);
}
public final void put(Object filterConstant, EventEvaluator matcher) {
constantsMap.put(filterConstant, matcher);
// Update bounds
Double constant = ((Number) filterConstant).doubleValue();
if ((lowerBounds == null) || (constant < lowerBounds)) {
lowerBounds = constant;
}
if ((upperBounds == null) || (constant > upperBounds)) {
upperBounds = constant;
}
}
public final void remove(Object filterConstant) {
if (constantsMap.remove(filterConstant) == null) {
return;
}
updateBounds();
}
public final int sizeExpensive() {
return constantsMap.size();
}
public boolean isEmpty() {
return constantsMap.isEmpty();
}
public final ReadWriteLock getReadWriteLock() {
return constantsMapRWLock;
}
public final void matchEvent(EventBean theEvent, Collection<FilterHandle> matches) {
Object propertyValue = lookupable.getGetter().get(theEvent);
if (InstrumentationHelper.ENABLED) {
InstrumentationHelper.get().qFilterReverseIndex(this, propertyValue);
}
if (propertyValue == null) {
if (InstrumentationHelper.ENABLED) {
InstrumentationHelper.get().aFilterReverseIndex(false);
}
return;
}
// A undefine lower bound indicates an empty index
if (lowerBounds == null) {
if (InstrumentationHelper.ENABLED) {
InstrumentationHelper.get().aFilterReverseIndex(false);
}
return;
}
FilterOperator filterOperator = this.getFilterOperator();
Double propertyValueDouble = ((Number) propertyValue).doubleValue();
// Based on current lower and upper bounds check if the property value falls outside - shortcut submap generation
if ((filterOperator == FilterOperator.GREATER) && (propertyValueDouble <= lowerBounds)) {
if (InstrumentationHelper.ENABLED) {
InstrumentationHelper.get().aFilterReverseIndex(false);
}
return;
} else if ((filterOperator == FilterOperator.GREATER_OR_EQUAL) && (propertyValueDouble < lowerBounds)) {
if (InstrumentationHelper.ENABLED) {
InstrumentationHelper.get().aFilterReverseIndex(false);
}
return;
} else if ((filterOperator == FilterOperator.LESS) && (propertyValueDouble >= upperBounds)) {
if (InstrumentationHelper.ENABLED) {
InstrumentationHelper.get().aFilterReverseIndex(false);
}
return;
} else if ((filterOperator == FilterOperator.LESS_OR_EQUAL) && (propertyValueDouble > upperBounds)) {
if (InstrumentationHelper.ENABLED) {
InstrumentationHelper.get().aFilterReverseIndex(false);
}
return;
}
// Look up in table
constantsMapRWLock.readLock().lock();
try {
// Get the head or tail end of the map depending on comparison type
Map<Object, EventEvaluator> subMap;
if ((filterOperator == FilterOperator.GREATER) ||
(filterOperator == FilterOperator.GREATER_OR_EQUAL)) {
// At the head of the map are those with a lower numeric constants
subMap = constantsMap.headMap(propertyValue);
} else {
subMap = constantsMap.tailMap(propertyValue);
}
// All entries in the subMap are elgibile, with an exception
EventEvaluator exactEquals = null;
if (filterOperator == FilterOperator.LESS) {
exactEquals = constantsMap.get(propertyValue);
}
for (EventEvaluator matcher : subMap.values()) {
// For the LESS comparison type we ignore the exactly equal case
// The subMap is sorted ascending, thus the exactly equals case is the first
if (exactEquals != null) {
exactEquals = null;
continue;
}
matcher.matchEvent(theEvent, matches);
}
if (filterOperator == FilterOperator.GREATER_OR_EQUAL) {
EventEvaluator matcher = constantsMap.get(propertyValue);
if (matcher != null) {
matcher.matchEvent(theEvent, matches);
}
}
} finally {
constantsMapRWLock.readLock().unlock();
}
if (InstrumentationHelper.ENABLED) {
InstrumentationHelper.get().aFilterReverseIndex(null);
}
}
private void updateBounds() {
if (constantsMap.isEmpty()) {
lowerBounds = null;
upperBounds = null;
return;
}
lowerBounds = ((Number) constantsMap.firstKey()).doubleValue();
upperBounds = ((Number) constantsMap.lastKey()).doubleValue();
}
private static final Logger log = LoggerFactory.getLogger(FilterParamIndexCompare.class);
}