/*
* Copyright Terracotta, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.ehcache.impl.internal.statistics;
import java.util.Set;
import org.terracotta.statistics.OperationStatistic;
import org.terracotta.statistics.ValueStatistic;
import org.terracotta.statistics.observer.ChainedOperationObserver;
/**
* An operation statistic that always return 0 for everything. Used as a null object.
*/
class ZeroOperationStatistic<T extends Enum<T>> implements OperationStatistic<T> {
@SuppressWarnings("rawtypes")
private static final OperationStatistic<?> INSTANCE = new ZeroOperationStatistic();
@SuppressWarnings("unchecked")
public static <T extends Enum<T>> OperationStatistic<T> get() {
return (OperationStatistic<T>) INSTANCE;
}
@Override
public Class<T> type() {
return null;
}
@Override
public ValueStatistic<Long> statistic(T result) {
return null;
}
@Override
public ValueStatistic<Long> statistic(Set<T> results) {
return null;
}
@Override
public long count(T type) {
return 0;
}
@Override
public long sum(Set<T> types) {
return 0;
}
@Override
public long sum() {
return 0;
}
@Override
public void addDerivedStatistic(ChainedOperationObserver<? super T> derived) {
}
@Override
public void removeDerivedStatistic(ChainedOperationObserver<? super T> derived) {
}
@Override
public void begin() {
}
@Override
public void end(T result) {
}
@Override
public void end(T result, long... parameters) {
}
}