/*
* Copyright (c) www.bugull.com
*
* 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 net.tooan.ynpay.third.mongodb.fs;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* Count the number of threads that accessing file in GridFS.
*
* @author Frank Wen(xbwen@hotmail.com)
*/
public class AccessCount {
private static AccessCount instance = new AccessCount();
private final Map<String, Integer> map = new ConcurrentHashMap<String, Integer>();
private AccessCount() {
}
public static AccessCount getInstance() {
return instance;
}
public int getCount(String resourceName) {
int count = 0;
Integer v = map.get(resourceName);
if (v != null) {
count = v;
}
return count;
}
public synchronized void increaseCount(String resourceName) {
int count = this.getCount(resourceName) + 1;
map.put(resourceName, count);
}
public synchronized void descreaseCount(String resourceName) {
int count = this.getCount(resourceName) - 1;
if (count < 0) {
count = 0;
}
map.put(resourceName, count);
}
}