/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.lucene.mockfile;
import java.io.IOException;
import java.nio.file.FileSystem;
import java.nio.file.FileSystemException;
import java.nio.file.Path;
import java.util.concurrent.atomic.AtomicInteger;
/**
* FileSystem that throws exception if file handles
* in use exceeds a specified limit
*/
public class HandleLimitFS extends HandleTrackingFS {
final int limit;
final AtomicInteger count = new AtomicInteger();
/**
* Create a new instance, limiting the maximum number
* of open files to {@code limit}
* @param delegate delegate filesystem to wrap.
* @param limit maximum number of open files.
*/
public HandleLimitFS(FileSystem delegate, int limit) {
super("handlelimit://", delegate);
this.limit = limit;
}
@Override
protected void onOpen(Path path, Object stream) throws IOException {
if (count.incrementAndGet() > limit) {
count.decrementAndGet();
throw new FileSystemException(path.toString(), null, "Too many open files");
}
}
@Override
protected void onClose(Path path, Object stream) throws IOException {
count.decrementAndGet();
}
}