flink-core/src/test/java/org/apache/flink/core/fs/FileSystemTestUtils.java

/*
 * 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.flink.core.fs;

import java.io.IOException;

import static org.junit.Assert.assertEquals;

/**
 * Various utility functions for testing {@link FileSystem} implementations.
 */
public class FileSystemTestUtils {

	/**
	 * Verifies that the given path eventually appears on / disappears from <tt>fs</tt> within
	 * <tt>deadline</tt> nanoseconds.
	 */
	public static void checkPathEventualExistence(
			FileSystem fs,
			Path path,
			boolean expectedExists,
			long deadline) throws IOException, InterruptedException {
		boolean dirExists;
		while ((dirExists = fs.exists(path)) != expectedExists &&
				System.nanoTime() < deadline) {
			Thread.sleep(10);
		}
		assertEquals(expectedExists, dirExists);
	}
}