/*
 * 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.contrib.streaming.state;

import org.apache.flink.runtime.operators.testutils.ExpectedTestException;

import org.junit.Assert;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import org.rocksdb.RocksDB;

import java.io.File;
import java.io.IOException;

import static org.junit.Assert.fail;

/**
 * Tests for {@link RocksDBStateBackend} on initialization.
 */
@RunWith(PowerMockRunner.class)
@PrepareForTest({RocksDB.class})
public class RocksDBInitTest {

	@Rule
	public final TemporaryFolder temporaryFolder = new TemporaryFolder();

	/**
	 * This test checks that the RocksDB native code loader still responds to resetting the init flag.
	 */
	@Test
	public void testResetInitFlag() throws Exception {
		RocksDBStateBackend.resetRocksDBLoadedFlag();
	}

	@Test
	public void testTempLibFolderDeletedOnFail() throws Exception {
		PowerMockito.spy(RocksDB.class);
		PowerMockito.when(RocksDB.class, "loadLibrary").thenThrow(new ExpectedTestException());

		File tempFolder = temporaryFolder.newFolder();
		try {
			RocksDBStateBackend.ensureRocksDBIsLoaded(tempFolder.getAbsolutePath());
			fail("Not throwing expected exception.");
		} catch (IOException ignored) {
			// ignored
		}
		File[] files = tempFolder.listFiles();
		Assert.assertNotNull(files);
		Assert.assertEquals(0, files.length);
	}
}