/* ###
 * IP: GHIDRA
 * REVIEWED: YES
 *
 * 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 generic.util;

import java.io.File;

public class LockFactory {

	private static Boolean supportsChannelLocking;

	public static FileLocker createFileLocker(File lockFile) {
		if (supportsChannelLocking(lockFile.getParentFile())) {
			return new ChannelLocker(lockFile);
		}
		return new FileLocker(lockFile);
	}

	private static boolean supportsChannelLocking(File testDir) {
		if (supportsChannelLocking == null) {
			// crude locking test
			File testFile = createTestFile(testDir);

			FileChannelLock channelLock = new FileChannelLock(testFile);
			boolean canLock = channelLock.lock();
			channelLock.release();
			supportsChannelLocking = canLock;
		}
		return supportsChannelLocking;
	}

	private static File createTestFile(File directory) {
		return new File(directory, ".ghidra.test.lock~");
	}
}
