Copyright (c) 2010, 2016 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Sergey Prigogin (Google) - ongoing development
/*******************************************************************************
 * Copyright (c) 2010, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Sergey Prigogin (Google) - ongoing development
 *******************************************************************************/
package org.eclipse.core.internal.filesystem.local;

import java.nio.file.FileSystems;
import java.util.Set;
import org.eclipse.core.filesystem.IFileInfo;
import org.eclipse.core.filesystem.provider.FileInfo;
import org.eclipse.core.internal.filesystem.local.nio.*;
import org.eclipse.core.internal.filesystem.local.unix.UnixFileHandler;
import org.eclipse.core.internal.filesystem.local.unix.UnixFileNatives;

Dispatches methods backed by native code to the appropriate platform specific
implementation depending on a library provided by a fragment. Failing this it tries
to use Java 7 NIO/2 API's.

Use of native libraries can be disabled by adding -Declipse.filesystem.useNatives=false to VM
arguments.

Please notice that the native implementation is significantly faster than the non-native one.
The BenchFileStore test runs 3.1 times faster on Linux with the native code than without it.
/**
 * Dispatches methods backed by native code to the appropriate platform specific
 * implementation depending on a library provided by a fragment. Failing this it tries
 * to use Java 7 NIO/2 API's.
 * <p>
 * Use of native libraries can be disabled by adding -Declipse.filesystem.useNatives=false to VM
 * arguments.
 * <p>
 * Please notice that the native implementation is significantly faster than the non-native one.
 * The BenchFileStore test runs 3.1 times faster on Linux with the native code than without it.
 */
public class LocalFileNativesManager {
	private static NativeHandler HANDLER;
	private static boolean USING_NATIVES;

	static {
		boolean nativesAllowed = Boolean.parseBoolean(System.getProperty("eclipse.filesystem.useNatives", "true")); //$NON-NLS-1$ //$NON-NLS-2$
		if (nativesAllowed && UnixFileNatives.isUsingNatives()) {
			HANDLER = new UnixFileHandler();
			USING_NATIVES = true;
		} else if (nativesAllowed && LocalFileNatives.isUsingNatives()) {
			HANDLER = new LocalFileHandler();
			USING_NATIVES = true;
		} else {
			Set<String> views = FileSystems.getDefault().supportedFileAttributeViews();
			if (views.contains("posix")) { //$NON-NLS-1$
				HANDLER = new PosixHandler();
			} else if (views.contains("dos")) { //$NON-NLS-1$
				HANDLER = new DosHandler();
			} else {
				HANDLER = new DefaultHandler();
			}
		}
	}

	public static int getSupportedAttributes() {
		return HANDLER.getSupportedAttributes();
	}

	public static FileInfo fetchFileInfo(String fileName) {
		return HANDLER.fetchFileInfo(fileName);
	}

	public static boolean putFileInfo(String fileName, IFileInfo info, int options) {
		return HANDLER.putFileInfo(fileName, info, options);
	}

	public static boolean isUsingNatives() {
		return USING_NATIVES;
	}
}