WatchServiceCache.java

/**
 * FreeDesktopSearch - A Search Engine for your Desktop
 * Copyright (C) 2013 Mirko Sertic
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, see <http://www.gnu.org/licenses/>.
 */
package de.mirkosertic.desktopsearch;

import java.io.IOException;
import java.nio.file.FileSystem;
import java.nio.file.Path;
import java.nio.file.WatchService;
import java.util.HashMap;
import java.util.Map;

public class WatchServiceCache {

    private final Map<FileSystem, WatchService> watchServices;

    public WatchServiceCache() {
        watchServices = new HashMap<>();
    }

    public synchronized WatchService getWatchServiceFor(Path aPath) throws IOException {
        FileSystem theFileSystem = aPath.getFileSystem();
        WatchService theService = watchServices.get(theFileSystem);
        if (theService == null) {
            theService = theFileSystem.newWatchService();
            watchServices.put(theFileSystem, theService);
        }

        return theService;
    }
}