/*
* Copyright (C) 2012, 2016 higherfrequencytrading.com
* Copyright (C) 2016 Roman Leventov
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License.
*
* 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package net.openhft.chronicle.hash.impl.util;
import net.openhft.chronicle.core.Jvm;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.concurrent.ConcurrentHashMap;
public final class CanonicalRandomAccessFiles {
private static class RafReference {
RandomAccessFile raf;
int refCount;
RafReference(RandomAccessFile raf) {
this.raf = raf;
refCount = 1;
}
}
private static final ConcurrentHashMap<File, RafReference> canonicalRafs =
new ConcurrentHashMap<>();
public static RandomAccessFile acquire(File file) throws FileNotFoundException {
return canonicalRafs.compute(file, (f, ref) -> {
if (ref == null) {
try {
return new RafReference(new RandomAccessFile(f, "rw"));
} catch (FileNotFoundException e) {
throw Jvm.rethrow(e);
}
} else {
ref.refCount++;
return ref;
}
}).raf;
}
public static void release(File file) throws IOException {
canonicalRafs.computeIfPresent(file, (f, ref) -> {
if (--ref.refCount == 0) {
try {
ref.raf.close();
} catch (IOException e) {
throw Jvm.rethrow(e);
}
return null;
} else {
return ref;
}
});
}
private CanonicalRandomAccessFiles() {}
}