/* * 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() {} }