/* 
 * Copyright 2015 Terracotta, Inc., a Software AG company.
 *
 * 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 org.terracotta.offheapstore.disk.persistent;

import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.nio.MappedByteBuffer;
import java.util.concurrent.locks.Lock;

import org.terracotta.offheapstore.AbstractOffHeapClockCache;
import org.terracotta.offheapstore.disk.paging.MappedPageSource;
import org.terracotta.offheapstore.util.FindbugsSuppressWarnings;

import java.nio.IntBuffer;

Author:Chris Dennis
/** * * @author Chris Dennis */
public abstract class AbstractPersistentOffHeapCache<K, V> extends AbstractOffHeapClockCache<K, V> implements Persistent { private static final int MAGIC = 0x494c4c49; public AbstractPersistentOffHeapCache(MappedPageSource tableSource, PersistentStorageEngine<? super K, ? super V> storageEngine, boolean bootstrap) { super(tableSource, storageEngine, bootstrap); } public AbstractPersistentOffHeapCache(MappedPageSource tableSource, PersistentStorageEngine<? super K, ? super V> storageEngine, int tableSize, boolean bootstrap) { super(tableSource, storageEngine, tableSize, bootstrap); } @Override public void flush() throws IOException { Lock l = writeLock(); l.lock(); try { ((MappedByteBuffer) hashTablePage.asByteBuffer()).force(); ((Persistent) storageEngine).flush(); } finally { l.unlock(); } } @Override public void close() throws IOException { Lock l = writeLock(); l.lock(); try { ((MappedPageSource) tableSource).close(); ((Persistent) storageEngine).close(); } finally { l.unlock(); } } @Override public void persist(ObjectOutput output) throws IOException { Lock l = writeLock(); l.lock(); try { output.writeInt(MAGIC); output.writeLong(((MappedPageSource) tableSource).getAddress(hashTablePage)); output.writeInt(hashTablePage.size()); output.writeInt(reprobeLimit); ((Persistent) storageEngine).persist(output); } finally { l.unlock(); } } @Override @FindbugsSuppressWarnings("VO_VOLATILE_INCREMENT") public void bootstrap(ObjectInput input) throws IOException { Lock l = writeLock(); l.lock(); try { if (hashtable != null) { throw new IllegalStateException(); } if (input.readInt() != MAGIC) { throw new IOException("Wrong magic number"); } long tableAddress = input.readLong(); long tableCapacity = input.readInt(); hashTablePage = ((MappedPageSource) tableSource).claimPage(tableAddress, tableCapacity); hashtable = hashTablePage.asIntBuffer(); reprobeLimit = input.readInt(); //need to scan the incoming table for (hashtable.clear(); hashtable.hasRemaining(); hashtable.position(hashtable.position() + ENTRY_SIZE)) { IntBuffer entry = (IntBuffer) hashtable.slice().limit(ENTRY_SIZE); if (isPresent(entry)) { size++; added(entry); } else if (isRemoved(entry)) { removedSlots++; } } ((Persistent) storageEngine).bootstrap(input); } finally { l.unlock(); } } }