| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.nifi.distributed.cache.server.set; |
| |
| import java.io.DataInputStream; |
| import java.io.DataOutputStream; |
| import java.io.EOFException; |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| import org.apache.nifi.wali.SequentialAccessWriteAheadLog; |
| import org.wali.SerDe; |
| import org.wali.SerDeFactory; |
| import org.wali.UpdateType; |
| import org.wali.WriteAheadRepository; |
| |
| public class PersistentSetCache implements SetCache { |
| |
| private final SetCache wrapped; |
| private final WriteAheadRepository<SetRecord> wali; |
| |
| private final AtomicLong modifications = new AtomicLong(0L); |
| |
| public PersistentSetCache(final String serviceIdentifier, final File persistencePath, final SetCache cacheToWrap) throws IOException { |
| wali = new SequentialAccessWriteAheadLog<>(persistencePath, new SerdeFactory()); |
| wrapped = cacheToWrap; |
| } |
| |
| public synchronized void restore() throws IOException { |
| final Collection<SetRecord> recovered = wali.recoverRecords(); |
| for (final SetRecord record : recovered) { |
| if (record.getUpdateType() == UpdateType.CREATE) { |
| addIfAbsent(record.getBuffer()); |
| } |
| } |
| } |
| |
| @Override |
| public synchronized SetCacheResult remove(final ByteBuffer value) throws IOException { |
| final SetCacheResult removeResult = wrapped.remove(value); |
| if (removeResult.getResult()) { |
| final SetRecord record = new SetRecord(UpdateType.DELETE, value); |
| final List<SetRecord> records = new ArrayList<>(); |
| records.add(record); |
| wali.update(records, false); |
| |
| final long modCount = modifications.getAndIncrement(); |
| if (modCount > 0 && modCount % 1000 == 0) { |
| wali.checkpoint(); |
| } |
| } |
| |
| return removeResult; |
| } |
| |
| @Override |
| public synchronized SetCacheResult addIfAbsent(final ByteBuffer value) throws IOException { |
| final SetCacheResult addResult = wrapped.addIfAbsent(value); |
| if (addResult.getResult()) { |
| final SetRecord record = new SetRecord(UpdateType.CREATE, value); |
| final List<SetRecord> records = new ArrayList<>(); |
| records.add(record); |
| |
| final SetCacheRecord evictedRecord = addResult.getEvictedRecord(); |
| if (evictedRecord != null) { |
| records.add(new SetRecord(UpdateType.DELETE, evictedRecord.getValue())); |
| } |
| |
| wali.update(records, false); |
| |
| final long modCount = modifications.getAndIncrement(); |
| if (modCount > 0 && modCount % 1000 == 0) { |
| wali.checkpoint(); |
| } |
| } |
| |
| return addResult; |
| } |
| |
| @Override |
| public synchronized SetCacheResult contains(final ByteBuffer value) throws IOException { |
| return wrapped.contains(value); |
| } |
| |
| @Override |
| public void shutdown() throws IOException { |
| wali.shutdown(); |
| } |
| |
| private static class SetRecord { |
| |
| private final UpdateType updateType; |
| private final ByteBuffer value; |
| |
| public SetRecord(final UpdateType updateType, final ByteBuffer value) { |
| this.updateType = updateType; |
| this.value = value; |
| } |
| |
| public UpdateType getUpdateType() { |
| return updateType; |
| } |
| |
| public ByteBuffer getBuffer() { |
| return value; |
| } |
| |
| public byte[] getData() { |
| return value.array(); |
| } |
| } |
| |
| private static class Serde implements SerDe<SetRecord> { |
| |
| @Override |
| public void serializeEdit(final SetRecord previousRecordState, final SetRecord newRecordState, final DataOutputStream out) throws IOException { |
| final UpdateType updateType = newRecordState.getUpdateType(); |
| if (updateType == UpdateType.DELETE) { |
| out.write(0); |
| } else { |
| out.write(1); |
| } |
| |
| final byte[] data = newRecordState.getData(); |
| out.writeInt(data.length); |
| out.write(newRecordState.getData()); |
| } |
| |
| @Override |
| public void serializeRecord(SetRecord record, DataOutputStream out) throws IOException { |
| serializeEdit(null, record, out); |
| } |
| |
| @Override |
| public SetRecord deserializeEdit(final DataInputStream in, final Map<Object, SetRecord> currentRecordStates, final int version) throws IOException { |
| final int value = in.read(); |
| if (value < 0) { |
| throw new EOFException(); |
| } |
| |
| final UpdateType updateType = (value == 0 ? UpdateType.DELETE : UpdateType.CREATE); |
| |
| final int size = in.readInt(); |
| final byte[] data = new byte[size]; |
| in.readFully(data); |
| |
| return new SetRecord(updateType, ByteBuffer.wrap(data)); |
| } |
| |
| @Override |
| public SetRecord deserializeRecord(DataInputStream in, int version) throws IOException { |
| return deserializeEdit(in, new HashMap<Object, SetRecord>(), version); |
| } |
| |
| @Override |
| public Object getRecordIdentifier(final SetRecord record) { |
| return record.getBuffer(); |
| } |
| |
| @Override |
| public UpdateType getUpdateType(final SetRecord record) { |
| return record.getUpdateType(); |
| } |
| |
| @Override |
| public String getLocation(final SetRecord record) { |
| return null; |
| } |
| |
| @Override |
| public int getVersion() { |
| return 1; |
| } |
| } |
| |
| private static class SerdeFactory implements SerDeFactory<SetRecord> { |
| |
| private Serde serde; |
| |
| public SerdeFactory() { |
| this.serde = new Serde(); |
| } |
| |
| @Override |
| public SerDe<SetRecord> createSerDe(String encodingName) { |
| return this.serde; |
| } |
| |
| @Override |
| public Object getRecordIdentifier(SetRecord record) { |
| return this.serde.getRecordIdentifier(record); |
| } |
| |
| @Override |
| public UpdateType getUpdateType(SetRecord record) { |
| return this.serde.getUpdateType(record); |
| } |
| |
| @Override |
| public String getLocation(SetRecord record) { |
| return this.serde.getLocation(record); |
| } |
| |
| } |
| } |