org.springframework.statemachine.kryo.AbstractKryoStateMachineSerialisationService Maven / Gradle / Ivy
/*
* Copyright 2017-2018 the original author or authors.
*
* 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
*
* https://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.springframework.statemachine.kryo;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.springframework.statemachine.StateMachineContext;
import org.springframework.statemachine.service.StateMachineSerialisationService;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;
import com.esotericsoftware.kryo.pool.KryoCallback;
import com.esotericsoftware.kryo.pool.KryoFactory;
import com.esotericsoftware.kryo.pool.KryoPool;
/**
* Abstract base implementation for {@link StateMachineSerialisationService} using kryo.
*
* @author Janne Valkealahti
*
* @param the type of state
* @param the type of event
*/
public abstract class AbstractKryoStateMachineSerialisationService implements StateMachineSerialisationService {
protected final KryoPool pool;
protected AbstractKryoStateMachineSerialisationService() {
KryoFactory factory = new KryoFactory() {
@Override
public Kryo create() {
Kryo kryo = new Kryo();
// kryo is really getting trouble checking things if class loaders
// doesn't match. for now just use below trick before we try
// to go fully on beans and get a bean class loader.
kryo.setClassLoader(ClassUtils.getDefaultClassLoader());
configureKryoInstance(kryo);
return kryo;
}
};
this.pool = new KryoPool.Builder(factory).softReferences().build();
}
@Override
public byte[] serialiseStateMachineContext(StateMachineContext context) throws Exception {
return encode(context);
}
@SuppressWarnings("unchecked")
@Override
public StateMachineContext deserialiseStateMachineContext(byte[] data) throws Exception {
return decode(data, StateMachineContext.class);
}
/**
* Subclasses implement this method to encode with Kryo.
*
* @param kryo the Kryo instance
* @param object the object to encode
* @param output the Kryo Output instance
*/
protected abstract void doEncode(Kryo kryo, Object object, Output output);
/**
* Subclasses implement this method to decode with Kryo.
*
* @param kryo the Kryo instance
* @param input the Kryo Input instance
* @param type the class of the decoded object
* @param the type for decoded object
* @return the decoded object
*/
protected abstract T doDecode(Kryo kryo, Input input, Class type);
/**
* Subclasses implement this to configure the kryo instance.
* This is invoked on each new Kryo instance when it is created.
*
* @param kryo the kryo instance
*/
protected abstract void configureKryoInstance(Kryo kryo);
private byte[] encode(Object object) throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
encode(object, bos);
byte[] bytes = bos.toByteArray();
bos.close();
return bytes;
}
private void encode(final Object object, OutputStream outputStream) throws IOException {
Assert.notNull(object, "cannot encode a null object");
Assert.notNull(outputStream, "'outputSteam' cannot be null");
final Output output = (outputStream instanceof Output ? (Output) outputStream : new Output(outputStream));
this.pool.run(new KryoCallback() {
@Override
public Void execute(Kryo kryo) {
doEncode(kryo, object, output);
return null;
}
});
output.close();
}
private T decode(byte[] bytes, Class type) throws IOException {
Assert.notNull(bytes, "'bytes' cannot be null");
final Input input = new Input(bytes);
try {
return decode(input, type);
}
finally {
input.close();
}
}
private T decode(InputStream inputStream, final Class type) throws IOException {
Assert.notNull(inputStream, "'inputStream' cannot be null");
Assert.notNull(type, "'type' cannot be null");
final Input input = (inputStream instanceof Input ? (Input) inputStream : new Input(inputStream));
T result = null;
try {
result = this.pool.run(new KryoCallback(){
@Override
public T execute(Kryo kryo) {
return doDecode(kryo, input, type);
}
});
}
finally {
input.close();
}
return result;
}
}