/*
* Copyright 2015 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
*
* 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.springframework.statemachine.redis;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.UUID;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.StringRedisSerializer;
import org.springframework.messaging.MessageHeaders;
import org.springframework.statemachine.StateMachineContext;
import org.springframework.statemachine.StateMachineContextRepository;
import org.springframework.statemachine.kryo.MessageHeadersSerializer;
import org.springframework.statemachine.kryo.StateMachineContextSerializer;
import org.springframework.statemachine.kryo.UUIDSerializer;
import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;
/**
* A {@link StateMachineContextRepository} backed by a redis and kryo serialization.
*
* @author Janne Valkealahti
*
* @param <S> the type of state
* @param <E> the type of event
*/
public class RedisStateMachineContextRepository<S, E> implements StateMachineContextRepository<S, E, StateMachineContext<S, E>> {
private static final ThreadLocal<Kryo> kryoThreadLocal = new ThreadLocal<Kryo>() {
@SuppressWarnings("rawtypes")
@Override
protected Kryo initialValue() {
Kryo kryo = new Kryo();
kryo.addDefaultSerializer(StateMachineContext.class, new StateMachineContextSerializer());
kryo.addDefaultSerializer(MessageHeaders.class, new MessageHeadersSerializer());
kryo.addDefaultSerializer(UUID.class, new UUIDSerializer());
return kryo;
}
};
private final RedisOperations<String,byte[]> redisOperations;
/**
* Instantiates a new redis state machine context repository.
*
* @param redisConnectionFactory the redis connection factory
*/
public RedisStateMachineContextRepository(RedisConnectionFactory redisConnectionFactory) {
redisOperations = createDefaultTemplate(redisConnectionFactory);
}
@Override
public void save(StateMachineContext<S, E> context, String id) {
redisOperations.opsForValue().set(id, serialize(context));
}
@Override
public StateMachineContext<S, E> getContext(String id) {
return deserialize(redisOperations.opsForValue().get(id));
}
private static RedisTemplate<String,byte[]> createDefaultTemplate(RedisConnectionFactory connectionFactory) {
RedisTemplate<String,byte[]> template = new RedisTemplate<String,byte[]>();
template.setKeySerializer(new StringRedisSerializer());
template.setHashKeySerializer(new StringRedisSerializer());
template.setConnectionFactory(connectionFactory);
template.afterPropertiesSet();
return template;
}
private byte[] serialize(StateMachineContext<S, E> context) {
Kryo kryo = kryoThreadLocal.get();
ByteArrayOutputStream out = new ByteArrayOutputStream();
Output output = new Output(out);
kryo.writeObject(output, context);
output.close();
return out.toByteArray();
}
@SuppressWarnings("unchecked")
private StateMachineContext<S, E> deserialize(byte[] data) {
if (data == null || data.length == 0) {
return null;
}
Kryo kryo = kryoThreadLocal.get();
ByteArrayInputStream in = new ByteArrayInputStream(data);
Input input = new Input(in);
return kryo.readObject(input, StateMachineContext.class);
}
}