com.flipkart.aesop.serializer.stateengine.StateTransitioner.java Source code

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Here is the source code for com.flipkart.aesop.serializer.stateengine.StateTransitioner.java

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/*
 * Copyright 2012-2015, 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 com.flipkart.aesop.serializer.stateengine;

import java.io.File;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.Assert;

import com.netflix.zeno.fastblob.FastBlobStateEngine;
import com.netflix.zeno.serializer.NFTypeSerializer;
import com.netflix.zeno.serializer.SerializerFactory;

/**
 * The <code>StateTransitioner</code> creates or suitably initializes an existing {@link FastBlobStateEngine} for producing snapshots or deltas.
 * 
 * @author Regunath B
 * @version 1.0, 5 March 2014
 */

public abstract class StateTransitioner<T> implements InitializingBean {

    /** The SerializerFactory used for creating the FastBlobStateEngine instance*/
    protected SerializerFactory serializerFactory;

    /** The root type NFTypeSerializer*/
    protected NFTypeSerializer<T> rootNFTypeSerializer;

    /** The file location for storing snapshots and deltas */
    protected String serializedDataLocation;

    /** Directory location derived from serialized data location */
    protected File serializedDataLocationDir;

    /**
     * Returns a newly created or suitably initialized FastBlobStateEngine 
     * @return FastBlobStateEngine instance
     */
    public abstract FastBlobStateEngine getStateEngine();

    /**
     * Saves the state held by the FastBlobStateEngine
     */
    public abstract void saveState();

    /**
     * Interface method implementation. Checks for mandatory dependencies
     * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
     */
    public void afterPropertiesSet() throws Exception {
        Assert.notNull(this.serializerFactory,
                "'serializerFactory' cannot be null. This state transitioner will not be initialized");
        Assert.notNull(this.rootNFTypeSerializer,
                "'rootNFTypeSerializer' cannot be null. This state transitioner will not be initialized");
        Assert.notNull(this.serializedDataLocation,
                "'serializedDataLocation' cannot be null. This state transitioner will not be initialized");
        this.serializedDataLocationDir = new File(this.serializedDataLocation);
        if (!this.serializedDataLocationDir.exists()) {
            this.serializedDataLocationDir.mkdirs();
        }
    }

    /** Getter/Setter methods */
    public void setSerializerFactory(SerializerFactory serializerFactory) {
        this.serializerFactory = serializerFactory;
    }

    public void setRootNFTypeSerializer(NFTypeSerializer<T> rootNFTypeSerializer) {
        this.rootNFTypeSerializer = rootNFTypeSerializer;
    }

    public void setSerializedDataLocation(String serializedDataLocation) {
        this.serializedDataLocation = serializedDataLocation;
    }

    public String getSerializedDataLocation() {
        return serializedDataLocation;
    }

}