org.apache.pulsar.shade.com.yahoo.sketches.ArrayOfItemsSerDe Maven / Gradle / Ivy
/*
* Copyright 2015-16, Yahoo! Inc.
* Licensed under the terms of the Apache License 2.0. See LICENSE file at the project root for terms.
*/
package org.apache.pulsar.shade.com.yahoo.sketches;
import org.apache.pulsar.shade.com.yahoo.memory.Memory;
/**
* Base class for serializing and deserializing custom types.
* @param Type of item
*
* @author Alexander Saydakov
*/
public abstract class ArrayOfItemsSerDe {
/**
* Serialize an array of items to byte array.
* The size of the array doesn't need to be serialized.
* This method is called by the sketch serialization process.
*
* @param items array of items to be serialized
* @return serialized representation of the given array of items
*/
public abstract byte[] serializeToByteArray(T[] items);
/**
* Deserialize an array of items from a given Memory object.
* This method is called by the sketch deserialization process.
*
* @param mem Memory containing a serialized array of items
* @param numItems number of items in the serialized array
* @return deserialized array of items
*/
public abstract T[] deserializeFromMemory(Memory mem, int numItems);
/**
* Provides a simple mechanism to check compatibility between SerDe implementations.
*
* You will need to override this in the following cases:
*
- If you want to rename the class or change its package hierarchy and keep the ID the
* same. This enables compatible deserialization of binary images that were serialized with a
* different class name or package hierarchy.
* - If you wish to change the binary layout of the serialization and don't want to change the
* class name or package hierarchy, you will need to change the returned code.
*
* @return a unique identifier of this SerDe
*/
@Deprecated
public short getId() {
/*
* Note that the hashCode() of a String is strictly a function of the content of the String
* and will be the same across different JVMs. This is not the case for Object.hashCode(),
* which generally computes the hash code from the native internal address of the object and
* will be DIFFERENT when computed on different JVMs. So if you override this method, make
* sure it will be repeatable across JVMs.
*/
return (short) getClass().getName().hashCode();
}
}