org.apache.hadoop.hive.serde2.avro

Class InstanceCache<SeedObject,Instance>

java.lang.Object

org.apache.hadoop.hive.serde2.avro.InstanceCache<SeedObject,Instance>

Type Parameters:

SeedObject - Object that determines the instance. The cache uses this object as a key for its hash which is why it is imperative to have appropriate equals and hashcode implementation for this object for the cache to work properly

Instance - Instance that will be created from SeedObject.

public abstract class InstanceCache<SeedObject,Instance>
extends Object

Cache for objects whose creation only depends on some other set of objects and therefore can be used against other equivalent versions of those objects. Essentially memoizes instance creation.

Constructor Summary

Constructors

Constructor and Description
InstanceCache()

Method Summary

Modifier and Type	Method and Description
protected abstract Instance	makeInstance(SeedObject hv, Set<SeedObject> seenSchemas)
Instance	retrieve(SeedObject hv) Retrieve (or create if it doesn't exist) the correct Instance for this SeedObject
Instance	retrieve(SeedObject hv, Set<SeedObject> seenSchemas) Retrieve (or create if it doesn't exist) the correct Instance for this SeedObject using 'seenSchemas' to resolve circular references

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

InstanceCache

public InstanceCache()

Method Detail

retrieve

public Instance retrieve(SeedObject hv)
                  throws AvroSerdeException

Retrieve (or create if it doesn't exist) the correct Instance for this SeedObject

Throws:

AvroSerdeException

retrieve

public Instance retrieve(SeedObject hv,
                         Set<SeedObject> seenSchemas)
                  throws AvroSerdeException

Retrieve (or create if it doesn't exist) the correct Instance for this SeedObject using 'seenSchemas' to resolve circular references

Throws:

AvroSerdeException

makeInstance

protected abstract Instance makeInstance(SeedObject hv,
                                         Set<SeedObject> seenSchemas)
                                  throws AvroSerdeException

Throws:

AvroSerdeException