io.appform.dropwizard.sharding.dao

Class CacheableLookupDao<T>

java.lang.Object

io.appform.dropwizard.sharding.dao.LookupDao<T>

io.appform.dropwizard.sharding.dao.CacheableLookupDao<T>

All Implemented Interfaces:

ShardedDao<T>

public class CacheableLookupDao<T>
extends LookupDao<T>

A write through/read through cache enabled dao to manage lookup and top level elements in the system. Can save and retrieve an object (tree) from any shard. Note: - The element must have only one String key for lookup. - The key needs to be annotated with LookupKey The entity can be retrieved from any shard using the key.

Nested Class Summary

Nested classes/interfaces inherited from class io.appform.dropwizard.sharding.dao.LookupDao

LookupDao.ReadOnlyContext<T>

Constructor Summary

Constructors

Constructor and Description
CacheableLookupDao(List<org.hibernate.SessionFactory> sessionFactories, Class<T> entityClass, ShardCalculator<String> shardCalculator, LookupCache<T> cache, ShardingBundleOptions shardingOptions, ShardInfoProvider shardInfoProvider, TransactionObserver observer)

Method Summary

Modifier and Type	Method and Description
boolean	exists(String key) Read through exists check on the basis of key (value of field annotated with LookupKey) from cache.
Optional<T>	get(String key) Read through an object on the basis of key (value of field annotated with LookupKey) from cache.
Optional<T>	save(T entity) Write through the entity on proper shard based on hash of the value in the key field in the object and into cache.
boolean	update(String id, Function<Optional<T>,T> updater) Update the entity with a given id and refresh the object in the cache.

Methods inherited from class io.appform.dropwizard.sharding.dao.LookupDao

count, createOrUpdate, delete, get, get, get, get, getKeyField, lockAndGetExecutor, readOnlyExecutor, readOnlyExecutor, readOnlyExecutor, readOnlyExecutor, run, run, runInSession, runInSession, save, saveAndGetExecutor, scatterGather, scrollDown, scrollUp, updateInLock, updateUsingQuery

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.appform.dropwizard.sharding.dao.ShardedDao

getShardCalculator

Constructor Detail

CacheableLookupDao

public CacheableLookupDao(List<org.hibernate.SessionFactory> sessionFactories,
                          Class<T> entityClass,
                          ShardCalculator<String> shardCalculator,
                          LookupCache<T> cache,
                          ShardingBundleOptions shardingOptions,
                          ShardInfoProvider shardInfoProvider,
                          TransactionObserver observer)

Method Detail

get

public Optional<T> get(String key)
                throws Exception

Read through an object on the basis of key (value of field annotated with LookupKey) from cache. Cache miss will be delegated to LookupDao.get(String) method. Note: Lazy loading will not work once the object is returned. If you need lazy loading functionality use the alternate LookupDao.get(String, Function) method.

Overrides:

get in class LookupDao<T>

Parameters:

key - The value of the key field to look for.

Returns:

The entity

Throws:

Exception - if backing dao throws

save

public Optional<T> save(T entity)
                 throws Exception

Write through the entity on proper shard based on hash of the value in the key field in the object and into cache. Note: Lazy loading will not work on the augmented entity.

Overrides:

save in class LookupDao<T>

Parameters:

entity - Entity to save

Returns:

Entity

Throws:

Exception - if backing dao throws

update

public boolean update(String id,
                      Function<Optional<T>,T> updater)

Update the entity with a given id and refresh the object in the cache. Actual save will be delegated to LookupDao.update(String, Function) method.

Overrides:

update in class LookupDao<T>

Parameters:

id - Id of the entity that will be updated

Returns:

True/False

exists

public boolean exists(String key)
               throws Exception

Read through exists check on the basis of key (value of field annotated with LookupKey) from cache. Cache miss will be delegated to LookupDao.exists(String) method.

Overrides:

exists in class LookupDao<T>

Parameters:

key - The value of the key field to look for.

Returns:

Whether the entity exists or not

Throws:

Exception - if backing dao throws