Package org.glassfish.ha.store.api

Class BackingStore<K extends Serializable,V extends Serializable>

java.lang.Object

org.glassfish.ha.store.api.BackingStore<K,V>

Direct Known Subclasses:

NoOpBackingStore

public abstract class BackingStore<K extends Serializable,V extends Serializable>
extends Object

An object that stores a given value against an id. This class defines the set of operations that a container could perform on a store.

An instance of BackingStore is created by calling BackingStoreFactory.createBackingStore() method.

The BackingStore instance is created and used for storing data that belongs to a single application or container.

The store implementation must be thread safe.

Author:

Mahesh.Kannan@Sun.Com, Larry.White@Sun.Com

Constructor Summary

Constructors

Constructor	Description
BackingStore()

Method Summary

Modifier and Type	Method	Description
void	close()	Typically called during shutdown of the process.
protected ObjectInputStream	createObjectInputStream(InputStream is)
protected ObjectOutputStream	createObjectOutputStream(OutputStream os)
void	destroy()	Called when the store is no longer needed.
protected BackingStoreConfiguration<K,V>	getBackingStoreConfiguration()
abstract BackingStoreFactory	getBackingStoreFactory()
protected void	initialize(BackingStoreConfiguration<K,V> conf)
abstract V	load(K key, String version)	Load and return the data for the given id.
abstract void	remove(K key)	Remove the association for the id.
int	removeExpired()	Remove expired entries
int	removeExpired(long idleForMillis)
abstract String	save(K key, V value, boolean isNew)	Save the value whose key is id.
abstract int	size()	Get the current size of the store
void	updateTimestamp(K key, long time)	TODO: BEGIN: REMOVE after shoal integration
String	updateTimestamp(K key, String version, Long accessTime)	Recomended way is to just do a save(k, v)

Methods inherited from class java.lang.Object

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

Constructor Detail

BackingStore

public BackingStore()

Method Detail

initialize

protected void initialize(BackingStoreConfiguration<K,V> conf)
                   throws BackingStoreException

Throws:

BackingStoreException

getBackingStoreConfiguration

protected BackingStoreConfiguration<K,V> getBackingStoreConfiguration()

getBackingStoreFactory

public abstract BackingStoreFactory getBackingStoreFactory()

load

public abstract V load(K key,
                       String version)
                throws BackingStoreException

Load and return the data for the given id. The store is expected to return the largest ever version that was saved in the stored using the save() method.

Parameters:

key - the key whose value must be returned

Returns:

the value if this store contains it or null. The implementation must return the exact same type as that was passed to it in the save method.

Throws:

NullPointerException - if the id is null

BackingStoreException - if the underlying store implementation encounters any exception

save

public abstract String save(K key,
                            V value,
                            boolean isNew)
                     throws BackingStoreException

Save the value whose key is id. The store is NOT expected to throw an exception if isNew is false but the entry doesn't exist in the store. (This is possible in some implementations (like in-memory) where packets could be lost.)

Parameters:

key - the id

value - The Metadata to be stored

Returns:

A (possibly null) String indicating the instance name where the data was saved.

Throws:

BackingStoreException - if the underlying store implementation encounters any exception

remove

public abstract void remove(K key)
                     throws BackingStoreException

Remove the association for the id.

After this call, any call to load(id) must return null. In addition, any association between id and container extra params must also be removed.

Parameters:

key - the id of the Metadata

Throws:

BackingStoreException - if the underlying store implementation encounters any exception

updateTimestamp

public void updateTimestamp(K key,
                            long time)
                     throws BackingStoreException

TODO: BEGIN: REMOVE after shoal integration

Throws:

BackingStoreException

removeExpired

public int removeExpired(long idleForMillis)
                  throws BackingStoreException

Throws:

BackingStoreException

updateTimestamp

public String updateTimestamp(K key,
                              String version,
                              Long accessTime)
                       throws BackingStoreException

Recomended way is to just do a save(k, v)

Parameters:

key -

version -

accessTime -

Throws:

BackingStoreException

removeExpired

public int removeExpired()
                  throws BackingStoreException

Remove expired entries

Throws:

BackingStoreException

size

public abstract int size()
                  throws BackingStoreException

Get the current size of the store

Returns:

the (approximate) number of entries in the store

Throws:

BackingStoreException - if the underlying store implementation encounters any exception

close

public void close()
           throws BackingStoreException

Typically called during shutdown of the process. The store must not be used after this call

Throws:

BackingStoreException

destroy

public void destroy()
             throws BackingStoreException

Called when the store is no longer needed. Must clean up and close any opened resources. The store must not be used after this call.

Throws:

BackingStoreException

createObjectOutputStream

protected ObjectOutputStream createObjectOutputStream(OutputStream os)
                                               throws IOException

Throws:

IOException

createObjectInputStream

protected ObjectInputStream createObjectInputStream(InputStream is)
                                             throws IOException

Throws:

IOException