org.jboss.cache.loader.bdbje
Class BdbjeCacheLoader

java.lang.Object
  org.jboss.cache.loader.AbstractCacheLoader
      org.jboss.cache.loader.bdbje.BdbjeCacheLoader

All Implemented Interfaces:

CacheLoader

@ThreadSafe
public class BdbjeCacheLoader
extends AbstractCacheLoader

A persistent CacheLoader based on Berkeley DB Java Edition.

The configuration string format is:

environmentDirectoryName[#databaseName]

where databaseName, if omitted, defaults to the ClusterName property of the CacheImpl.

A je.properties file may optionally be placed in the JE environment directory and used to customize the default JE configuration.

Version:

$Id: BdbjeCacheLoader.java 5760 2008-04-29 23:25:47Z manik.surtani@jboss.com $

Author:

Mark Hayes May 16, 2004, Bela Ban

Field Summary

Fields inherited from class org.jboss.cache.loader.AbstractCacheLoader

cache, regionManager, transactions

Constructor Summary

BdbjeCacheLoader()

Method Summary

void	commit(Object tx) Commits the given transaction, or throws IllegalArgumentException if the given key is not associated with an uncommited transaction.
void	create() Does nothing since start() does all the work.
boolean	exists(Fqn name) Returns whether the given node exists.
Map<Object,Object>	get(Fqn name) Returns a map containing all key-value pairs for the given FQN, or null if the node is not present.
CacheLoaderConfig.IndividualCacheLoaderConfig	getConfig() Gets the configuration.
Set<String>	getChildrenNames(Fqn name) Returns an unmodifiable set of relative children names (strings), or returns null if the parent node is not found or if no children are found.
void	prepare(Object tx, List<Modification> modifications, boolean onePhase) Begins a transaction and applies the given modifications.
void	put(Fqn name, Map values) Stores a map of key-values for a given FQN, but does not delete existing key-value pairs (that is, it does not erase).
Object	put(Fqn name, Object key, Object value) Stores a single FQN-key-value record.
void	put(List<Modification> modifications) Applies the given modifications.
void	remove(Fqn name) Deletes the node for a given FQN and all its descendent nodes.
Object	remove(Fqn name, Object key) Deletes a single FQN-key-value record.
void	removeData(Fqn name) Clears the map for the given node, but does not remove the node.
void	rollback(Object tx) Commits the given transaction, or throws IllegalArgumentException if the given key is not associated with an uncommited transaction.
void	setCache(CacheSPI c) Sets the CacheImpl owner of this cache loader.
void	setConfig(CacheLoaderConfig.IndividualCacheLoaderConfig base) Sets the configuration string for this cache loader.
void	start() Opens the JE environment and the database specified by the configuration string.
void	stop() Closes the JE databases and environment, and nulls references to them.

Methods inherited from class org.jboss.cache.loader.AbstractCacheLoader

destroy, doMarshall, doUnmarshall, getMarshaller, getNodeDataList, loadEntireState, loadState, loadStateHelper, put, regionAwareMarshall, regionAwareUnmarshall, setRegionManager, storeEntireState, storeState

Methods inherited from class java.lang.Object

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

Constructor Detail

BdbjeCacheLoader

public BdbjeCacheLoader()

Method Detail

create

public void create()
            throws Exception

Does nothing since start() does all the work.

Specified by:

create in interface CacheLoader

Overrides:

create in class AbstractCacheLoader

Throws:

Exception

start

public void start()
           throws Exception

Opens the JE environment and the database specified by the configuration string. The environment and databases are created if necessary.

Specified by:

start in interface CacheLoader

Overrides:

start in class AbstractCacheLoader

Throws:

Exception

stop

public void stop()

Closes the JE databases and environment, and nulls references to them. The environment and databases are not removed from the file system. Exceptions during close are ignored.

Specified by:

stop in interface CacheLoader

Overrides:

stop in class AbstractCacheLoader

setConfig

public void setConfig(CacheLoaderConfig.IndividualCacheLoaderConfig base)

Sets the configuration string for this cache loader.

Parameters:

base - May be an instance of the CacheLoaderConfig.IndividualCacheLoaderConfig base class, in which case the cache loader should use the CacheLoaderConfig.IndividualCacheLoaderConfig.getProperties() method to find configuration information. Alternatively, may be a type-specific subclass of CacheLoaderConfig.IndividualCacheLoaderConfig, if there is one.

getConfig

public CacheLoaderConfig.IndividualCacheLoaderConfig getConfig()

Description copied from interface: CacheLoader

Gets the configuration.

Returns:

the configuration, represented by a CacheLoaderConfig.IndividualCacheLoaderConfig object.

setCache

public void setCache(CacheSPI c)

Sets the CacheImpl owner of this cache loader.

Specified by:

setCache in interface CacheLoader

Overrides:

setCache in class AbstractCacheLoader

Parameters:

c - The cache on which this loader works

getChildrenNames

public Set<String> getChildrenNames(Fqn name)
                             throws Exception

Returns an unmodifiable set of relative children names (strings), or returns null if the parent node is not found or if no children are found. This is a fairly expensive operation, and is assumed to be performed by browser applications. Calling this method as part of a run-time transaction is not recommended.

Parameters:

name - The Fqn of the parent

Returns:

Set a set of children. Returns null if no children nodes are present, or the parent is not present

Throws:

Exception

get

public Map<Object,Object> get(Fqn name)
                       throws Exception

Returns a map containing all key-value pairs for the given FQN, or null if the node is not present. This operation is always non-transactional, even in a transactional environment.

Parameters:

name - the Fqn to search for.

Returns:

Map keys and values for the given node. Returns null if the node is not found. If the node is found but has no attributes, this method returns an empty Map.

Throws:

Exception

exists

public boolean exists(Fqn name)
               throws Exception

Returns whether the given node exists.

Returns:

true if node exists, false otherwise

Throws:

Exception

put

public Object put(Fqn name,
                  Object key,
                  Object value)
           throws Exception

Stores a single FQN-key-value record. Intended to be used in a non-transactional environment, but will use auto-commit in a transactional environment.

Throws:

Exception

put

public void put(Fqn name,
                Map values)
         throws Exception

Stores a map of key-values for a given FQN, but does not delete existing key-value pairs (that is, it does not erase). Intended to be used in a non-transactional environment, but will use auto-commit in a transactional environment.

Parameters:

name - The fully qualified name of the node

values - A Map of attributes. Can be null

Throws:

Exception

put

public void put(List<Modification> modifications)
         throws Exception

Applies the given modifications. Intended to be used in a non-transactional environment, but will use auto-commit in a transactional environment.

Specified by:

put in interface CacheLoader

Overrides:

put in class AbstractCacheLoader

Parameters:

modifications - A List of modifications

Throws:

Exception

remove

public void remove(Fqn name)
            throws Exception

Deletes the node for a given FQN and all its descendent nodes. Intended to be used in a non-transactional environment, but will use auto-commit in a transactional environment.

Parameters:

name - the Fqn of the node

Throws:

Exception

remove

public Object remove(Fqn name,
                     Object key)
              throws Exception

Deletes a single FQN-key-value record. Intended to be used in a non-transactional environment, but will use auto-commit in a transactional environment.

Throws:

Exception

removeData

public void removeData(Fqn name)
                throws Exception

Clears the map for the given node, but does not remove the node.

Parameters:

name - the Fqn of the node

Throws:

Exception

prepare

public void prepare(Object tx,
                    List<Modification> modifications,
                    boolean onePhase)
             throws Exception

Begins a transaction and applies the given modifications.

If onePhase is true, commits the transaction; otherwise, associates the txn value with the transaction and expects commit() or rollback() to be called later with the same tx value. Performs retries if necessary to resolve deadlocks.

Specified by:

prepare in interface CacheLoader

Overrides:

prepare in class AbstractCacheLoader

Parameters:

tx - The transaction, indended to be used by implementations as an identifier of the transaction (and not necessarily a JTA Transaction object)

modifications - A List containing Modifications, for the given transaction

onePhase - Persist immediately and (for example) commit the local JDBC transaction as well. When true, we won't get a CacheLoader.commit(Object) or CacheLoader.rollback(Object) method call later

Throws:

Exception

commit

public void commit(Object tx)
            throws Exception

Commits the given transaction, or throws IllegalArgumentException if the given key is not associated with an uncommited transaction.

Specified by:

commit in interface CacheLoader

Overrides:

commit in class AbstractCacheLoader

Parameters:

tx - transaction to commit

Throws:

Exception

rollback

public void rollback(Object tx)

Commits the given transaction, or throws IllegalArgumentException if the given key is not associated with an uncommited transaction.

Specified by:

rollback in interface CacheLoader

Overrides:

rollback in class AbstractCacheLoader

Parameters:

tx - transaction to roll back