org.apache.openjpa.datacache
Class PartitionedDataCache

java.lang.Object
  org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager
      org.apache.openjpa.datacache.AbstractDataCache
          org.apache.openjpa.datacache.ConcurrentDataCache
              org.apache.openjpa.datacache.PartitionedDataCache

All Implemented Interfaces:

Serializable, DataCache, RemoteCommitListener, Configurable, Clearable, Closeable, EventManager

public class PartitionedDataCache
extends ConcurrentDataCache

A partitioned data cache maintains a set of partitions that are DataCache themselves. Each of the partitioned DataCaches can be individually configured. However, all partitions must be of the same type. By default, this cache uses ConcurrentDataCache as its partitions.
This cache can be configured as a plug-in as follows:
<property name='openjpa.DataCache" value="partitioned(name=X, PartitionType=concurrent,Partitions='(name=a,cacheSize=100), (name=b,cacheSize=200)')
Notice that the individual partition properties are enclosed parentheses, separated by comma and finally the whole property string is enclosed in single quote. Each partition must have a non-empty name that are unique among the partitions. The policy can return the name of a partition to distribute the managed instances to be cached in respective partition. The above configuration will configure a partitioned cache named X with two partitions named a and b with cache size 100 and 200 respectively. Besides the two partitions, this cache instance itself can store data and referred by its own name (X in the above example).

Since:

2.0.0

Author:

Pinaki Poddar

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.openjpa.datacache.AbstractDataCache

_excludedTypes, _includedTypes, conf, log, stats

Fields inherited from class org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager

_listeners

Fields inherited from interface org.apache.openjpa.datacache.DataCache

NAME_DEFAULT

Constructor Summary

PartitionedDataCache()

Method Summary

void	endConfiguration()
DataCache	getPartition(String name, boolean create) Gets the named partition.
Set<String>	getPartitionNames() Gets the name of the configured partitions.
List<String>	getPartitions() Returns the individual partition configuration properties.
boolean	isPartitioned() Always returns true.
void	setPartitions(String parts) Set partitions from a String configuration.
void	setPartitionType(String type) Sets the type of the partitions.

Methods inherited from class org.apache.openjpa.datacache.ConcurrentDataCache

clearInternal, getCacheMap, getCacheSize, getInternal, getSoftReferenceSize, initialize, newCacheMap, pinInternal, putInternal, removeAllInternal, removeInternal, setCacheSize, setSoftReferenceSize, unpinAll, unpinInternal, writeLock, writeUnlock

Methods inherited from class org.apache.openjpa.datacache.AbstractDataCache

addExpirationListener, afterCommit, clear, close, close, commit, contains, containsAll, fireEvent, get, getAll, getEnableStatistics, getEvictionSchedule, getExcludedTypes, getName, getStatistics, getTypes, isClosed, keyRemoved, pin, pinAll, pinAll, put, putAllInternal, recacheUpdates, remove, removeAll, removeAll, removeAllInternal, removeAllTypeNamesInternal, removeExpirationListener, setConfiguration, setEnableStatistics, setEvictionSchedule, setExcludedTypes, setExcludedTypes, setName, setTypes, setTypes, startConfiguration, toString, unpin, unpinAll, update

Methods inherited from class org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager

addListener, fireEvent, getListeners, hasListener, hasListeners, isFailFast, newListenerCollection, removeListener, setFailFast

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.openjpa.event.RemoteCommitListener

afterCommit, close

Constructor Detail

PartitionedDataCache

public PartitionedDataCache()

Method Detail

setPartitionType

public void setPartitionType(String type)
                      throws Exception

Sets the type of the partitions. Each partition is a DataCache itself.

Parameters:

type - the name of the type that implements DataCache interface. Aliases such as "concurrent" is also recognized.

Throws:

Exception - if the given type is not resolvable to a loadable type.

setPartitions

public void setPartitions(String parts)

Set partitions from a String configuration.

Parameters:

parts - a String of the form (p1, p2, p3) where p1, p2 etc. itself are plug-in strings for individual Data Cache configuration.

getPartitions

public List<String> getPartitions()

Returns the individual partition configuration properties.

getPartition

public DataCache getPartition(String name,
                              boolean create)

Description copied from interface: DataCache

Gets the named partition. Note that a partition itself is another cache.

Specified by:

getPartition in interface DataCache

Overrides:

getPartition in class AbstractDataCache

Parameters:

name - name of the given partition.

create - if true optionally create a new partition.

Returns:

a partition of the given name. Or null, if either no such partition exists or can not be created.

getPartitionNames

public Set<String> getPartitionNames()

Gets the name of the configured partitions.

Specified by:

getPartitionNames in interface DataCache

Overrides:

getPartitionNames in class AbstractDataCache

Returns:

empty set if no partition exists.

isPartitioned

public final boolean isPartitioned()

Always returns true.

Specified by:

isPartitioned in interface DataCache

Overrides:

isPartitioned in class AbstractDataCache

endConfiguration

public void endConfiguration()

Specified by:

endConfiguration in interface Configurable

Overrides:

endConfiguration in class AbstractDataCache