Package org.apache.openjpa.datacache

Class PartitionedDataCache

  • All Implemented Interfaces:
    java.io.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

    • Constructor Detail

      • PartitionedDataCache

        public PartitionedDataCache()

    • Method Detail

      • setPartitionType

        public void setPartitionType​(java.lang.String type)
                      throws java.lang.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:
        java.lang.Exception - if the given type is not resolvable to a loadable type.

      • setPartitions

        public void setPartitions​(java.lang.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 java.util.List<java.lang.String> getPartitions()
        Returns the individual partition configuration properties.

      • getPartition

        public DataCache getPartition​(java.lang.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.