org.jboss.cache.loader

Class JDBCCacheLoader

java.lang.Object

org.jboss.cache.loader.AbstractCacheLoader

org.jboss.cache.loader.AdjListJDBCCacheLoader

org.jboss.cache.loader.JDBCCacheLoader

All Implemented Interfaces:

Lifecycle, CacheLoader

@ThreadSafe
public class JDBCCacheLoader
extends AdjListJDBCCacheLoader

JDBC implementation of AdjListJDBCCacheLoader. Represents a faster alternative than JDBCCacheLoaderOld and relies on the same database structrure. It is backward compatible with data created by existing JDBCCacheLoaderOld implemetation. All configuration elements described there JDBCCacheLoaderOld also apply for this implementation.

Additional configuration info:

• cache.jdbc.batch.enable: whether or not to use batching on repetitive operations (e.g. inserts during state transfer). Enabling batching should give an important performance boost. It might be required to disable this if the JDBC driver does not support batching. Default set to 'true'
• cache.jdbc.batch.size: number of operations afer which the batching buffer will be flushed. If 'cache.jdbc.batch.enable' is false, this will be ignored. Default value is 1000.

Version:

1.0

Author:

Mircea.Markus@iquestint.com, Galder Zamarreno

Field Summary

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

cf, driverName, lock, NULL_NODE_IN_ROW

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

buddyFqnTransformer, cache, regionManager, transactions

Constructor Summary

Constructors

Constructor and Description
JDBCCacheLoader()

Method Summary

Methods

Modifier and Type	Method and Description
CacheLoaderConfig.IndividualCacheLoaderConfig	getConfig() Gets the configuration.
protected org.apache.commons.logging.Log	getLogger()
int	getNodeCount() Returns a number representing the count of persisted children.
protected void	getNodeDataList(Fqn fqn, List<NodeData> list) Subscribes to contract.
protected AdjListJDBCCacheLoaderConfig	processConfig(CacheLoaderConfig.IndividualCacheLoaderConfig base) Builds a AdjListJDBCCacheLoaderConfig based on the supplied base config.
void	put(Fqn name, Map attributes) As per interface's contract.
Object	put(Fqn name, Object key, Object value) As per interface's contract.
void	remove(Fqn fqn) As per interface's contrect.
void	start() Start is overwritten for the sake of backward compatibility only.
void	storeState(Fqn subtree, ObjectInputStream in) Stores the given portion of the cache tree's state in secondary storage.
protected void	storeStateHelper(Fqn subtree, List nodeData, boolean moveToBuddy)

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

commit, exists, get, getChildrenNames, getDriverName, insertNode, loadNode, marshall, populatePreparedStatementForInsert, prepare, prepareAndLogStatement, remove, removeData, reportAndRethrowError, rollback, safeClose, safeClose, safeClose, setConfig, stop, tableExists, unmarshall, updateNode

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

create, destroy, doMarshall, doUnmarshall, getMarshaller, loadEntireState, loadState, loadStateHelper, move, put, put, regionAwareMarshall, regionAwareUnmarshall, setCache, setRegionManager, storeEntireState

Methods inherited from class java.lang.Object

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

Constructor Detail

JDBCCacheLoader

public JDBCCacheLoader()

Method Detail

processConfig

protected AdjListJDBCCacheLoaderConfig processConfig(CacheLoaderConfig.IndividualCacheLoaderConfig base)

Builds a AdjListJDBCCacheLoaderConfig based on the supplied base config.

Specified by:

processConfig in class AdjListJDBCCacheLoader

put

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

As per interface's contract. Performance Note: Optimised O(nodeDepth) db calls.

Throws:

Exception

put

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

As per interface's contract. Performance Note: Optimised O(nodeDepth) db calls.

Parameters:

name - The fully qualified name of the node

attributes - A Map of attributes. Can be null

Throws:

Exception

storeStateHelper

protected void storeStateHelper(Fqn subtree,
                    List nodeData,
                    boolean moveToBuddy)
                         throws Exception

Overrides:

storeStateHelper in class AbstractCacheLoader

Throws:

Exception

remove

public void remove(Fqn fqn)
            throws Exception

As per interface's contrect. Performance Note: O(1) db calls.

Parameters:

fqn - the Fqn of the node

Throws:

Exception

getNodeDataList

protected void getNodeDataList(Fqn fqn,
                   List<NodeData> list)
                        throws Exception

Subscribes to contract. Performance Note: O(2) db calls.

Overrides:

getNodeDataList in class AbstractCacheLoader

Throws:

Exception

getLogger

protected org.apache.commons.logging.Log getLogger()

Specified by:

getLogger in class AdjListJDBCCacheLoader

start

public void start()
           throws Exception

Start is overwritten for the sake of backward compatibility only. Here is the issue: old implementation does not create a Fqn.ROOT if not specifically told so. As per put's contract, when calling put('/a/b/c', 'key', 'value') all parent nodes should be created up to root. Root is not created, though. The compatibility problem comes in the case of loade ENTIRE state. The implementation checks node's existence firstly, and based on that continues or not. As root is not persisted nothing is loaded etc.

Specified by:

start in interface Lifecycle

Overrides:

start in class AdjListJDBCCacheLoader

Throws:

Exception

getNodeCount

public int getNodeCount()
                 throws Exception

Returns a number representing the count of persisted children.

Throws:

Exception

storeState

public void storeState(Fqn subtree,
              ObjectInputStream in)
                throws Exception

Description copied from interface: CacheLoader

Stores the given portion of the cache tree's state in secondary storage. Overwrite whatever is currently in secondary storage. If the transferred state has Fqns equal to or children of parameter subtree, then no special behavior is required. Otherwise, ensure that the state is integrated under the given subtree. Typically in the latter case subtree would be the Fqn of the buddy backup region for a buddy group; e.g.

If the the transferred state had Fqns starting with "/a" and subtree was "/_BUDDY_BACKUP_/192.168.1.2:5555" then the state should be stored in the local persistent store under "/_BUDDY_BACKUP_/192.168.1.2:5555/a"

Implementations of this method should not catch any exception or close the given ObjectInputStream parameter. In order to ensure cacheloader interoperability contents of the cache are read from the ObjectInputStream as a sequence of NodeData objects.

Default implementation is provided by AbstractCacheLoader and ensures cacheloader interoperability. Implementors are encouraged to consider extending AbstractCacheLoader prior to implementing completely custom cacheloader.

Specified by:

storeState in interface CacheLoader

Overrides:

storeState in class AbstractCacheLoader

Parameters:

subtree - Fqn naming the root (i.e. highest level parent) node of the subtree included in state. If the Fqns of the data included in state are not already children of subtree, then their Fqns should be altered to make them children of subtree before they are persisted.

in - ObjectInputStream to read state

Throws:

Exception

See Also:

AbstractCacheLoader.storeState(Fqn,ObjectInputStream), NodeData

getConfig

public CacheLoaderConfig.IndividualCacheLoaderConfig getConfig()

Description copied from interface: CacheLoader

Gets the configuration.

Returns:

the configuration, represented by a CacheLoaderConfig.IndividualCacheLoaderConfig object.