org.apache.jackrabbit.core.persistence.bundle

Class AbstractBundlePersistenceManager

java.lang.Object

org.apache.jackrabbit.core.persistence.bundle.AbstractBundlePersistenceManager

All Implemented Interfaces:

CacheAccessListener, CachingPersistenceManager, ConsistencyChecker, IterablePersistenceManager, PersistenceManager

Direct Known Subclasses:

BundleDbPersistenceManager, BundleFsPersistenceManager, InMemBundlePersistenceManager

public abstract class AbstractBundlePersistenceManager
extends Object
implements PersistenceManager, CachingPersistenceManager, IterablePersistenceManager, CacheAccessListener, ConsistencyChecker

The AbstractBundlePersistenceManager acts as base for all persistence managers that store the state in a NodePropBundle.

The state and all property states of one node are stored together in one record. Property values of a certain size can be stored outside of the bundle. This currently only works for binary properties. NodeReferences are not included in the bundle since they are addressed by the target id.

Some strings like namespaces and local names are additionally managed by separate indexes. only the index number is serialized to the records which reduces the amount of memory used.

Special treatment is performed for the properties "jcr:uuid", "jcr:primaryType" and "jcr:mixinTypes". As they are also stored in the node state they are not included in the bundle but generated when required.

In order to increase performance, there are two caches being maintained. One is the bundle cache that caches already loaded bundles. The other is the LRUNodeIdCache that caches non-existent bundles. This is useful because a lot of exists(NodeId) calls are issued that would result in a useless persistence lookup if the desired bundle does not exist.

Configuration:

• <param name="bundleCacheSize" value="8"/>

Field Summary

Fields

Modifier and Type	Field and Description
protected PMContext	context the persistence manager context
protected static String	NODEFILENAME the prefix of a node file
protected static String	NODEREFSFILENAME the prefix of a node references file
protected static String	RES_NAME_INDEX the name of the names-index resource
protected static String	RES_NS_INDEX the name of the namespace-index resource

Fields inherited from interface org.apache.jackrabbit.core.cache.CacheAccessListener

ACCESS_INTERVAL

Constructor Summary

Constructors

Constructor and Description
AbstractBundlePersistenceManager()

Method Summary

Modifier and Type	Method and Description
protected StringBuffer	buildBlobFilePath(StringBuffer buf, PropertyId id, int i) Creates the file path for the given property id and value index that is suitable for storing property values in a filesystem.
protected StringBuffer	buildNodeFilePath(StringBuffer buf, NodeId id) Creates the file path for the given node id that is suitable for storing node states in a filesystem.
protected StringBuffer	buildNodeFolderPath(StringBuffer buf, NodeId id) Creates the folder path for the given node id that is suitable for storing states in a filesystem.
protected StringBuffer	buildNodeReferencesFilePath(StringBuffer buf, NodeId id) Creates the file path for the given references id that is suitable for storing reference states in a filesystem.
protected StringBuffer	buildPropFilePath(StringBuffer buf, PropertyId id) Creates the folder path for the given property id that is suitable for storing states in a filesystem.
void	cacheAccessed(long accessCount) The cache calls this method after a number of cache accesses. For statistical purposes, the cache access count since the last call is included.
ConsistencyReport	check(String[] uuids, boolean recursive, boolean fix, String lostNFoundId, ConsistencyCheckListener listener) Perform a consistency check of the data.
void	checkConsistency(String[] uuids, boolean recursive, boolean fix) Perform a consistency check of the data.
void	close() Closes the persistence manager.
NodeState	createNew(NodeId id) Creates a new node state instance with the given id.
PropertyState	createNew(PropertyId id) Creates a new property state instance with the given id.
protected abstract void	destroy(NodeReferences refs) Deletes the node references from the underlying system.
protected abstract void	destroyBundle(NodePropBundle bundle) Deletes the bundle from the underlying system.
void	disposeCache(Cache cache) Called after the cache is no longer used.
protected void	evictBundle(NodeId id) Evicts the bundle with id from the bundle cache.
boolean	exists(NodeId id) Checks whether the identified node exists.
boolean	exists(PropertyId id) Checks whether the identified property exists.
Map<NodeId,NodeInfo>	getAllNodeInfos(NodeId after, int maxCount) Get all NodeInfos.
protected abstract BLOBStore	getBlobStore() Returns the BLOB store used by this persistence manager.
String	getBundleCacheSize() Returns the size of the bundle cache in megabytes.
StringIndex	getNameIndex() Returns the local name index
StringIndex	getNsIndex() Returns the namespace index
void	init(PMContext context) Initializes the persistence manager.
NodeState	load(NodeId id) Load the persistent members of a node state.
PropertyState	load(PropertyId id) Load the persistent members of a property state.
protected abstract NodePropBundle	loadBundle(NodeId id) Loads a bundle from the underlying system.
void	onExternalUpdate(ChangeLog changes) Notifies the persistence manager that an external (cluster) modification occurred.
void	setBundleCacheSize(String bundleCacheSize) Sets the size of the bundle cache in megabytes.
void	setEventChannel(UpdateEventChannel eventChannel) Set the update event channel.
void	store(ChangeLog changeLog) Right now, this iterates over all items in the changelog and calls the individual methods that handle single item states or node references objects.
protected abstract void	store(NodeReferences refs) Stores a node references to the underlying system.
protected abstract void	storeBundle(NodePropBundle bundle) Stores a bundle to the underlying system.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.jackrabbit.core.persistence.IterablePersistenceManager

getAllNodeIds

Methods inherited from interface org.apache.jackrabbit.core.persistence.PersistenceManager

existsReferencesTo, loadReferencesTo

Field Detail

NODEFILENAME

protected static final String NODEFILENAME

the prefix of a node file

See Also:

Constant Field Values

NODEREFSFILENAME

protected static final String NODEREFSFILENAME

the prefix of a node references file

See Also:

Constant Field Values

RES_NAME_INDEX

protected static final String RES_NAME_INDEX

the name of the names-index resource

See Also:

Constant Field Values

RES_NS_INDEX

protected static final String RES_NS_INDEX

the name of the namespace-index resource

See Also:

Constant Field Values

context

protected PMContext context

the persistence manager context

Constructor Detail

AbstractBundlePersistenceManager

public AbstractBundlePersistenceManager()

Method Detail

getBundleCacheSize

public String getBundleCacheSize()

Returns the size of the bundle cache in megabytes.

Returns:

the size of the bundle cache in megabytes.

setBundleCacheSize

public void setBundleCacheSize(String bundleCacheSize)

Sets the size of the bundle cache in megabytes. the default is 8.

Parameters:

bundleCacheSize - the bundle cache size in megabytes.

buildNodeFolderPath

protected StringBuffer buildNodeFolderPath(StringBuffer buf,
                                           NodeId id)

Creates the folder path for the given node id that is suitable for storing states in a filesystem.

Parameters:

buf - buffer to append to or null

id - the id of the node

Returns:

the buffer with the appended data.

buildPropFilePath

protected StringBuffer buildPropFilePath(StringBuffer buf,
                                         PropertyId id)

Creates the folder path for the given property id that is suitable for storing states in a filesystem.

Parameters:

buf - buffer to append to or null

id - the id of the property

Returns:

the buffer with the appended data.

buildBlobFilePath

protected StringBuffer buildBlobFilePath(StringBuffer buf,
                                         PropertyId id,
                                         int i)

Creates the file path for the given property id and value index that is suitable for storing property values in a filesystem.

Parameters:

buf - buffer to append to or null

id - the id of the property

i - the index of the property value

Returns:

the buffer with the appended data.

buildNodeFilePath

protected StringBuffer buildNodeFilePath(StringBuffer buf,
                                         NodeId id)

Creates the file path for the given node id that is suitable for storing node states in a filesystem.

Parameters:

buf - buffer to append to or null

id - the id of the node

Returns:

the buffer with the appended data.

buildNodeReferencesFilePath

protected StringBuffer buildNodeReferencesFilePath(StringBuffer buf,
                                                   NodeId id)

Creates the file path for the given references id that is suitable for storing reference states in a filesystem.

Parameters:

buf - buffer to append to or null

id - the id of the node

Returns:

the buffer with the appended data.

getNsIndex

public StringIndex getNsIndex()

Returns the namespace index

Returns:

the namespace index

Throws:

IllegalStateException - if an error occurs.

getNameIndex

public StringIndex getNameIndex()

Returns the local name index

Returns:

the local name index

Throws:

IllegalStateException - if an error occurs.

onExternalUpdate

public void onExternalUpdate(ChangeLog changes)

Notifies the persistence manager that an external (cluster) modification occurred.

Specified by:

onExternalUpdate in interface CachingPersistenceManager

Parameters:

changes - the set of changes of the external modification.

getAllNodeInfos

public Map<NodeId,NodeInfo> getAllNodeInfos(NodeId after,
                                            int maxCount)
                                     throws ItemStateException,
                                            RepositoryException

Description copied from interface: IterablePersistenceManager

Get all NodeInfos. A typical application will call this method multiple time, where 'after' is the last row read previously. The maxCount parameter defines the maximum number of node ids returned, 0 meaning no limit. The order of the node ids is specific for the given persistence manager. Items that are added concurrently may not be included.

Specified by:

getAllNodeInfos in interface IterablePersistenceManager

Parameters:

after - the lower limit, or null for no limit.

maxCount - the maximum number of node infos to return, or 0 for no limit.

Returns:

a list of all node infos.

Throws:

ItemStateException - if an error while loading occurs.

RepositoryException - if a repository exception occurs.

loadBundle

protected abstract NodePropBundle loadBundle(NodeId id)
                                      throws ItemStateException

Loads a bundle from the underlying system.

Parameters:

id - the node id of the bundle

Returns:

the loaded bundle or null if the bundle does not exist.

Throws:

ItemStateException - if an error while loading occurs.

storeBundle

protected abstract void storeBundle(NodePropBundle bundle)
                             throws ItemStateException

Stores a bundle to the underlying system.

Parameters:

bundle - the bundle to store

Throws:

ItemStateException - if an error while storing occurs.

destroyBundle

protected abstract void destroyBundle(NodePropBundle bundle)
                               throws ItemStateException

Deletes the bundle from the underlying system.

Parameters:

bundle - the bundle to destroy

Throws:

ItemStateException - if an error while destroying occurs.

destroy

protected abstract void destroy(NodeReferences refs)
                         throws ItemStateException

Deletes the node references from the underlying system.

Parameters:

refs - the node references to destroy.

Throws:

ItemStateException - if an error while destroying occurs.

store

protected abstract void store(NodeReferences refs)
                       throws ItemStateException

Stores a node references to the underlying system.

Parameters:

refs - the node references to store.

Throws:

ItemStateException - if an error while storing occurs.

getBlobStore

protected abstract BLOBStore getBlobStore()

Returns the BLOB store used by this persistence manager.

Returns:

BLOB store

init

public void init(PMContext context)
          throws Exception

Initializes the persistence manager. The persistence manager is permanently bound to the given context, and any required external resources are acquired.

An appropriate exception is thrown if the persistence manager initialization fails for whatever reason. In this case the state of the persistence manager is undefined and the instance should be discarded. Initializes the internal structures of this abstract persistence manager.

Specified by:

init in interface PersistenceManager

Parameters:

context - persistence manager context

Throws:

Exception - if the persistence manager initialization failed

close

public void close()
           throws Exception

Closes the persistence manager. The consistency of the persistent storage is guaranteed and all acquired resources are released. It is an error to invoke any methods on a closed persistence manager, and implementations are free to enforce this constraint by throwing IllegalStateExceptions in such cases.

An appropriate exception is thrown if the persistence manager could not be closed properly. In this case the state of the persistence manager is undefined and the instance should be discarded. Closes the persistence manager, release acquired resources.

Specified by:

close in interface PersistenceManager

Throws:

Exception - if the persistence manager failed to close properly

load

public NodeState load(NodeId id)
               throws NoSuchItemStateException,
                      ItemStateException

Load the persistent members of a node state. Loads the state via the appropriate NodePropBundle.

Specified by:

load in interface PersistenceManager

Parameters:

id - node id

Returns:

loaded node state

Throws:

NoSuchItemStateException - if the node state does not exist

ItemStateException - if another error occurs

load

public PropertyState load(PropertyId id)
                   throws NoSuchItemStateException,
                          ItemStateException

Load the persistent members of a property state. Loads the state via the appropriate NodePropBundle.

Specified by:

load in interface PersistenceManager

Parameters:

id - property id

Returns:

loaded property state

Throws:

NoSuchItemStateException - if the property state does not exist

ItemStateException - if another error occurs

exists

public boolean exists(PropertyId id)
               throws ItemStateException

Checks whether the identified property exists. Loads the state via the appropriate NodePropBundle.

Specified by:

exists in interface PersistenceManager

Parameters:

id - property id

Returns:

true if the property exists, false otherwise

Throws:

ItemStateException - on persistence manager errors

exists

public boolean exists(NodeId id)
               throws ItemStateException

Checks whether the identified node exists. Checks the existence via the appropriate NodePropBundle.

Specified by:

exists in interface PersistenceManager

Parameters:

id - node id

Returns:

true if the node exists, false otherwise

Throws:

ItemStateException - on persistence manager errors

createNew

public NodeState createNew(NodeId id)

Creates a new node state instance with the given id.

Specified by:

createNew in interface PersistenceManager

Parameters:

id - node id

Returns:

node state instance

createNew

public PropertyState createNew(PropertyId id)

Creates a new property state instance with the given id.

Specified by:

createNew in interface PersistenceManager

Parameters:

id - property id

Returns:

property state instance

store

public void store(ChangeLog changeLog)
           throws ItemStateException

Right now, this iterates over all items in the changelog and calls the individual methods that handle single item states or node references objects. Properly implemented, this method should ensure that changes are either written completely to the underlying persistence layer, or not at all. Atomically saves the given set of changes.

Specified by:

store in interface PersistenceManager

Parameters:

changeLog - change log containing states that were changed

Throws:

ItemStateException - if the changes could not be saved

checkConsistency

public void checkConsistency(String[] uuids,
                             boolean recursive,
                             boolean fix)

Perform a consistency check of the data. An example are non-existent nodes referenced in a child node entry. The existence of this feature and the scope of the implementation can vary in different PersistenceManager implementations.

Specified by:

checkConsistency in interface PersistenceManager

Parameters:

uuids - list of UUIDs of nodes to be checked. if null, all nodes will be checked

recursive - if true, the tree(s) below the given node(s) will be traversed and checked as well

fix - if true, any problems found that can be repaired will be repaired. if false, no data will be modified, instead all inconsistencies will only get logged

setEventChannel

public void setEventChannel(UpdateEventChannel eventChannel)

Description copied from interface: ConsistencyChecker

Set the update event channel. Needed to inform the cluster of any changes made during repairs.

Specified by:

setEventChannel in interface ConsistencyChecker

Parameters:

eventChannel - the update event channel

check

public ConsistencyReport check(String[] uuids,
                               boolean recursive,
                               boolean fix,
                               String lostNFoundId,
                               ConsistencyCheckListener listener)
                        throws RepositoryException

Perform a consistency check of the data. An example are non-existent nodes referenced in a child node entry. The existence of this feature and the scope of the implementation can vary in different PersistenceManager implementations.

Specified by:

check in interface ConsistencyChecker

Parameters:

uuids - list of UUIDs of nodes to be checked. if null, all nodes will be checked

recursive - if true, the tree(s) below the given node(s) will be traversed and checked as well

fix - if true, any problems found that can be repaired will be repaired. if false, no data will be modified, instead all inconsistencies will only get logged

lostNFoundId - node to which to attach orphaned nodes (or null, in which case orphaned nodes will not get moved); this node should be of a node type that allows adding arbitrary child nodes

listener - to be called on each node that was checked (may be null)

Throws:

RepositoryException

evictBundle

protected void evictBundle(NodeId id)

Evicts the bundle with id from the bundle cache.

Parameters:

id - the id of the bundle.

cacheAccessed

public void cacheAccessed(long accessCount)

Description copied from interface: CacheAccessListener

The cache calls this method after a number of cache accesses.
For statistical purposes, the cache access count since the last call is included. In normal circumstances this is equal to CacheAccessListener.ACCESS_INTERVAL

Specified by:

cacheAccessed in interface CacheAccessListener

Parameters:

accessCount - number of cache accesses since the last call

disposeCache

public void disposeCache(Cache cache)

Description copied from interface: CacheAccessListener

Called after the cache is no longer used.

Specified by:

disposeCache in interface CacheAccessListener