org.opends.server.api

Class Backend<C extends Configuration>

java.lang.Object

org.opends.server.api.Backend<C>

Type Parameters:

C - the type of the BackendCfg for the current backend

Direct Known Subclasses:

BackendImpl, BackupBackend, ChangelogBackend, ConfigHandler, LDIFBackend, MemoryBackend, MonitorBackend, NullBackend, RootDSEBackend, SchemaBackend, TaskBackend, TrustStoreBackend

@PublicAPI(stability=VOLATILE,
           mayInstantiate=false,
           mayExtend=true,
           mayInvoke=false)
public abstract class Backend<C extends Configuration>
extends Object

This class defines the set of methods and structures that must be implemented for a Directory Server backend.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Backend.BackendOperation Enumeration of optional backend operations.

Constructor Summary

Constructors

Constructor and Description
Backend()

Method Summary

Methods

Modifier and Type	Method and Description
abstract void	addEntry(Entry entry, AddOperation addOperation) Adds the provided entry to this backend.
void	addSubordinateBackend(Backend<?> subordinateBackend) Adds the provided backend to the set of subordinate backends for this backend.
void	closeBackend() Performs any necessary work to finally close this backend, particularly closing any underlying databases or connections and deregistering any suffixes that it manages with the Directory Server.
abstract void	configureBackend(C cfg, ServerContext serverContext) Configure this backend based on the information in the provided configuration.
abstract void	createBackup(BackupConfig backupConfig) Creates a backup of the contents of this backend in a form that may be restored at a later date if necessary.
abstract void	deleteEntry(DN entryDN, DeleteOperation deleteOperation) Removes the specified entry from this backend.
boolean	entryExists(DN entryDN) Indicates whether an entry with the specified DN exists in the backend.
abstract void	exportLDIF(LDIFExportConfig exportConfig) Exports the contents of this backend to LDIF.
void	finalizeBackend() Performs any necessary work to finalize this backend.
String	getBackendID() Retrieves the unique identifier for this backend.
BackendMonitor	getBackendMonitor() Retrieves the backend monitor that is associated with this backend.
abstract DN[]	getBaseDNs() Retrieves the set of base-level DNs that may be used within this backend.
abstract Entry	getEntry(DN entryDN) Retrieves the requested entry from this backend.
abstract long	getEntryCount() Retrieves the total number of entries contained in this backend, if that information is available.
abstract long	getNumberOfChildren(DN parentDN) Retrieves the number of subordinates immediately below the requested entry.
abstract long	getNumberOfEntriesInBaseDN(DN baseDN) Retrieves the number of entries for the specified base DN including all entries from the requested entry to the lowest level in the tree.
Backend<?>	getParentBackend() Retrieves the parent backend for this backend.
Queue<PersistentSearch>	getPersistentSearches() Returns the persistent searches currently active against this local backend.
Backend<?>[]	getSubordinateBackends() Retrieves the set of subordinate backends for this backend.
abstract Set<String>	getSupportedControls() Retrieves the OIDs of the controls that may be supported by this backend.
abstract Set<String>	getSupportedFeatures() Retrieves the OIDs of the features that may be supported by this backend.
WritabilityMode	getWritabilityMode() Retrieves the writability mode for this backend.
boolean	handlesEntry(DN entryDN) Indicates whether this backend should be used to handle operations for the provided entry.
static boolean	handlesEntry(DN entryDN, Collection<DN> baseDNs, Collection<DN> excludeDNs) Indicates whether a backend should be used to handle operations for the provided entry given the set of base DNs and exclude DNs.
abstract org.forgerock.opendj.ldap.ConditionResult	hasSubordinates(DN entryDN) Indicates whether the requested entry has any subordinates.
abstract LDIFImportResult	importLDIF(LDIFImportConfig importConfig, ServerContext serverContext) Imports information from an LDIF file into this backend.
boolean	isConfigurationAcceptable(C configuration, List<LocalizableMessage> unacceptableReasons, ServerContext serverContext) Indicates whether the provided configuration is acceptable for this backend.
abstract boolean	isIndexed(AttributeType attributeType, IndexType indexType) Indicates whether search operations which target the specified attribute in the indicated manner would be considered indexed in this backend.
boolean	isIndexed(SearchFilter filter) Indicates whether a subtree search using the provided filter would be indexed in this backend.
boolean	isPrivateBackend() Indicates whether this backend holds private data or user data.
abstract void	openBackend() Opens this backend based on the information provided when the backend was configured.
void	rebuildBackend(RebuildConfig rebuildConfig, ServerContext serverContext) Rebuild indexes in the backend instance.
void	registerPersistentSearch(PersistentSearch persistentSearch) Registers the provided persistent search operation with this backend so that it will be notified of any add, delete, modify, or modify DN operations that are performed.
abstract void	removeBackup(BackupDirectory backupDirectory, String backupID) Removes the specified backup if it is possible to do so.
void	removeSubordinateBackend(Backend<?> subordinateBackend) Removes the provided backend from the set of subordinate backends for this backend.
abstract void	renameEntry(DN currentDN, Entry entry, ModifyDNOperation modifyDNOperation) Moves and/or renames the provided entry in this backend, altering any subordinate entries as necessary.
abstract void	replaceEntry(Entry oldEntry, Entry newEntry, ModifyOperation modifyOperation) Replaces the specified entry with the provided entry in this backend.
abstract void	restoreBackup(RestoreConfig restoreConfig) Restores a backup of the contents of this backend.
abstract void	search(SearchOperation searchOperation) Processes the specified search in this backend.
void	setBackendID(String backendID) Specifies the unique identifier for this backend.
void	setBackendMonitor(BackendMonitor backendMonitor) Sets the backend monitor for this backend.
void	setParentBackend(Backend<?> parentBackend) Specifies the parent backend for this backend.
void	setPrivateBackend(boolean isPrivateBackend) Specifies whether this backend holds private data or user data.
void	setWritabilityMode(WritabilityMode writabilityMode) Specifies the writability mode for this backend.
abstract boolean	supports(Backend.BackendOperation backendOperation) Indicates whether this backend supports the provided backend operation.
boolean	supportsControl(String controlOID) Indicates whether this backend supports the specified control.
long	verifyBackend(VerifyConfig verifyConfig) Verify the integrity of the backend instance.

Methods inherited from class java.lang.Object

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

Constructor Detail

Backend

public Backend()

Method Detail

configureBackend

public abstract void configureBackend(C cfg,
                    ServerContext serverContext)
                               throws org.forgerock.opendj.config.server.ConfigException

Configure this backend based on the information in the provided configuration. When the method returns, the backend will have been configured (ready to be opened) but still unable to process operations.

Parameters:

cfg - The configuration of this backend.

serverContext - The server context for this instance

Throws:

org.forgerock.opendj.config.server.ConfigException - If there is an error in the configuration.

isConfigurationAcceptable

public boolean isConfigurationAcceptable(C configuration,
                                List<LocalizableMessage> unacceptableReasons,
                                ServerContext serverContext)

Indicates whether the provided configuration is acceptable for this backend. It should be possible to call this method on an uninitialized backend instance in order to determine whether the backend would be able to use the provided configuration.

Note that implementations which use a subclass of the provided configuration class will likely need to cast the configuration to the appropriate subclass type.

Parameters:

configuration - The backend configuration for which to make the determination.

unacceptableReasons - A list that may be used to hold the reasons that the provided configuration is not acceptable.

serverContext - this Directory Server instance's server context

Returns:

true if the provided configuration is acceptable for this backend, or false if not.

openBackend

public abstract void openBackend()
                          throws org.forgerock.opendj.config.server.ConfigException,
                                 InitializationException

Opens this backend based on the information provided when the backend was configured. It also should open any underlying storage and register all suffixes with the server.

Throws:

org.forgerock.opendj.config.server.ConfigException - If an unrecoverable problem arises while opening the backend.

InitializationException - If a problem occurs during opening that is not related to the server configuration.

See Also:

configureBackend(C, org.opends.server.core.ServerContext)

finalizeBackend

public final void finalizeBackend()

Performs any necessary work to finalize this backend. The backend must be an opened backend, so do not use this method on backends where only configureBackend() has been called. This may be called during the Directory Server shutdown process or if a backend is disabled with the server online. It must not return until the backend is closed.

This method may not throw any exceptions. If any problems are encountered, then they may be logged but the closure should progress as completely as possible.

closeBackend

public void closeBackend()

Performs any necessary work to finally close this backend, particularly closing any underlying databases or connections and deregistering any suffixes that it manages with the Directory Server.

It will be called as final step of finalizeBackend(), so subclasses might override it.

getBaseDNs

public abstract DN[] getBaseDNs()

Retrieves the set of base-level DNs that may be used within this backend.

Returns:

The set of base-level DNs that may be used within this backend.

isIndexed

public abstract boolean isIndexed(AttributeType attributeType,
                IndexType indexType)

Indicates whether search operations which target the specified attribute in the indicated manner would be considered indexed in this backend. The operation should be considered indexed only if the specified operation can be completed efficiently within the backend.

Note that this method should return a general result that covers all values of the specified attribute. If a the specified attribute is indexed in the indicated manner but some particular values may still be treated as unindexed (e.g., if the number of entries with that attribute value exceeds some threshold), then this method should still return true for the specified attribute and index type.

Parameters:

attributeType - The attribute type for which to make the determination.

indexType - The index type for which to make the determination.

Returns:

true if search operations targeting the specified attribute in the indicated manner should be considered indexed, or false if not.

isIndexed

public boolean isIndexed(SearchFilter filter)

Indicates whether a subtree search using the provided filter would be indexed in this backend. This default implementation uses a rough set of logic that makes a best-effort determination. Subclasses that provide a more complete indexing mechanism may wish to override this method and provide a more accurate result.

Parameters:

filter - The search filter for which to make the determination.

Returns:

true if it is believed that the provided filter would be indexed in this backend, or false if not.

getEntry

public abstract Entry getEntry(DN entryDN)
                        throws DirectoryException

Retrieves the requested entry from this backend. The caller is not required to hold any locks on the specified DN.

Parameters:

entryDN - The distinguished name of the entry to retrieve.

Returns:

The requested entry, or null if the entry does not exist.

Throws:

DirectoryException - If a problem occurs while trying to retrieve the entry.

hasSubordinates

public abstract org.forgerock.opendj.ldap.ConditionResult hasSubordinates(DN entryDN)
                                                                   throws DirectoryException

Indicates whether the requested entry has any subordinates.

Parameters:

entryDN - The distinguished name of the entry.

Returns:

ConditionResult.TRUE if the entry has one or more subordinates or ConditionResult.FALSE otherwise or ConditionResult.UNDEFINED if it can not be determined.

Throws:

DirectoryException - If a problem occurs while trying to retrieve the entry.

getNumberOfChildren

public abstract long getNumberOfChildren(DN parentDN)
                                  throws DirectoryException

Retrieves the number of subordinates immediately below the requested entry.

Parameters:

parentDN - The distinguished name of the parent.

Returns:

The number of subordinate entries for the requested entry.

Throws:

DirectoryException - If baseDN isn't a base dn managed by this backend or if a problem occurs while trying to retrieve the entry.

NullPointerException - if baseDN is null.

getNumberOfEntriesInBaseDN

public abstract long getNumberOfEntriesInBaseDN(DN baseDN)
                                         throws DirectoryException

Retrieves the number of entries for the specified base DN including all entries from the requested entry to the lowest level in the tree.

Parameters:

baseDN - The base distinguished name.

Returns:

The number of subordinate entries including the base dn.

Throws:

DirectoryException - If baseDN isn't a base dn managed by this backend or if a problem occurs while trying to retrieve the entry.

NullPointerException - if baseDN is null.

entryExists

public boolean entryExists(DN entryDN)
                    throws DirectoryException

Indicates whether an entry with the specified DN exists in the backend. The default implementation calls getEntry, but backend implementations may override this with a more efficient version. The caller is not required to hold any locks on the specified DN.

Parameters:

entryDN - The DN of the entry for which to determine existence.

Returns:

true if the specified entry exists in this backend, or false if it does not.

Throws:

DirectoryException - If a problem occurs while trying to make the determination.

addEntry

public abstract void addEntry(Entry entry,
            AddOperation addOperation)
                       throws DirectoryException,
                              CanceledOperationException

Adds the provided entry to this backend. This method must ensure that the entry is appropriate for the backend and that no entry already exists with the same DN. The caller must hold a write lock on the DN of the provided entry.

Parameters:

entry - The entry to add to this backend.

addOperation - The add operation with which the new entry is associated. This may be null for adds performed internally.

Throws:

DirectoryException - If a problem occurs while trying to add the entry.

CanceledOperationException - If this backend noticed and reacted to a request to cancel or abandon the add operation.

deleteEntry

public abstract void deleteEntry(DN entryDN,
               DeleteOperation deleteOperation)
                          throws DirectoryException,
                                 CanceledOperationException

Removes the specified entry from this backend. This method must ensure that the entry exists and that it does not have any subordinate entries (unless the backend supports a subtree delete operation and the client included the appropriate information in the request). The caller must hold a write lock on the provided entry DN.

Parameters:

entryDN - The DN of the entry to remove from this backend.

deleteOperation - The delete operation with which this action is associated. This may be null for deletes performed internally.

Throws:

DirectoryException - If a problem occurs while trying to remove the entry.

CanceledOperationException - If this backend noticed and reacted to a request to cancel or abandon the delete operation.

replaceEntry

public abstract void replaceEntry(Entry oldEntry,
                Entry newEntry,
                ModifyOperation modifyOperation)
                           throws DirectoryException,
                                  CanceledOperationException

Replaces the specified entry with the provided entry in this backend. The backend must ensure that an entry already exists with the same DN as the provided entry. The caller must hold a write lock on the DN of the provided entry.

Parameters:

oldEntry - The original entry that is being replaced.

newEntry - The new entry to use in place of the existing entry with the same DN.

modifyOperation - The modify operation with which this action is associated. This may be null for modifications performed internally.

Throws:

DirectoryException - If a problem occurs while trying to replace the entry.

CanceledOperationException - If this backend noticed and reacted to a request to cancel or abandon the modify operation.

renameEntry

public abstract void renameEntry(DN currentDN,
               Entry entry,
               ModifyDNOperation modifyDNOperation)
                          throws DirectoryException,
                                 CanceledOperationException

Moves and/or renames the provided entry in this backend, altering any subordinate entries as necessary. This must ensure that an entry already exists with the provided current DN, and that no entry exists with the target DN of the provided entry. The caller must hold write locks on both the current DN and the new DN for the entry.

Parameters:

currentDN - The current DN of the entry to be moved/renamed.

entry - The new content to use for the entry.

modifyDNOperation - The modify DN operation with which this action is associated. This may be null for modify DN operations performed internally.

Throws:

DirectoryException - If a problem occurs while trying to perform the rename.

CanceledOperationException - If this backend noticed and reacted to a request to cancel or abandon the modify DN operation.

search

public abstract void search(SearchOperation searchOperation)
                     throws DirectoryException,
                            CanceledOperationException

Processes the specified search in this backend. Matching entries should be provided back to the core server using the SearchOperation.returnEntry method. The caller is not required to have any locks when calling this operation.

Parameters:

searchOperation - The search operation to be processed.

Throws:

DirectoryException - If a problem occurs while processing the search.

CanceledOperationException - If this backend noticed and reacted to a request to cancel or abandon the search operation.

getSupportedControls

public abstract Set<String> getSupportedControls()

Retrieves the OIDs of the controls that may be supported by this backend.

Returns:

The OIDs of the controls that may be supported by this backend.

supportsControl

public final boolean supportsControl(String controlOID)

Indicates whether this backend supports the specified control.

Parameters:

controlOID - The OID of the control for which to make the determination.

Returns:

true if this backends supports the control with the specified OID, or false if it does not.

getSupportedFeatures

public abstract Set<String> getSupportedFeatures()

Retrieves the OIDs of the features that may be supported by this backend.

Returns:

The OIDs of the features that may be supported by this backend.

supports

public abstract boolean supports(Backend.BackendOperation backendOperation)

Indicates whether this backend supports the provided backend operation.

Parameters:

backendOperation - the backend operation

Returns:

true if this backend supports the provided backend operation, false otherwise.

exportLDIF

public abstract void exportLDIF(LDIFExportConfig exportConfig)
                         throws DirectoryException

Exports the contents of this backend to LDIF. This method should only be called if supports(BackendOperation) with Backend.BackendOperation.LDIF_EXPORT returns true.

Note that the server will not explicitly initialize this backend before calling this method.

Parameters:

exportConfig - The configuration to use when performing the export.

Throws:

DirectoryException - If a problem occurs while performing the LDIF export.

importLDIF

public abstract LDIFImportResult importLDIF(LDIFImportConfig importConfig,
                          ServerContext serverContext)
                                     throws DirectoryException

Imports information from an LDIF file into this backend. This method should only be called if supports(BackendOperation) with Backend.BackendOperation.LDIF_IMPORT returns true.

Note that the server will not explicitly initialize this backend before calling this method.

Parameters:

importConfig - The configuration to use when performing the import.

serverContext - The server context

Returns:

Information about the result of the import processing.

Throws:

DirectoryException - If a problem occurs while performing the LDIF import.

verifyBackend

public long verifyBackend(VerifyConfig verifyConfig)
                   throws InitializationException,
                          org.forgerock.opendj.config.server.ConfigException,
                          DirectoryException

Verify the integrity of the backend instance.

Parameters:

verifyConfig - The verify configuration.

Returns:

The results of the operation.

Throws:

org.forgerock.opendj.config.server.ConfigException - If an unrecoverable problem arises during initialization.

InitializationException - If a problem occurs during initialization that is not related to the server configuration.

DirectoryException - If a Directory Server error occurs.

rebuildBackend

public void rebuildBackend(RebuildConfig rebuildConfig,
                  ServerContext serverContext)
                    throws InitializationException,
                           org.forgerock.opendj.config.server.ConfigException,
                           DirectoryException

Rebuild indexes in the backend instance. Note that the server will not explicitly initialize this backend before calling this method.

Parameters:

rebuildConfig - The rebuild configuration.

serverContext - The server context for this instance

Throws:

org.forgerock.opendj.config.server.ConfigException - If an unrecoverable problem arises during initialization.

InitializationException - If a problem occurs during initialization that is not related to the server configuration.

DirectoryException - If a Directory Server error occurs.

createBackup

public abstract void createBackup(BackupConfig backupConfig)
                           throws DirectoryException

Creates a backup of the contents of this backend in a form that may be restored at a later date if necessary. This method should only be called if supports(BackendOperation) with Backend.BackendOperation.BACKUP returns true.

Note that the server will not explicitly initialize this backend before calling this method.

Parameters:

backupConfig - The configuration to use when performing the backup.

Throws:

DirectoryException - If a problem occurs while performing the backup.

removeBackup

public abstract void removeBackup(BackupDirectory backupDirectory,
                String backupID)
                           throws DirectoryException

Removes the specified backup if it is possible to do so.

Parameters:

backupDirectory - The backup directory structure with which the specified backup is associated.

backupID - The backup ID for the backup to be removed.

Throws:

DirectoryException - If it is not possible to remove the specified backup for some reason (e.g., no such backup exists or there are other backups that are dependent upon it).

restoreBackup

public abstract void restoreBackup(RestoreConfig restoreConfig)
                            throws DirectoryException

Restores a backup of the contents of this backend. This method should only be called if supports(BackendOperation) with Backend.BackendOperation.RESTORE returns true.

Note that the server will not explicitly initialize this backend before calling this method.

Parameters:

restoreConfig - The configuration to use when performing the restore.

Throws:

DirectoryException - If a problem occurs while performing the restore.

getBackendID

public final String getBackendID()

Retrieves the unique identifier for this backend.

Returns:

The unique identifier for this backend.

setBackendID

public final void setBackendID(String backendID)

Specifies the unique identifier for this backend.

Parameters:

backendID - The unique identifier for this backend.

isPrivateBackend

public final boolean isPrivateBackend()

Indicates whether this backend holds private data or user data.

Returns:

true if this backend holds private data, or false if it holds user data.

setPrivateBackend

public final void setPrivateBackend(boolean isPrivateBackend)

Specifies whether this backend holds private data or user data.

Parameters:

isPrivateBackend - Specifies whether this backend holds private data or user data.

getWritabilityMode

public final WritabilityMode getWritabilityMode()

Retrieves the writability mode for this backend.

Returns:

The writability mode for this backend.

setWritabilityMode

public final void setWritabilityMode(WritabilityMode writabilityMode)

Specifies the writability mode for this backend.

Parameters:

writabilityMode - The writability mode for this backend.

getBackendMonitor

public final BackendMonitor getBackendMonitor()

Retrieves the backend monitor that is associated with this backend.

Returns:

The backend monitor that is associated with this backend, or null if none has been assigned.

registerPersistentSearch

public void registerPersistentSearch(PersistentSearch persistentSearch)
                              throws DirectoryException

Registers the provided persistent search operation with this backend so that it will be notified of any add, delete, modify, or modify DN operations that are performed.

Parameters:

persistentSearch - The persistent search operation to register with this backend

Throws:

DirectoryException - If a problem occurs while registering the persistent search

getPersistentSearches

public Queue<PersistentSearch> getPersistentSearches()

Returns the persistent searches currently active against this local backend.

Returns:

the list of persistent searches currently active against this local backend

setBackendMonitor

public final void setBackendMonitor(BackendMonitor backendMonitor)

Sets the backend monitor for this backend.

Parameters:

backendMonitor - The backend monitor for this backend.

getEntryCount

public abstract long getEntryCount()

Retrieves the total number of entries contained in this backend, if that information is available.

Returns:

The total number of entries contained in this backend, or -1 if that information is not available.

getParentBackend

public final Backend<?> getParentBackend()

Retrieves the parent backend for this backend.

Returns:

The parent backend for this backend, or null if there is none.

setParentBackend

public final void setParentBackend(Backend<?> parentBackend)

Specifies the parent backend for this backend.

Parameters:

parentBackend - The parent backend for this backend.

getSubordinateBackends

public final Backend<?>[] getSubordinateBackends()

Retrieves the set of subordinate backends for this backend.

Returns:

The set of subordinate backends for this backend, or an empty array if none exist.

addSubordinateBackend

public final void addSubordinateBackend(Backend<?> subordinateBackend)

Adds the provided backend to the set of subordinate backends for this backend.

Parameters:

subordinateBackend - The backend to add to the set of subordinate backends for this backend.

removeSubordinateBackend

public final void removeSubordinateBackend(Backend<?> subordinateBackend)

Removes the provided backend from the set of subordinate backends for this backend.

Parameters:

subordinateBackend - The backend to remove from the set of subordinate backends for this backend.

handlesEntry

public final boolean handlesEntry(DN entryDN)

Indicates whether this backend should be used to handle operations for the provided entry.

Parameters:

entryDN - The DN of the entry for which to make the determination.

Returns:

true if this backend handles operations for the provided entry, or false if it does not.

handlesEntry

public static boolean handlesEntry(DN entryDN,
                   Collection<DN> baseDNs,
                   Collection<DN> excludeDNs)

Indicates whether a backend should be used to handle operations for the provided entry given the set of base DNs and exclude DNs.

Parameters:

entryDN - The DN of the entry for which to make the determination.

baseDNs - The set of base DNs for the backend.

excludeDNs - The set of DNs that should be excluded from the backend.

Returns:

true if the backend should handle operations for the provided entry, or false if it does not.