com.antelmann.db
Class ArchiveDBClassStore<T extends DBEntry>

java.lang.Object
  com.antelmann.db.WrappedDBClassStore<T>
      com.antelmann.db.ArchiveDBClassStore<T>

All Implemented Interfaces:

ArchivedStore<T>, DBClassStore<T>, ProcessedFilterOption<T>, TransactionRequired, ProcessorHook<T,DatabaseException>, Wrapped<DBClassStore<T>>

@Warning(value="due to missing X/A support, updates of the archive may not be transactionally consistent")
@Todo(value="support X/A via TransactionListener")
public class ArchiveDBClassStore<T extends DBEntry>
extends WrappedDBClassStore<T>
implements ArchivedStore<T>

allows to add an archive store to any given store, which enables to extend the data set.

Since:

01.09.2011, 09:48:43

Author:

Holger Antelmann

Nested Class Summary

Nested classes/interfaces inherited from interface com.antelmann.db.DBClassStore

DBClassStore.DBMethod

Field Summary

Fields inherited from class com.antelmann.db.WrappedDBClassStore

store

Constructor Summary

ArchiveDBClassStore(DBClassStore<T> store, DBClassStore<T> archive, boolean enableArchive)

Method Summary

boolean	containsID(Object id) determines whether the given ID is present in this store.
int	deleteEntries(Filter<? super T> filter) deletes all DBEntry objects that match the given filter; if the filter is null, all resources are deleted.
boolean	deleteEntry(Object id) removes the entry with the given ID from this store in the database.
DBEnumeration<T>	fetch(Filter<? super T> filter) allows to retrieve the entries of this storage via iteration.
DBEnumeration<Stub<T>>	fetchStubs(Filter<? super Stub<?>> filter) allows to access objects from this store w/o having to instantiate the entire original objects, but instead use Stubs to be able to display the list properly for selection.
T	getEntry(Object id) returns the DBEntry based on its ID.
Stub<T>	getStub(Object id) returns a Stub representing the resource for the given ID or null.
boolean	isArchiveEnabled() if true, each data access call also reaches through to the embedded archived store
boolean	isEnableArchiveEdit()
int	moveToArchive(Filter<? super T> filter) requires transactional context on both stores
void	setArchiveEnabled(boolean flag) if set to true, each data access call also reaches through to the embedded archived store
void	setEnableArchiveEdit(boolean enableArchiveEdit) if set to true, delete and update operations are propagated to the archive (insertions will always only affect the 'normal' store).
int	size(Filter<? super T> filter) returns the total number of T elements in this store based on the given filter (which may be null)
void	update(T entry) updates the given entry in the database.

Methods inherited from class com.antelmann.db.WrappedDBClassStore

add, checkReadAccess, checkWriteAccess, deleteEntriesIndividually, exposesInterfaces, generateNewID, getAccessFilter, getAccessStubFilter, getDatabase, getEntryClass, getFetchProcessor, getPreStoreHandler, getStoreHandler, getStubProcessor, insert, insertAsNew, isApplyFilterProcessingRecursively, isDeleteEntriesIndividually, isEnsureTransactionsOnFetch, isProcessBeforeFiltering, queryForInterface, remove, setAccessFilter, setAccessStubFilter, setApplyFilterProcessingRecursively, setDeleteEntriesIndividually, setEnsureTransactionsOnFetch, setExposesInterfaces, setFetchProcessor, setPreStoreHandler, setProcessBeforeFiltering, setProcessBeforeFiltering, setStoreHandler, setStubProcessor, unwrap, wrapFilterForProcessing

Methods inherited from class java.lang.Object

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

Constructor Detail

ArchiveDBClassStore

public ArchiveDBClassStore(DBClassStore<T> store,
                           DBClassStore<T> archive,
                           boolean enableArchive)

Method Detail

isArchiveEnabled

public boolean isArchiveEnabled()

Description copied from interface: ArchivedStore

if true, each data access call also reaches through to the embedded archived store

Specified by:

isArchiveEnabled in interface ArchivedStore<T extends DBEntry>

setArchiveEnabled

public void setArchiveEnabled(boolean flag)

Description copied from interface: ArchivedStore

if set to true, each data access call also reaches through to the embedded archived store

Specified by:

setArchiveEnabled in interface ArchivedStore<T extends DBEntry>

isEnableArchiveEdit

public boolean isEnableArchiveEdit()

Specified by:

isEnableArchiveEdit in interface ArchivedStore<T extends DBEntry>

See Also:

ArchivedStore.setEnableArchiveEdit(boolean)

setEnableArchiveEdit

@Warning(value="if set to true, updates/deletes on the archive may commit even if the current transaction aborts in the current implementation")
public void setEnableArchiveEdit(boolean enableArchiveEdit)

Description copied from interface: ArchivedStore

if set to true, delete and update operations are propagated to the archive (insertions will always only affect the 'normal' store). Read operations are dependent on ArchivedStore.isArchiveEnabled().

Specified by:

setEnableArchiveEdit in interface ArchivedStore<T extends DBEntry>

containsID

public boolean containsID(Object id)
                   throws DatabaseException

Description copied from interface: DBClassStore

determines whether the given ID is present in this store.

Specified by:

containsID in interface DBClassStore<T extends DBEntry>

Overrides:

containsID in class WrappedDBClassStore<T extends DBEntry>

Throws:

DatabaseException

deleteEntry

public boolean deleteEntry(Object id)
                    throws DatabaseException

Description copied from interface: DBClassStore

removes the entry with the given ID from this store in the database.

Specified by:

deleteEntry in interface DBClassStore<T extends DBEntry>

Overrides:

deleteEntry in class WrappedDBClassStore<T extends DBEntry>

Returns:

true only if the DBEntry with the given ID was actually found and deleted.

Throws:

DatabaseException

deleteEntries

public int deleteEntries(Filter<? super T> filter)
                  throws DatabaseException

Description copied from interface: DBClassStore

deletes all DBEntry objects that match the given filter; if the filter is null, all resources are deleted. Calling this method does not necessarily entail that DBClassStore.deleteEntry(Object) is called for each entry passing the filter (although stores may choose to do so)! Consequently, if a store's implementation does not call DBClassStore.deleteEntry(Object) on each instance, calling this method may result in changes that are hard to monitor for versioning purposes.

Specified by:

deleteEntries in interface DBClassStore<T extends DBEntry>

Overrides:

deleteEntries in class WrappedDBClassStore<T extends DBEntry>

Returns:

the number of objects that were deleted

Throws:

DatabaseException

See Also:

WrappedDBClassStore.setProcessBeforeFiltering(boolean)

update

public void update(T entry)
            throws DatabaseException

Description copied from interface: DBClassStore

updates the given entry in the database.

Specified by:

update in interface DBClassStore<T extends DBEntry>

Overrides:

update in class WrappedDBClassStore<T extends DBEntry>

Throws:

DatabaseException - if the database was not able to perform the update or it the entry didn't exist in the database before calling this method

fetch

public DBEnumeration<T> fetch(Filter<? super T> filter)
                                       throws DatabaseException

Description copied from interface: DBClassStore

allows to retrieve the entries of this storage via iteration. Note that the order of the entries is undefined, unless a specially designed filter hints a sorting order to an implementing class that additionally supports sorting.

As all relevant entries may not completely fit into memory, an Enumeration is returned instead of a list. To directly get all entries as a list (and thus avoid concurrency problems), consider using methods from AbstractIterator to quickly retrieve all resources before processing them.

Be aware that the result of the enumeration may become undefined if data is inserted/deleted/updated while the elements are accessed. To guarantee consistency, all access to the returned Enumeration must be externally synchronized by holding the monitor of the database transaction throughout maintaining the Enumeration.

Note that you may have IterationExceptions being thrown on calling methods on the returned Enumeration, which are caused by either DatabaseExceptions or InstantiationExceptions on trying to fetch the next element, as not all possible errors may be caught on calling this method (as it possibly cannot instantiate all entries in advance).

All access to the returned Enumeration must be made within an active transaction.

As the returned Enumeration may hold resources to the database while iterating, the caller must ensure that these resources can be properly release. This is usually achieved by simply completely iterating through the return value, in which case the DBEnumeration is expected to properly clean up automatically. But in cases where the caller doesn't intend to go all the way through the Enumeration, the caller has to clean up explicitly, which can be done by calling the close() method on the returned DBEnumeration.

Specified by:

fetch in interface DBClassStore<T extends DBEntry>

Overrides:

fetch in class WrappedDBClassStore<T extends DBEntry>

Parameters:

filter - may be null, in which case all entries from are returned.

Throws:

DatabaseException

See Also:

WrappedDBClassStore.setProcessBeforeFiltering(boolean)

fetchStubs

public DBEnumeration<Stub<T>> fetchStubs(Filter<? super Stub<?>> filter)
                                                  throws DatabaseException

Description copied from interface: DBClassStore

allows to access objects from this store w/o having to instantiate the entire original objects, but instead use Stubs to be able to display the list properly for selection. The given filter may be null. Other than that, the same transactional implications apply as for fetch(Filter).

Specified by:

fetchStubs in interface DBClassStore<T extends DBEntry>

Overrides:

fetchStubs in class WrappedDBClassStore<T extends DBEntry>

Throws:

DatabaseException

See Also:

WrappedDBClassStore.setProcessBeforeFiltering(boolean)

getEntry

public T getEntry(Object id)
                           throws DatabaseException

Description copied from interface: DBClassStore

returns the DBEntry based on its ID.

Specified by:

getEntry in interface DBClassStore<T extends DBEntry>

Overrides:

getEntry in class WrappedDBClassStore<T extends DBEntry>

Parameters:

id - the ID that is retrieved from Resource.getID()

Returns:

the associated DBEntry or null if the id is unknown

Throws:

DatabaseException

See Also:

DBEntry.getID()

getStub

public Stub<T> getStub(Object id)
                                throws DatabaseException

Description copied from interface: DBClassStore

returns a Stub representing the resource for the given ID or null. This method allows to display the object w/o having to retrieve the full DBEntry.

Specified by:

getStub in interface DBClassStore<T extends DBEntry>

Overrides:

getStub in class WrappedDBClassStore<T extends DBEntry>

Throws:

DatabaseException

size

public int size(Filter<? super T> filter)
         throws DatabaseException

Description copied from interface: DBClassStore

returns the total number of T elements in this store based on the given filter (which may be null)

Specified by:

size in interface DBClassStore<T extends DBEntry>

Overrides:

size in class WrappedDBClassStore<T extends DBEntry>

Parameters:

filter - if non-null, only those elements will be counted that are applicable to the filter

Throws:

DatabaseException

See Also:

WrappedDBClassStore.setProcessBeforeFiltering(boolean)

moveToArchive

public int moveToArchive(Filter<? super T> filter)
                  throws DatabaseException

Description copied from interface: ArchivedStore

requires transactional context on both stores

Specified by:

moveToArchive in interface ArchivedStore<T extends DBEntry>

Throws:

DatabaseException