A root storage is created by StorageFactory
and is controlled by refcounting. In case refcounting
is decreased to zero the storage will be disposed
automatically. It is still strongly recommended that
a root storage is disposed explicitly since in garbage
collector based languages the refcounting can be
decreased too late and resources locked by the storage
will not be freed until then.
A substorage is created by XStorage
interface of storage. Each time a substorage is opened
it is locked ( in case it is opened in readonly mode
it is locked for writing, in case it is opened in
read-write mode it is locked for reading and writing )
until it is disposed. The lifetime of substorage is
also controlled by refcounting but because of mentioned
garbage collection specific it is strongly recommended
to dispose substorages explicitly.
In case a storage object is disposed all the elements
( substorages and substreams ) retrieved from the
object are disposed. If the storage was opened in
read-write mode all noncommited changes will be lost.
This method returns StorageStream
service implementation.
If the child stream is an encrypted one a corect
common storage password should be set through
XEncryptionProtectedSource interface to
this storage or to a one of storages in parent
hierarchy. In case the password is not set or is a
wrong one an exception will be thrown.
XStorage::openEncryptedStreamElement
This method allows to specify reading password for the
stream explicitly. The password will be used to read
the stream. It is possible to specify a new password
for stream storing through
XEncryptionProtectedSource interface. In
case a new password is not specified an old one will
be used for storing.
XStorage::openStorageElement
This method returns Storage service
implementation.
XStorage::cloneStreamElement
This method returns StorageStream service
implementation.
The latest flashed version of the stream will be used.
The stream can be flashed explicitly by
XOutputStream::flush
call.
A storage flashes on commit all the child streams it
owns. So in case after the stream is changed neither
the storage was commited nor the stream was flushed
explicitly, the changes will not appear in the new
created stream. This method allows to retrieve copy of
a child stream even in case it is already opened for
writing.
If the child stream is an encrypted one a corect
common storage password should be set through
XEncryptionProtectedSource interface to
this storage or to a one of storages in parent
hierarchy. In case the password is not set or is a
wrong one an exception will be thrown.
XStorage::cloneEncryptedStreamElement
This method returns StorageStream service
implementation.
The latest flashed version of the stream will be used.
The stream can be flashed explicitly by
XOutputStream::flush
call.
A storage flashes on commit all the child streams it
owns. So in case after the stream is changed neither
the storage was commited nor the stream was flushed
explicitly, the changes will not appear in the new
created stream. This method allows to retrieve copy of
a child stream even in case it is already opened for
writing.
XStorage::copyLastCommitTo
This method gets Storage service
implementation and fills it in with the latest
commited version of this storage. So in case the
storage was not commited after it was changed, the
changes will not appear in the new created storage.
XStorage::copyStorageElementLastCommitTo
This method gets Storage service
implementation and fills it in with the contents of
the requested substorage. The latest commited version
of child storage will be used. So in case the child
storage was not commited after it was changed, the
changes will not appear in the new created storage.
This method allows to retrieve copy of a child storage
even in case it is already opened for writing.
XStorage::removeStorageElement
If the element is opened the removing will fail.
property URL
If the storage is created based on url this property allows
to retrieve it.
allows to commit or revert changes that were done for the storage.
If a storage is commited all changes made to it will be integrated to
it's parent storage. This is recursive process, so the last commited
storage should be the root one. For the package based storages commit
of a root storage also means flashing to the related medium. If
a storage is not commited, no changes for it or it's child elements
will be stored.
This interface can be supported by a storage to allow to set
a common storage password. This password is used as default password
to decrypt all encrypted streams and to encrypt streams that are
marked to use common storage password on storing.
Specifying of the password for a storage allows to use it for the
whole subtree. Of course substorage can allow to overwrite the common
storage password for own subtree.
allows to detect whether mediatype is detected by using fallback
approach.
Can be set to true if the mediatype can not be detected in standard
way, but there is a fallback solution allows to do it.
Usually means that the document validity is questionable, although
the package itself is not corrupted. The decision about document
validity in this case is in application hands. It is up to user of
the storage to deside whether he accepts the fallback approach for
an implementation of this service, outputs a warning or an error.
allows to detect if the storage contains encrypted entries.
In case it is set to true the storage itself and/or a tree of
substorages contain encrypted streams. Usually in case this property
is supported the implementation supports
XEncryptionProtectedSource interface.
allows to detect if the storage contains nonencrypted entries.
In case it is set to true the storage itself and/or a tree of
substorages contains nonencrypted streams. Usually in case this
property is supported the implementation supports
XEncryptionProtectedSource interface.
