org.apache.marmotta.kiwi.versioning.sail

Class KiWiVersioningSail

java.lang.Object

org.openrdf.sail.helpers.SailWrapper

org.openrdf.sail.helpers.NotifyingSailWrapper

org.apache.marmotta.commons.sesame.transactions.wrapper.TransactionalSailWrapper

org.apache.marmotta.kiwi.versioning.sail.KiWiVersioningSail

All Implemented Interfaces:

TransactionalSail, TransactionListener, VersioningSail, org.openrdf.sail.NotifyingSail, org.openrdf.sail.Sail, org.openrdf.sail.StackableSail

public class KiWiVersioningSail
extends TransactionalSailWrapper
implements TransactionListener, VersioningSail

A KiWi Stackable Sail offering versioning support for transactional sails. The versioning sail create a new version entry in the database whenever a transaction commits successfully (implemented through transaction listener).

This SAIL offers three additional methods (need to be accessed directly):

• getSnapshot(Date) returns a read-only SailConnection operating on a historic snapshot of the repository, i.e. it is possible to query the triple store with its state at any given point in history
• getVersions() returns a list of all versions that have been tracked in the triple store
• getVersions(Date from, Date to) returns a list of all versions that have been tracked between the given dates

Further functionalities like removing old versions or undoing certain versions are planned but currently not yet implemented.

Author: Sebastian Schaffert

Field Summary

Fields

Modifier and Type	Field and Description
protected static long	DEFAULT_CONNECTION_TIMEOUT

Constructor Summary

Constructors

Constructor and Description
KiWiVersioningSail(TransactionalSail parent) Build a new KiWiVersioningSail based on the provided parent TransactionalSail.
KiWiVersioningSail(TransactionalSail parent, org.apache.marmotta.commons.sesame.filter.SesameFilter<org.openrdf.model.Statement> filter) Build a new selective KiWiVersioningSail based on the provided parent TransactionalSail.

Method Summary

Methods

Modifier and Type	Method and Description
void	afterCommit(TransactionData data) Called after a transaction has committed.
void	beforeCommit(TransactionData data) Called before a transaction commits.
protected void	closeSnapshotConnection(KiWiSnapshotConnection con) Unregister the snapshot connection, it has been cleaned up properly.
KiWiStore	getBaseStore() Return the KiWi store that is at the base of the SAIL stack.
Version	getLatestVersion(org.openrdf.model.Resource r, Date date) Return the version that is the most recent version for a resource given a reference date.
KiWiVersioningPersistence	getPersistence() Return the versioning persistence object underlying this SAIL.
KiWiSnapshotConnection	getSnapshot(Date snapshotDate) Get a read-only snapshot of the repository at the given date.
Version	getVersion(Long id)
void	initialize() Ensure that the versioning tables are properly initialised in the database.
org.openrdf.repository.RepositoryResult<Version>	listVersions() List all versions of this repository.
org.openrdf.repository.RepositoryResult<Version>	listVersions(Date from, Date to) List all versions of this repository between a start and end date.
org.openrdf.repository.RepositoryResult<Version>	listVersions(org.openrdf.model.Resource r) List all versions of this repository affecting the given resource as subject.
org.openrdf.repository.RepositoryResult<Version>	listVersions(org.openrdf.model.Resource r, Date from, Date to) List all versions of this repository affecting the given resource as subject between a start and end date.
void	removeVersion(Long id) Remove the version with the id passed as argument, including all references to added and removed triples.
void	removeVersions(Date until) Remove all versions until the date given as argument.
void	removeVersions(Date from, Date to) Remove all versions in the given time interval.
void	revertVersion(Version version) Revert (undo) the version given as argument.
void	rollback(TransactionData data) Called when a transaction rolls back.
void	shutDown()

Methods inherited from class org.apache.marmotta.commons.sesame.transactions.wrapper.TransactionalSailWrapper

addTransactionListener, isTransactionsEnabled, removeTransactionListener, setTransactionsEnabled

Methods inherited from class org.openrdf.sail.helpers.NotifyingSailWrapper

addSailChangedListener, getBaseSail, getConnection, removeSailChangedListener, setBaseSail

Methods inherited from class org.openrdf.sail.helpers.SailWrapper

getDataDir, getValueFactory, isWritable, setDataDir, verifyBaseSailSet

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.marmotta.commons.sesame.transactions.api.TransactionalSail

addTransactionListener, isTransactionsEnabled, removeTransactionListener, setTransactionsEnabled

Methods inherited from interface org.openrdf.sail.NotifyingSail

addSailChangedListener, getConnection, removeSailChangedListener

Methods inherited from interface org.openrdf.sail.Sail

getDataDir, getValueFactory, isWritable, setDataDir

Field Detail

DEFAULT_CONNECTION_TIMEOUT

protected static final long DEFAULT_CONNECTION_TIMEOUT

See Also:

Constant Field Values

Constructor Detail

KiWiVersioningSail

public KiWiVersioningSail(TransactionalSail parent)

Build a new KiWiVersioningSail based on the provided parent TransactionalSail.

Parameters:

parent - the TransactionalSail to base the KiWiVersioningSail on.

KiWiVersioningSail

public KiWiVersioningSail(TransactionalSail parent,
                  org.apache.marmotta.commons.sesame.filter.SesameFilter<org.openrdf.model.Statement> filter)

Build a new selective KiWiVersioningSail based on the provided parent TransactionalSail. Only Statements that are accepted by the filter are included in versioning.

Parameters:

parent - the TransactionalSail to base the KiWiVersioningSail on.

filter - a SesameFilter to filter out Statements that should not be versioned. Only a Statement that is accepted by this filter will be versioned.

See Also:

SesameFilter.accept(Object)

Method Detail

initialize

public void initialize()
                throws org.openrdf.sail.SailException

Ensure that the versioning tables are properly initialised in the database.

Specified by:

initialize in interface org.openrdf.sail.Sail

Overrides:

initialize in class org.openrdf.sail.helpers.SailWrapper

Throws:

org.openrdf.sail.SailException

getBaseStore

public KiWiStore getBaseStore()

Return the KiWi store that is at the base of the SAIL stack. Throws an IllegalArgumentException in case the base store is not a KiWi store.

Returns:

getPersistence

public KiWiVersioningPersistence getPersistence()

Return the versioning persistence object underlying this SAIL.

Returns:

afterCommit

public void afterCommit(TransactionData data)

Called after a transaction has committed. This method will take the transaction data and convert it into a Version object, which will then be persisted in the KiWiVersioningPersistence.

Specified by:

afterCommit in interface TransactionListener

Parameters:

data -

beforeCommit

public void beforeCommit(TransactionData data)

Called before a transaction commits. The transaction data will contain all changes done in the transaction since the last commit. This method should be used in case the transaction listener aims to perform additional activities in the same transaction, like inserting or updating database tables.

Specified by:

beforeCommit in interface TransactionListener

Parameters:

data -

rollback

public void rollback(TransactionData data)

Called when a transaction rolls back.

Specified by:

rollback in interface TransactionListener

getSnapshot

public KiWiSnapshotConnection getSnapshot(Date snapshotDate)
                                   throws org.openrdf.sail.SailException

Get a read-only snapshot of the repository at the given date. Returns a sail connection that can be used to access the triple data. Any attempts to modify the underlying data will throw a SailReadOnlyException.

Specified by:

getSnapshot in interface VersioningSail

Parameters:

snapshotDate - the date of which to take the snapshot; the snapshot will consist of all triples that have been created before or at the date and deleted after that date (or not deleted at all).

Returns:

a read-only sail connection to access the data of the triple store at the given date

Throws:

org.openrdf.sail.SailException

closeSnapshotConnection

protected void closeSnapshotConnection(KiWiSnapshotConnection con)

Unregister the snapshot connection, it has been cleaned up properly.

Parameters:

con -

listVersions

public org.openrdf.repository.RepositoryResult<Version> listVersions()
                                                              throws org.openrdf.sail.SailException

List all versions of this repository.

Specified by:

listVersions in interface VersioningSail

Returns:

Throws:

org.openrdf.sail.SailException

listVersions

public org.openrdf.repository.RepositoryResult<Version> listVersions(Date from,
                                                            Date to)
                                                              throws org.openrdf.sail.SailException

List all versions of this repository between a start and end date.

Specified by:

listVersions in interface VersioningSail

Returns:

Throws:

org.openrdf.sail.SailException

getVersion

public Version getVersion(Long id)
                   throws org.openrdf.sail.SailException

Throws:

org.openrdf.sail.SailException

removeVersion

public void removeVersion(Long id)
                   throws org.openrdf.sail.SailException

Remove the version with the id passed as argument, including all references to added and removed triples. The triples themselves are not deleted immediately, we let the garbage collector carry this out periodically.

Parameters:

id - the database ID of the version (see Version.getId())

Throws:

org.openrdf.sail.SailException

removeVersions

public void removeVersions(Date until)
                    throws org.openrdf.sail.SailException

Remove all versions until the date given as argument. Iterates over all versions and deletes them individually. Entries in join tables (added/removed triples) are also deleted, the triples themselves not. Deleted triples without version will later be cleaned up by the garbage collector

Parameters:

until - date until when to delete versions

Throws:

org.openrdf.sail.SailException

removeVersions

public void removeVersions(Date from,
                  Date to)
                    throws org.openrdf.sail.SailException

Remove all versions in the given time interval. Iterates over all versions and deletes them individually. Entries in join tables (added/removed triples) are also deleted, the triples themselves not. Deleted triples without version will later be cleaned up by the garbage collector

Parameters:

from - date after which versions will be deleted

to - date before which versions will be deleted

Throws:

org.openrdf.sail.SailException

getLatestVersion

public Version getLatestVersion(org.openrdf.model.Resource r,
                       Date date)
                         throws org.openrdf.sail.SailException

Return the version that is the most recent version for a resource given a reference date. The method will either return the version that was current for the resource at the given date or return null in case such a version does not exist (e.g. before the resource was created).

Parameters:

r - the resource for which to find a version

date - the reference date

Returns:

the latest version of the resource at the given date, or null if such a version does not exist

Throws:

SQLException

org.openrdf.sail.SailException

listVersions

public org.openrdf.repository.RepositoryResult<Version> listVersions(org.openrdf.model.Resource r)
                                                              throws org.openrdf.sail.SailException

List all versions of this repository affecting the given resource as subject.

Specified by:

listVersions in interface VersioningSail

Returns:

Throws:

org.openrdf.sail.SailException

listVersions

public org.openrdf.repository.RepositoryResult<Version> listVersions(org.openrdf.model.Resource r,
                                                            Date from,
                                                            Date to)
                                                              throws org.openrdf.sail.SailException

List all versions of this repository affecting the given resource as subject between a start and end date.

Specified by:

listVersions in interface VersioningSail

Returns:

Throws:

org.openrdf.sail.SailException

revertVersion

public void revertVersion(Version version)
                   throws org.openrdf.sail.SailException

Revert (undo) the version given as argument. This method creates a new transaction, adds all triples that were deleted in the old version, removes all triples that were added in the old version, and commits the transaction, effectively creating a new (reverted) version.

Parameters:

version - the version to revert

Throws:

org.openrdf.sail.SailException - in case reverting the version failed

shutDown

public void shutDown()
              throws org.openrdf.sail.SailException

Specified by:

shutDown in interface org.openrdf.sail.Sail

Overrides:

shutDown in class org.openrdf.sail.helpers.SailWrapper

Throws:

org.openrdf.sail.SailException