org.apache.directory.server.core.changelog

Class MemoryChangeLogStore

java.lang.Object

org.apache.directory.server.core.changelog.MemoryChangeLogStore

All Implemented Interfaces:

ChangeLogStore, TaggableChangeLogStore

public class MemoryChangeLogStore
extends Object
implements TaggableChangeLogStore

A change log store that keeps it's information in memory.

Author:

Apache Directory Project

Constructor Summary

Constructors

Constructor and Description
MemoryChangeLogStore()

Method Summary

Modifier and Type	Method and Description
void	destroy() Save logs, tags and revision on disk, and clean everything in memory
org.apache.directory.api.ldap.model.cursor.Cursor<ChangeLogEvent>	find() Gets a Cursor over all the ChangeLogEvents within the system since revision 0.
org.apache.directory.api.ldap.model.cursor.Cursor<ChangeLogEvent>	find(long startRevision, long endRevision) Finds the ChangeLogEvents that occurred between a revision range inclusive.
org.apache.directory.api.ldap.model.cursor.Cursor<ChangeLogEvent>	findAfter(long revision) Finds the ChangeLogEvents that occurred after a revision exclusive.
org.apache.directory.api.ldap.model.cursor.Cursor<ChangeLogEvent>	findBefore(long revision) Gets a Cursor over the ChangeLogEvents that occurred before a revision exclusive.
long	getCurrentRevision() Gets the current revision of the server (a.k.a.
Tag	getLatest() Gets the latest tag if one was at all taken.
void	init(DirectoryService service) Initialize the store.
ChangeLogEvent	log(LdapPrincipal principal, org.apache.directory.api.ldap.model.ldif.LdifEntry forward, org.apache.directory.api.ldap.model.ldif.LdifEntry reverse) Records a change as a forward LDIF, a reverse change to revert the change and the authorized principal triggering the revertable change event.
ChangeLogEvent	log(LdapPrincipal principal, org.apache.directory.api.ldap.model.ldif.LdifEntry forward, List<org.apache.directory.api.ldap.model.ldif.LdifEntry> reverses) Records a change as a forward LDIF, some reverse changes to revert the change and the authorized principal triggering the revertable change event.
ChangeLogEvent	lookup(long revision) Looks up the ChangeLogEvent for a revision.
Tag	removeTag(long revision) Removes a Tag created for a given revision.
void	sync() Write the changes on disk
Tag	tag() Creates a snapshot of the server at the current revision.
Tag	tag(long revision) Creates a tag for a snapshot of the server in a specific state at a revision.
Tag	tag(long revision, String descrition) Creates a tag with the given description for a snapshot of the server in a specific state at a revision.
Tag	tag(String description) Creates a snapshot of the server at the current revision with a description of the snapshot tag.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryChangeLogStore

public MemoryChangeLogStore()

Method Detail

tag

public Tag tag(long revision)
        throws Exception

Creates a tag for a snapshot of the server in a specific state at a revision.

Specified by:

tag in interface TaggableChangeLogStore

Parameters:

revision - the revision to tag the snapshot

Returns:

the Tag associated with the revision

Throws:

Exception - if there is a problem taking a tag, or if the revision does not exist

tag

public Tag tag()
        throws Exception

Creates a snapshot of the server at the current revision.

Specified by:

tag in interface TaggableChangeLogStore

Returns:

the revision at which the tag is created

Throws:

Exception - if there is a problem taking a tag

tag

public Tag tag(String description)
        throws Exception

Description copied from interface: TaggableChangeLogStore

Creates a snapshot of the server at the current revision with a description of the snapshot tag.

Specified by:

tag in interface TaggableChangeLogStore

Parameters:

description - a description of the state associate with the tag

Returns:

the revision at which the tag is created

Throws:

Exception - if there is a problem taking a tag

init

public void init(DirectoryService service)
          throws Exception

Description copied from interface: ChangeLogStore

Initialize the store.

Specified by:

init in interface ChangeLogStore

Parameters:

service - The associated DirectoryService

Throws:

Exception - If the initialization failed

sync

public void sync()
          throws Exception

Description copied from interface: ChangeLogStore

Write the changes on disk

Specified by:

sync in interface ChangeLogStore

Throws:

Exception - If the write failed

destroy

public void destroy()
             throws Exception

Save logs, tags and revision on disk, and clean everything in memory

Specified by:

destroy in interface ChangeLogStore

Throws:

Exception - If we can't destroy the logs

getCurrentRevision

public long getCurrentRevision()

Description copied from interface: ChangeLogStore

Gets the current revision of the server (a.k.a. the HEAD revision).

Specified by:

getCurrentRevision in interface ChangeLogStore

Returns:

the current revision of the server

log

public ChangeLogEvent log(LdapPrincipal principal,
                          org.apache.directory.api.ldap.model.ldif.LdifEntry forward,
                          org.apache.directory.api.ldap.model.ldif.LdifEntry reverse)
                   throws Exception

Records a change as a forward LDIF, a reverse change to revert the change and the authorized principal triggering the revertable change event.

Specified by:

log in interface ChangeLogStore

Parameters:

principal - the authorized LDAP principal triggering the change

forward - LDIF of the change going to the next state

reverse - LDIF (anti-operation): the change required to revert this change

Returns:

the new revision reached after having applied the forward LDIF

Throws:

Exception - if there are problems logging the change

log

public ChangeLogEvent log(LdapPrincipal principal,
                          org.apache.directory.api.ldap.model.ldif.LdifEntry forward,
                          List<org.apache.directory.api.ldap.model.ldif.LdifEntry> reverses)
                   throws Exception

Records a change as a forward LDIF, some reverse changes to revert the change and the authorized principal triggering the revertable change event.

Specified by:

log in interface ChangeLogStore

Parameters:

principal - the authorized LDAP principal triggering the change

forward - LDIF of the change going to the next state

reverses - LDIF (anti-operation): the changes required to revert this change

Returns:

the new revision reached after having applied the forward LDIF

Throws:

Exception - if there are problems logging the change

lookup

public ChangeLogEvent lookup(long revision)
                      throws Exception

Description copied from interface: ChangeLogStore

Looks up the ChangeLogEvent for a revision.

Specified by:

lookup in interface ChangeLogStore

Parameters:

revision - to get a ChangeLogEvent for

Returns:

the ChangeLogEvent associated with the revision

Throws:

Exception - if there are failures accessing the store

IllegalArgumentException - if the revision is out of range (less than 0 and greater than the current revision)

find

public org.apache.directory.api.ldap.model.cursor.Cursor<ChangeLogEvent> find()
                                                                       throws Exception

Description copied from interface: ChangeLogStore

Gets a Cursor over all the ChangeLogEvents within the system since revision 0. This method should exhibit isolation characteristics: meaning if the request is initiated at revision 100, then any subsequent log entries increasing the revision should not be seen.

Specified by:

find in interface ChangeLogStore

Returns:

a Cursor over all the ChangeLogEvents

Throws:

Exception - if there are failures accessing the store

findBefore

public org.apache.directory.api.ldap.model.cursor.Cursor<ChangeLogEvent> findBefore(long revision)
                                                                             throws Exception

Description copied from interface: ChangeLogStore

Gets a Cursor over the ChangeLogEvents that occurred before a revision exclusive.

Specified by:

findBefore in interface ChangeLogStore

Parameters:

revision - the revision number to get the ChangeLogEvents before

Returns:

a Cursor over the ChangeLogEvents before a revision

Throws:

Exception - if there are failures accessing the store

IllegalArgumentException - if the revision is out of range (less than 0 and greater than the current revision)

findAfter

public org.apache.directory.api.ldap.model.cursor.Cursor<ChangeLogEvent> findAfter(long revision)
                                                                            throws org.apache.directory.api.ldap.model.exception.LdapException

Description copied from interface: ChangeLogStore

Finds the ChangeLogEvents that occurred after a revision exclusive. This method should exhibit isolation characteristics: meaning if the request is initiated at revision 100 then any subsequent log entries increasing the revision should not be seen.

Specified by:

findAfter in interface ChangeLogStore

Parameters:

revision - the revision number to get the ChangeLogEvents after

Returns:

a Cursor of all the ChangeLogEvents after and including the revision

Throws:

org.apache.directory.api.ldap.model.exception.LdapException

find

public org.apache.directory.api.ldap.model.cursor.Cursor<ChangeLogEvent> find(long startRevision,
                                                                              long endRevision)
                                                                       throws Exception

Description copied from interface: ChangeLogStore

Finds the ChangeLogEvents that occurred between a revision range inclusive.

Specified by:

find in interface ChangeLogStore

Parameters:

startRevision - the revision number to start getting the ChangeLogEvents above

endRevision - the revision number to start getting the ChangeLogEvents below

Returns:

an enumeration of all the ChangeLogEvents within some revision range inclusive

Throws:

Exception - if there are failures accessing the store

IllegalArgumentException - if the start and end revisions are out of range (less than 0 and greater than the current revision), or if startRevision > endRevision

getLatest

public Tag getLatest()
              throws org.apache.directory.api.ldap.model.exception.LdapException

Description copied from interface: TaggableChangeLogStore

Gets the latest tag if one was at all taken.

Specified by:

getLatest in interface TaggableChangeLogStore

Returns:

the last tag to have been created (youngest), or null if no tags have been created

Throws:

org.apache.directory.api.ldap.model.exception.LdapException

removeTag

public Tag removeTag(long revision)
              throws Exception

Description copied from interface: TaggableChangeLogStore

Removes a Tag created for a given revision.

Specified by:

removeTag in interface TaggableChangeLogStore

Parameters:

revision - the revision number that was tagged

Returns:

the removed tag, null if there is no Tag present with the given revision

Throws:

Exception - on failures to access the tag store

See Also:

TaggableChangeLogStore.removeTag(long)

tag

public Tag tag(long revision,
               String descrition)
        throws Exception

Description copied from interface: TaggableChangeLogStore

Creates a tag with the given description for a snapshot of the server in a specific state at a revision.

Specified by:

tag in interface TaggableChangeLogStore

Parameters:

revision - the revision number that was tagged

descrition - a description of the state associate with the tag

Returns:

the Tag associated with the revision

Throws:

Exception - on failures to access the tag store

See Also:

TaggableChangeLogStore.tag(long, String)

toString

public String toString()

Overrides:

toString in class Object

See Also:

Object.toString()