org.apache.jackrabbit.mk.persistence
Class InMemPersistence

java.lang.Object
  org.apache.jackrabbit.mk.persistence.InMemPersistence

All Implemented Interfaces:

Closeable, GCPersistence, Persistence

public class InMemPersistence
extends Object
implements GCPersistence

Constructor Summary

InMemPersistence()

Method Summary

void	close()
void	initialize(File homeDir)
boolean	markCNEMap(Id id) Mark a child node entry map.
boolean	markCommit(Id id) Mark a commit.
boolean	markNode(Id id) Mark a node.
ChildNodeEntriesMap	readCNEMap(Id id)
StoredCommit	readCommit(Id id)
Id[]	readIds() Return an array of ids, where the first is the head id (as stored with Persistence.writeHead(Id)) and the second is the highest commit id found or null.
void	readNode(StoredNode node) Read a node from storage.
void	replaceCommit(Id id, Commit commit) Replace a commit.
void	start() Start a GC cycle.
int	sweep() Sweep all objects that are not marked and were written before the GC started.
Id	writeCNEMap(ChildNodeEntries map)
void	writeCommit(Id id, Commit commit) Persist a commit with an id provided by the caller.
void	writeHead(Id id)
Id	writeNode(Node node)

Methods inherited from class java.lang.Object

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

Constructor Detail

InMemPersistence

public InMemPersistence()

Method Detail

initialize

public void initialize(File homeDir)

Specified by:

initialize in interface Persistence

readIds

public Id[] readIds()
             throws Exception

Description copied from interface: Persistence

Return an array of ids, where the first is the head id (as stored with Persistence.writeHead(Id)) and the second is the highest commit id found or null.

This method is not guaranteed to deliver "live" results, after something is written to the storage, so it should better be used once after initialization.

Specified by:

readIds in interface Persistence

Returns:

array of ids

Throws:

Exception - if an error occurs

writeHead

public void writeHead(Id id)

Specified by:

writeHead in interface Persistence

readNode

public void readNode(StoredNode node)
              throws NotFoundException,
                     Exception

Description copied from interface: Persistence

Read a node from storage.

Specified by:

readNode in interface Persistence

Parameters:

node - node to read, with id given in StoredNode.getId()

Throws:

NotFoundException - if no such node is found

Exception - if some other error occurs

writeNode

public Id writeNode(Node node)
             throws Exception

Specified by:

writeNode in interface Persistence

Throws:

Exception

readCommit

public StoredCommit readCommit(Id id)
                        throws NotFoundException,
                               Exception

Specified by:

readCommit in interface Persistence

Throws:

NotFoundException

Exception

writeCommit

public void writeCommit(Id id,
                        Commit commit)
                 throws Exception

Description copied from interface: Persistence

Persist a commit with an id provided by the caller.

Specified by:

writeCommit in interface Persistence

Parameters:

id - commit id

commit - commit

Throws:

Exception - if an error occurs

readCNEMap

public ChildNodeEntriesMap readCNEMap(Id id)
                               throws NotFoundException,
                                      Exception

Specified by:

readCNEMap in interface Persistence

Throws:

NotFoundException

Exception

writeCNEMap

public Id writeCNEMap(ChildNodeEntries map)
               throws Exception

Specified by:

writeCNEMap in interface Persistence

Throws:

Exception

close

public void close()

Specified by:

close in interface Closeable

start

public void start()

Description copied from interface: GCPersistence

Start a GC cycle. All objects written to the persistence in subsequent calls are marked implicitely, i.e. they must be retained on GCPersistence.sweep().

Specified by:

start in interface GCPersistence

markCommit

public boolean markCommit(Id id)
                   throws NotFoundException

Description copied from interface: GCPersistence

Mark a commit.

Specified by:

markCommit in interface GCPersistence

Parameters:

id - commit id

Returns:

true if the commit was not marked before; false otherwise

Throws:

NotFoundException

markNode

public boolean markNode(Id id)
                 throws NotFoundException

Description copied from interface: GCPersistence

Mark a node.

Specified by:

markNode in interface GCPersistence

Parameters:

id - node id

Returns:

true if the node was not marked before; false otherwise

Throws:

NotFoundException

markCNEMap

public boolean markCNEMap(Id id)
                   throws NotFoundException

Description copied from interface: GCPersistence

Mark a child node entry map.

Specified by:

markCNEMap in interface GCPersistence

Parameters:

id - child node entry map id

Returns:

true if the child node entry map was not marked before; false otherwise

Throws:

NotFoundException

replaceCommit

public void replaceCommit(Id id,
                          Commit commit)
                   throws Exception

Description copied from interface: GCPersistence

Replace a commit. Introduced to replace dangling parent commits where a parent commit might be collected.

Specified by:

replaceCommit in interface GCPersistence

Parameters:

id - commit id

Throws:

Exception - if an error occurs

sweep

public int sweep()

Description copied from interface: GCPersistence

Sweep all objects that are not marked and were written before the GC started.

Specified by:

sweep in interface GCPersistence

Returns:

number of swept items or -1 if number is unknown