com.bigdata.rdf.changesets

Class InMemChangeLog

java.lang.Object

com.bigdata.rdf.changesets.InMemChangeLog

All Implemented Interfaces:

IChangeLog

public class InMemChangeLog
extends Object
implements IChangeLog

This is a very simple implementation of a change log. NOTE: This is not a particularly great implementation. First of all it ends up storing two copies of the change set. Secondly it needs to be smarter about concurrency, or maybe we can be smart about it when we do the implementation on the other side (the SAIL connection can just write change events to a buffer and then the buffer can be drained by another thread that doesn't block the actual read/write operations, although then we need to be careful not to issue the committed() notification before the buffer is drained).

Author:

mike

Constructor Summary

Constructors

Constructor and Description
InMemChangeLog()

Method Summary

Methods

Modifier and Type	Method and Description
void	changeEvent(IChangeRecord record) See IChangeLog.changeEvent(IChangeRecord).
void	close() See IChangeLog.close().
Collection<IChangeRecord>	getLastCommit() Return the change set as of the last commmit point.
Collection<IChangeRecord>	getLastCommit(AbstractTripleStore db) Return the change set as of the last commmit point, using the supplied database to resolve ISPOs to BigdataStatements.
void	transactionAborted() See IChangeLog.transactionAborted().
void	transactionBegin() Message issued when a new transaction will begin.
void	transactionCommited(long commitTime) See IChangeLog.transactionCommited(long).
void	transactionPrepare() Message issued when preparing for a commit.

Methods inherited from class java.lang.Object

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

Constructor Detail

InMemChangeLog

public InMemChangeLog()

Method Detail

changeEvent

public void changeEvent(IChangeRecord record)

See IChangeLog.changeEvent(IChangeRecord).

Specified by:

changeEvent in interface IChangeLog

Parameters:

record - the IChangeRecord

transactionBegin

public void transactionBegin()

Description copied from interface: IChangeLog

Message issued when a new transaction will begin.

Specified by:

transactionBegin in interface IChangeLog

transactionPrepare

public void transactionPrepare()

Description copied from interface: IChangeLog

Message issued when preparing for a commit. The next message will be either IChangeLog.transactionCommited(long) or IChangeLog.transactionAborted().

Note: The listener will have observed all updates by the time this message is generated. Thus, this message can be used to validate post-conditions for the transaction.

Specified by:

transactionPrepare in interface IChangeLog

transactionCommited

public void transactionCommited(long commitTime)

See IChangeLog.transactionCommited(long).

Specified by:

transactionCommited in interface IChangeLog

Parameters:

commitTime - The timestamp associated with the commit point.

transactionAborted

public void transactionAborted()

See IChangeLog.transactionAborted().

Specified by:

transactionAborted in interface IChangeLog

close

public void close()

See IChangeLog.close().

Specified by:

close in interface IChangeLog

getLastCommit

public Collection<IChangeRecord> getLastCommit()

Return the change set as of the last commmit point.

Returns:

a collection of IChangeRecords as of the last commit point

getLastCommit

public Collection<IChangeRecord> getLastCommit(AbstractTripleStore db)

Return the change set as of the last commmit point, using the supplied database to resolve ISPOs to BigdataStatements.

Returns:

a collection of IChangeRecords as of the last commit point