org.neodatis.odb.impl.core.transaction

Class DefaultTransaction

java.lang.Object

org.neodatis.odb.impl.core.transaction.DefaultTransaction

All Implemented Interfaces:

ITransaction

public class DefaultTransaction
extends java.lang.Object
implements ITransaction

 The transaction class is used to guarantee ACID behavior. It keep tracks of all session
 operations. It uses the WriteAction class to store all changes that can not be written to the file
 before the commit.
 The transaction is held by The Session class and manage commits and rollbacks.
 
 All WriteActions are written in a transaction file to be sure to be able to commit and in case 
 of very big transaction where all WriteActions can not be stored in memory.
 

Field Summary

Fields

Modifier and Type	Field and Description
IWriteAction	currentWriteAction The same write action is reused for successive writes
long	currentWritePositionInWA The position of the next write for WriteAction
IFileSystemInterface	fsi A file interface to the transaction file - used to read/write the file
static java.lang.String	LOG_ID the log module name
int	numberOfWriteActions The number of write actions
ISession	session The transaction session

Constructor Summary

Constructors

Constructor and Description
DefaultTransaction(ISession session) The main constructor
DefaultTransaction(ISession session, IFileSystemInterface fsiToApplyTransaction)
DefaultTransaction(ISession session, java.lang.String overrideTransactionName)

Method Summary

Modifier and Type	Method and Description
void	addWriteAction(IWriteAction writeAction) Adds a write action to the transaction
void	addWriteAction(IWriteAction writeAction, boolean persistWriteAcion) Adds a write action to the transaction
ClassInfo	buildClassInfoForCommit(ClassInfo classInfo) Shift all unconnected infos to connected (committed) infos
void	clear() clear the transaction
void	commit() Execute the commit process of the transaction
long	getCreationDateTime()
IFileSystemInterface	getFsi()
java.lang.String	getName()
int	getNumberOfWriteActions()
IOdbList<IWriteAction>	getWriteActions()
void	init(ISession session)
boolean	isArchiveLog()
boolean	isCommited()
void	loadWriteActions(boolean apply)
void	loadWriteActions(java.lang.String filename, boolean apply)
void	loadWriteActionsBackwards(java.lang.String filename, boolean apply)
void	manageWriteAction(long position, byte[] bytes) The public method to add a write action to the transaction.
static DefaultTransaction	read(java.lang.String fileName)
void	reset() Reset the transaction
void	rollback()
void	setArchiveLog(boolean archiveLog)
void	setFsiToApplyWriteActions(IFileSystemInterface fsi)
void	setWritePosition(long position) Set the write position (position in main database file).
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

LOG_ID

public static final java.lang.String LOG_ID

the log module name

See Also:

Constant Field Values

currentWriteAction

public IWriteAction currentWriteAction

The same write action is reused for successive writes

currentWritePositionInWA

public long currentWritePositionInWA

The position of the next write for WriteAction

numberOfWriteActions

public int numberOfWriteActions

The number of write actions

fsi

public IFileSystemInterface fsi

A file interface to the transaction file - used to read/write the file

session

public ISession session

The transaction session

Constructor Detail

DefaultTransaction

public DefaultTransaction(ISession session)
                   throws java.io.IOException

The main constructor

Parameters:

session - The transaction session

Throws:

java.io.IOException

DefaultTransaction

public DefaultTransaction(ISession session,
                          java.lang.String overrideTransactionName)
                   throws java.io.IOException

Throws:

java.io.IOException

DefaultTransaction

public DefaultTransaction(ISession session,
                          IFileSystemInterface fsiToApplyTransaction)

Method Detail

init

public void init(ISession session)

clear

public void clear()

Description copied from interface: ITransaction

clear the transaction

Specified by:

clear in interface ITransaction

reset

public void reset()

Reset the transaction

Specified by:

reset in interface ITransaction

addWriteAction

public void addWriteAction(IWriteAction writeAction)

Adds a write action to the transaction

Parameters:

writeAction - The write action to be added

addWriteAction

public void addWriteAction(IWriteAction writeAction,
                           boolean persistWriteAcion)

Adds a write action to the transaction

Parameters:

writeAction - The write action to be added

persistWriteAcion - To indicate if write action must be persisted

getName

public java.lang.String getName()

Specified by:

getName in interface ITransaction

getWriteActions

public IOdbList<IWriteAction> getWriteActions()

getCreationDateTime

public long getCreationDateTime()

isCommited

public boolean isCommited()

Specified by:

isCommited in interface ITransaction

rollback

public void rollback()

Specified by:

rollback in interface ITransaction

commit

public void commit()

Description copied from interface: ITransaction

Execute the commit process of the transaction

Specified by:

commit in interface ITransaction

buildClassInfoForCommit

public ClassInfo buildClassInfoForCommit(ClassInfo classInfo)

Shift all unconnected infos to connected (committed) infos

Parameters:

classInfo -

Returns:

The updated class info

read

public static DefaultTransaction read(java.lang.String fileName)
                               throws java.io.IOException,
                                      java.lang.ClassNotFoundException

Throws:

java.io.IOException

java.lang.ClassNotFoundException

loadWriteActions

public void loadWriteActions(boolean apply)

loadWriteActions

public void loadWriteActions(java.lang.String filename,
                             boolean apply)

loadWriteActionsBackwards

public void loadWriteActionsBackwards(java.lang.String filename,
                                      boolean apply)
                               throws java.io.IOException,
                                      java.lang.ClassNotFoundException

Throws:

java.io.IOException

java.lang.ClassNotFoundException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

setFsiToApplyWriteActions

public void setFsiToApplyWriteActions(IFileSystemInterface fsi)

Specified by:

setFsiToApplyWriteActions in interface ITransaction

isArchiveLog

public boolean isArchiveLog()

Specified by:

isArchiveLog in interface ITransaction

Returns:

Returns the archiveLog.

setArchiveLog

public void setArchiveLog(boolean archiveLog)

Specified by:

setArchiveLog in interface ITransaction

Parameters:

archiveLog - The archiveLog to set.

getNumberOfWriteActions

public int getNumberOfWriteActions()

Specified by:

getNumberOfWriteActions in interface ITransaction

Returns:

Returns the numberOfWriteActions.

getFsi

public IFileSystemInterface getFsi()
                            throws java.io.IOException

Throws:

java.io.IOException

setWritePosition

public void setWritePosition(long position)

Set the write position (position in main database file). This is used to know if the next write can be appended to the previous one (in the same current Write Action) or not.

Specified by:

setWritePosition in interface ITransaction

Parameters:

position -

manageWriteAction

public void manageWriteAction(long position,
                              byte[] bytes)

Description copied from interface: ITransaction

The public method to add a write action to the transaction. If first checks if the new write action action can be appended to the current write action. It is done by checking the currentWritePositioninWA. If yes (position==currentPositioninWA, just append the WA. If not, adds the current one to the transaction and creates a new one (as current)

Specified by:

manageWriteAction in interface ITransaction