Package db

Class Database

java.lang.Object

db.Database

Direct Known Subclasses:

PackedDatabase, PrivateDatabase, VersionedDatabase

public abstract class Database
extends java.lang.Object

Database facilitates the creation of a DBHandle for accessing a database.

Public constructors are only provided for use with "Non-Versioned" databases. This class should be extended when additional management features are needed, such as for a "Versioned" database.

This class assumes exclusive control of the associated files contained within the associated database directory and relies on the proper establishment of a syncObject to midigate potential concurrent modification issues.

Nested Class Summary

Nested Classes

Change	Modifier and Type	Class	Description
	protected class	Database.DBBufferFileManager

Field Summary

Fields

Change	Modifier and Type	Field	Description
NEW	protected BufferFileManager	bfMgr
NEW	protected static java.lang.String	CHANGE_FILE_PREFIX
NEW	protected static java.lang.String	CUMULATIVE_CHANGE_FILENAME
NEW	protected static java.lang.String	CUMULATIVE_MODMAP_FILENAME
NEW	protected int	currentVersion
NEW	protected static java.lang.String	DATABASE_FILE_PREFIX
NEW	protected java.io.File	dbDir
NEW	protected boolean	dbDirCreated
NEW	protected DBFileListener	dbFileListener
NEW	protected boolean	isCheckOutCopy
NEW	protected boolean	isVersioned
NEW	protected long	lastModified
NEW	protected int	minVersion
NEW	protected java.lang.Object	syncObject
NEW	protected boolean	updateAllowed
NEW	protected static java.lang.String	VERSION_FILE_PREFIX

Constructor Summary

Constructors

Change	Modifier	Constructor	Description
	protected	Database(java.io.File dbDir)	Constructor for an existing "Non-Versioned" Database.
	protected	Database(java.io.File dbDir, boolean isVersioned, boolean create)	General Database Constructor.
	protected	Database(java.io.File dbDir, DBFileListener dbFileListener, boolean create)	Constructor for a new or existing "Non-Versioned" Database.

Method Summary

Change	Modifier and Type	Method	Description
NEW	protected static boolean	deleteDir(java.io.File dir)	Delete a directory and all of its contents.
	int	getCurrentVersion()	Returns the version number associated with the latest buffer file version.
	long	lastModified()	Returns the time at which this database was last saved.
	long	length()	Returns the length of this domain file.
	DBHandle	open(TaskMonitor monitor)	Open the stored database for non-update use.
	DBHandle	openForUpdate(TaskMonitor monitor)	Open the stored database for update use.
	void	refresh()	Scan files and update state.
NEW	protected void	scanFiles(boolean repair)	Scan files and update state.
	void	setSynchronizationObject(java.lang.Object syncObject)	Set the object to be used for synchronization.

Methods inherited from class java.lang.Object

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

Field Detail

DATABASE_FILE_PREFIX NEW

protected static final java.lang.String DATABASE_FILE_PREFIX

See Also:

Constant Field Values

VERSION_FILE_PREFIX NEW

protected static final java.lang.String VERSION_FILE_PREFIX

See Also:

Constant Field Values

CHANGE_FILE_PREFIX NEW

protected static final java.lang.String CHANGE_FILE_PREFIX

See Also:

Constant Field Values

CUMULATIVE_CHANGE_FILENAME NEW

protected static final java.lang.String CUMULATIVE_CHANGE_FILENAME

See Also:

Constant Field Values

CUMULATIVE_MODMAP_FILENAME NEW

protected static final java.lang.String CUMULATIVE_MODMAP_FILENAME

See Also:

Constant Field Values

minVersion NEW

protected int minVersion

currentVersion NEW

protected int currentVersion

lastModified NEW

protected long lastModified

isVersioned NEW

protected boolean isVersioned

isCheckOutCopy NEW

protected boolean isCheckOutCopy

updateAllowed NEW

protected boolean updateAllowed

bfMgr NEW

protected BufferFileManager bfMgr

dbDir NEW

protected java.io.File dbDir

dbFileListener NEW

protected DBFileListener dbFileListener

dbDirCreated NEW

protected boolean dbDirCreated

syncObject NEW

protected java.lang.Object syncObject

Constructor Detail

Database

protected Database(java.io.File dbDir,
                   boolean isVersioned,
                   boolean create)
            throws java.io.IOException

General Database Constructor.

Parameters:

dbDir -

isVersioned -

create - if true the database will be created.

Throws:

java.io.IOException

Database

protected Database(java.io.File dbDir,
                   DBFileListener dbFileListener,
                   boolean create)
            throws java.io.IOException

Constructor for a new or existing "Non-Versioned" Database.

Parameters:

dbDir -

dbFileListener - file version listener

create -

Throws:

java.io.IOException

Database

protected Database(java.io.File dbDir)
            throws java.io.IOException

Constructor for an existing "Non-Versioned" Database.

Parameters:

dbDir - database directory

Throws:

java.io.IOException

Method Detail

setSynchronizationObject

public void setSynchronizationObject(java.lang.Object syncObject)

Set the object to be used for synchronization.

Parameters:

syncObject -

lastModified

public long lastModified()

Returns the time at which this database was last saved.

deleteDir NEW

protected static final boolean deleteDir(java.io.File dir)

Delete a directory and all of its contents.

Parameters:

dir -

Returns:

true if delete was successful. If false is returned, a partial delete may have occurred.

getCurrentVersion

public int getCurrentVersion()

Returns the version number associated with the latest buffer file version.

open

public DBHandle open(TaskMonitor monitor)
              throws java.io.IOException,
                     CancelledException

Open the stored database for non-update use. The returned handle does not support the Save operation.

Parameters:

monitor - task monitor (may be null)

Returns:

database handle

Throws:

FileInUseException - thrown if unable to obtain the required database lock(s).

java.io.IOException - thrown if IO error occurs.

CancelledException - if cancelled by monitor

openForUpdate

public DBHandle openForUpdate(TaskMonitor monitor)
                       throws java.io.IOException,
                              CancelledException

Open the stored database for update use.

Parameters:

monitor - task monitor (may be null)

Returns:

buffer file

Throws:

FileInUseException - thrown if unable to obtain the required database lock(s).

java.io.IOException - thrown if IO error occurs.

CancelledException - if cancelled by monitor

length

public long length()
            throws java.io.IOException

Returns the length of this domain file. This size is the minimum disk space used for storing this file, but does not account for additional storage space used to tracks changes, etc.

Returns:

file length

Throws:

java.io.IOException - thrown if IO or access error occurs

refresh

public void refresh()
             throws java.io.FileNotFoundException

Scan files and update state.

Throws:

java.io.FileNotFoundException

scanFiles NEW

protected void scanFiles(boolean repair)
                  throws java.io.FileNotFoundException

Scan files and update state.

Parameters:

repair - if true files are repaired if needed.

Throws:

java.io.FileNotFoundException