com.tangosol.io.bdb
Class DatabaseFactory.EnvironmentHolder

java.lang.Object
  com.tangosol.io.bdb.DatabaseFactory.EnvironmentHolder

All Implemented Interfaces:

Runnable

Enclosing class:

DatabaseFactory

protected static class DatabaseFactory.EnvironmentHolder
extends Object
implements Runnable

Holder for Berkeley DB Environment and its Databases.

The Environment and Databases will be automatically flushed upon JVM shutdown or GC of the associated DatabaseFactory. For temporary Environments, the data will also be deleted. These operations are accomplished by registering this class as a JVM shutdown hook.

This logic is maintained externally from DatabaseFactory to allow for the Factory to be GC'd. If the Factory acted as the shutdown hook then it would never be GC'd as the Runtime would always hold a reference to it via the registered shutdown hook.

Author:

mf 2005.10.04

Nested Class Summary

protected static class

DatabaseFactory.EnvironmentHolder.DirectoryLock Directory based lock.

Field Summary

static String	ENVIRONMENT_NAME_PREFIX Prefix for temporary environment names.
static String	JE_PROPERTY_PREFIX Prefix for all Berkeley DB JE configuration settings.
protected Collection	m_colRegisteredDbs Databases to close prior to deleting the Environment.
protected File	m_dirEnv Environment directory.
protected DatabaseFactory.EnvironmentHolder.DirectoryLock	m_dirLock Lock held on the directory associated with the Environment.
protected File	m_dirParent Configuration setting for parent directory.
protected com.sleepycat.je.Environment	m_env Berkeley DB Environment for managing Databases.
protected com.sleepycat.je.EnvironmentConfig	m_envConfig Berkeley DB Environment Configuration.
protected boolean	m_fTemporary Flag indicating if this is a temporary environment.
protected Thread	m_threadShutdownHook Shutdown hook for closing environment.
protected XmlElement	m_xmlConfig Configuration.
static String	SUB_DIR_NAME Default directory name for berkeley db environments.
static String	TEMP_FILE_NAME_PREFIX Prefix for temporary file names.

Constructor Summary

DatabaseFactory.EnvironmentHolder(BerkeleyDBBinaryStoreManager bdbManager)
Construct a EnvironmentHolder for a given Berkeley DB Environment.

Method Summary

void	closeEnvironment(boolean fDeregister) Close an Environment.
protected File	computeTmpDir() Compute the system's temp directory.
protected void	configure(BerkeleyDBBinaryStoreManager bdbManager) Configure the new Environment.
protected void	createPersistentEnvironment() Create a persistent Environment.
protected void	createTemporaryEnvironment() Create a temporary Environment.
void	forgetDatabase(com.sleepycat.je.Database db) Remove a database handle from the cleanup list.
protected String	generateEnvironmentName() Generate a potentially unique Environment name.
File	getDirEnv() Get the Environment Directory.
DatabaseFactory.EnvironmentHolder.DirectoryLock	getDirLock() Get the DirectoryLock held on a temporary Environment.
File	getDirParent() Get the Parent Directory.
com.sleepycat.je.EnvironmentConfig	getEnvConfig() Get the Environment Configuration.
com.sleepycat.je.Environment	getEnvironment() Get underlying Berkeley DB Environment.
Collection	getRegisteredDbs() Get the registered Databases.
XmlElement	getXmlConfig() Get the XML Configuration.
boolean	isTemporary() Return true if this is a temporary environment.
void	run() Shutdown hook runnable method.
String	toString() Return a human readable description of the EnvironmentHolder.
void	trackDatabase(com.sleepycat.je.Database db) Add a database handle to the trackings list.

Field Detail

SUB_DIR_NAME

public static final String SUB_DIR_NAME

Default directory name for berkeley db environments.

ENVIRONMENT_NAME_PREFIX

public static final String ENVIRONMENT_NAME_PREFIX

Prefix for temporary environment names.

See Also:

Constant Field Values

TEMP_FILE_NAME_PREFIX

public static final String TEMP_FILE_NAME_PREFIX

Prefix for temporary file names.

See Also:

Constant Field Values

JE_PROPERTY_PREFIX

public static final String JE_PROPERTY_PREFIX

Prefix for all Berkeley DB JE configuration settings.

See Also:

Constant Field Values

m_xmlConfig

protected XmlElement m_xmlConfig

Configuration.

m_dirParent

protected File m_dirParent

Configuration setting for parent directory.

m_dirEnv

protected File m_dirEnv

Environment directory.

m_envConfig

protected com.sleepycat.je.EnvironmentConfig m_envConfig

Berkeley DB Environment Configuration.

m_env

protected com.sleepycat.je.Environment m_env

Berkeley DB Environment for managing Databases.

m_colRegisteredDbs

protected Collection m_colRegisteredDbs

Databases to close prior to deleting the Environment.

m_dirLock

protected DatabaseFactory.EnvironmentHolder.DirectoryLock m_dirLock

Lock held on the directory associated with the Environment.

m_fTemporary

protected boolean m_fTemporary

Flag indicating if this is a temporary environment.

m_threadShutdownHook

protected Thread m_threadShutdownHook

Shutdown hook for closing environment.

Constructor Detail

DatabaseFactory.EnvironmentHolder

public DatabaseFactory.EnvironmentHolder(BerkeleyDBBinaryStoreManager bdbManager)
                                  throws com.sleepycat.je.DatabaseException

Construct a EnvironmentHolder for a given Berkeley DB Environment.

Berkeley DB Environments are bound to a single directory. Java File locking is used to ensure that only one JVM uses the Environment. The new environment will be created in a unique sub directory of the specificed parent directory.

Parameters:

bdbManager - the BinaryStoreManager to create an environment for

Throws:

com.sleepycat.je.DatabaseException - if the Berkeley DB Environment could not be created

Method Detail

toString

public String toString()

Return a human readable description of the EnvironmentHolder.

Returns:

a human readable description of the EnvironmentHolder

forgetDatabase

public void forgetDatabase(com.sleepycat.je.Database db)

Remove a database handle from the cleanup list.

Databases which are closed externally may be removed from tracking.

Parameters:

db - the Database to remove from list

run

public void run()

Shutdown hook runnable method.

This is responsible for cleaning up the databases and associated directories when the JVM exits.

Specified by:

run in interface Runnable

closeEnvironment

public void closeEnvironment(boolean fDeregister)

Close an Environment.

This includes closing the environment and databases, and if temporary deleting the associated files.

Parameters:

fDeregister - indicates if the shutdown hook should be deregistered

trackDatabase

public void trackDatabase(com.sleepycat.je.Database db)

Add a database handle to the trackings list.

Databases for the environment must be tracked so that they may be closed prior to closing the environment.

Parameters:

db - the Database to add to the list

configure

protected void configure(BerkeleyDBBinaryStoreManager bdbManager)

Configure the new Environment.

Parameters:

bdbManager - the BinaryStoreManager to create an environment for

computeTmpDir

protected File computeTmpDir()

Compute the system's temp directory.

Returns:

the system temp directory, or null if it could not be determined

createTemporaryEnvironment

protected void createTemporaryEnvironment()
                                   throws com.sleepycat.je.DatabaseException

Create a temporary Environment.

Throws:

com.sleepycat.je.DatabaseException - if environment creation fails

createPersistentEnvironment

protected void createPersistentEnvironment()
                                    throws com.sleepycat.je.DatabaseException

Create a persistent Environment.

Throws:

com.sleepycat.je.DatabaseException - if environment creation fails

generateEnvironmentName

protected String generateEnvironmentName()

Generate a potentially unique Environment name.

Returns:

an environment name

getEnvironment

public com.sleepycat.je.Environment getEnvironment()

Get underlying Berkeley DB Environment.

Returns:

the Berkeley DB Environment held by this EnvironmentHolder

getXmlConfig

public XmlElement getXmlConfig()

Get the XML Configuration.

Returns:

the XML Configuration for this Environments.

getDirParent

public File getDirParent()

Get the Parent Directory.

Returns:

the Environment's parent directory

getDirEnv

public File getDirEnv()

Get the Environment Directory.

Returns:

the Environment's directory

getEnvConfig

public com.sleepycat.je.EnvironmentConfig getEnvConfig()

Get the Environment Configuration.

Returns:

the Environment's configuration

getRegisteredDbs

public Collection getRegisteredDbs()

Get the registered Databases.

Returns:

a collection of open Databases from this Environment

getDirLock

public DatabaseFactory.EnvironmentHolder.DirectoryLock getDirLock()

Get the DirectoryLock held on a temporary Environment.

Returns:

the DirectoryLock held on the temporary Environment

isTemporary

public boolean isTemporary()

Return true if this is a temporary environment.

Returns:

true if this is a temporary environment