org.jpos.space
Class JDBMSpace<K,V>

java.lang.Object
  java.util.TimerTask
      org.jpos.space.JDBMSpace<K,V>

All Implemented Interfaces:

Runnable, Space<K,V>

public class JDBMSpace<K,V>
extends TimerTask
implements Space<K,V>

JDBM based persistent space implementation

Since:

1.4.7

Version:

$Revision$ $Date$

Author:

Alejandro Revilla, Kris Leite

Field Summary

protected boolean	autoCommit
static long	GCDELAY
protected jdbm.htree.HTree	htree
protected String	name
protected jdbm.RecordManager	recman
protected static jdbm.helper.Serializer	refSerializer
protected static Map<String,Space>	spaceRegistrar

Constructor Summary

protected

JDBMSpace(String name, String filename) protected constructor.

Method Summary

void	close() close this space - use with care
void	commit() force commit
boolean	existAny(Object[] keys)
boolean	existAny(Object[] keys, long timeout)
void	gc() garbage collector.
String	getKeys()
static JDBMSpace	getSpace()
static JDBMSpace	getSpace(String name) creates a named JDBMSpace (filename used for storage is the same as the given name)
static JDBMSpace	getSpace(String name, String filename) creates a named JDBMSpace
V	in(Object key) Take an entry from the space, waiting forever until one exists.
V	in(Object key, long timeout) Take an entry from the space, waiting forever until one exists.
V	inp(Object key) In probe takes an entry from the space if one exists, return null otherwise.
void	out(K key, V value) Write a new entry into the Space
void	out(K key, V value, long timeout) Write a new entry into the Space The entry will timeout after the specified period
void	push(K key, V value) Write a new entry at the head of a queue.
void	push(Object key, Object value, long timeout) Write a new entry into the Space at the head of a queue The entry will timeout after the specified period
void	put(K key, V value) Write a single entry at the head of the queue discarding the other entries
void	put(K key, V value, long timeout) Write a single entry at the head of the queue discarding the other entries, with timeout.
V	rd(Object key) Read an entry from the space, waiting forever until one exists.
V	rd(Object key, long timeout) Read an entry from the space, waiting a limited amount of time until one exists.
V	rdp(Object key) Read probe reads an entry from the space if one exists, return null otherwise.
void	rollback() force rollback
void	run()
void	setAutoCommit(boolean b) Use with utmost care and at your own risk.
long	size(Object key)

Methods inherited from class java.util.TimerTask

cancel, scheduledExecutionTime

Methods inherited from class java.lang.Object

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

Field Detail

htree

protected jdbm.htree.HTree htree

recman

protected jdbm.RecordManager recman

refSerializer

protected static final jdbm.helper.Serializer refSerializer

spaceRegistrar

protected static final Map<String,Space> spaceRegistrar

autoCommit

protected boolean autoCommit

name

protected String name

GCDELAY

public static final long GCDELAY

See Also:

Constant Field Values

Constructor Detail

JDBMSpace

protected JDBMSpace(String name,
                    String filename)

protected constructor.

Parameters:

name - Space Name

filename - underlying JDBM filename

See Also:

SpaceFactory().getSpace()

Method Detail

getSpace

public static JDBMSpace getSpace()

Returns:

reference to default JDBMSpace

getSpace

public static JDBMSpace getSpace(String name)

creates a named JDBMSpace (filename used for storage is the same as the given name)

Parameters:

name - the Space name

Returns:

reference to named JDBMSpace

getSpace

public static JDBMSpace getSpace(String name,
                                 String filename)

creates a named JDBMSpace

Parameters:

name - the Space name

filename - the storage file name

Returns:

reference to named JDBMSpace

setAutoCommit

public void setAutoCommit(boolean b)

Use with utmost care and at your own risk. If you are to perform several operations on the space you should synchronize on the space, i.e:

   synchronized (sp) {
     sp.setAutoCommit (false);
     sp.out (..., ...)
     sp.out (..., ...)
     ...
     ...
     sp.inp (...);
     sp.commit ();    // or sp.rollback ();
     sp.setAutoCommit (true);
   }
 

Parameters:

b - true or false

commit

public void commit()

force commit

rollback

public void rollback()

force rollback

close

public void close()

close this space - use with care

out

public void out(K key,
                V value)

Write a new entry into the Space

Specified by:

out in interface Space<K,V>

Parameters:

key - Entry's key

value - Object value

out

public void out(K key,
                V value,
                long timeout)

Write a new entry into the Space The entry will timeout after the specified period

Specified by:

out in interface Space<K,V>

Parameters:

key - Entry's key

value - Object value

timeout - entry timeout in millis

push

public void push(K key,
                 V value)

Description copied from interface: Space

Write a new entry at the head of a queue.

Specified by:

push in interface Space<K,V>

Parameters:

key - Entry's key

value - Object value

push

public void push(Object key,
                 Object value,
                 long timeout)

Write a new entry into the Space at the head of a queue The entry will timeout after the specified period

Specified by:

push in interface Space<K,V>

Parameters:

key - Entry's key

value - Object value

timeout - entry timeout in millis

rdp

public V rdp(Object key)

Read probe reads an entry from the space if one exists, return null otherwise.

Specified by:

rdp in interface Space<K,V>

Parameters:

key - Entry's key

Returns:

value or null

inp

public V inp(Object key)

In probe takes an entry from the space if one exists, return null otherwise.

Specified by:

inp in interface Space<K,V>

Parameters:

key - Entry's key

Returns:

value or null

in

public V in(Object key)

Description copied from interface: Space

Take an entry from the space, waiting forever until one exists.

Specified by:

in in interface Space<K,V>

Parameters:

key - Entry's key

Returns:

value

in

public V in(Object key,
            long timeout)

Take an entry from the space, waiting forever until one exists.

Specified by:

in in interface Space<K,V>

Parameters:

key - Entry's key

timeout - millis to wait

Returns:

value

rd

public V rd(Object key)

Read an entry from the space, waiting forever until one exists.

Specified by:

rd in interface Space<K,V>

Parameters:

key - Entry's key

Returns:

value

rd

public V rd(Object key,
            long timeout)

Read an entry from the space, waiting a limited amount of time until one exists.

Specified by:

rd in interface Space<K,V>

Parameters:

key - Entry's key

timeout - millis to wait

Returns:

value or null

size

public long size(Object key)

Parameters:

key - the Key

Returns:

aproximately queue size

existAny

public boolean existAny(Object[] keys)

Specified by:

existAny in interface Space<K,V>

Parameters:

keys - array of keys to check

Returns:

true if one or more keys are available in the space

existAny

public boolean existAny(Object[] keys,
                        long timeout)

Specified by:

existAny in interface Space<K,V>

Parameters:

keys - array of keys to check

timeout - to wait for any of the entries to become available

Returns:

true if one or more keys are available in the space

put

public void put(K key,
                V value,
                long timeout)

Description copied from interface: Space

Write a single entry at the head of the queue discarding the other entries, with timeout.

Specified by:

put in interface Space<K,V>

Parameters:

key - Entry's key

value - Object value

timeout - timeout value

put

public void put(K key,
                V value)

Description copied from interface: Space

Write a single entry at the head of the queue discarding the other entries

Specified by:

put in interface Space<K,V>

Parameters:

key - Entry's key

value - Object value

run

public void run()

Specified by:

run in interface Runnable

Specified by:

run in class TimerTask

gc

public void gc()

garbage collector. removes expired entries

getKeys

public String getKeys()