jdbm.htree
Class HTree<K,V>

java.lang.Object
  jdbm.htree.HTree<K,V>

All Implemented Interfaces:

JdbmBase<K,V>

public class HTree<K,V>
extends java.lang.Object
implements JdbmBase<K,V>

Persistent hashtable implementation for PageManager. Implemented as an H*Tree structure. WARNING! If this instance is used in a transactional context, it *must* be discarded after a rollback.

Version:

$Id: HTree.java,v 1.3 2005/06/25 23:12:32 doomdark Exp $

Author:

Alex Boisvert

Method Summary

void	addRecordListener(RecordListener<K,V> listener) add RecordListener which is notified about record changes
HTreeMap<K,V>	asMap()
static <K,V> HTree<K,V>	createInstance(RecordManager recman) Create a persistent hashtable.
V	find(K key) Returns the value which is associated with the given key.
long	getRecid() Get the record identifier used to load this hashtable.
RecordManager	getRecordManager()
java.util.Iterator<K>	keys() Returns an enumeration of the keys contained in this
static <K,V> HTree<K,V>	load(RecordManager recman, long root_recid) Load a persistent hashtable
void	put(K key, V value) Associates the specified value with the specified key.
void	remove(K key) Remove the value which is associated with the given key.
void	removeRecordListener(RecordListener<K,V> listener) remove RecordListener which is notified about record changes
java.util.Iterator<V>	values() Returns an enumeration of the values contained in this

Methods inherited from class java.lang.Object

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

Method Detail

createInstance

public static <K,V> HTree<K,V> createInstance(RecordManager recman)
                                 throws java.io.IOException

Create a persistent hashtable.

Parameters:

recman - Record manager used for persistence.

Throws:

java.io.IOException

load

public static <K,V> HTree<K,V> load(RecordManager recman,
                                    long root_recid)
                       throws java.io.IOException

Load a persistent hashtable

Parameters:

recman - RecordManager used to store the persistent hashtable

root_recid - Record id of the root directory of the HTree

Throws:

java.io.IOException

put

public void put(K key,
                V value)
         throws java.io.IOException

Associates the specified value with the specified key.

Parameters:

key - key with which the specified value is to be assocated.

value - value to be associated with the specified key.

Throws:

java.io.IOException

find

public V find(K key)
       throws java.io.IOException

Returns the value which is associated with the given key. Returns null if there is not association for this key.

Specified by:

find in interface JdbmBase<K,V>

Parameters:

key - key whose associated value is to be returned

Returns:

value or null if not found

Throws:

java.io.IOException

remove

public void remove(K key)
            throws java.io.IOException

Remove the value which is associated with the given key. If the key does not exist, this method simply ignores the operation.

Parameters:

key - key whose associated value is to be removed

Throws:

java.io.IOException

keys

public java.util.Iterator<K> keys()
                           throws java.io.IOException

Returns an enumeration of the keys contained in this

Throws:

java.io.IOException

values

public java.util.Iterator<V> values()
                             throws java.io.IOException

Returns an enumeration of the values contained in this

Throws:

java.io.IOException

getRecid

public long getRecid()

Get the record identifier used to load this hashtable.

asMap

public HTreeMap<K,V> asMap()

addRecordListener

public void addRecordListener(RecordListener<K,V> listener)

add RecordListener which is notified about record changes

Specified by:

addRecordListener in interface JdbmBase<K,V>

Parameters:

listener -

removeRecordListener

public void removeRecordListener(RecordListener<K,V> listener)

remove RecordListener which is notified about record changes

Specified by:

removeRecordListener in interface JdbmBase<K,V>

Parameters:

listener -

getRecordManager

public RecordManager getRecordManager()

Specified by:

getRecordManager in interface JdbmBase<K,V>

Returns:

underlying record manager