org.mmbase.util

Class LRUHashtable<K,V>

java.lang.Object

org.mmbase.util.LRUHashtable<K,V>

All Implemented Interfaces:

Cloneable, Map<K,V>, CacheImplementationInterface<K,V>, SizeMeasurable

Direct Known Subclasses:

MultilevelCacheHandler

Deprecated.

use org.mmbase.cache.implementation.LRUCache

public class LRUHashtable<K,V>
extends Object
implements Cloneable, CacheImplementationInterface<K,V>, SizeMeasurable

A hashtable which has a maximum of entries. Old entries are removed when the maximum is reached. This table is used mostly to implement a simple caching system.

Version:

$Id$

Author:

Rico Jansen, Michiel Meeuwissen

See Also:

Cache

Move:

consider moving to org.mmbase.cache

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	LRUHashtable.LRUEntry Deprecated. Element used to store information from the LRUHashtable.
protected class	LRUHashtable.LRUEntrySet Deprecated. Used by 'entrySet' implementation, to make the Map modifiable.
protected class	LRUHashtable.LRUEntrySetIterator Deprecated. Used by 'entrySet' implementation, to make the Map modifiable.
protected class	LRUHashtable.LRUValues Deprecated.

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
LRUHashtable() Deprecated. Creates the URL Hashtable with maximum capacity 100, starting capacity 101, and growing capacity 0.75.
LRUHashtable(int size) Deprecated. Creates the URL Hashtable with starting capacity 101 and growing capacity 0.75.
LRUHashtable(int size, int cap) Deprecated. Creates the URL Hashtable with growing capacity 0.75.
LRUHashtable(int size, int cap, float lf) Deprecated. Creates the URL Hashtable.

Method Summary

Modifier and Type	Method and Description
void	clear() Deprecated. Clears the table.
Object	clone() Deprecated. NOT IMPLEMENTED
void	config(Map<String,String> map) Deprecated. Configure the implementation with the given configuration values
boolean	containsKey(Object o) Deprecated.
boolean	containsValue(Object o) Deprecated.
Enumeration<V>	elements() Deprecated. Returns an Enumeration on the table's element values.
Set<Map.Entry<K,V>>	entrySet() Deprecated. Returns the entries of this Map.
V	get(Object key) Deprecated. Retrieves an element from the table.
int	getByteSize() Deprecated. Determines the byte-size of this object
int	getByteSize(SizeOf sizeof) Deprecated. Determines the byte-size of this object using the given SizeOf instance.
int	getCount(Object key) Deprecated. Retrieves the count of the object with a certain key.
Object	getLock() Deprecated. The cache implementation must be somehow thread-safe.
Enumeration<V>	getOrderedElements() Deprecated. use getOrderedEntries
Enumeration<V>	getOrderedElements(int maxnumber) Deprecated. use getOrderedEntries
List<? extends Map.Entry<K,V>>	getOrderedEntries() Deprecated. Returns an ordered list of Map.Entry's.
List<? extends Map.Entry<K,V>>	getOrderedEntries(int maxNumber) Deprecated. Returns an ordered list of Map.Entry's.
boolean	isEmpty() Deprecated.
Set<K>	keySet() Deprecated. You should only remove entries from LRUHashtable using the 'remove' function, or using the iterator of entrySet() otherwise the linked list gets messed up.
int	maxSize() Deprecated. Return the maximum size of the table
V	put(K key, V value) Deprecated. Store an element in the table.
void	putAll(Map<? extends K,? extends V> t) Deprecated.
V	remove(Object key) Deprecated. Remove an element from the table.
void	setMaxSize(int size) Deprecated. Change the maximum size of the table.
int	size() Deprecated. Return the current size of the table
String	toString() Deprecated. Returns a description of the table.
String	toString(boolean which) Deprecated. Returns a description of the table.
Collection<V>	values() Deprecated.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll

Constructor Detail

LRUHashtable

public LRUHashtable(int size,
                    int cap,
                    float lf)

Deprecated.

Creates the URL Hashtable.

Parameters:

size - the maximum capacity

cap - the starting capacity (used to improve performance)

lf - the amount with which current capacity frows

LRUHashtable

public LRUHashtable(int size,
                    int cap)

Deprecated.

Creates the URL Hashtable with growing capacity 0.75.

Parameters:

size - the maximum capacity

cap - the starting capacity (used to improve performance)

LRUHashtable

public LRUHashtable(int size)

Deprecated.

Creates the URL Hashtable with starting capacity 101 and growing capacity 0.75.

Parameters:

size - the maximum capacity

LRUHashtable

public LRUHashtable()

Deprecated.

Creates the URL Hashtable with maximum capacity 100, starting capacity 101, and growing capacity 0.75.

Method Detail

getLock

public Object getLock()

Deprecated.

Description copied from interface: CacheImplementationInterface

The cache implementation must be somehow thread-safe. This method should return the object on which to synchronize, e.g. when looping over entrySet.

Specified by:

getLock in interface CacheImplementationInterface<K,V>

put

public V put(K key,
             V value)

Deprecated.

Store an element in the table.

Specified by:

put in interface Map<K,V>

Parameters:

key - the key of the element

value - the value of the element

Returns:

the original value of the element if it existed, null if it could not be found

putAll

public void putAll(Map<? extends K,? extends V> t)

Deprecated.

Specified by:

putAll in interface Map<K,V>

containsValue

public boolean containsValue(Object o)

Deprecated.

Specified by:

containsValue in interface Map<K,V>

containsKey

public boolean containsKey(Object o)

Deprecated.

Specified by:

containsKey in interface Map<K,V>

isEmpty

public boolean isEmpty()

Deprecated.

Specified by:

isEmpty in interface Map<K,V>

getCount

public int getCount(Object key)

Deprecated.

Retrieves the count of the object with a certain key.

Specified by:

getCount in interface CacheImplementationInterface<K,V>

Parameters:

key - the key of the element

Returns:

the times the key has been requested

get

public V get(Object key)

Deprecated.

Retrieves an element from the table.

Specified by:

get in interface Map<K,V>

Parameters:

key - the key of the element

Returns:

the value of the element, or null if it could not be found

remove

public V remove(Object key)

Deprecated.

Remove an element from the table.

Specified by:

remove in interface Map<K,V>

Parameters:

key - the key of the element

Returns:

the original value of the element if it existed, null if it could not be found

keySet

public Set<K> keySet()

Deprecated.

You should only remove entries from LRUHashtable using the 'remove' function, or using the iterator of entrySet() otherwise the linked list gets messed up. The keySet of LRUHashtable therefore returns an unmodifiable set.

Specified by:

keySet in interface Map<K,V>

Since:

MMBase-1.6.3

entrySet

public Set<Map.Entry<K,V>> entrySet()

Deprecated.

Returns the entries of this Map. Modification are reflected.

Specified by:

entrySet in interface Map<K,V>

Since:

MMBase-1.6.3

values

public Collection<V> values()

Deprecated.

Specified by:

values in interface Map<K,V>

Since:

MMBase-1.6.3

See Also:

keySet()

size

public int size()

Deprecated.

Return the current size of the table

Specified by:

size in interface Map<K,V>

setMaxSize

public void setMaxSize(int size)

Deprecated.

Change the maximum size of the table. This may result in removal of entries in the table.

Specified by:

setMaxSize in interface CacheImplementationInterface<K,V>

Parameters:

size - the new desired size

maxSize

public int maxSize()

Deprecated.

Return the maximum size of the table

Specified by:

maxSize in interface CacheImplementationInterface<K,V>

toString

public String toString()

Deprecated.

Returns a description of the table. The information shown includes current size, maximum size, ratio of misses and hits, and a description of the underlying hashtable

Overrides:

toString in class Object

toString

public String toString(boolean which)

Deprecated.

Returns a description of the table. The information shown includes current size, maximum size, ratio of misses and hits, and either a description of the underlying hashtable, or a list of all stored values.

Parameters:

which - if true, the stored values are described.

Returns:

a description of the table.

clear

public void clear()

Deprecated.

Clears the table.

Specified by:

clear in interface Map<K,V>

clone

public Object clone()

Deprecated.

NOT IMPLEMENTED

Overrides:

clone in class Object

elements

public Enumeration<V> elements()

Deprecated.

Returns an Enumeration on the table's element values.

getOrderedElements

public Enumeration<V> getOrderedElements()

Deprecated. use getOrderedEntries

getOrderedElements

public Enumeration<V> getOrderedElements(int maxnumber)

Deprecated. use getOrderedEntries

getOrderedEntries

public List<? extends Map.Entry<K,V>> getOrderedEntries()

Deprecated.

Returns an ordered list of Map.Entry's.

Since:

MMBase-1.6

getOrderedEntries

public List<? extends Map.Entry<K,V>> getOrderedEntries(int maxNumber)

Deprecated.

Returns an ordered list of Map.Entry's. This can be used to present the contents of the LRU Map.

Since:

MMBase-1.6

config

public void config(Map<String,String> map)

Deprecated.

Description copied from interface: CacheImplementationInterface

Configure the implementation with the given configuration values

Specified by:

config in interface CacheImplementationInterface<K,V>

getByteSize

public int getByteSize()

Deprecated.

Description copied from interface: SizeMeasurable

Determines the byte-size of this object

Specified by:

getByteSize in interface SizeMeasurable

getByteSize

public int getByteSize(SizeOf sizeof)

Deprecated.

Description copied from interface: SizeMeasurable

Determines the byte-size of this object using the given SizeOf instance. A SizeOf instance stores a Set already counted objects. So this method is typically called by SizeOf itself (recursion).

Specified by:

getByteSize in interface SizeMeasurable