org.waarp.common.lru

Class SynchronizedLruCache<K,V>

java.lang.Object

org.waarp.common.lru.AbstractLruCache<K,V>

org.waarp.common.lru.SynchronizedLruCache<K,V>

All Implemented Interfaces:

InterfaceLruCache<K,V>

Direct Known Subclasses:

SoftReferenceSynchronizedLruCache

public class SynchronizedLruCache<K,V>
extends AbstractLruCache<K,V>

Threadsafe synchronized implementation of LruCache based on LinkedHashMap. Threadsafety is provided by method synchronization. This cache implementation should be used with low number of threads.

Author:

Frederic Bregier, Damian Momot

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_INITIAL_CAPACITY
static float	DEFAULT_LOAD_FACTOR

Constructor Summary

Constructors

Constructor and Description
SynchronizedLruCache(int capacity, long ttl) Creates new SynchronizedLruCache with DEFAULT_LOAD_FACTOR and DEFAULT_INITIAL_CAPACITY
SynchronizedLruCache(int capacity, long ttl, int initialCapacity) Creates new SynchronizedLruCache with DEFAULT_LOAD_FACTOR
SynchronizedLruCache(int capacity, long ttl, int initialCapacity, float loadFactor) Creates new SynchronizedLruCache

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Removes all entries from cache
int	forceClearOldest() Removes all oldest entries from cache (ttl based)
V	get(K key) Returns value cached with key.
int	getCapacity() Returns cache capacity
protected InterfaceLruCacheEntry<V>	getEntry(K key) Returns LruCacheEntry mapped by key or null if it does not exist
void	put(K key, V value, long ttl) Puts value under key into cache with desired TTL
protected void	putEntry(K key, InterfaceLruCacheEntry<V> entry) Puts entry into cache
V	remove(K key) Removes entry from cache (if exists)
int	size() Returns number of entries stored in cache (including invalid ones)

Methods inherited from class org.waarp.common.lru.AbstractLruCache

contains, createEntry, get, get, getTtl, getValue, isEmpty, put, setNewTtl, updateTtl

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_INITIAL_CAPACITY

public static final int DEFAULT_INITIAL_CAPACITY

See Also:

Constant Field Values

DEFAULT_LOAD_FACTOR

public static final float DEFAULT_LOAD_FACTOR

See Also:

Constant Field Values

Constructor Detail

SynchronizedLruCache

public SynchronizedLruCache(int capacity,
                    long ttl,
                    int initialCapacity,
                    float loadFactor)

Creates new SynchronizedLruCache

Parameters:

capacity - max cache capacity

ttl - time to live in milliseconds

initialCapacity - initial cache capacity

loadFactor -

SynchronizedLruCache

public SynchronizedLruCache(int capacity,
                    long ttl,
                    int initialCapacity)

Creates new SynchronizedLruCache with DEFAULT_LOAD_FACTOR

Parameters:

capacity - max cache capacity

ttl - time to live in milliseconds

initialCapacity - initial cache capacity

SynchronizedLruCache

public SynchronizedLruCache(int capacity,
                    long ttl)

Creates new SynchronizedLruCache with DEFAULT_LOAD_FACTOR and DEFAULT_INITIAL_CAPACITY

Parameters:

capacity - max cache capacity

ttl - time to live in milliseconds

Method Detail

clear

public void clear()

Description copied from interface: InterfaceLruCache

Removes all entries from cache

get

public V get(K key)

Description copied from interface: InterfaceLruCache

Returns value cached with key.

Specified by:

get in interface InterfaceLruCache<K,V>

Overrides:

get in class AbstractLruCache<K,V>

Returns:

value or null if key doesn't exist or entry is not valid

getCapacity

public int getCapacity()

Description copied from interface: InterfaceLruCache

Returns cache capacity

Returns:

capacity of cache

getEntry

protected InterfaceLruCacheEntry<V> getEntry(K key)

Description copied from class: AbstractLruCache

Returns LruCacheEntry mapped by key or null if it does not exist

Specified by:

getEntry in class AbstractLruCache<K,V>

Returns:

LruCacheEntry

size

public int size()

Description copied from interface: InterfaceLruCache

Returns number of entries stored in cache (including invalid ones)

Returns:

number of entries

put

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

Description copied from interface: InterfaceLruCache

Puts value under key into cache with desired TTL

Specified by:

put in interface InterfaceLruCache<K,V>

Overrides:

put in class AbstractLruCache<K,V>

ttl - time to live in milliseconds

putEntry

protected void putEntry(K key,
            InterfaceLruCacheEntry<V> entry)

Description copied from class: AbstractLruCache

Puts entry into cache

Specified by:

putEntry in class AbstractLruCache<K,V>

remove

public V remove(K key)

Description copied from interface: InterfaceLruCache

Removes entry from cache (if exists)

Returns:

the value if it still exists

forceClearOldest

public int forceClearOldest()

Description copied from interface: InterfaceLruCache

Removes all oldest entries from cache (ttl based)

Returns:

the number of removed entries