libcore.util

Class BasicLruCache<K,V>

java.lang.Object

libcore.util.BasicLruCache<K,V>

Direct Known Subclasses:

TimeZoneNames.ZoneStringsCache

public class BasicLruCache<K,V>
extends Object

A minimal least-recently-used cache for libcore. Prefer android.util.LruCache where that is available.

Constructor Summary

Constructors

Constructor and Description
BasicLruCache(int maxSize)

Method Summary

Modifier and Type	Method and Description
protected V	create(K key) Called after a cache miss to compute a value for the corresponding key.
protected void	entryEvicted(K key, V value) Called for entries that have reached the tail of the least recently used queue and are be removed.
void	evictAll() Clear the cache, calling entryEvicted(K, V) on each removed entry.
V	get(K key) Returns the value for key if it exists in the cache or can be created by #create.
V	put(K key, V value) Caches value for key.
Map<K,V>	snapshot() Returns a copy of the current contents of the cache, ordered from least recently accessed to most recently accessed.

Methods inherited from class java.lang.Object

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

Constructor Detail

BasicLruCache

public BasicLruCache(int maxSize)

Method Detail

get

public final V get(K key)

Returns the value for key if it exists in the cache or can be created by #create. If a value was returned, it is moved to the head of the queue. This returns null if a value is not cached and cannot be created.

put

public final V put(K key,
                   V value)

Caches value for key. The value is moved to the head of the queue.

Returns:

the previous value mapped by key. Although that entry is no longer cached, it has not been passed to entryEvicted(K, V).

entryEvicted

protected void entryEvicted(K key,
                            V value)

Called for entries that have reached the tail of the least recently used queue and are be removed. The default implementation does nothing.

create

protected V create(K key)

Called after a cache miss to compute a value for the corresponding key. Returns the computed value or null if no value can be computed. The default implementation returns null.

snapshot

public final Map<K,V> snapshot()

Returns a copy of the current contents of the cache, ordered from least recently accessed to most recently accessed.

evictAll

public final void evictAll()

Clear the cache, calling entryEvicted(K, V) on each removed entry.