Package org.openhab.core.cache.lru

Class LRUMediaCache<V>

java.lang.Object

org.openhab.core.cache.lru.LRUMediaCache<V>

@NonNullByDefault
public class LRUMediaCache<V>
extends Object

Cache system for media files, and their metadata This is a LRU cache (least recently used entry is evicted if the size is exceeded). Size is based on the size on disk (in bytes)

Author:

Gwendal Roulleau - Initial contribution

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	cacheIsOK
protected final long	maxCacheSize	The size limit, in bytes.

Constructor Summary

Constructors

Constructor	Description
LRUMediaCache(StorageService storageService, long maxCacheSize, String pid, @Nullable ClassLoader clazzLoader)	Constructs a cache system.

Method Summary

Modifier and Type	Method	Description
LRUMediaCacheEntry<V>	get(String key, Supplier<LRUMediaCacheEntry<V>> supplier)	Returns a LRUMediaCacheEntry from the cache, or if not already in the cache : resolve it, stores it, and returns it.
protected void	makeSpace()	Check if the cache is not already full and make space if needed.
protected void	put(LRUMediaCacheEntry<V> result)

Methods inherited from class java.lang.Object

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

Field Details

maxCacheSize

protected final long maxCacheSize

The size limit, in bytes. The size is not a hard one, because the final size of the current request is not known and may or may not exceed the limit.

cacheIsOK

protected boolean cacheIsOK

Constructor Details

LRUMediaCache

public LRUMediaCache(StorageService storageService,
 long maxCacheSize,
 String pid,
 @Nullable ClassLoader clazzLoader)

Constructs a cache system.

Parameters:

storageService - Storage service to store metadata

cacheSize - Limit size, in byte

pid - A pid identifying the cache on disk

Method Details

get

public LRUMediaCacheEntry<V> get(String key,
 Supplier<LRUMediaCacheEntry<V>> supplier)

Returns a LRUMediaCacheEntry from the cache, or if not already in the cache : resolve it, stores it, and returns it. key A unique key identifying the result supplier the data and metadata supplier. It is OK to launch a DataRetrievalException from this, as it will be rethrown.

put

protected void put(LRUMediaCacheEntry<V> result)

makeSpace

protected void makeSpace()

Check if the cache is not already full and make space if needed. We don't use the removeEldestEntry test method from the linkedHashMap because it can only remove one element.