org.conqat.lib.commons.cache4j

Class ThreadLocalCache<K,V,X extends java.lang.Exception>

java.lang.Object

org.conqat.lib.commons.cache4j.ThreadLocalCache<K,V,X>

Type Parameters:

K - the key type. This must have both Object.equals(Object) and Object.hashCode() correctly implemented.

V - the value type. It is generally recommended to use an immutable type here, but this is not required.

X - the type of exception thrown. If no exception will be throws, use NeverThrownRuntimeException.

All Implemented Interfaces:

ICache<K,V,X>

public class ThreadLocalCache<K,V,X extends java.lang.Exception>
extends java.lang.Object
implements ICache<K,V,X>

Implementation of a cache that manages a separate backend for each thread, thus isolating threads from each other. Note that accessing this cache from many temporary threads can lead to memory leaks (as the cached data is still stored) for certain backends.

Constructor Summary

Constructors

Constructor and Description
ThreadLocalCache(java.lang.String name, IParameterizedFactory<V,K,X> factory, ICacheBackend<K,V> backend) Constructor.

Method Summary

Modifier and Type	Method and Description
void	clear(boolean allThreads) Clears the cache, i.e.
int	getHits() Returns the number of cache hits so far.
long	getMissCostMillis() Returns an estimation of the overhead caused by cache misses in milliseconds.
int	getMisses() Returns the number of cache misses so far.
java.lang.String	getName() Returns the name (used for reporting).
V	obtain(K parameter) Obtain the value for a key.

Methods inherited from class java.lang.Object

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

Constructor Detail

ThreadLocalCache

public ThreadLocalCache(java.lang.String name,
                        IParameterizedFactory<V,K,X> factory,
                        ICacheBackend<K,V> backend)

Constructor.

Parameters:

factory - the factory has to either support multi-threaded access or to be synchronized!

Method Detail

obtain

public V obtain(K parameter)
         throws X extends java.lang.Exception

Obtain the value for a key. This returns the cached element is possible. Otherwise the value is calculated (and stored in the cache for later use).

Specified by:

obtain in interface ICache<K,V,X extends java.lang.Exception>

Throws:

X extends java.lang.Exception

clear

public void clear(boolean allThreads)

Clears the cache, i.e. removes all cached data.

Specified by:

clear in interface ICache<K,V,X extends java.lang.Exception>

Parameters:

allThreads - if this is true, data will be discarded for all threads, otherwise only data for the current thread will be cleaned (if possible).

getName

public java.lang.String getName()

Returns the name (used for reporting).

Specified by:

getName in interface ICache<K,V,X extends java.lang.Exception>

getHits

public int getHits()

Returns the number of cache hits so far.

Specified by:

getHits in interface ICache<K,V,X extends java.lang.Exception>

getMisses

public int getMisses()

Returns the number of cache misses so far.

Specified by:

getMisses in interface ICache<K,V,X extends java.lang.Exception>

getMissCostMillis

public long getMissCostMillis()

Returns an estimation of the overhead caused by cache misses in milliseconds.

Specified by:

getMissCostMillis in interface ICache<K,V,X extends java.lang.Exception>