com.helger.commons.cache

Class AbstractCache<KEYTYPE,VALUETYPE>

java.lang.Object

com.helger.commons.cache.AbstractCache<KEYTYPE,VALUETYPE>

Type Parameters:

KEYTYPE - The cache key type

VALUETYPE - The cache value type

All Implemented Interfaces:

ICache<KEYTYPE,VALUETYPE>, IMutableCache<KEYTYPE,VALUETYPE>, IHasSize, IHasName

Direct Known Subclasses:

AbstractNotifyingCache, CacheWithConversion

@ThreadSafe
public abstract class AbstractCache<KEYTYPE,VALUETYPE>
extends Object
implements IMutableCache<KEYTYPE,VALUETYPE>

Abstract base implementation of ICache

Author:

Philip Helger

Field Summary

Fields

Modifier and Type	Field and Description
protected IMutableStatisticsHandlerCache	m_aCacheAccessStats
protected SimpleReadWriteLock	m_aRWLock
static String	STATISTICS_PREFIX The prefix to be used for statistics elements

Constructor Summary

Constructors

Constructor and Description
AbstractCache(int nMaxSize, String sCacheName)
AbstractCache(String sCacheName)

Method Summary

Modifier and Type	Method and Description
EChange	clearCache() Remove all cached elements.
protected Map<KEYTYPE,VALUETYPE>	createCache() Create a new cache map.
VALUETYPE	getFromCache(KEYTYPE aKey) Get the cached value associated with the passed key.
protected VALUETYPE	getFromCacheNoStats(KEYTYPE aKey)
protected VALUETYPE	getFromCacheNoStatsNotLocked(KEYTYPE aKey)
protected VALUETYPE	getFromCacheNotLocked(KEYTYPE aKey)
int	getMaxSize()
String	getName()
int	getSize()
boolean	hasMaxSize()
boolean	isEmpty()
boolean	isNotEmpty()
protected void	putInCache(KEYTYPE aKey, VALUETYPE aValue) Put a new value into the cache.
protected void	putInCacheNotLocked(KEYTYPE aKey, VALUETYPE aValue) Put a new value into the cache.
EChange	removeFromCache(KEYTYPE aKey) Remove the given key from the cache.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

STATISTICS_PREFIX

public static final String STATISTICS_PREFIX

The prefix to be used for statistics elements

See Also:

Constant Field Values

m_aRWLock

protected final SimpleReadWriteLock m_aRWLock

m_aCacheAccessStats

protected final IMutableStatisticsHandlerCache m_aCacheAccessStats

Constructor Detail

AbstractCache

public AbstractCache(@Nonnull
                     String sCacheName)

AbstractCache

public AbstractCache(@CheckForSigned
                     int nMaxSize,
                     @Nonnull @Nonempty
                     String sCacheName)

Method Detail

getMaxSize

public final int getMaxSize()

hasMaxSize

public final boolean hasMaxSize()

getName

@Nonnull
 @Nonempty
public final String getName()

Specified by:

getName in interface IHasName

Returns:

The name of the object. May not be null.

createCache

@Nonnull
 @ReturnsMutableCopy
 @OverrideOnDemand
protected Map<KEYTYPE,VALUETYPE> createCache()

Create a new cache map.

Returns:

Never null.

putInCacheNotLocked

@MustBeLocked(value=WRITE)
protected final void putInCacheNotLocked(@Nonnull
                                                                     KEYTYPE aKey,
                                                                     @Nonnull
                                                                     VALUETYPE aValue)

Put a new value into the cache.

Parameters:

aKey - The cache key. May not be null.

aValue - The cache value. May not be null.

putInCache

protected final void putInCache(@Nonnull
                                KEYTYPE aKey,
                                @Nonnull
                                VALUETYPE aValue)

Put a new value into the cache.

Parameters:

aKey - The cache key. May not be null.

aValue - The cache value. May not be null.

getFromCacheNoStatsNotLocked

@MustBeLocked(value=READ)
 @Nullable
protected final VALUETYPE getFromCacheNoStatsNotLocked(@Nullable
                                                                                              KEYTYPE aKey)

getFromCacheNoStats

@Nullable
 @OverridingMethodsMustInvokeSuper
protected final VALUETYPE getFromCacheNoStats(@Nullable
                                                                                             KEYTYPE aKey)

getFromCacheNotLocked

@Nullable
protected final VALUETYPE getFromCacheNotLocked(@Nullable
                                                           KEYTYPE aKey)

getFromCache

@Nullable
 @OverridingMethodsMustInvokeSuper
public VALUETYPE getFromCache(KEYTYPE aKey)

Description copied from interface: ICache

Get the cached value associated with the passed key.

Specified by:

getFromCache in interface ICache<KEYTYPE,VALUETYPE>

Parameters:

aKey - The key to be looked up. May be nullable or not - depends upon the implementation.

Returns:

null if no such value is in the cache.

removeFromCache

@Nonnull
 @OverridingMethodsMustInvokeSuper
public EChange removeFromCache(KEYTYPE aKey)

Description copied from interface: IMutableCache

Remove the given key from the cache.

Specified by:

removeFromCache in interface IMutableCache<KEYTYPE,VALUETYPE>

Parameters:

aKey - The key to be removed. May be nullable or not - depends upon the implementation.

Returns:

EChange.CHANGED upon success, EChange.UNCHANGED if the key was not within the cache,

clearCache

@Nonnull
 @OverridingMethodsMustInvokeSuper
public EChange clearCache()

Description copied from interface: IMutableCache

Remove all cached elements.

Specified by:

clearCache in interface IMutableCache<KEYTYPE,VALUETYPE>

Returns:

EChange.

getSize

@Nonnegative
public int getSize()

Specified by:

getSize in interface IHasSize

Returns:

The number of contained elements. Always ≥ 0.

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface IHasSize

Returns:

true if no items are present, false if at least a single item is present.

See Also:

IHasSize.getSize()

isNotEmpty

public boolean isNotEmpty()

toString

public String toString()

Overrides:

toString in class Object