net.dontdrinkandroot.cache.impl
Class AbstractMapBackedCache<K,V,M extends MetaData>

java.lang.Object
  net.dontdrinkandroot.cache.impl.AbstractCache<K,V>
      net.dontdrinkandroot.cache.impl.AbstractMapBackedCache<K,V,M>

All Implemented Interfaces:

Cache<K,V>

Direct Known Subclasses:

AbstractMapBackedCustomTtlCache, FileCache

public abstract class AbstractMapBackedCache<K,V,M extends MetaData>
extends AbstractCache<K,V>
implements Cache<K,V>

Author:

Philip W. Sorst

Field Summary

Fields inherited from interface net.dontdrinkandroot.cache.Cache

UNLIMITED_IDLE_TIME

Constructor Summary

AbstractMapBackedCache(String name, long defaultTimeToLive, ExpungeStrategy expungeStrategy)
Construct a new AbstractCache.

AbstractMapBackedCache(String name, long defaultTimeToLive, long defaultMaxIdleTime, ExpungeStrategy expungeStrategy)
Construct a new AbstractCache.

Method Summary

void	cleanUp() Cleanup the cache.
void	delete(K key) Manually remove an entry from the cache.
void	delete(K key, M metaData)
protected abstract void	doDelete(K key, M metaData) Performs deletion of the data belonging to the metadata.
protected abstract <T extends V> T	doGet(K key, M metaData) Performs retrieval of the data belonging to the metadata.
protected abstract <T extends V> T	doPut(K key, T data) Performs storage of the given data and adds new metadata to the map.
protected void	expunge(Collection<Map.Entry<K,M>> expungeEntriesMetaData) Performs the actual expunging of entries with the given metadata.
<T extends V> T	get(K key) Retrieve an entry from the cache if it is available.
List<M>	getEntriesMetaData() Returns a copy of the List of all metadata entries.
protected Map<K,M>	getEntriesMetaDataMap()
ExpungeStrategy	getExpungeStrategy()
MetaData	getMetaData(K key) Retrieve the MetaData of a cached entry if it is available.
SimpleCacheStatistics	getStatistics() Get statistics of the cache like hitrate, or size.
<T extends V> T	getWithErrors(K key) Retrieve an entry from the cache if it is available.
<T extends V> T	put(K key, T data) Store an entry in the cache with the default time to live.
<T extends V> T	putWithErrors(K key, T data) Store an entry in the cache with the default time to live.
protected void	setEntriesMetaDataMap(Map<K,M> map)
void	setExpungeStrategy(ExpungeStrategy expungeStrategy)

Methods inherited from class net.dontdrinkandroot.cache.impl.AbstractCache

getCleanUpLogger, getDefaultMaxIdleTime, getDefaultTtl, getLogger, getName, setDefaultMaxIdleTime, setDefaultTtl

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.dontdrinkandroot.cache.Cache

getDefaultMaxIdleTime, getDefaultTtl, getName

Constructor Detail

AbstractMapBackedCache

public AbstractMapBackedCache(String name,
                              long defaultTimeToLive,
                              ExpungeStrategy expungeStrategy)

Construct a new AbstractCache.

Parameters:

name - The name of the cache.

defaultTimeToLive - The default time to live for Cache entries.

expungeStrategy - The ExpungeStrategy to use.

AbstractMapBackedCache

public AbstractMapBackedCache(String name,
                              long defaultTimeToLive,
                              long defaultMaxIdleTime,
                              ExpungeStrategy expungeStrategy)

Construct a new AbstractCache.

Parameters:

name - The name of the cache.

defaultTimeToLive - The default time to live for Cache entries.

defaultMaxIdleTime - The default max idle time for cache entries.

expungeStrategy - The ExpungeStrategy to use.

Method Detail

put

public <T extends V> T put(K key,
                           T data)

Description copied from interface: Cache

Store an entry in the cache with the default time to live. Any errors are swallowed, use Cache.putWithErrors(Object, Object) if you want to handle them.

Specified by:

put in interface Cache<K,V>

Parameters:

key - A unique identifier.

data - The data to store. Make sure that you don't alter the data after it has been put to cache as (depending on the implementation) this might lead to altering the entry in the cache. Use the returned data instead.

Returns:

The entry that has been stored in the cache. It is save to alter this as implementations as implementations make sure that this is always (at least) a copy.

putWithErrors

public final <T extends V> T putWithErrors(K key,
                                           T data)
                                throws CacheException

Description copied from interface: Cache

Store an entry in the cache with the default time to live.

Specified by:

putWithErrors in interface Cache<K,V>

Parameters:

key - A unique identifier.

data - The data to store. Make sure that you don't alter the data after it has been put to cache as (depending on the implementation) this might lead to altering the entry in the cache. Use the returned data instead.

Returns:

The entry that has been stored in the cache. It is save to alter this as implementations as implementations make sure that this is always (at least) a copy.

Throws:

CacheException - Thrown on any errors encountered, supposed to include the stacktrace (if any).

delete

public final void delete(K key)
                  throws CacheException

Description copied from interface: Cache

Manually remove an entry from the cache.

Specified by:

delete in interface Cache<K,V>

Parameters:

key - The key under which the entry was stored.

Throws:

CacheException - Thrown on any errors encountered, supposed to include the stacktrace (if any).

cleanUp

public final void cleanUp()
                   throws CacheException

Description copied from interface: Cache

Cleanup the cache. Usually this means that expired entries are deleted but this can also incorporate optimization functions etc. depending on the implementation.

Specified by:

cleanUp in interface Cache<K,V>

Throws:

CacheException - Thrown on any errors encountered, supposed to include the stacktrace (if any).

getMetaData

public MetaData getMetaData(K key)
                     throws CacheException

Description copied from interface: Cache

Retrieve the MetaData of a cached entry if it is available.

Specified by:

getMetaData in interface Cache<K,V>

Parameters:

key - The key under which the entry was stored.

Returns:

The MetaData of the entry if found, null otherwise.

Throws:

CacheException - Thrown on any errors encountered, supposed to include the stacktrace (if any).

get

public <T extends V> T get(K key)

Description copied from interface: Cache

Retrieve an entry from the cache if it is available. Any errors are swallowed, use Cache.getWithErrors(Object) if you want to handle them.

Specified by:

get in interface Cache<K,V>

Parameters:

key - The unique key under which the entry was stored.

Returns:

The cache entry if it is valid and not expired, null otherwise.

getWithErrors

public final <T extends V> T getWithErrors(K key)
                                throws CacheException

Description copied from interface: Cache

Retrieve an entry from the cache if it is available.

Specified by:

getWithErrors in interface Cache<K,V>

Parameters:

key - The unique key under which the entry was stored.

Returns:

The cache entry if it is valid and not expired, null otherwise.

Throws:

CacheException - Thrown on any errors encountered, supposed to include the stacktrace (if any).

getStatistics

public SimpleCacheStatistics getStatistics()

Description copied from interface: Cache

Get statistics of the cache like hitrate, or size.

Specified by:

getStatistics in interface Cache<K,V>

Returns:

Statistics of the cache.

getExpungeStrategy

public ExpungeStrategy getExpungeStrategy()

setExpungeStrategy

public void setExpungeStrategy(ExpungeStrategy expungeStrategy)

setEntriesMetaDataMap

protected void setEntriesMetaDataMap(Map<K,M> map)

getEntriesMetaDataMap

protected Map<K,M> getEntriesMetaDataMap()

expunge

protected void expunge(Collection<Map.Entry<K,M>> expungeEntriesMetaData)
                throws CacheException

Performs the actual expunging of entries with the given metadata. Can be subclasses as they might want to chain or do some other magic, by default the entries will simply be deleted.

Parameters:

expungeEntriesMetaData - A List of the MetaData of the entries to expunge.

Throws:

CacheException - Thrown on any errors encountered.

delete

public void delete(K key,
                   M metaData)
            throws CacheException

Throws:

CacheException

getEntriesMetaData

public List<M> getEntriesMetaData()

Returns a copy of the List of all metadata entries.

Returns:

a copy of the List of all metadata entries.

doDelete

protected abstract void doDelete(K key,
                                 M metaData)
                          throws CacheException

Performs deletion of the data belonging to the metadata. Removal from the map is done by the superclass.

Throws:

CacheException

doGet

protected abstract <T extends V> T doGet(K key,
                                         M metaData)
                              throws CacheException

Performs retrieval of the data belonging to the metadata.

Throws:

CacheException

doPut

protected abstract <T extends V> T doPut(K key,
                                         T data)
                              throws CacheException

Performs storage of the given data and adds new metadata to the map.

Throws:

CacheException