org.gjt.rec.cache
Class FixedCache

java.lang.Object
  |
  +--org.gjt.rec.cache.MapCache
        |
        +--org.gjt.rec.cache.FixedCache

All Implemented Interfaces:

Cache

public class FixedCache

extends MapCache

implements Cache

FixedCache is an implementation of the Cache interface that uses a fixed size element store, so that the heap usage is always capped.

Author:

Neil Stockbridge

See Also:

Cache, CacheElementSource

Nested Class Summary

Nested classes inherited from class org.gjt.rec.cache.MapCache

MapCache.MapType

Field Summary

static String

REVISION

Constructor Summary

FixedCache(int fixedSize)
Constructs a FixedCache that refers to its elements using weak references.

FixedCache(int fixedSize, CacheElementSource src)
Constructs a FixedCache that refers to its elements using weak references.

FixedCache(int fixedSize, MapCache.MapType type)
Constructs a FixedCache that refers to its elements in a particular manner.

FixedCache(int fixedSize, MapCache.MapType type, CacheElementSource src)
Constructs a FixedCache that refers to its elements in a particular manner.

Method Summary

void	invalidate(Object id) Invalidates the entry in this cache with a particular id.
void	invalidateAll() Invalidates all entries in this cache.
Object	lookup(Object id) Tries to find an element with a particular id in this cache.
void	put(Object id, Object element) Puts a particular element in this cache associated with a particular id.
String	toString()

Methods inherited from class org.gjt.rec.cache.MapCache

elementCount, hitCount, requestCount, resetStatistics

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.gjt.rec.cache.Cache

elementCount, hitCount, requestCount, resetStatistics

Field Detail

REVISION

public static final String REVISION

See Also:

Constant Field Values

Constructor Detail

FixedCache

public FixedCache(int fixedSize)

Constructs a FixedCache that refers to its elements using weak references.

Parameters:

fixedSize - the maximum number of elements to hold in the cache.

FixedCache

public FixedCache(int fixedSize,
                  MapCache.MapType type)

Constructs a FixedCache that refers to its elements in a particular manner.

Parameters:

fixedSize - the maximum number of elements to hold in the cache.

type - if this argument is MapCache.MapType.WEAK, this cache will refer to its elements using weak references. if the argument is MapCache.MapType.STRONG, strong references will be used instead.

FixedCache

public FixedCache(int fixedSize,
                  CacheElementSource src)

Constructs a FixedCache that refers to its elements using weak references. Cache elements will be obtained from the supplied CacheElementSource.

Parameters:

fixedSize - the maximum number of elements to hold in the cache.

src - the element source from which the cache will obtain its elements in the event of a cache miss.

FixedCache

public FixedCache(int fixedSize,
                  MapCache.MapType type,
                  CacheElementSource src)

Constructs a FixedCache that refers to its elements in a particular manner. Cache elements will be obtained from the supplied CacheElementSource.

Parameters:

fixedSize - the maximum number of elements to hold in the cache.

type - if this argument is MapCache.MapType.WEAK, this cache will refer to its elements using weak references. if the argument is MapCache.MapType.STRONG, strong references will be used instead.

src - the element source from which the cache will obtain its elements in the event of a cache miss.

Method Detail

lookup

public Object lookup(Object id)

Description copied from interface: Cache

Tries to find an element with a particular id in this cache.

Specified by:

lookup in interface Cache

Overrides:

lookup in class MapCache

Parameters:

id - the id of the desired element.

Returns:

the element corresponding to the supplied id or null if no such element could be found.

put

public void put(Object id,
                Object element)

Description copied from interface: Cache

Puts a particular element in this cache associated with a particular id. Note that invoking this method does not guarantee that the element will stay in the cache even long enough to be returned by a subsequent invocation of the lookup(Object) method.

Specified by:

put in interface Cache

Overrides:

put in class MapCache

Parameters:

id - the id associated with the supplied element.

element - the element to store in the cache.

invalidate

public void invalidate(Object id)

Description copied from interface: Cache

Invalidates the entry in this cache with a particular id.

Specified by:

invalidate in interface Cache

Overrides:

invalidate in class MapCache

Parameters:

id - the id corresponding to the element to invalidate.

invalidateAll

public void invalidateAll()

Description copied from interface: Cache

Invalidates all entries in this cache.

Specified by:

invalidateAll in interface Cache

Overrides:

invalidateAll in class MapCache

toString

public String toString()

Overrides:

toString in class MapCache