Class ChronicleMapCardinalityCache

java.lang.Object

se.liu.ida.hefquin.engine.federation.access.impl.cache.ChronicleMapCardinalityCache

Type Parameters:

K - The key type for caching cardinality responses.

All Implemented Interfaces:

Cache<CardinalityCacheKey,CardinalityCacheEntry>, PersistableCache<CardinalityCacheKey,CardinalityCacheEntry>

public class ChronicleMapCardinalityCache
extends Object
implements PersistableCache<CardinalityCacheKey,CardinalityCacheEntry>

A thread-safe persistent cache implementation for storing cardinality entries. This cache uses a ChronicleMap.

Field Summary

Fields

Modifier and Type	Field	Description
protected final int	capacity
protected static final int	defaultCapacity
protected static final String	defaultFilename
protected final CacheEntryFactory<CardinalityCacheEntry,Integer>	entryFactory
protected final CacheInvalidationPolicy<CardinalityCacheEntry,Integer>	invalidationPolicy
protected final Map<CardinalityCacheKey,CardinalityCacheEntry>	map
protected final CacheReplacementPolicy<CardinalityCacheKey,Integer,CardinalityCacheEntry>	replacementPolicy

Constructor Summary

Constructors

Constructor	Description
ChronicleMapCardinalityCache(CachePolicies<CardinalityCacheKey,Integer,CardinalityCacheEntry> policies)	Constructs a new ChronicleMapCardinalityCache with the default cache file and the default capacity.
ChronicleMapCardinalityCache(CachePolicies<CardinalityCacheKey,Integer,CardinalityCacheEntry> policies, int capacity)	Constructs a new ChronicleMapCardinalityCache with the default cache file and a maximum capacity.
ChronicleMapCardinalityCache(CachePolicies<CardinalityCacheKey,Integer,CardinalityCacheEntry> policies, int capacity, String filename)	Constructs a new ChronicleMapCardinalityCache with a custom file path.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears all entries from the cache.
boolean	evict(CardinalityCacheKey key)	Removes the cache entry associated with the given key from the cache.
boolean	evict(CardinalityCacheKey key, Integer value)	Removes the specified entry from the cache only if the current value matches.
boolean	evict(CardinalityCacheKey key, CardinalityCacheEntry entry)	Removes the specified entry from the cache only if the current value matches.
void	evictExcessEntries()	Shrinks the cache to match its capacity.
CardinalityCacheEntry	get(CardinalityCacheKey key)	Retrieves the cache entry associated with the given key.
boolean	isEmpty()	Checks whether the cache is currently empty.
void	load()	No-op since ChronicleMap automatically loads data.
void	put(CardinalityCacheKey key, Integer value)	Adds a new value to the cache, associated with the given key.
void	put(CardinalityCacheKey key, CardinalityCacheEntry entry)	Adds a new cache entry to the cache, associated with the given key.
void	save()	No-op since ChronicleMap persists changes automatically.

Methods inherited from class java.lang.Object

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

Field Details

map

protected final Map<CardinalityCacheKey,CardinalityCacheEntry> map

defaultCapacity

protected static final int defaultCapacity

See Also:

• Constant Field Values

defaultFilename

protected static final String defaultFilename

See Also:

• Constant Field Values

capacity

protected final int capacity

entryFactory

protected final CacheEntryFactory<CardinalityCacheEntry,Integer> entryFactory

invalidationPolicy

protected final CacheInvalidationPolicy<CardinalityCacheEntry,Integer> invalidationPolicy

replacementPolicy

protected final CacheReplacementPolicy<CardinalityCacheKey,Integer,CardinalityCacheEntry> replacementPolicy

Constructor Details

ChronicleMapCardinalityCache

public ChronicleMapCardinalityCache(CachePolicies<CardinalityCacheKey,Integer,CardinalityCacheEntry> policies)
                             throws IOException

Constructs a new ChronicleMapCardinalityCache with the default cache file and the default capacity.

Throws:

IOException

ChronicleMapCardinalityCache

public ChronicleMapCardinalityCache(CachePolicies<CardinalityCacheKey,Integer,CardinalityCacheEntry> policies,
 int capacity)
                             throws IOException

Constructs a new ChronicleMapCardinalityCache with the default cache file and a maximum capacity.

Parameters:

capacity - Maximum cache capacity.

Throws:

IOException

ChronicleMapCardinalityCache

public ChronicleMapCardinalityCache(CachePolicies<CardinalityCacheKey,Integer,CardinalityCacheEntry> policies,
 int capacity,
 String filename)
                             throws IOException

Constructs a new ChronicleMapCardinalityCache with a custom file path.

Parameters:

filename - Path to the cache file.

Throws:

IOException

Method Details

put

public void put(CardinalityCacheKey key,
 Integer value)

Adds a new value to the cache, associated with the given key. If an entry already exists for this key, it is replaced.

Parameters:

key - The key identifying the response.

value - The entry to store.

put

public void put(CardinalityCacheKey key,
 CardinalityCacheEntry entry)

Adds a new cache entry to the cache, associated with the given key. If an entry already exists for this key, it is replaced.

Specified by:

put in interface Cache<CardinalityCacheKey,CardinalityCacheEntry>

Parameters:

key - The key identifying the response.

value - The entry to store.

get

public CardinalityCacheEntry get(CardinalityCacheKey key)

Retrieves the cache entry associated with the given key.

Specified by:

get in interface Cache<CardinalityCacheKey,CardinalityCacheEntry>

Parameters:

key - The key to look up.

Returns:

The entry, or

invalid @link

{@link null

} if not found.

evict

public boolean evict(CardinalityCacheKey key)

Removes the cache entry associated with the given key from the cache.

Specified by:

evict in interface Cache<CardinalityCacheKey,CardinalityCacheEntry>

Parameters:

key - The key to remove.

Returns:

invalid @link

{@link true

} if an entry was removed,

invalid @link

{@link false

} otherwise.

evict

public boolean evict(CardinalityCacheKey key,
 Integer value)

Removes the specified entry from the cache only if the current value matches.

Parameters:

key - The key to remove.

value - The expected value to match before removal.

Returns:

invalid @link

{@link true

} if the entry was removed,

invalid @link

{@link false

} otherwise.

evict

public boolean evict(CardinalityCacheKey key,
 CardinalityCacheEntry entry)

Removes the specified entry from the cache only if the current value matches.

Specified by:

evict in interface Cache<CardinalityCacheKey,CardinalityCacheEntry>

Parameters:

key - The key to remove.

value - The expected value to match before removal.

Returns:

invalid @link

{@link true

} if the entry was removed,

invalid @link

{@link false

} otherwise.

isEmpty

public boolean isEmpty()

Checks whether the cache is currently empty.

Specified by:

isEmpty in interface Cache<CardinalityCacheKey,CardinalityCacheEntry>

Returns:

invalid @link

{@link true

} if the cache is empty,

invalid @link

{@link false

} otherwise.

clear

public void clear()

Clears all entries from the cache.

Specified by:

clear in interface Cache<CardinalityCacheKey,CardinalityCacheEntry>

evictExcessEntries

public void evictExcessEntries()

Shrinks the cache to match its capacity.

save

public void save()

No-op since ChronicleMap persists changes automatically.

Specified by:

save in interface PersistableCache<CardinalityCacheKey,CardinalityCacheEntry>

load

public void load()

No-op since ChronicleMap automatically loads data.

Specified by:

load in interface PersistableCache<CardinalityCacheKey,CardinalityCacheEntry>