Class StampedCommonCache<K,V>
java.lang.Object
org.codehaus.groovy.runtime.memoize.StampedCommonCache<K,V>
- Type Parameters:
K- type of the keysV- type of the values
- All Implemented Interfaces:
Serializable,Map<K,,V> EvictableCache<K,,V> MemoizeCache<K,,V> ValueConvertable<V,Object>
@ThreadSafe
public class StampedCommonCache<K,V>
extends Object
implements EvictableCache<K,V>, ValueConvertable<V,Object>, Serializable
Represents a simple key-value cache, which is thread safe and backed by a
Map instance.
StampedCommonCache has better performance than ConcurrentCommonCache,
but it is not reentrant, in other words, it may cause deadlock if getAndPut(Object, MemoizeCache.ValueProvider)
or getAndPut(Object, MemoizeCache.ValueProvider, boolean) is called recursively:
readlock -> upgrade to writelock -> readlock (fails to get and waits forever)- Since:
- 3.0.0
- See Also:
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Nested Class Summary
Nested classes/interfaces inherited from interface org.codehaus.groovy.runtime.memoize.EvictableCache
EvictableCache.Action<K,V, R>, EvictableCache.EvictionStrategy Nested classes/interfaces inherited from interface java.util.Map
Map.Entry<K extends Object,V extends Object> Nested classes/interfaces inherited from interface org.codehaus.groovy.runtime.memoize.MemoizeCache
MemoizeCache.ValueProvider<K,V> -
Constructor Summary
ConstructorsConstructorDescriptionConstructs a cache with unlimited sizeStampedCommonCache(int maxSize) Constructs an LRU cache with the default initial capacity(16)StampedCommonCache(int initialCapacity, int maxSize) Constructs an LRU cache with the specified initial capacity and max size.StampedCommonCache(int initialCapacity, int maxSize, EvictableCache.EvictionStrategy evictionStrategy) Constructs a cache with limited sizeStampedCommonCache(Map<K, V> map) Constructs a cache backed by the specifiedMapinstance -
Method Summary
Modifier and TypeMethodDescriptionvoidInvoked when some of the held SoftReferences have been evicted by the garbage collector and so should be removed from the cache.clearAll()Clear the cachebooleancontainsKey(Object key) Determines if the cache contains an entry for the specified key.booleancontainsValue(Object value) convertValue(V value) convert the original value to the target valueentrySet()Gets a value from the cachegetAndPut(K key, MemoizeCache.ValueProvider<? super K, ? extends V> valueProvider) Try to get the value from cache.getAndPut(K key, MemoizeCache.ValueProvider<? super K, ? extends V> valueProvider, boolean shouldCache) booleanisEmpty()keys()Get all keys associated to cached valueskeySet()Associates the specified value with the specified key in the cache.voidRemove the cached value by the keyintsize()Get the size of the cachevalues()Get all cached valuesMethods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitMethods inherited from interface org.codehaus.groovy.runtime.memoize.EvictableCache
clearMethods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll
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Constructor Details
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StampedCommonCache
public StampedCommonCache()Constructs a cache with unlimited size -
StampedCommonCache
public StampedCommonCache(int initialCapacity, int maxSize, EvictableCache.EvictionStrategy evictionStrategy) Constructs a cache with limited size- Parameters:
initialCapacity- initial capacity of the cachemaxSize- max size of the cacheevictionStrategy- LRU or FIFO, seeEvictableCache.EvictionStrategy
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StampedCommonCache
public StampedCommonCache(int initialCapacity, int maxSize) Constructs an LRU cache with the specified initial capacity and max size. The LRU cache is slower thanLRUCache- Parameters:
initialCapacity- initial capacity of the LRU cachemaxSize- max size of the LRU cache
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StampedCommonCache
public StampedCommonCache(int maxSize) Constructs an LRU cache with the default initial capacity(16)- Parameters:
maxSize- max size of the LRU cache- See Also:
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StampedCommonCache
Constructs a cache backed by the specifiedMapinstance- Parameters:
map- theMapinstance
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Method Details
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get
Gets a value from the cache -
put
Associates the specified value with the specified key in the cache. -
getAndPut
Try to get the value from cache. If not found, create the value byMemoizeCache.ValueProviderand put it into the cache, at last return the value.- Specified by:
getAndPutin interfaceMemoizeCache<K,V> - Parameters:
key- the key to look upvalueProvider- provide the value if the associated value not found- Returns:
- the cached value
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getAndPut
public V getAndPut(K key, MemoizeCache.ValueProvider<? super K, ? extends V> valueProvider, boolean shouldCache) -
values
Get all cached values -
entrySet
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keys
Get all keys associated to cached values- Specified by:
keysin interfaceEvictableCache<K,V> - Returns:
- all keys
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containsKey
Determines if the cache contains an entry for the specified key.- Specified by:
containsKeyin interfaceEvictableCache<K,V> - Specified by:
containsKeyin interfaceMap<K,V> - Parameters:
key- key whose presence in this cache is to be tested.- Returns:
- true if the cache contains a mapping for the specified key
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containsValue
- Specified by:
containsValuein interfaceMap<K,V>
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size
public int size()Get the size of the cache -
isEmpty
public boolean isEmpty() -
remove
Remove the cached value by the key -
putAll
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keySet
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clearAll
Clear the cache- Specified by:
clearAllin interfaceEvictableCache<K,V> - Returns:
- returns the content of the cleared map
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cleanUpNullReferences
public void cleanUpNullReferences()Invoked when some of the held SoftReferences have been evicted by the garbage collector and so should be removed from the cache. The implementation must ensure that concurrent invocations of all methods on the cache may occur from other threads and thus should protect any shared resources.- Specified by:
cleanUpNullReferencesin interfaceMemoizeCache<K,V>
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convertValue
convert the original value to the target value- Specified by:
convertValuein interfaceValueConvertable<K,V> - Parameters:
value- the original value- Returns:
- the converted value
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