StampedCommonCache (Groovy 3.0.0)

java.lang.Object
- org.codehaus.groovy.runtime.memoize.StampedCommonCache<K,V>

Type Parameters:

K - type of the keys

V - 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:

Serialized Form

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 org.codehaus.groovy.runtime.memoize.MemoizeCache
  MemoizeCache.ValueProvider<K,V>
- Nested classes/interfaces inherited from interface java.util.Map
  Map.Entry<K,V>

Constructor Summary

Constructors
Constructor and Description
`StampedCommonCache()` Constructs a cache with unlimited size
`StampedCommonCache(int maxSize)` Constructs a LRU cache with the default initial capacity(16)
`StampedCommonCache(int initialCapacity, int maxSize)` Constructs a LRU cache with the specified initial capacity and max size.
`StampedCommonCache(int initialCapacity, int maxSize, EvictableCache.EvictionStrategy evictionStrategy)` Constructs a cache with limited size
`StampedCommonCache(Map<K,V> map)` Constructs a cache backed by the specified `Map` instance

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`cleanUpNullReferences()` Invoked when some of the held SoftReferences have been evicted by the garbage collector and so should be removed from the cache.
`Map<K,V>`	`clearAll()` Clear the cache
`boolean`	`containsKey(Object key)` Determines if the cache contains an entry for the specified key.
`boolean`	`containsValue(Object value)`
`Object`	`convertValue(V value)` convert the original value to the target value
`Set<Map.Entry<K,V>>`	`entrySet()`
`V`	`get(Object key)` Gets a value from the cache
`V`	`getAndPut(K key, MemoizeCache.ValueProvider<? super K,? extends V> valueProvider)` Try to get the value from cache.
`V`	`getAndPut(K key, MemoizeCache.ValueProvider<? super K,? extends V> valueProvider, boolean shouldCache)`
`boolean`	`isEmpty()`
`Set<K>`	`keys()` Get all keys associated to cached values
`Set<K>`	`keySet()`
`V`	`put(K key, V value)` Associates the specified value with the specified key in the cache.
`void`	`putAll(Map<? extends K,? extends V> m)`
`V`	`remove(Object key)` Remove the cached value by the key
`int`	`size()` Get the size of the cache
`Collection<V>`	`values()` Get all cached values

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.codehaus.groovy.runtime.memoize.EvictableCache
clear

Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll

- Constructor Detail
  - 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 cache
    
    maxSize - max size of the cache
    
    evictionStrategy - LRU or FIFO, see EvictableCache.EvictionStrategy
  - StampedCommonCache
```
public StampedCommonCache(int initialCapacity,
                          int maxSize)
```
    Constructs a LRU cache with the specified initial capacity and max size. The LRU cache is slower than LRUCache
    
    Parameters:
    
    initialCapacity - initial capacity of the LRU cache
    
    maxSize - max size of the LRU cache
  - StampedCommonCache
```
public StampedCommonCache(int maxSize)
```
    Constructs a LRU cache with the default initial capacity(16)
    
    Parameters:
    
    maxSize - max size of the LRU cache
    
    See Also:
    
    StampedCommonCache(int, int)
  - StampedCommonCache
```
public StampedCommonCache(Map<K,V> map)
```
    Constructs a cache backed by the specified Map instance
    
    Parameters:
    
    map - the Map instance
- Method Detail
  - get
```
public V get(Object key)
```
    Gets a value from the cache
    
    Specified by:
    
    get in interface Map<K,V>
    
    Specified by:
    
    get in interface MemoizeCache<K,V>
    
    Parameters:
    
    key - the key whose associated value is to be returned
    
    Returns:
    
    the value, or null, if it does not exist.
  - put
```
public V put(K key,
             V value)
```
    Associates the specified value with the specified key in the cache.
    
    Specified by:
    
    put in interface Map<K,V>
    
    Specified by:
    
    put in interface MemoizeCache<K,V>
    
    Parameters:
    
    key - key with which the specified value is to be associated
    
    value - value to be associated with the specified key
    
    Returns:
    
    null, or the old value if the key associated with the specified key.
  - getAndPut
```
public V getAndPut(K key,
                   MemoizeCache.ValueProvider<? super K,? extends V> valueProvider)
```
    Try to get the value from cache. If not found, create the value by MemoizeCache.ValueProvider and put it into the cache, at last return the value.
    
    Specified by:
    
    getAndPut in interface MemoizeCache<K,V>
    
    valueProvider - provide the value if the associated value not found
    
    Returns:
    
    the cached value
  - getAndPut
```
public V getAndPut(K key,
                   MemoizeCache.ValueProvider<? super K,? extends V> valueProvider,
                   boolean shouldCache)
```
  - values
```
public Collection<V> values()
```
    Get all cached values
    
    Specified by:
    
    values in interface Map<K,V>
    
    Specified by:
    
    values in interface EvictableCache<K,V>
    
    Returns:
    
    all cached values
  - entrySet
```
public Set<Map.Entry<K,V>> entrySet()
```
    Specified by:
    
    entrySet in interface Map<K,V>
  - keys
```
public Set<K> keys()
```
    Get all keys associated to cached values
    
    Specified by:
    
    keys in interface EvictableCache<K,V>
    
    Returns:
    
    all keys
  - containsKey
```
public boolean containsKey(Object key)
```
    Determines if the cache contains an entry for the specified key.
    
    Specified by:
    
    containsKey in interface Map<K,V>
    
    Specified by:
    
    containsKey in interface EvictableCache<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
  - containsValue
```
public boolean containsValue(Object value)
```
    Specified by:
    
    containsValue in interface Map<K,V>
  - size
```
public int size()
```
    Get the size of the cache
    
    Specified by:
    
    size in interface Map<K,V>
    
    Specified by:
    
    size in interface EvictableCache<K,V>
    
    Returns:
    
    the size of the cache
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface Map<K,V>
  - remove
```
public V remove(Object key)
```
    Remove the cached value by the key
    
    Specified by:
    
    remove in interface Map<K,V>
    
    Specified by:
    
    remove in interface EvictableCache<K,V>
    
    Parameters:
    
    key - of the cached value
    
    Returns:
    
    returns the removed value
  - putAll
```
public void putAll(Map<? extends K,? extends V> m)
```
    Specified by:
    
    putAll in interface Map<K,V>
  - keySet
```
public Set<K> keySet()
```
    Specified by:
    
    keySet in interface Map<K,V>
  - clearAll
```
public Map<K,V> clearAll()
```
    Clear the cache
    
    Specified by:
    
    clearAll in interface EvictableCache<K,V>
    
    Returns:
    
    returns the content of the cleared map
  - 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:
    
    cleanUpNullReferences in interface MemoizeCache<K,V>
  - convertValue
```
public Object convertValue(V value)
```
    convert the original value to the target value
    
    Specified by:
    
    convertValue in interface ValueConvertable<V,Object>
    
    Parameters:
    
    value - the original value
    
    Returns:
    
    the converted value

Class StampedCommonCache<K,V>

Nested Class Summary

Nested classes/interfaces inherited from interface org.codehaus.groovy.runtime.memoize.EvictableCache

Nested classes/interfaces inherited from interface org.codehaus.groovy.runtime.memoize.MemoizeCache

Nested classes/interfaces inherited from interface java.util.Map

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface org.codehaus.groovy.runtime.memoize.EvictableCache

Methods inherited from interface java.util.Map

Constructor Detail

StampedCommonCache

StampedCommonCache

StampedCommonCache

StampedCommonCache

StampedCommonCache

Method Detail

get

put

getAndPut

getAndPut

values

entrySet

keys

containsKey

containsValue

size

isEmpty

remove

putAll

keySet

clearAll

cleanUpNullReferences

convertValue