CacheEntry (Grails 2.5.6.BUILD-SNAPSHOT)

grails.util.CacheEntry

Wrapper for a value inside a cache that adds timestamp information for expiration and prevents "cache storms" with a Lock. JMM happens-before is ensured with AtomicReference. Objects in cache are assumed to not change after publication.
Authors:
Lari Hotari
Since:
2.3.4

Nested Class Summary

Nested classes
Modifiers	Name	Description
`static class`	`CacheEntry.UpdateException`

Constructor Summary

Constructors
Constructor and description
`CacheEntry ()`
`CacheEntry (V value)`

Methods Summary

Methods
Type Params	Return Type	Name and description
	`void`	`expire()`
	`long`	`getCreatedMillis()`
`<K, V>`	`static V`	`getValue(java.util.concurrent.ConcurrentMap<K, CacheEntry<V>> map, K key, long timeoutMillis, java.util.concurrent.Callable<V> updater, java.util.concurrent.Callable<? extends CacheEntry> cacheEntryFactory, boolean returnExpiredWhileUpdating, java.lang.Object cacheRequestObject)` Gets a value from cache.
`<K, V>`	`static V`	`getValue(java.util.concurrent.ConcurrentMap<K, CacheEntry<V>> map, K key, long timeoutMillis, java.util.concurrent.Callable<V> updater)`
`<K, V>`	`static V`	`getValue(java.util.concurrent.ConcurrentMap<K, CacheEntry<V>> map, K key, long timeoutMillis, java.util.concurrent.Callable<V> updater, boolean returnExpiredWhileUpdating)`
	`V`	`getValue(long timeout, java.util.concurrent.Callable<V> updater)`
	`V`	`getValue(long timeout, java.util.concurrent.Callable<V> updater, boolean returnExpiredWhileUpdating, java.lang.Object cacheRequestObject)` gets the current value from the entry and updates it if it's older than timeout
	`V`	`getValue()`
	`protected V`	`getValueWhileUpdating(java.lang.Object cacheRequestObject)`
	`protected boolean`	`hasExpired(long timeout, java.lang.Object cacheRequestObject)`
	`boolean`	`isInitialized()`
	`protected void`	`resetTimestamp(boolean updated)`
	`void`	`setInitialized(boolean initialized)`
	`void`	`setValue(V val)`
	`protected boolean`	`shouldUpdate(long beforeLockingCreatedMillis, java.lang.Object cacheRequestObject)`
	`protected V`	`updateValue(V oldValue, java.util.concurrent.Callable<V> updater, java.lang.Object cacheRequestObject)`

Inherited Methods Summary

Inherited Methods
Methods inherited from class	Name
`class java.lang.Object`	`java.lang.Object#wait(long, int), java.lang.Object#wait(long), java.lang.Object#wait(), java.lang.Object#equals(java.lang.Object), java.lang.Object#toString(), java.lang.Object#hashCode(), java.lang.Object#getClass(), java.lang.Object#notify(), java.lang.Object#notifyAll()`

- Constructor Detail
  - public CacheEntry()
  - public CacheEntry(V value)
- Method Detail
  - public void expire()
  - public long getCreatedMillis()
  - <K, V> @java.lang.SuppressWarnings({ "unchecked", "rawtypes" }) public static V getValue(java.util.concurrent.ConcurrentMap<K, CacheEntry<V>> map, K key, long timeoutMillis, java.util.concurrent.Callable<V> updater, java.util.concurrent.Callable<? extends CacheEntry> cacheEntryFactory, boolean returnExpiredWhileUpdating, java.lang.Object cacheRequestObject)
    
    Gets a value from cache. If the key doesn't exist, it will create the value using the updater callback Prevents cache storms with a lock The key is always added to the cache. Null return values will also be cached. You can use this together with ConcurrentLinkedHashMap to create a bounded LRU cache
    Parameters:
    map - the cache map
    key - the key to look up
    timeoutMillis - cache entry timeout
    updater - callback to create/update value
    cacheEntryClass - CacheEntry implementation class to use
    returnExpiredWhileUpdating - when true, return expired value while updating new value
    cacheRequestObject - context object that gets passed to hasExpired, shouldUpdate and updateValue methods, not used in default implementation
    Returns:
  - <K, V> public static V getValue(java.util.concurrent.ConcurrentMap<K, CacheEntry<V>> map, K key, long timeoutMillis, java.util.concurrent.Callable<V> updater)
  - <K, V> public static V getValue(java.util.concurrent.ConcurrentMap<K, CacheEntry<V>> map, K key, long timeoutMillis, java.util.concurrent.Callable<V> updater, boolean returnExpiredWhileUpdating)
  - public V getValue(long timeout, java.util.concurrent.Callable<V> updater)
  - public V getValue(long timeout, java.util.concurrent.Callable<V> updater, boolean returnExpiredWhileUpdating, java.lang.Object cacheRequestObject)
    
    gets the current value from the entry and updates it if it's older than timeout updater is a callback for creating an updated value.
    Parameters:
    timeout
    updater
    returnExpiredWhileUpdating
    cacheRequestObject
    Returns:
    the current value
  - public V getValue()
  - protected V getValueWhileUpdating(java.lang.Object cacheRequestObject)
  - protected boolean hasExpired(long timeout, java.lang.Object cacheRequestObject)
  - public boolean isInitialized()
  - protected void resetTimestamp(boolean updated)
  - public void setInitialized(boolean initialized)
  - public void setValue(V val)
  - protected boolean shouldUpdate(long beforeLockingCreatedMillis, java.lang.Object cacheRequestObject)
  - protected V updateValue(V oldValue, java.util.concurrent.Callable<V> updater, java.lang.Object cacheRequestObject)

Summary:
Nested
Constructor
Method

| Detail:
Constructor
Method

Groovy Documentation

[Java] Class CacheEntry<V>

Nested Class Summary

Constructor Summary

Methods Summary

Inherited Methods Summary

Constructor Detail

public CacheEntry()

public CacheEntry(V value)

Method Detail

public void expire()

public long getCreatedMillis()

<K, V> public static V getValue(java.util.concurrent.ConcurrentMap<K, CacheEntry<V>> map, K key, long timeoutMillis, java.util.concurrent.Callable<V> updater)

<K, V> public static V getValue(java.util.concurrent.ConcurrentMap<K, CacheEntry<V>> map, K key, long timeoutMillis, java.util.concurrent.Callable<V> updater, boolean returnExpiredWhileUpdating)

public V getValue(long timeout, java.util.concurrent.Callable<V> updater)

public V getValue(long timeout, java.util.concurrent.Callable<V> updater, boolean returnExpiredWhileUpdating, java.lang.Object cacheRequestObject)

public V getValue()

protected V getValueWhileUpdating(java.lang.Object cacheRequestObject)

protected boolean hasExpired(long timeout, java.lang.Object cacheRequestObject)

public boolean isInitialized()

protected void resetTimestamp(boolean updated)

public void setInitialized(boolean initialized)

public void setValue(V val)

protected boolean shouldUpdate(long beforeLockingCreatedMillis, java.lang.Object cacheRequestObject)

protected V updateValue(V oldValue, java.util.concurrent.Callable<V> updater, java.lang.Object cacheRequestObject)