org.codehaus.groovy.runtime.memoize

Class Memoize

java.lang.Object

org.codehaus.groovy.runtime.memoize.Memoize

public abstract class Memoize
extends Object

Implements memoize for Closures. It is supposed to be used by the Closure class itself to implement the memoize() family of methods.

Author:

Vaclav Pech

Constructor Summary

Constructors

Constructor and Description
Memoize()

Method Summary

Methods

Modifier and Type	Method and Description
static <V> Closure<V>	buildMemoizeFunction(MemoizeCache<Object,Object> cache, Closure<V> closure) Creates a new closure delegating to the supplied one and memoizing all return values by the arguments.
static <V> Closure<V>	buildSoftReferenceMemoizeFunction(int protectedCacheSize, MemoizeCache<Object,Object> cache, Closure<V> closure) Creates a new closure delegating to the supplied one and memoizing all return values by the arguments.

Methods inherited from class java.lang.Object

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

Constructor Detail

Memoize

public Memoize()

Method Detail

buildMemoizeFunction

public static <V> Closure<V> buildMemoizeFunction(MemoizeCache<Object,Object> cache,
                                  Closure<V> closure)

Creates a new closure delegating to the supplied one and memoizing all return values by the arguments. The supplied cache is used to store the memoized values and it is the cache's responsibility to put limits on the cache size or implement cache eviction strategy. The LRUCache, for example, allows to set the maximum cache size constraint and implements the LRU (Last Recently Used) eviction strategy.

Type Parameters:

V - The closure's return type

Parameters:

cache - A map to hold memoized return values

closure - The closure to memoize

Returns:

A new memoized closure

buildSoftReferenceMemoizeFunction

public static <V> Closure<V> buildSoftReferenceMemoizeFunction(int protectedCacheSize,
                                               MemoizeCache<Object,Object> cache,
                                               Closure<V> closure)

Creates a new closure delegating to the supplied one and memoizing all return values by the arguments. The memoizing closure will use SoftReferences to remember the return values allowing the garbage collector to reclaim the memory, if needed. The supplied cache is used to store the memoized values and it is the cache's responsibility to put limits on the cache size or implement cache eviction strategy. The LRUCache, for example, allows to set the maximum cache size constraint and implements the LRU (Last Recently Used) eviction strategy. If the protectedCacheSize argument is greater than 0 an optional LRU (Last Recently Used) cache of hard references is maintained to protect recently touched memoized values against eviction by the garbage collector.

Type Parameters:

V - The closure's return type

Parameters:

protectedCacheSize - The number of hard references to keep in order to prevent some (LRU) memoized return values from eviction

cache - A map to hold memoized return values

closure - The closure to memoize

Returns:

A new memoized closure