groovy.transform
[Java] Annotation Type Memoized

java.lang.Object
  groovy.transform.Memoized

@java.lang.annotation.Retention(RetentionPolicy.SOURCE)
@java.lang.annotation.Target({ ElementType.METHOD })
@GroovyASTTransformationClass("org.codehaus.groovy.transform.MemoizedASTTransformation")
public @interface Memoized

Method annotation that creates a cache for the results of the execution of the annotated method. Whenever the method is called, the mapping between the parameters and the return value is preserved in a cache making subsequent calls with the same arguments fast.

Example usage:

 class MemoizedExample {
 
     @Memoized
     int sum(int n1, int n2) {
         println "$n1 + $n2 = ${n1 + n2}" 
         n1 + n2
     }
 }
 

 class MemoizedExample {
 
     private final Closure memoizedSum = { int n1, int n2 ->
         private$method$memoizedSum(n1,n2)
     }.memoize()
 
     int sum(int n1, int n2) {
         memoizedSum(n1, n2)
     }

     private private$method$mzmoizeSum(int n1, int n2) {
         println "$n1 + $n2 = ${n1 + n2}"
         n1 + n2
     }
 }
 

Upon execution of this code:

 def instance = new MemoizedExample()
 println instance.sum(1, 2)
 println instance.sum(1, 2)
 println instance.sum(2, 3)
 println instance.sum(2, 3)
 

 1 + 2 = 3
 3
 3
 2 + 3 = 5
 5
 5
 

Authors:

Andrey Bloschetsov

maxCacheSize

public int maxCacheSize

The maximum size the cache can grow to. @default 0

protectedCacheSize

public int protectedCacheSize

Number of cached return values to protect from garbage collection. @default 0

Groovy Documentation