Package groovy.transform
Annotation Type Memoized
-
@Documented @Retention(SOURCE) @Target(METHOD) public @interface MemoizedMethod 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 {which becomes (approximately):@Memoizedint 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$memoizedSum(int n1, int n2) { println "$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)
The following will be output:1 + 2 = 3 3 3 2 + 3 = 5 5 5
More examples:
import groovy.transform.* // Script variable which is changed when increment() // method is invoked. // If cached method call is invoked then the value // of this variable will not change. @Field boolean incrementChange = false @Memoized int increment(int value) { incrementChange = true value + 1 } // Invoke increment with argument 10. increment(10) // increment is invoked so incrementChange is true. assert incrementChange // Set incrementChange back to false. incrementChange = false // Invoke increment with argument 10. increment(10) // Now the cached method is used and // incrementChange is not changed. assert !incrementChange // Invoke increment with other argument value. increment(11) // increment is invoked so incrementChange is true. assert incrementChange- Since:
- 2.2.0
-
-
Optional Element Summary
Optional Elements Modifier and Type Optional Element Description intmaxCacheSizeThe maximum size the cache can grow to.intprotectedCacheSizeNumber of cached return values to protect from garbage collection.
-