memoization-guava/src/main/java/de/xn__ho_hia/memoization/guava/GuavaCacheBasedBiPredicateMemoizer.java

   1 /*
   2  * This file is part of memoization.java. It is subject to the license terms in the LICENSE file found in the top-level
   3  * directory of this distribution and at http://creativecommons.org/publicdomain/zero/1.0/. No part of memoization.java,
   4  * including this file, may be copied, modified, propagated, or distributed except according to the terms contained
   5  * in the LICENSE file.
   6  */
   7 package de.xn__ho_hia.memoization.guava;
   8
   9 import java.util.function.BiFunction;
  10 import java.util.function.BiPredicate;
  11
  12 import com.google.common.cache.Cache;
  13
  14 final class GuavaCacheBasedBiPredicateMemoizer<FIRST, SECOND, KEY>
  15         extends AbstractGuavaCacheBasedMemoizer<KEY, Boolean>
  16         implements BiPredicate<FIRST, SECOND> {
  17
  18     private final BiFunction<FIRST, SECOND, KEY> keyFunction;
  19     private final BiPredicate<FIRST, SECOND>     biPredicate;
  20
  21     GuavaCacheBasedBiPredicateMemoizer(
  22             final Cache<KEY, Boolean> cache,
  23             final BiFunction<FIRST, SECOND, KEY> keyFunction,
  24             final BiPredicate<FIRST, SECOND> biPredicate) {
  25         super(cache);
  26         this.keyFunction = keyFunction;
  27         this.biPredicate = biPredicate;
  28     }
  29
  30     @Override
  31     public boolean test(final FIRST first, final SECOND second) {
  32         final KEY key = keyFunction.apply(first, second);
  33         return get(key, givenKey -> Boolean.valueOf(biPredicate.test(first, second))).booleanValue();
  34     }
  35
  36 }