EnchantStyleCustomizer rewrite (#406)

Co-authored-by: nea <romangraef@gmail.com>
Co-authored-by: nea <roman.graef@gmail.com>
Co-authored-by: nea <nea@nea.moe>
Co-authored-by: nea <romangraef@loves.dicksinhisan.us>
Co-authored-by: nea <roman.graef@grb-online.net>
Co-authored-by: nea <hello@nea89.moe>
Co-authored-by: nea <roman.graef@stud.tu-darmstadt.de>

1 files changed, 63 insertions, 0 deletions

diff --git a/src/main/java/io/github/moulberry/notenoughupdates/util/LRUCache.java b/src/main/java/io/github/moulberry/notenoughupdates/util/LRUCache.java
new file mode 100644
index 00000000..f107d522
--- /dev/null
+++ b/src/main/java/io/github/moulberry/notenoughupdates/util/LRUCache.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2022 NotEnoughUpdates contributors
+ *
+ * This file is part of NotEnoughUpdates.
+ *
+ * NotEnoughUpdates is free software: you can redistribute it
+ * and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * NotEnoughUpdates is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with NotEnoughUpdates. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package io.github.moulberry.notenoughupdates.util;
+
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.function.IntSupplier;
+
+public interface LRUCache<K, V> extends Function<K, V> {
+
+	static <K, V> LRUCache<K, V> memoize(Function<K, V> mapper, int maxCacheSize) {
+		return memoize(mapper, () -> maxCacheSize);
+	}
+
+	static <K, V> LRUCache<K, V> memoize(Function<K, V> mapper, IntSupplier maxCacheSize) {
+		Map<K, V> cache = new LinkedHashMap<K, V>(10, 0.75F, true) {
+			@Override
+			protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
+				return this.size() > maxCacheSize.getAsInt();
+			}
+		};
+		Map<K, V> synchronizedCache = Collections.synchronizedMap(cache);
+		return new LRUCache<K, V>() {
+			@Override
+			public void clearCache() {
+				synchronizedCache.clear();
+			}
+
+			@Override
+			public int size() {
+				return synchronizedCache.size();
+			}
+
+			@Override
+			public V apply(K k) {
+				return synchronizedCache.computeIfAbsent(k, mapper);
+			}
+		};
+	}
+
+	int size();
+
+	void clearCache();
+}