/*
* This file is part of LanternServer, licensed under the MIT License (MIT).
*
* Copyright (c) LanternPowered <https://www.lanternpowered.org>
* Copyright (c) SpongePowered <https://www.spongepowered.org>
* Copyright (c) contributors
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the Software), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package org.lanternpowered.server.event.filter;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.github.benmanes.caffeine.cache.CacheLoader;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.github.benmanes.caffeine.cache.LoadingCache;
import org.lanternpowered.server.event.gen.DefineableClassLoader;
import java.lang.reflect.Method;
import java.util.concurrent.atomic.AtomicInteger;
import javax.annotation.Nullable;
public class FilterFactory {
private final AtomicInteger id = new AtomicInteger();
private final DefineableClassLoader classLoader;
private final LoadingCache<Method, Class<? extends EventFilter>> cache =
Caffeine.newBuilder().weakValues().build((CacheLoader<Method, Class<? extends EventFilter>>) this::createClass);
private final String targetPackage;
public FilterFactory(String targetPackage, DefineableClassLoader classLoader) {
checkNotNull(targetPackage, "targetPackage");
checkArgument(!targetPackage.isEmpty(), "targetPackage cannot be empty");
this.targetPackage = targetPackage + '.';
this.classLoader = checkNotNull(classLoader, "classLoader");
}
@Nullable
public Class<? extends EventFilter> createFilter(Method method) throws Exception {
return this.cache.get(method);
}
private Class<? extends EventFilter> createClass(Method method) {
Class<?> handle = method.getDeclaringClass();
Class<?> eventClass = method.getParameterTypes()[0];
String name = this.targetPackage + eventClass.getSimpleName() + "Filter_" + handle.getSimpleName() + '_'
+ method.getName() + this.id.incrementAndGet();
byte[] cls = FilterGenerator.getInstance().generateClass(name, method);
return this.classLoader.defineClass(name, cls);
}
}