jnr.ffi.provider.NativeInvocationHandler Maven / Gradle / Ivy
/*
* Copyright (C) 2008-2012 Wayne Meissner
*
* This file is part of the JNR project.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package jnr.ffi.provider;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.IdentityHashMap;
import java.util.Map;
/**
* InvocationHandler used to map invocations on a java interface to the correct native function.
*/
public class NativeInvocationHandler implements InvocationHandler {
private volatile Map fastLookupTable;
private final Map invokerMap;
/**
* Creates a new InvocationHandler instance.
*
* @param invokers A map of method invokers
*
*/
public NativeInvocationHandler(Map invokers) {
this.invokerMap = invokers;
this.fastLookupTable = Collections.emptyMap();
}
public Object invoke(Object self, Method method, Object[] argArray) throws Throwable {
Invoker invoker = fastLookupTable.get(method);
return invoker != null ? invoker.invoke(self, argArray) : lookupAndCacheInvoker(method).invoke(self, argArray);
}
private synchronized Invoker lookupAndCacheInvoker(Method method) {
Invoker invoker;
if ((invoker = fastLookupTable.get(method)) != null) {
return invoker;
}
Map map = new IdentityHashMap(fastLookupTable);
map.put(method, invoker = invokerMap.get(method));
if (invoker == null) {
throw new UnsatisfiedLinkError("no invoker for native method " + method.getName());
}
fastLookupTable = map;
return invoker;
}
}