|
Java example source code file (InflightNameResolver.java)
This example Java source code file (InflightNameResolver.java) is included in the alvinalexander.com
"Java Source Code
Warehouse" project. The intent of this project is to help you "Learn
Java by Example" TM.
Learn more about this Java project at its project page.
The InflightNameResolver.java Java example source code
/*
* Copyright 2016 The Netty Project
*
* The Netty Project licenses this file to you 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 io.netty.resolver.dns;
import io.netty.resolver.NameResolver;
import io.netty.util.concurrent.EventExecutor;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.FutureListener;
import io.netty.util.concurrent.Promise;
import io.netty.util.internal.StringUtil;
import java.util.List;
import java.util.concurrent.ConcurrentMap;
import static io.netty.util.internal.ObjectUtil.checkNotNull;
// FIXME(trustin): Find a better name and move it to the 'resolver' module.
final class InflightNameResolver<T> implements NameResolver {
private final EventExecutor executor;
private final NameResolver<T> delegate;
private final ConcurrentMap<String, Promise resolvesInProgress;
private final ConcurrentMap<String, Promise> resolveAllsInProgress;
InflightNameResolver(EventExecutor executor, NameResolver<T> delegate,
ConcurrentMap<String, Promise resolvesInProgress,
ConcurrentMap<String, Promise> resolveAllsInProgress) {
this.executor = checkNotNull(executor, "executor");
this.delegate = checkNotNull(delegate, "delegate");
this.resolvesInProgress = checkNotNull(resolvesInProgress, "resolvesInProgress");
this.resolveAllsInProgress = checkNotNull(resolveAllsInProgress, "resolveAllsInProgress");
}
@Override
public Future<T> resolve(String inetHost) {
return resolve(inetHost, executor.<T>newPromise());
}
@Override
public Future<List resolveAll(String inetHost) {
return resolveAll(inetHost, executor.<ListnewPromise());
}
@Override
public void close() {
delegate.close();
}
@Override
public Promise<T> resolve(String inetHost, Promise promise) {
return resolve(resolvesInProgress, inetHost, promise, false);
}
@Override
public Promise<List resolveAll(String inetHost, Promise> promise) {
return resolve(resolveAllsInProgress, inetHost, promise, true);
}
private <U> Promise resolve(
final ConcurrentMap<String, Promise resolveMap,
final String inetHost, final Promise<U> promise, boolean resolveAll) {
final Promise<U> earlyPromise = resolveMap.putIfAbsent(inetHost, promise);
if (earlyPromise != null) {
// Name resolution for the specified inetHost is in progress already.
if (earlyPromise.isDone()) {
transferResult(earlyPromise, promise);
} else {
earlyPromise.addListener(new FutureListener<U>() {
@Override
public void operationComplete(Future<U> f) throws Exception {
transferResult(f, promise);
}
});
}
} else {
try {
if (resolveAll) {
@SuppressWarnings("unchecked")
final Promise<List castPromise = (Promise>) promise; // U is List
delegate.resolveAll(inetHost, castPromise);
} else {
@SuppressWarnings("unchecked")
final Promise<T> castPromise = (Promise) promise; // U is T
delegate.resolve(inetHost, castPromise);
}
} finally {
if (promise.isDone()) {
resolveMap.remove(inetHost);
} else {
promise.addListener(new FutureListener<U>() {
@Override
public void operationComplete(Future<U> f) throws Exception {
resolveMap.remove(inetHost);
}
});
}
}
}
return promise;
}
private static <T> void transferResult(Future src, Promise dst) {
if (src.isSuccess()) {
dst.trySuccess(src.getNow());
} else {
dst.tryFailure(src.cause());
}
}
@Override
public String toString() {
return StringUtil.simpleClassName(this) + '(' + delegate + ')';
}
}
Other Java examples (source code examples)
Here is a short list of links related to this Java InflightNameResolver.java source code file:
|