| /* |
| * Copyright (C) 2011 The Guava Authors |
| * |
| * 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 com.google.common.util.concurrent; |
| |
| import com.google.common.annotations.GwtCompatible; |
| import java.util.concurrent.Future; |
| import org.checkerframework.checker.nullness.compatqual.NullableDecl; |
| |
| /** |
| * Transforms a value, possibly asynchronously. For an example usage and more information, see |
| * {@link Futures#transformAsync(ListenableFuture, AsyncFunction, Executor)}. |
| * |
| * @author Chris Povirk |
| * @since 11.0 |
| */ |
| @GwtCompatible |
| public interface AsyncFunction<I, O> { |
| /** |
| * Returns an output {@code Future} to use in place of the given {@code input}. The output {@code |
| * Future} need not be {@linkplain Future#isDone done}, making {@code AsyncFunction} suitable for |
| * asynchronous derivations. |
| * |
| * <p>Throwing an exception from this method is equivalent to returning a failing {@code Future}. |
| */ |
| ListenableFuture<O> apply(@NullableDecl I input) throws Exception; |
| } |