1/*
2 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package sun.nio.ch;
27
28import java.util.concurrent.Future;
29import java.util.concurrent.TimeUnit;
30import java.util.concurrent.ExecutionException;
31import java.io.IOException;
32
33/**
34 * A Future representing the result of an I/O operation that has already
35 * completed.
36 */
37
38final class CompletedFuture<V> implements Future<V> {
39    private final V result;
40    private final Throwable exc;
41
42    private CompletedFuture(V result, Throwable exc) {
43        this.result = result;
44        this.exc = exc;
45    }
46
47    static <V> CompletedFuture<V> withResult(V result) {
48        return new CompletedFuture<V>(result, null);
49    }
50
51    static <V> CompletedFuture<V> withFailure(Throwable exc) {
52        // exception must be IOException or SecurityException
53        if (!(exc instanceof IOException) && !(exc instanceof SecurityException))
54            exc = new IOException(exc);
55        return new CompletedFuture<V>(null, exc);
56    }
57
58    static <V> CompletedFuture<V> withResult(V result, Throwable exc) {
59        if (exc == null) {
60            return withResult(result);
61        } else {
62            return withFailure(exc);
63        }
64    }
65
66    @Override
67    public V get() throws ExecutionException {
68        if (exc != null)
69            throw new ExecutionException(exc);
70        return result;
71    }
72
73    @Override
74    public V get(long timeout, TimeUnit unit) throws ExecutionException {
75        if (unit == null)
76            throw new NullPointerException();
77        if (exc != null)
78            throw new ExecutionException(exc);
79        return result;
80    }
81
82    @Override
83    public boolean isCancelled() {
84        return false;
85    }
86
87    @Override
88    public boolean isDone() {
89        return true;
90    }
91
92    @Override
93    public boolean cancel(boolean mayInterruptIfRunning) {
94        return false;
95    }
96}
97