Coverage Summary for Class: ImmediateFuture (com.google.common.util.concurrent)

1 /*
2  * Copyright (C) 2006 The Guava Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5  * in compliance with the License. You may obtain a copy of the License at
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software distributed under the License
10  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11  * or implied. See the License for the specific language governing permissions and limitations under
12  * the License.
13  */
14 
15 package com.google.common.util.concurrent;
16 
17 import static com.google.common.base.Preconditions.checkNotNull;
18 
19 import com.google.common.annotations.GwtCompatible;
20 import com.google.common.util.concurrent.AbstractFuture.TrustedFuture;
21 import java.util.concurrent.ExecutionException;
22 import java.util.concurrent.Executor;
23 import java.util.concurrent.TimeUnit;
24 import java.util.logging.Level;
25 import java.util.logging.Logger;
26 import org.checkerframework.checker.nullness.qual.Nullable;
27 
28 /** Implementation of {@link Futures#immediateFuture}. */
29 @GwtCompatible
30 @ElementTypesAreNonnullByDefault
31 // TODO(cpovirk): Make this final (but that may break Mockito spy calls).
32 class ImmediateFuture<V extends @Nullable Object> implements ListenableFuture<V> {
33   static final ListenableFuture<?> NULL = new ImmediateFuture<@Nullable Object>(null);
34 
35   private static final Logger log = Logger.getLogger(ImmediateFuture.class.getName());
36 
37   @ParametricNullness private final V value;
38 
39   ImmediateFuture(@ParametricNullness V value) {
40     this.value = value;
41   }
42 
43   @Override
44   public void addListener(Runnable listener, Executor executor) {
45     checkNotNull(listener, "Runnable was null.");
46     checkNotNull(executor, "Executor was null.");
47     try {
48       executor.execute(listener);
49     } catch (RuntimeException e) {
50       // ListenableFuture's contract is that it will not throw unchecked exceptions, so log the bad
51       // runnable and/or executor and swallow it.
52       log.log(
53           Level.SEVERE,
54           "RuntimeException while executing runnable " + listener + " with executor " + executor,
55           e);
56     }
57   }
58 
59   @Override
60   public boolean cancel(boolean mayInterruptIfRunning) {
61     return false;
62   }
63 
64   // TODO(lukes): Consider throwing InterruptedException when appropriate.
65   @Override
66   @ParametricNullness
67   public V get() {
68     return value;
69   }
70 
71   @Override
72   @ParametricNullness
73   public V get(long timeout, TimeUnit unit) throws ExecutionException {
74     checkNotNull(unit);
75     return get();
76   }
77 
78   @Override
79   public boolean isCancelled() {
80     return false;
81   }
82 
83   @Override
84   public boolean isDone() {
85     return true;
86   }
87 
88   @Override
89   public String toString() {
90     // Behaviour analogous to AbstractFuture#toString().
91     return super.toString() + "[status=SUCCESS, result=[" + value + "]]";
92   }
93 
94   static final class ImmediateFailedFuture<V extends @Nullable Object> extends TrustedFuture<V> {
95     ImmediateFailedFuture(Throwable thrown) {
96       setException(thrown);
97     }
98   }
99 
100   static final class ImmediateCancelledFuture<V extends @Nullable Object> extends TrustedFuture<V> {
101     ImmediateCancelledFuture() {
102       cancel(false);
103     }
104   }
105 }