GenericMapMaker.java revision 3c77433663281544363151bf284b0240dfd22a42 
1/*
2 * Copyright (C) 2010 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS-IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.collect;
18
19import com.google.common.annotations.Beta;
20import com.google.common.annotations.GwtCompatible;
21import com.google.common.annotations.GwtIncompatible;
22import com.google.common.base.Equivalence;
23import com.google.common.base.Function;
24import com.google.common.base.Objects;
25import com.google.common.collect.MapMaker.RemovalListener;
26import com.google.common.collect.MapMaker.RemovalNotification;
27
28import java.util.concurrent.ConcurrentMap;
29import java.util.concurrent.TimeUnit;
30
31/**
32 * A class exactly like {@link MapMaker}, except restricted in the types of maps it can build.
33 * For the most part, you should probably just ignore the existence of this class.
34 *
35 * @param  the base type for all key types of maps built by this map maker
36 * @param  the base type for all value types of maps built by this map maker
37 * @author Kevin Bourrillion
38 * @since 7.0
39 */
40@Beta
41@GwtCompatible(emulated = true)
42public abstract class GenericMapMaker<K0, V0> {
43  @GwtIncompatible("To be supported")
44  enum NullListener implements RemovalListener<Object, Object> {
45    INSTANCE;
46
47    @Override
48    public void onRemoval(RemovalNotification<Object, Object> notification) {}
49  }
50
51  // Set by MapMaker, but sits in this class to preserve the type relationship
52  @GwtIncompatible("To be supported")
53  RemovalListener<K0, V0> removalListener;
54
55  // No subclasses but our own
56  GenericMapMaker() {}
57
58  /**
59   * See {@link MapMaker#keyEquivalence}.
60   */
61  @GwtIncompatible("To be supported")
62  abstract GenericMapMaker<K0, V0> keyEquivalence(Equivalence<Object> equivalence);
63
64  /**
65   * See {@link MapMaker#initialCapacity}.
66   */
67  public abstract GenericMapMaker<K0, V0> initialCapacity(int initialCapacity);
68
69  /**
70   * See {@link MapMaker#maximumSize}.
71   */
72  abstract GenericMapMaker<K0, V0> maximumSize(int maximumSize);
73
74  /**
75   * See {@link MapMaker#concurrencyLevel}.
76   */
77  public abstract GenericMapMaker<K0, V0> concurrencyLevel(int concurrencyLevel);
78
79  /**
80   * See {@link MapMaker#weakKeys}.
81   */
82  @GwtIncompatible("java.lang.ref.WeakReference")
83  public abstract GenericMapMaker<K0, V0> weakKeys();
84
85  /**
86   * See {@link MapMaker#weakValues}.
87   */
88  @GwtIncompatible("java.lang.ref.WeakReference")
89  public abstract GenericMapMaker<K0, V0> weakValues();
90
91  /**
92   * See {@link MapMaker#softValues}.
93   */
94  @GwtIncompatible("java.lang.ref.SoftReference")
95  public abstract GenericMapMaker<K0, V0> softValues();
96
97  /**
98   * See {@link MapMaker#expireAfterWrite}.
99   */
100  abstract GenericMapMaker<K0, V0> expireAfterWrite(long duration, TimeUnit unit);
101
102  /**
103   * See {@link MapMaker#expireAfterAccess}.
104   */
105  @GwtIncompatible("To be supported")
106  abstract GenericMapMaker<K0, V0> expireAfterAccess(long duration, TimeUnit unit);
107
108  /*
109   * Note that MapMaker's removalListener() is not here, because once you're interacting with a
110   * GenericMapMaker you've already called that, and shouldn't be calling it again.
111   */
112
113  @SuppressWarnings("unchecked") // safe covariant cast
114  @GwtIncompatible("To be supported")
115  <K extends K0, V extends V0> RemovalListener<K, V> getRemovalListener() {
116    return (RemovalListener<K, V>) Objects.firstNonNull(removalListener, NullListener.INSTANCE);
117  }
118
119  /**
120   * See {@link MapMaker#makeMap}.
121   */
122  public abstract <K extends K0, V extends V0> ConcurrentMap<K, V> makeMap();
123
124  /**
125   * See {@link MapMaker#makeCustomMap}.
126   */
127  @GwtIncompatible("MapMakerInternalMap")
128  abstract <K, V> MapMakerInternalMap<K, V> makeCustomMap();
129
130  /**
131   * See {@link MapMaker#makeComputingMap}.
132   */
133  @Deprecated
134  public abstract <K extends K0, V extends V0> ConcurrentMap<K, V> makeComputingMap(
135      Function<? super K, ? extends V> computingFunction);
136}
137