    001    /*
    002     * Copyright (C) 2010 The Guava Authors
    003     *
    004     * Licensed under the Apache License, Version 2.0 (the "License");
    005     * you may not use this file except in compliance with the License.
    006     * You may obtain a copy of the License at
    007     *
    008     *      http://www.apache.org/licenses/LICENSE-2.0
    009     *
    010     * Unless required by applicable law or agreed to in writing, software
    011     * distributed under the License is distributed on an "AS-IS" BASIS,
    012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    013     * See the License for the specific language governing permissions and
    014     * limitations under the License.
    015     */
    016
    017    package com.google.common.collect;
    018
    019    import com.google.common.annotations.Beta;
    020    import com.google.common.annotations.GwtCompatible;
    021    import com.google.common.annotations.GwtIncompatible;
    022    import com.google.common.base.Equivalence;
    023    import com.google.common.base.Function;
    024    import com.google.common.base.Objects;
    025    import com.google.common.collect.MapMaker.RemovalListener;
    026    import com.google.common.collect.MapMaker.RemovalNotification;
    027
    028    import java.util.concurrent.ConcurrentMap;
    029    import java.util.concurrent.TimeUnit;
    030
    031    /**
    032     * A class exactly like {@link MapMaker}, except restricted in the types of maps it can build.
    033     * For the most part, you should probably just ignore the existence of this class.
    034     *
    035     * @param <K0> the base type for all key types of maps built by this map maker
    036     * @param <V0> the base type for all value types of maps built by this map maker
    037     * @author Kevin Bourrillion
    038     * @since 7.0
    039     */
    040    @Beta
    041    @GwtCompatible(emulated = true)
    042    public abstract class GenericMapMaker<K0, V0> {
    043      @GwtIncompatible("To be supported")
    044      enum NullListener implements RemovalListener<Object, Object> {
    045        INSTANCE;
    046
    047        @Override
    048        public void onRemoval(RemovalNotification<Object, Object> notification) {}
    049      }
    050
    051      // Set by MapMaker, but sits in this class to preserve the type relationship
    052      @GwtIncompatible("To be supported")
    053      RemovalListener<K0, V0> removalListener;
    054
    055      // No subclasses but our own
    056      GenericMapMaker() {}
    057
    058      /**
    059       * See {@link MapMaker#keyEquivalence}.
    060       */
    061      @GwtIncompatible("To be supported")
    062      abstract GenericMapMaker<K0, V0> keyEquivalence(Equivalence<Object> equivalence);
    063
    064      /**
    065       * See {@link MapMaker#valueEquivalence}.
    066       */
    067      @GwtIncompatible("To be supported")
    068      abstract GenericMapMaker<K0, V0> valueEquivalence(Equivalence<Object> equivalence);
    069
    070      /**
    071       * See {@link MapMaker#initialCapacity}.
    072       */
    073      public abstract GenericMapMaker<K0, V0> initialCapacity(int initialCapacity);
    074
    075      /**
    076       * See {@link MapMaker#maximumSize}.
    077       *
    078       * @since 8.0
    079       */
    080      @Beta
    081      @Deprecated
    082      public abstract GenericMapMaker<K0, V0> maximumSize(int maximumSize);
    083
    084      /**
    085       * See {@link MapMaker#strongKeys}.
    086       */
    087      abstract GenericMapMaker<K0, V0> strongKeys();
    088
    089      /**
    090       * See {@link MapMaker#concurrencyLevel}.
    091       */
    092      public abstract GenericMapMaker<K0, V0> concurrencyLevel(int concurrencyLevel);
    093
    094      /**
    095       * See {@link MapMaker#weakKeys}.
    096       */
    097      @GwtIncompatible("java.lang.ref.WeakReference")
    098      public abstract GenericMapMaker<K0, V0> weakKeys();
    099
    100      /**
    101       * See {@link MapMaker#strongValues}.
    102       */
    103      abstract GenericMapMaker<K0, V0> strongValues();
    104
    105      /**
    106       * See {@link MapMaker#softKeys}.
    107       */
    108      @Deprecated
    109      @GwtIncompatible("java.lang.ref.SoftReference")
    110      public abstract GenericMapMaker<K0, V0> softKeys();
    111
    112      /**
    113       * See {@link MapMaker#weakValues}.
    114       */
    115      @GwtIncompatible("java.lang.ref.WeakReference")
    116      public abstract GenericMapMaker<K0, V0> weakValues();
    117
    118      /**
    119       * See {@link MapMaker#softValues}.
    120       */
    121      @GwtIncompatible("java.lang.ref.SoftReference")
    122      public abstract GenericMapMaker<K0, V0> softValues();
    123
    124      /**
    125       * See {@link MapMaker#expiration}.
    126       */
    127      @Deprecated
    128      public
    129      abstract GenericMapMaker<K0, V0> expiration(long duration, TimeUnit unit);
    130
    131      /**
    132       * See {@link MapMaker#expireAfterWrite}.
    133       *
    134       * @since 8.0
    135       */
    136      @Deprecated
    137      public abstract GenericMapMaker<K0, V0> expireAfterWrite(long duration, TimeUnit unit);
    138
    139      /**
    140       * See {@link MapMaker#expireAfterAccess}.
    141       *
    142       * @since 8.0
    143       */
    144      @GwtIncompatible("To be supported")
    145      @Deprecated
    146      public abstract GenericMapMaker<K0, V0> expireAfterAccess(long duration, TimeUnit unit);
    147
    148      /*
    149       * Note that MapMaker's removalListener() is not here, because once you're interacting with a
    150       * GenericMapMaker you've already called that, and shouldn't be calling it again.
    151       */
    152
    153      @SuppressWarnings("unchecked") // safe covariant cast
    154      @GwtIncompatible("To be supported")
    155      <K extends K0, V extends V0> RemovalListener<K, V> getRemovalListener() {
    156        return (RemovalListener<K, V>) Objects.firstNonNull(removalListener, NullListener.INSTANCE);
    157      }
    158
    159      /**
    160       * See {@link MapMaker#makeMap}.
    161       */
    162      public abstract <K extends K0, V extends V0> ConcurrentMap<K, V> makeMap();
    163
    164      /**
    165       * See {@link MapMaker#makeCustomMap}.
    166       */
    167      @GwtIncompatible("CustomConcurrentHashMap")
    168      abstract <K, V> CustomConcurrentHashMap<K, V> makeCustomMap();
    169
    170      /**
    171       * See {@link MapMaker#makeComputingMap}.
    172       */
    173      @Deprecated
    174      public abstract <K extends K0, V extends V0> ConcurrentMap<K, V> makeComputingMap(
    175          Function<? super K, ? extends V> computingFunction);
    176    }