    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#initialCapacity}.
    066       */
    067      public abstract GenericMapMaker<K0, V0> initialCapacity(int initialCapacity);
    068
    069      /**
    070       * See {@link MapMaker#maximumSize}.
    071       */
    072      abstract GenericMapMaker<K0, V0> maximumSize(int maximumSize);
    073
    074      /**
    075       * See {@link MapMaker#concurrencyLevel}.
    076       */
    077      public abstract GenericMapMaker<K0, V0> concurrencyLevel(int concurrencyLevel);
    078
    079      /**
    080       * See {@link MapMaker#weakKeys}.
    081       */
    082      @GwtIncompatible("java.lang.ref.WeakReference")
    083      public abstract GenericMapMaker<K0, V0> weakKeys();
    084
    085      /**
    086       * See {@link MapMaker#softKeys}.
    087       */
    088      @Deprecated
    089      @GwtIncompatible("java.lang.ref.SoftReference")
    090      public abstract GenericMapMaker<K0, V0> softKeys();
    091
    092      /**
    093       * See {@link MapMaker#weakValues}.
    094       */
    095      @GwtIncompatible("java.lang.ref.WeakReference")
    096      public abstract GenericMapMaker<K0, V0> weakValues();
    097
    098      /**
    099       * See {@link MapMaker#softValues}.
    100       */
    101      @GwtIncompatible("java.lang.ref.SoftReference")
    102      public abstract GenericMapMaker<K0, V0> softValues();
    103
    104      /**
    105       * See {@link MapMaker#expireAfterWrite}.
    106       */
    107      abstract GenericMapMaker<K0, V0> expireAfterWrite(long duration, TimeUnit unit);
    108
    109      /**
    110       * See {@link MapMaker#expireAfterAccess}.
    111       */
    112      @GwtIncompatible("To be supported")
    113      abstract GenericMapMaker<K0, V0> expireAfterAccess(long duration, TimeUnit unit);
    114
    115      /*
    116       * Note that MapMaker's removalListener() is not here, because once you're interacting with a
    117       * GenericMapMaker you've already called that, and shouldn't be calling it again.
    118       */
    119
    120      @SuppressWarnings("unchecked") // safe covariant cast
    121      @GwtIncompatible("To be supported")
    122      <K extends K0, V extends V0> RemovalListener<K, V> getRemovalListener() {
    123        return (RemovalListener<K, V>) Objects.firstNonNull(removalListener, NullListener.INSTANCE);
    124      }
    125
    126      /**
    127       * See {@link MapMaker#makeMap}.
    128       */
    129      public abstract <K extends K0, V extends V0> ConcurrentMap<K, V> makeMap();
    130
    131      /**
    132       * See {@link MapMaker#makeCustomMap}.
    133       */
    134      @GwtIncompatible("MapMakerInternalMap")
    135      abstract <K, V> MapMakerInternalMap<K, V> makeCustomMap();
    136
    137      /**
    138       * See {@link MapMaker#makeComputingMap}.
    139       */
    140      @Deprecated
    141      public abstract <K extends K0, V extends V0> ConcurrentMap<K, V> makeComputingMap(
    142          Function<? super K, ? extends V> computingFunction);
    143    }