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Java example source code file (MultiDimensionalMap.java)

This example Java source code file (MultiDimensionalMap.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

collection, concurrenthashmap, concurrentskiplistmap, entry, hashset, k,t,v, multidimensionalmap, pair, serializable, set, threading, threads, treemap, util

The MultiDimensionalMap.java Java example source code

/*
 *
 *  * Copyright 2015 Skymind,Inc.
 *  *
 *  *    Licensed under the Apache License, Version 2.0 (the "License");
 *  *    you may not use this file except in compliance with the License.
 *  *    You may obtain a copy of the License at
 *  *
 *  *        http://www.apache.org/licenses/LICENSE-2.0
 *  *
 *  *    Unless required by applicable law or agreed to in writing, software
 *  *    distributed under the License is distributed on an "AS IS" BASIS,
 *  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  *    See the License for the specific language governing permissions and
 *  *    limitations under the License.
 *
 */

package org.deeplearning4j.util;

import org.deeplearning4j.berkeley.Pair;

import java.io.Serializable;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentSkipListMap;

/**
 * Multiple key map
 */
public class MultiDimensionalMap<K,T,V>  implements Serializable  {

    private Map<Pair backedMap;

    /**
     * Thread safe sorted map implementation
     * @param <K>
     * @param <T>
     * @param <V>
     * @return
     */
    public static <K,T,V>  MultiDimensionalMap newThreadSafeTreeBackedMap() {
        return new MultiDimensionalMap<>(new ConcurrentSkipListMap,V>());
    }

    /**
     * Thread safe hash map implementation
     * @param <K>
     * @param <T>
     * @param <V>
     * @return
     */
    public static <K,T,V>  MultiDimensionalMap newThreadSafeHashBackedMap() {
        return new MultiDimensionalMap<>(new ConcurrentHashMap,V>());
    }

    /**
     * Thread safe hash map impl
     * @param <K>
     * @param <T>
     * @param <V>
     * @return
     */
    public static <K,T,V>  MultiDimensionalMap newHashBackedMap() {
        return new MultiDimensionalMap<>(new HashMap,V>());
    }

    /**
     * Tree map implementation
     * @param <K>
     * @param <T>
     * @param <V>
     * @return
     */
    public static <K,T,V>  MultiDimensionalMap newTreeBackedMap() {
        return new MultiDimensionalMap<>(new TreeMap,V>());
    }

    public MultiDimensionalMap(Map<Pair backedMap) {
        this.backedMap = backedMap;
    }

    /**
     * Returns the number of key-value mappings in this map.  If the
     * map contains more than <tt>Integer.MAX_VALUE elements, returns
     * <tt>Integer.MAX_VALUE.
     *
     * @return the number of key-value mappings in this map
     */
    
    public int size() {
        return backedMap.size();
    }

    /**
     * Returns <tt>true if this map contains no key-value mappings.
     *
     * @return <tt>true if this map contains no key-value mappings
     */
    
    public boolean isEmpty() {
        return backedMap.isEmpty();
    }

    /**
     * Returns <tt>true if this map contains a mapping for the specified
     * key.  More formally, returns <tt>true if and only if
     * this map contains a mapping for a key <tt>k such that
     * <tt>(key==null ? k==null : key.equals(k)).  (There can be
     * at most one such mapping.)
     *
     * @param key key whose presence in this map is to be tested
     * @return <tt>true if this map contains a mapping for the specified
     * key
     * @throws ClassCastException   if the key is of an inappropriate type for
     *                              this map
     *                              (<a href="Collection.html#optional-restrictions">optional)
     * @throws NullPointerException if the specified key is null and this map
     *                              does not permit null keys
     *                              (<a href="Collection.html#optional-restrictions">optional)
     */
    
    public boolean containsKey(Object key) {
        return backedMap.containsKey(key);
    }

    /**
     * Returns <tt>true if this map maps one or more keys to the
     * specified value.  More formally, returns <tt>true if and only if
     * this map contains at least one mapping to a value <tt>v such that
     * <tt>(value==null ? v==null : value.equals(v)).  This operation
     * will probably require time linear in the map size for most
     * implementations of the <tt>Map interface.
     *
     * @param value value whose presence in this map is to be tested
     * @return <tt>true if this map maps one or more keys to the
     * specified value
     * @throws ClassCastException   if the value is of an inappropriate type for
     *                              this map
     *                              (<a href="Collection.html#optional-restrictions">optional)
     * @throws NullPointerException if the specified value is null and this
     *                              map does not permit null values
     *                              (<a href="Collection.html#optional-restrictions">optional)
     */
    
    public boolean containsValue(Object value) {
        return backedMap.containsValue(value);
    }

    /**
     * Returns the value to which the specified key is mapped,
     * or {@code null} if this map contains no mapping for the key.
     * <p/>
     * <p>More formally, if this map contains a mapping from a key
     * {@code k} to a value {@code v} such that {@code (key==null ? k==null :
     * key.equals(k))}, then this method returns {@code v}; otherwise
     * it returns {@code null}.  (There can be at most one such mapping.)
     * <p/>
     * <p>If this map permits null values, then a return value of
     * {@code null} does not <i>necessarily indicate that the map
     * contains no mapping for the key; it's also possible that the map
     * explicitly maps the key to {@code null}.  The {@link #containsKey
     * containsKey} operation may be used to distinguish these two cases.
     *
     * @param key the key whose associated value is to be returned
     * @return the value to which the specified key is mapped, or
     * {@code null} if this map contains no mapping for the key
     * @throws ClassCastException   if the key is of an inappropriate type for
     *                              this map
     *                              (<a href="Collection.html#optional-restrictions">optional)
     * @throws NullPointerException if the specified key is null and this map
     *                              does not permit null keys
     *                              (<a href="Collection.html#optional-restrictions">optional)
     */
    
    public V get(Object key) {
        return backedMap.get(key);
    }

    /**
     * Associates the specified value with the specified key in this map
     * (optional operation).  If the map previously contained a mapping for
     * the key, the old value is replaced by the specified value.  (A map
     * <tt>m is said to contain a mapping for a key k if and only
     * if {@link #containsKey(Object) m.containsKey(k)} would return
     * <tt>true.)
     *
     * @param key   key with which the specified value is to be associated
     * @param value value to be associated with the specified key
     * @return the previous value associated with <tt>key, or
     * <tt>null if there was no mapping for key.
     * (A <tt>null return can also indicate that the map
     * previously associated <tt>null with key,
     * if the implementation supports <tt>null values.)
     * @throws UnsupportedOperationException if the <tt>put operation
     *                                       is not supported by this map
     * @throws ClassCastException            if the class of the specified key or value
     *                                       prevents it from being stored in this map
     * @throws NullPointerException          if the specified key or value is null
     *                                       and this map does not permit null keys or values
     * @throws IllegalArgumentException      if some property of the specified key
     *                                       or value prevents it from being stored in this map
     */
    
    public V put(Pair<K, T> key, V value) {
        return backedMap.put(key,value);
    }

    /**
     * Removes the mapping for a key from this map if it is present
     * (optional operation).   More formally, if this map contains a mapping
     * from key <tt>k to value v such that
     * <code>(key==null ?  k==null : key.equals(k)), that mapping
     * is removed.  (The map can contain at most one such mapping.)
     * <p/>
     * <p>Returns the value to which this map previously associated the key,
     * or <tt>null if the map contained no mapping for the key.
     * <p/>
     * <p>If this map permits null values, then a return value of
     * <tt>null does not necessarily indicate that the map
     * contained no mapping for the key; it's also possible that the map
     * explicitly mapped the key to <tt>null.
     * <p/>
     * <p>The map will not contain a mapping for the specified key once the
     * call returns.
     *
     * @param key key whose mapping is to be removed from the map
     * @return the previous value associated with <tt>key, or
     * <tt>null if there was no mapping for key.
     * @throws UnsupportedOperationException if the <tt>remove operation
     *                                       is not supported by this map
     * @throws ClassCastException            if the key is of an inappropriate type for
     *                                       this map
     *                                       (<a href="Collection.html#optional-restrictions">optional)
     * @throws NullPointerException          if the specified key is null and this
     *                                       map does not permit null keys
     *                                       (<a href="Collection.html#optional-restrictions">optional)
     */
    
    public V remove(Object key) {
        return backedMap.remove(key);
    }

    /**
     * Copies all of the mappings from the specified map to this map
     * (optional operation).  The effect of this call is equivalent to that
     * of calling {@link Map<>#put(k, v)} on this map once
     * for each mapping from key <tt>k to value v in the
     * specified map.  The behavior of this operation is undefined if the
     * specified map is modified while the operation is in progress.
     *
     * @param m mappings to be stored in this map
     * @throws UnsupportedOperationException if the <tt>putAll operation
     *                                       is not supported by this map
     * @throws ClassCastException            if the class of a key or value in the
     *                                       specified map prevents it from being stored in this map
     * @throws NullPointerException          if the specified map is null, or if
     *                                       this map does not permit null keys or values, and the
     *                                       specified map contains null keys or values
     * @throws IllegalArgumentException      if some property of a key or value in
     *                                       the specified map prevents it from being stored in this map
     */
    
    public void putAll(Map<? extends Pair m) {
        backedMap.putAll(m);
    }

    /**
     * Removes all of the mappings from this map (optional operation).
     * The map will be empty after this call returns.
     *
     * @throws UnsupportedOperationException if the <tt>clear operation
     *                                       is not supported by this map
     */
    
    public void clear() {
        backedMap.clear();
    }

    /**
     * Returns a {@link java.util.Set} view of the keys contained in this map.
     * The applyTransformToDestination is backed by the map, so changes to the map are
     * reflected in the applyTransformToDestination, and vice-versa.  If the map is modified
     * while an iteration over the applyTransformToDestination is in progress (except through
     * the iterator's own <tt>remove operation), the results of
     * the iteration are undefined.  The applyTransformToDestination supports element removal,
     * which removes the corresponding mapping from the map, via the
     * <tt>Iterator.remove, Set.remove,
     * <tt>removeAll, retainAll, and clear
     * operations.  It does not support the <tt>add or addAll
     * operations.
     *
     * @return a applyTransformToDestination view of the keys contained in this map
     */
    
    public Set<Pair keySet() {
        return backedMap.keySet();
    }

    /**
     * Returns a {@link java.util.Collection} view of the values contained in this map.
     * The collection is backed by the map, so changes to the map are
     * reflected in the collection, and vice-versa.  If the map is
     * modified while an iteration over the collection is in progress
     * (except through the iterator's own <tt>remove operation),
     * the results of the iteration are undefined.  The collection
     * supports element removal, which removes the corresponding
     * mapping from the map, via the <tt>Iterator.remove,
     * <tt>Collection.remove, removeAll,
     * <tt>retainAll and clear operations.  It does not
     * support the <tt>add or addAll operations.
     *
     * @return a collection view of the values contained in this map
     */
    
    public Collection<V> values() {
        return backedMap.values();
    }

    /**
     * Returns a {@link java.util.Set} view of the mappings contained in this map.
     * The applyTransformToDestination is backed by the map, so changes to the map are
     * reflected in the applyTransformToDestination, and vice-versa.  If the map is modified
     * while an iteration over the applyTransformToDestination is in progress (except through
     * the iterator's own <tt>remove operation, or through the
     * <tt>setValue operation on a map entry returned by the
     * iterator) the results of the iteration are undefined.  The applyTransformToDestination
     * supports element removal, which removes the corresponding
     * mapping from the map, via the <tt>Iterator.remove,
     * <tt>Set.remove, removeAll, retainAll and
     * <tt>clear operations.  It does not support the
     * <tt>add or addAll operations.
     *
     * @return a applyTransformToDestination view of the mappings contained in this map
     */

    public Set<Entry entrySet() {
        Set<Entry ret  = new HashSet<>();
        for(Pair<K,T> pair : backedMap.keySet()) {
            ret.add(new Entry<>(pair.getFirst(),pair.getSecond(),backedMap.get(pair)));
        }
        return ret;
    }

    public V get(K k,T t) {
        return get(new Pair<>(k,t));
    }

    public void put(K k,T t, V v) {
        put(new Pair<>(k,t),v);
    }

    
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof MultiDimensionalMap)) return false;

        MultiDimensionalMap that = (MultiDimensionalMap) o;

        return !(backedMap != null ? !backedMap.equals(that.backedMap) : that.backedMap != null);

    }

    
    public int hashCode() {
        return backedMap != null ? backedMap.hashCode() : 0;
    }

    
    public String toString() {
        return "MultiDimensionalMap{" +
                "backedMap=" + backedMap +
                '}';
    }


    public boolean contains(K k ,T t) {
        return containsKey(new Pair<>(k,t));
    }


    public static class Entry<K,T,V> implements Map.Entry,V> {

        private K firstKey;
        private T secondKey;
        private V value;

        public Entry(K firstKey, T secondKey, V value) {
            this.firstKey = firstKey;
            this.secondKey = secondKey;
            this.value = value;
        }

        public K getFirstKey() {
            return firstKey;
        }

        public void setFirstKey(K firstKey) {
            this.firstKey = firstKey;
        }

        public T getSecondKey() {
            return secondKey;
        }

        public void setSecondKey(T secondKey) {
            this.secondKey = secondKey;
        }

        public V getValue() {
            return value;
        }

        /**
         * Replaces the value corresponding to this entry with the specified
         * value (optional operation).  (Writes through to the map.)  The
         * behavior of this call is undefined if the mapping has already been
         * removed from the map (by the iterator's <tt>remove operation).
         *
         * @param value new value to be stored in this entry
         * @return old value corresponding to the entry
         * @throws UnsupportedOperationException if the <tt>put operation
         *                                       is not supported by the backing map
         * @throws ClassCastException            if the class of the specified value
         *                                       prevents it from being stored in the backing map
         * @throws NullPointerException          if the backing map does not permit
         *                                       null values, and the specified value is null
         * @throws IllegalArgumentException      if some property of this value
         *                                       prevents it from being stored in the backing map
         * @throws IllegalStateException         implementations may, but are not
         *                                       required to, throw this exception if the entry has been
         *                                       removed from the backing map.
         */
        
        public V setValue(V value) {
            V old = this.value;
            this.value = value;
            return old;
        }


        /**
         * Returns the key corresponding to this entry.
         *
         * @return the key corresponding to this entry
         * @throws IllegalStateException implementations may, but are not
         *                               required to, throw this exception if the entry has been
         *                               removed from the backing map.
         */
        
        public Pair<K, T> getKey() {
            return new Pair<>(firstKey,secondKey);
        }
    }




}

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