alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

What this is

This file is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Other links

The source code

///////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2001, Eric D. Friedman All Rights Reserved.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
///////////////////////////////////////////////////////////////////////////////

package gnu.trove;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

/**
 * An open addressed Map implementation for int keys and double values.
 *
 * Created: Sun Nov  4 08:52:45 2001
 *
 * @author Eric D. Friedman
 * @version $Id: TIntDoubleHashMap.java,v 1.15 2003/11/21 17:32:30 ericdf Exp $
 */
public class TIntDoubleHashMap extends TIntHash implements Serializable {

    /** the values of the map */
    protected transient double[] _values;

    /**
     * Creates a new TIntDoubleHashMap instance with the default
     * capacity and load factor.
     */
    public TIntDoubleHashMap() {
        super();
    }

    /**
     * Creates a new TIntDoubleHashMap instance with a prime
     * capacity equal to or greater than initialCapacity and
     * with the default load factor.
     *
     * @param initialCapacity an int value
     */
    public TIntDoubleHashMap(int initialCapacity) {
        super(initialCapacity);
    }

    /**
     * Creates a new TIntDoubleHashMap instance with a prime
     * capacity equal to or greater than initialCapacity and
     * with the specified load factor.
     *
     * @param initialCapacity an int value
     * @param loadFactor a float value
     */
    public TIntDoubleHashMap(int initialCapacity, float loadFactor) {
        super(initialCapacity, loadFactor);
    }

    /**
     * Creates a new TIntDoubleHashMap instance with the default
     * capacity and load factor.
     * @param strategy used to compute hash codes and to compare keys.
     */
    public TIntDoubleHashMap(TIntHashingStrategy strategy) {
        super(strategy);
    }

    /**
     * Creates a new TIntDoubleHashMap instance whose capacity
     * is the next highest prime above initialCapacity + 1
     * unless that value is already prime.
     *
     * @param initialCapacity an int value
     * @param strategy used to compute hash codes and to compare keys.
     */
    public TIntDoubleHashMap(int initialCapacity, TIntHashingStrategy strategy) {
        super(initialCapacity, strategy);
    }

    /**
     * Creates a new TIntDoubleHashMap instance with a prime
     * value at or near the specified capacity and load factor.
     *
     * @param initialCapacity used to find a prime capacity for the table.
     * @param loadFactor used to calculate the threshold over which
     * rehashing takes place.
     * @param strategy used to compute hash codes and to compare keys.
     */
    public TIntDoubleHashMap(int initialCapacity, float loadFactor, TIntHashingStrategy strategy) {
        super(initialCapacity, loadFactor, strategy);
    }

    /**
     * @return a deep clone of this collection
     */
    public Object clone() {
      TIntDoubleHashMap m = (TIntDoubleHashMap)super.clone();
      m._values = (double[])this._values.clone();
      return m;
    }

    /**
     * @return a TIntDoubleIterator with access to this map's keys and values
     */
    public TIntDoubleIterator iterator() {
        return new TIntDoubleIterator(this);
    }

    /**
     * initializes the hashtable to a prime capacity which is at least
     * initialCapacity + 1.  
     *
     * @param initialCapacity an int value
     * @return the actual capacity chosen
     */
    protected int setUp(int initialCapacity) {
        int capacity;

        capacity = super.setUp(initialCapacity);
        _values = new double[capacity];
        return capacity;
    }

    /**
     * Inserts a key/value pair into the map.
     *
     * @param key an int value
     * @param value an double value
     * @return the previous value associated with key,
     * or (double)0 if none was found.
     */
    public double put(int key, double value) {
        byte previousState;
        double previous = (double)0;
        int index = insertionIndex(key);
        boolean isNewMapping = true;
        if (index < 0) {
            index = -index -1;
            previous = _values[index];
            isNewMapping = false;
        }
        previousState = _states[index];
        _set[index] = key;
        _states[index] = FULL;
        _values[index] = value;
        if (isNewMapping) {
            postInsertHook(previousState == FREE);
        }

        return previous;
    }

    /**
     * rehashes the map to the new capacity.
     *
     * @param newCapacity an int value
     */
    protected void rehash(int newCapacity) {
        int oldCapacity = _set.length;
        int oldKeys[] = _set;
        double oldVals[] = _values;
        byte oldStates[] = _states;

        _set = new int[newCapacity];
        _values = new double[newCapacity];
        _states = new byte[newCapacity];

        for (int i = oldCapacity; i-- > 0;) {
            if(oldStates[i] == FULL) {
                int o = oldKeys[i];
                int index = insertionIndex(o);
                _set[index] = o;
                _values[index] = oldVals[i];
                _states[index] = FULL;
            }
        }
    }

    /**
     * retrieves the value for key
     *
     * @param key an int value
     * @return the value of key or (double)0 if no such mapping exists.
     */
    public double get(int key) {
        int index = index(key);
        return index < 0 ? (double)0 : _values[index];
    }

    /**
     * Empties the map.
     *
     */
    public void clear() {
        super.clear();
        int[] keys = _set;
        double[] vals = _values;
        byte[] states = _states;

        for (int i = keys.length; i-- > 0;) {
            keys[i] = (int)0;
            vals[i] = (double)0;
            states[i] = FREE;
        }
    }

    /**
     * Deletes a key/value pair from the map.
     *
     * @param key an int value
     * @return an double value, or (double)0 if no mapping for key exists
     */
    public double remove(int key) {
        double prev = (double)0;
        int index = index(key);
        if (index >= 0) {
            prev = _values[index];
            removeAt(index);    // clear key,state; adjust size
        }
        return prev;
    }

    /**
     * Compares this map with another map for equality of their stored
     * entries.
     *
     * @param other an Object value
     * @return a boolean value
     */
    public boolean equals(Object other) {
        if (! (other instanceof TIntDoubleHashMap)) {
            return false;
        }
        TIntDoubleHashMap that = (TIntDoubleHashMap)other;
        if (that.size() != this.size()) {
            return false;
        }
        return forEachEntry(new EqProcedure(that));
    }

    public int hashCode() {
        HashProcedure p = new HashProcedure();
        forEachEntry(p);
        return p.getHashCode();
    }	

    private final class HashProcedure implements TIntDoubleProcedure {
        private int h = 0;
        
        public int getHashCode() {
            return h;
        }
        
        public final boolean execute(int key, double value) {
            h += (_hashingStrategy.computeHashCode(key) ^ HashFunctions.hash(value));
            return true;
        }
    }

    private static final class EqProcedure implements TIntDoubleProcedure {
        private final TIntDoubleHashMap _otherMap;

        EqProcedure(TIntDoubleHashMap otherMap) {
            _otherMap = otherMap;
        }

        public final boolean execute(int key, double value) {
            int index = _otherMap.index(key);
            if (index >= 0 && eq(value, _otherMap.get(key))) {
                return true;
            }
            return false;
        }

        /**
         * Compare two doubles for equality.
         */
        private final boolean eq(double v1, double v2) {
            return v1 == v2;
        }

    }

    /**
     * removes the mapping at index from the map.
     *
     * @param index an int value
     */
    protected void removeAt(int index) {
        super.removeAt(index);  // clear key, state; adjust size
        _values[index] = (double)0;
    }

    /**
     * Returns the values of the map.
     *
     * @return a Collection value
     */
    public double[] getValues() {
        double[] vals = new double[size()];
        double[] v = _values;
        byte[] states = _states;

        for (int i = v.length, j = 0; i-- > 0;) {
          if (states[i] == FULL) {
            vals[j++] = v[i];
          }
        }
        return vals;
    }

    /**
     * returns the keys of the map.
     *
     * @return a Set value
     */
    public int[] keys() {
        int[] keys = new int[size()];
        int[] k = _set;
        byte[] states = _states;

        for (int i = k.length, j = 0; i-- > 0;) {
          if (states[i] == FULL) {
            keys[j++] = k[i];
          }
        }
        return keys;
    }

    /**
     * checks for the presence of val in the values of the map.
     *
     * @param val an double value
     * @return a boolean value
     */
    public boolean containsValue(double val) {
        byte[] states = _states;
        double[] vals = _values;

        for (int i = vals.length; i-- > 0;) {
            if (states[i] == FULL && val == vals[i]) {
                return true;
            }
        }
        return false;
    }


    /**
     * checks for the present of key in the keys of the map.
     *
     * @param key an int value
     * @return a boolean value
     */
    public boolean containsKey(int key) {
        return contains(key);
    }

    /**
     * Executes procedure for each key in the map.
     *
     * @param procedure a TIntProcedure value
     * @return false if the loop over the keys terminated because
     * the procedure returned false for some key.
     */
    public boolean forEachKey(TIntProcedure procedure) {
        return forEach(procedure);
    }

    /**
     * Executes procedure for each value in the map.
     *
     * @param procedure a TDoubleProcedure value
     * @return false if the loop over the values terminated because
     * the procedure returned false for some value.
     */
    public boolean forEachValue(TDoubleProcedure procedure) {
        byte[] states = _states;
        double[] values = _values;
        for (int i = values.length; i-- > 0;) {
            if (states[i] == FULL && ! procedure.execute(values[i])) {
                return false;
            }
        }
        return true;
    }

    /**
     * Executes procedure for each key/value entry in the
     * map.
     *
     * @param procedure a TOIntDoubleProcedure value
     * @return false if the loop over the entries terminated because
     * the procedure returned false for some entry.
     */
    public boolean forEachEntry(TIntDoubleProcedure procedure) {
        byte[] states = _states;
        int[] keys = _set;
        double[] values = _values;
        for (int i = keys.length; i-- > 0;) {
            if (states[i] == FULL && ! procedure.execute(keys[i],values[i])) {
                return false;
            }
        }
        return true;
    }

    /**
     * Retains only those entries in the map for which the procedure
     * returns a true value.
     *
     * @param procedure determines which entries to keep
     * @return true if the map was modified.
     */
    public boolean retainEntries(TIntDoubleProcedure procedure) {
        boolean modified = false;
        byte[] states = _states;
        int[] keys = _set;
        double[] values = _values;
        for (int i = keys.length; i-- > 0;) {
            if (states[i] == FULL && ! procedure.execute(keys[i],values[i])) {
                removeAt(i);
                modified = true;
            }
        }
        return modified;
    }

    /**
     * Transform the values in this map using function.
     *
     * @param function a TDoubleFunction value
     */
    public void transformValues(TDoubleFunction function) {
        byte[] states = _states;
        double[] values = _values;
        for (int i = values.length; i-- > 0;) {
            if (states[i] == FULL) {
                values[i] = function.execute(values[i]);
            }
        }
    }

    /**
     * Increments the primitive value mapped to key by 1
     *
     * @param key the key of the value to increment
     * @return true if a mapping was found and modified.
     */
    public boolean increment(int key) {
        return adjustValue(key, (double)1);
    }

    /**
     * Adjusts the primitive value mapped to key.
     *
     * @param key the key of the value to increment
     * @param amount the amount to adjust the value by.
     * @return true if a mapping was found and modified.
     */
    public boolean adjustValue(int key, double amount) {
        int index = index(key);
        if (index < 0) {
            return false;
        } else {
            _values[index] += amount;
            return true;
        }
    }


    private void writeObject(ObjectOutputStream stream)
        throws IOException {
        stream.defaultWriteObject();

        // number of entries
        stream.writeInt(_size);

        SerializationProcedure writeProcedure = new SerializationProcedure(stream);
        if (! forEachEntry(writeProcedure)) {
            throw writeProcedure.exception;
        }
    }

    private void readObject(ObjectInputStream stream)
        throws IOException, ClassNotFoundException {
        stream.defaultReadObject();

        int size = stream.readInt();
        setUp(size);
        while (size-- > 0) {
            int key = stream.readInt();
            double val = stream.readDouble();
            put(key, val);
        }
    }
} // TIntDoubleHashMap
... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.