SquirrelJME/SquirrelJME

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modules/cldc-compact/src/main/java/java/util/Hashtable.java

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// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package java.util;

import cc.squirreljme.runtime.cldc.annotation.Api;
import cc.squirreljme.runtime.cldc.annotation.ImplementationNote;
import cc.squirreljme.runtime.cldc.debug.Debugging;
import cc.squirreljme.runtime.cldc.util.IteratorToEnumeration;
import cc.squirreljme.runtime.cldc.util.MapKeySetView;
import cc.squirreljme.runtime.cldc.util.SynchronizedEntrySetNotNull;

/**
 * This is similar to {@link HashMap} except that it is thread safe and does
 * not permit null keys or values.
 *
 * @since 2019/05/05
 */
@Api
public class Hashtable<K, V>
    implements Map<K, V>, Cloneable
{
    /** Internal map. */
    private final __BucketMap__<K, V> _map;
    
    /**
     * Initializes the map with the given capacity and load factor.
     *
     * @param __cap The capacity used.
     * @param __load The load factor used.
     * @throws IllegalArgumentException If the capacity is negative or the
     * load factor is not positive.
     * @since 2019/05/05
     */
    @Api
    public Hashtable(int __cap, float __load)
    {
        this._map = new __BucketMap__<K, V>(false, false, __cap, __load);
    }
    
    /**
     * Initializes the map with the given capacity and the default load factor.
     *
     * @param __cap The capacity used.
     * @throws IllegalArgumentException If the capacity is negative.
     * @since 2019/05/05
     */
    @Api
    public Hashtable(int __cap)
        throws IllegalArgumentException
    {
        this._map = new __BucketMap__<K, V>(false, __cap);
    }
    
    /**
     * Initializes the map with the default capacity and load factor.
     *
     * @since 2019/05/05
     */
    @Api
    public Hashtable()
    {
        this._map = new __BucketMap__<K, V>(false);
    }
    
    /**
     * Initializes a map which is a copy of the other map.
     *
     * The default load factor is used and the capacity is set to the
     * capacity of the input map.
     *
     * @param __m The map to copy from.
     * @throws NullPointerException If {@code __m} is null or it contains
     * null keys or values.
     * @since 2018/10/07
     */
    @Api
    public Hashtable(Map<? extends K, ? extends V> __m)
        throws NullPointerException
    {
        if (__m == null)
            throw new NullPointerException("NARG");
        
        // Capacity is just the number of entries in the map
        this._map = new __BucketMap__<K, V>(false,
            Math.max(__BucketMap__._DEFAULT_CAPACITY, __m.size()));
        
        // Put all entries
        this.putAll(__m);
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public void clear()
    {
        synchronized (this)
        {
            this._map.clear();
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    @SuppressWarnings({"unchecked"})
    @ImplementationNote("This creates a new instance of this class and " +
        "then places all the entries into it.")
    public Object clone()
    {
        synchronized (this)
        {
            try
            {
                // Create a new instance of this class to put into, since the
                // class is always of the same type
                Map<K, V> copy = (Map<K, V>)this.getClass().newInstance();
                
                // Copy all the elements over
                copy.putAll(this);
                
                return copy;
            }
            
            // Oops
            catch (IllegalAccessException|InstantiationException e)
            {
                /* {@squirreljme.error ZZ2r Could not clone the hashtable.} */
                throw new RuntimeException("ZZ2r", e);
            }
        }
    }
    
    /**
     * Checks if the map contains the specified value.
     *
     * @param __v The value to check.
     * @return If the map contains the value or not.
     * @since 2019/05/05
     */
    @SuppressWarnings("RedundantCollectionOperation")
    public boolean contains(Object __v)
    {
        synchronized (this)
        {
            return this.values().contains(__v);
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public boolean containsKey(Object __k)
    {
        synchronized (this)
        {
            return null != this._map.getEntry(__k);
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @SuppressWarnings("RedundantCollectionOperation")
    @Override
    public boolean containsValue(Object __v)
    {
        synchronized (this)
        {
            return this.values().contains(__v);
        }
    }
    
    /**
     * Returns an enumeration over the elements.
     *
     * @return The enumerator over the elements.
     * @since 2019/05/05
     */
    @Api
    public Enumeration<V> elements()
    {
        synchronized (this)
        {
            return new IteratorToEnumeration<V>(this.values().iterator());
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public Set<Map.Entry<K, V>> entrySet()
    {
        synchronized (this)
        {
            return new SynchronizedEntrySetNotNull<K, V>(this,
                this._map.entrySet());
        }
    }
    
    @Override
    public boolean equals(Object __a)
    {
        synchronized (this)
        {
            throw Debugging.todo();
        }
    }
    
    /**
     * {@inheritDoc}
     * @throws NullPointerException If the requested key is null.
     * @since 2019/05/05
     * @param __k
     */
    @Override
    public V get(Object __k)
        throws NullPointerException
    {
        if (__k == null)
            throw new NullPointerException("NARG");
        
        synchronized (this)
        {
            __BucketMapEntry__<K, V> e = this._map.getEntry(__k);
            if (e == null)
                return null;
            return e.getValue();
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public int hashCode()
    {
        synchronized (this)
        {
            int rv = 0;
            for (Map.Entry<K, V> e : this.entrySet())
                rv += e.hashCode();
            return rv;
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public boolean isEmpty()
    {
        synchronized (this)
        {
            return this._map.isEmpty();
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public Set<K> keySet()
    {
        return new MapKeySetView<K, V>(this, false);
    }
    
    /**
     * Returns an enumeration over the keys.
     *
     * @return The key enumeration.
     * @since 2019/05/05
     */
    @Api
    public Enumeration<K> keys()
    {
        synchronized (this)
        {
            return new IteratorToEnumeration<K>(this.keySet().iterator());
        }
    }
    
    /**
     * {@inheritDoc}
     * @throws NullPointerException If the key or value is null.
     * @since 2019/05/05
     */
    @Override
    public V put(K __k, V __v)
        throws NullPointerException
    {
        if (__k == null || __v == null)
            throw new NullPointerException("NARG");
        
        __BucketMap__<K, V> map = this._map;
        synchronized (this)
        {
            // To detect rehashing
            int numrehash = map._numrehash;
            
            // Set value, remember old one
            V rv = this._map.putEntry(__k).setValue(__v);
            
            // If the map was ever rehashed, then call this method
            if (map._numrehash != numrehash)
                this.rehash();
            
            // Done
            return rv;
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public void putAll(Map<? extends K, ? extends V> __m)
        throws NullPointerException
    {
        if (__m == null)
            throw new NullPointerException("NARG");
        
        synchronized (this)
        {
            // Copy everything
            for (Map.Entry<? extends K, ? extends V> e : __m.entrySet())
                this.put(e.getKey(), e.getValue());
        }
    }
    
    /**
     * This reorganizes and reorders the entries internally in the hash map,
     * this is called automatically when the map has been reordered.
     *
     * @since 2019/05/05
     */
    @Api
    @ImplementationNote("In SquirrelJME this has no actual effect because " +
        "it is internally handled, however code might rely on overriding " +
        "this method to determine when the map has been rehashed.")
    protected void rehash()
    {
    }
    
    /**
     * {@inheritDoc}
     * @throws NullPointerException If a null key was specified.
     * @since 2019/05/05
     */
    @Override
    public V remove(Object __k)
        throws NullPointerException
    {
        if (__k == null)
            throw new NullPointerException("NARG");
        
        __BucketMap__<K, V> map = this._map;
        synchronized (this)
        {
            // To detect rehashing
            int numrehash = map._numrehash;
            
            // Remove key
            V rv = this._map.remove(__k);
            
            // If the map was ever rehashed, then call this method
            if (map._numrehash != numrehash)
                this.rehash();
            
            // Done
            return rv;
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public int size()
    {
        synchronized (this)
        {
            return this._map.size();
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public String toString()
    {
        synchronized (this)
        {
            StringBuilder sb = new StringBuilder("{");
            
            // Go through and append
            boolean comma = false;
            for (Map.Entry<?, ?> e : this.entrySet())
            {
                // Space comma
                if (comma)
                    sb.append(", ");
                comma = true;
                
                // Key is equal to the value
                sb.append(e.getKey());
                sb.append('=');
                sb.append(e.getValue());
            }
            
            sb.append('}');
            return sb.toString();
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public Collection<V> values()
    {
        return new __AbstractMapValues__<K, V>(this);
    }
}