/*
 * @(#)ActiveObjectMap.java	1.18 03/12/19
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package com.sun.corba.se.impl.oa.poa;

import java.util.Set ;
import java.util.HashSet ;
import java.util.Map ;
import java.util.HashMap ;
import java.util.Iterator ;
import java.util.Vector ;

import org.omg.PortableServer.Servant ;
import org.omg.PortableServer.POAPackage.WrongPolicy ;
import org.omg.CORBA.INTERNAL ;

/**  The ActiveObjectMap maintains associations between servants and 
 * their keys.  There are two variants, to support whether or not
 * multiple IDs per servant are allowed.  This class suppots bidirectional
 * traversal of the key-servant association.  Access to an instance of this
 * class is serialized by the POA mutex.
 */
public abstract class ActiveObjectMap
{
    public static class Key {
	public byte[] id;

	Key(byte[] id) {
	    this.id = id;
	}

	public String toString() {
	    StringBuffer buffer = new StringBuffer();
	    for(int i = 0; i < id.length; i++) {
		buffer.append(Integer.toString((int) id[i], 16));
		if (i != id.length-1)
		    buffer.append(":");
	    }
	    return buffer.toString();
	}

	public boolean equals(java.lang.Object key) {
	    if (!(key instanceof Key))
		return false;
	    Key k = (Key) key;
	    if (k.id.length != this.id.length)
		return false;
	    for(int i = 0; i < this.id.length; i++)
		if (this.id[i] != k.id[i])
		    return false;
	    return true;
	}

	// Use the same hash function as for String
	public int hashCode() {
	    int h = 0;
	    for (int i = 0; i < id.length; i++)
		h = 31*h + id[i];
	    return h;
	}
    }
   
    protected POAImpl poa ;

    protected ActiveObjectMap( POAImpl poa ) 
    {
	this.poa = poa ;
    }

    public static ActiveObjectMap create( POAImpl poa, boolean multipleIDsAllowed ) 
    {
	if (multipleIDsAllowed)
	    return new MultipleObjectMap( poa ) ;
	else
	    return new SingleObjectMap(poa ) ;
    }

    private Map keyToEntry = new HashMap() ;	 // Map< Key, AOMEntry >
    private Map entryToServant = new HashMap() ; // Map< AOMEntry, Servant >
    private Map servantToEntry = new HashMap() ; // Map< Servant, AOMEntry >

    public final boolean contains(Servant value)  
    {
	return servantToEntry.containsKey( value ) ;
    }

    public final boolean containsKey(Key key) 
    {
	return keyToEntry.containsKey(key);
    }

    /** get Returbs the entry assigned to the key, or creates a new
    * entry in state INVALID if none is present.
    */
    public final AOMEntry get(Key key) 
    {
	AOMEntry result = (AOMEntry)keyToEntry.get(key);
	if (result == null) {
	    result = new AOMEntry( poa ) ;
	    putEntry( key, result ) ;
	}

	return result ;
    }

    public final Servant getServant( AOMEntry entry ) 
    {
	return (Servant)entryToServant.get( entry ) ;
    }

    public abstract Key getKey(AOMEntry value) throws WrongPolicy ;

    public Key getKey(Servant value) throws WrongPolicy 
    {
	AOMEntry entry = (AOMEntry)servantToEntry.get( value ) ;
	return getKey( entry ) ;
    }

    protected void putEntry( Key key, AOMEntry value ) 
    {
	keyToEntry.put( key, value ) ;
    }

    public final void putServant( Servant servant, AOMEntry value )
    {
	entryToServant.put( value, servant ) ;
	servantToEntry.put( servant, value ) ;
    }

    protected abstract void removeEntry( AOMEntry entry, Key key ) ;

    public final void remove( Key key ) 
    {
	AOMEntry entry = (AOMEntry)keyToEntry.remove( key ) ;
	Servant servant = (Servant)entryToServant.remove( entry ) ;
	if (servant != null)
	    servantToEntry.remove( servant ) ;

	removeEntry( entry, key ) ;
    }

    public abstract boolean hasMultipleIDs(AOMEntry value) ;

    protected  void clear() 
    {
        keyToEntry.clear();
    }

    public final Set keySet()
    {
	return keyToEntry.keySet() ;
    }
}

class SingleObjectMap extends ActiveObjectMap
{
    private Map entryToKey = new HashMap() ;	// Map< AOMEntry, Key >

    public SingleObjectMap( POAImpl poa )
    {
	super( poa ) ;
    }

    public  Key getKey(AOMEntry value) throws WrongPolicy
    {
	return (Key)entryToKey.get( value ) ;
    }

    protected void putEntry(Key key, AOMEntry value) 
    {
	super.putEntry( key, value);

	entryToKey.put( value, key ) ;
    }

    public  boolean hasMultipleIDs(AOMEntry value) 
    {
	return false;
    }

    // This case does not need the key.
    protected void removeEntry(AOMEntry entry, Key key) 
    {
	entryToKey.remove( entry ) ;
    }

    public  void clear() 
    {
	super.clear() ;
	entryToKey.clear() ;
    }
}

class MultipleObjectMap extends ActiveObjectMap 
{
    private Map entryToKeys = new HashMap() ;	// Map< AOMEntry, Set< Key > >

    public MultipleObjectMap( POAImpl poa )
    {
	super( poa ) ;
    }

    public  Key getKey(AOMEntry value) throws WrongPolicy
    {
	throw new WrongPolicy() ;
    }

    protected void putEntry(Key key, AOMEntry value) 
    {
	super.putEntry( key, value);

	Set set = (Set)entryToKeys.get( value ) ;
	if (set == null) {
	    set = new HashSet() ;
	    entryToKeys.put( value, set ) ;
	}
	set.add( key ) ;
    }

    public  boolean hasMultipleIDs(AOMEntry value) 
    {
	Set set = (Set)entryToKeys.get( value ) ;
	if (set == null)
	    return false ;
	return set.size() > 1 ;
    }

    protected void removeEntry(AOMEntry entry, Key key) 
    {
	Set keys = (Set)entryToKeys.get( entry ) ;
	if (keys != null) {
	    keys.remove( key ) ;
	    if (keys.isEmpty())
		entryToKeys.remove( entry ) ;
	}
    }

    public  void clear() 
    {
	super.clear() ;
	entryToKeys.clear() ;
    }
}