| /* BidiHasthable.java -- Bidirectional hash table. |
| Copyright (C) 2006 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.java.rmi.activation; |
| |
| import java.util.Collection; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| /** |
| * The bidirectional hash table, maps both a to b and b to a. |
| * |
| * @author Audrius Meskauskas (audriusa@bioinformatics.org) |
| */ |
| public class BidiTable |
| { |
| /** |
| * Use serialVerionUID for interoperability. |
| */ |
| private static final long serialVersionUID = 1; |
| |
| /** |
| * Maps keys to values |
| */ |
| protected Map k2v; |
| |
| /** |
| * Maps values to keys (in reverse) |
| */ |
| protected Map v2k; |
| |
| /** |
| * Create a new table that is ready to use. |
| */ |
| public BidiTable() |
| { |
| k2v = new HashMap(); |
| v2k = new HashMap(); |
| } |
| |
| /** |
| * Create a new instance where the hashtable fields are not initialised |
| * (called from derivatives that intialise hashtables in they own way. |
| * |
| * @param flags currently used to mark the different constructor only. |
| */ |
| protected BidiTable(int flags) |
| { |
| } |
| |
| /** |
| * Get key by value |
| */ |
| public synchronized Object getKey(Object value) |
| { |
| return v2k.get(value); |
| } |
| |
| /** |
| * Put key-value pair. |
| */ |
| public synchronized void put(Object key, Object value) |
| { |
| k2v.put(key, value); |
| v2k.put(value, key); |
| } |
| |
| /** |
| * Get value from key |
| */ |
| public synchronized Object get(Object key) |
| { |
| return k2v.get(key); |
| } |
| |
| /** |
| * Remove the key-value pair by key |
| */ |
| public synchronized void removeKey(Object key) |
| { |
| Object value = k2v.get(key); |
| if (value!=null) |
| { |
| k2v.remove(key); |
| v2k.remove(value); |
| } |
| } |
| |
| /** |
| * Check if the table contains this key. |
| */ |
| public synchronized boolean containsKey(Object key) |
| { |
| return k2v.containsKey(key); |
| } |
| |
| /** |
| * This method is called before exit and may be used to write the database |
| * to the disk. The default method does nothing. |
| */ |
| public synchronized void shutdown() |
| { |
| } |
| |
| /** |
| * Get the size. |
| */ |
| public synchronized int size() |
| { |
| return k2v.size(); |
| } |
| |
| /** |
| * Get the key collection. |
| */ |
| public synchronized Object[] keys() |
| { |
| Collection keys = k2v.keySet(); |
| Object[] k = new Object[keys.size()]; |
| |
| Iterator iter = keys.iterator(); |
| for (int i = 0; i < k.length; i++) |
| k[i] = iter.next(); |
| |
| return k; |
| } |
| } |