Canned in favor of LRU+regular hash map approach.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@1025 6335cc39-0255-0410-8fd6-9bcaacd3b74c
2003-01-17 00:22:43 +00:00
parent 492cf45c4c
commit 50201e804c
1 changed files with 0 additions and 84 deletions
@@ -1,84 +0,0 @@
-//
-// $Id: LockableLRUHashMap.java,v 1.2 2002/11/26 21:14:36 ray Exp $
-
-package com.samskivert.util;
-
-import java.util.HashSet;
-import java.util.Map;
-
-/**
- * A LRU HashMap that allows specified keys to be locked such that they
- * cannot be removed.
- */
-public class LockableLRUHashMap extends LRUHashMap
-{
-    /**
-     * Construct a LockableLRUHashMap with the specified maximum number
-     * of <em>unlocked</em> elements.
-     */
-    public LockableLRUHashMap (int baseMaxSize)
-    {
-        super(baseMaxSize);
-    }
-
-    /**
-     * Clear all entries but those that are currently locked.
-     */
-    public void clear ()
-    {
-        // unfortunately there's not a better way to do this because all the
-        // appropriate variables have package access
-        Object[] keys = keySet().toArray();
-        for (int ii=0, nn=keys.length; ii < nn; ii++) {
-            if (! _locks.contains(keys[ii])) {
-                remove(keys[ii]);
-            }
-        }
-    }
-
-    /**
-     * Lock the specified key from being removed.
-     * This has the side effect of increasing the maximum size by 1.
-     *
-     * @return false if the key was already locked and the max size was
-     * not altered.
-     */
-    public boolean lock (Object key)
-    {
-        if (_locks.add(key)) {
-            _maxSize++;
-            return true;
-        }
-        return false;
-    }
-
-    /**
-     * Unlock the specified key so that it can be removed.
-     * This has the side effect of decreasing the maximum size by 1.
-     * If the map is bigger than the new maximum size, the object with that
-     * key will be immediately removed.
-     *
-     * @return false if the key was not even locked in the first place.
-     */
-    public boolean unlock (Object key) 
-    {
-        if (_locks.remove(key)) {
-            _maxSize--;
-            if (size() > _maxSize) {
-                remove(key);
-            }
-            return true;
-        }
-        return false;
-    }
-
-    // documentation inherited
-    protected boolean removeEldestEntry (Map.Entry eldest)
-    {
-        return (! _locks.contains(eldest.getKey())) &&
-            super.removeEldestEntry(eldest);
-    }
-
-    /** The set of keys that are locked. */
-    protected HashSet _locks = new HashSet();
-}