Fix AR-350: Transactional caches for node ownership and permissions statuses

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@2354 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/cache/AutoExpireCache.java

@@ -1,151 +0,0 @@
-/*
- * Copyright (C) 2005 Alfresco, Inc.
- *
- * Licensed under the Mozilla Public License version 1.1 
- * with a permitted attribution clause. You may obtain a
- * copy of the License at
- *
- *   http://www.alfresco.org/legal/license.txt
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
- * either express or implied. See the License for the specific
- * language governing permissions and limitations under the
- * License.
- */
-package org.alfresco.repo.cache;
-
-import java.io.Serializable;
-import java.util.HashMap;
-import java.util.Map;
-
-/**
- * A cache implementation that maintains items up to a threshold size. If the threshold size is reached
- * it begins removing old items during get() calls as they time-out after a specified timeout value.
- * <p>
- * If the threshold value is not reached, the items are not removed unless specifically requested with
- * a call to remove() or clear().
- * <p>
- * If the max size value is reached then no more items are added to the cache until some are removed
- * either explicitly or automically via timed-out values. 
- * 
- * @author Kevin Roast
- */
-public class AutoExpireCache<K extends Serializable, V extends Serializable> implements SimpleCache<K, V>
-{
-    // TODO: configure these values via Spring
-    private final long  TIMEDIFF  = 1000000L * 1000L * 60L * 5L;    // 5 mins in nano-seconds
-    private final int   MAXSIZE   = 4096;                           // maximum size of the cache
-    private final float THRESHOLD = 0.75f;                          // before we start removing items
-    private int maxsize = MAXSIZE;
-    private float threshold = THRESHOLD;
-    private Map<Object, CacheItem<K, V>> cache = new HashMap<Object, CacheItem<K, V>>(maxsize, 1.0f);
-
-    /**
-     * Default constructor
-     */
-    public AutoExpireCache()
-    {
-    }
-    
-    /**
-     * Constructor
-     */
-    public AutoExpireCache(int maxsize, float threshold)
-    {
-        maxsize = maxsize;
-        threshold = threshold;
-    }
-
-    /**
-     * @see org.alfresco.repo.cache.SimpleCache#get(K)
-     */
-    public synchronized V get(K key)
-    {
-        CacheItem<K, V> wrapper = cache.get(key);
-        if (wrapper != null)
-        {
-            // we cache values till a specific timeout then remove them
-            // this also gives other values a chance to get added if we are nearing the max size
-            if (cache.size() > (maxsize * threshold) &&
-                System.nanoTime() > (wrapper.Timestamp + TIMEDIFF))
-            {
-                //if (log.isDebugEnabled())
-                //   log.debug("*****Removing timedout key: " + key);
-                cache.remove(key);
-                wrapper = null;
-            }
-        }
-        return wrapper != null ? wrapper.Value : null;
-    }
-
-    /**
-     * @see org.alfresco.repo.cache.SimpleCache#put(K, V)
-     */
-    public synchronized void put(K key, V value)
-    {
-        if (cache.size() < maxsize)
-        {
-            //if (log.isDebugEnabled())
-            //   log.debug("***Adding new key: " + key + "   size: " + cache.size());
-            cache.put(key, new CacheItem(key, value));
-        }
-    }
-
-    /**
-     * @see org.alfresco.repo.cache.SimpleCache#remove(K)
-     */
-    public synchronized void remove(K key)
-    {
-        cache.remove(key);
-    }
-
-    /**
-     * @see org.alfresco.repo.cache.SimpleCache#clear()
-     */
-    public void clear()
-    {
-        // better to let the GC deal with removing the old map in one shot
-        // rather than try to clear each slot slowly using clear()
-        cache = new HashMap<Object, CacheItem<K, V>>(maxsize, 1.0f);
-    }
-
-    /**
-     * @see org.alfresco.repo.cache.SimpleCache#contains(K)
-     */
-    public synchronized boolean contains(K key)
-    {
-        return false;
-    }
-    
-    
-    /**
-     * Simple wrapper class for a cache item.
-     * Stores a timestamp of when the item was added so it can be purged from the cache later.
-     */
-    private static class CacheItem<K, V>
-    {
-        CacheItem(K key, V value)
-        {
-            this.key = key;
-            Value = value;
-            Timestamp = System.nanoTime();
-        }
-        
-        public int hashCode()
-        {
-            return key.hashCode();
-        }
-        
-        public boolean equals(Object o)
-        {
-            if (o instanceof CacheItem == false) return false;
-            return key.equals( ((CacheItem)o).key );
-        }
-        
-        private K key;
-        long Timestamp;
-        V Value;
-    }
-}