--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/eclipse/jetty/server/session/HashSessionIdManager.java	Wed Sep 07 21:15:48 2016 -0600
@@ -0,0 +1,222 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.server.session;
+
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Random;
+import java.util.Set;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpSession;
+
+import org.eclipse.jetty.server.SessionIdManager;
+
+/* ------------------------------------------------------------ */
+/**
+ * HashSessionIdManager. An in-memory implementation of the session ID manager.
+ */
+public class HashSessionIdManager extends AbstractSessionIdManager
+{
+    private final Map<String, Set<WeakReference<HttpSession>>> _sessions = new HashMap<String, Set<WeakReference<HttpSession>>>();
+
+    /* ------------------------------------------------------------ */
+    public HashSessionIdManager()
+    {
+    }
+
+    /* ------------------------------------------------------------ */
+    public HashSessionIdManager(Random random)
+    {
+        super(random);
+    }
+
+    /* ------------------------------------------------------------ */
+    /**
+     * @return Collection of String session IDs
+     */
+    public Collection<String> getSessions()
+    {
+        return Collections.unmodifiableCollection(_sessions.keySet());
+    }
+    
+    /* ------------------------------------------------------------ */
+    /**
+     * @return Collection of Sessions for the passed session ID
+     */
+    public Collection<HttpSession> getSession(String id)
+    {
+        ArrayList<HttpSession> sessions = new ArrayList<HttpSession>();
+        Set<WeakReference<HttpSession>> refs =_sessions.get(id);
+        if (refs!=null)
+        {
+            for (WeakReference<HttpSession> ref: refs)
+            {
+                HttpSession session = ref.get();
+                if (session!=null)
+                    sessions.add(session);
+            }
+        }
+        return sessions;
+    }
+    /* ------------------------------------------------------------ */
+    /** Get the session ID with any worker ID.
+     * 
+     * @param clusterId
+     * @param request
+     * @return sessionId plus any worker ID.
+     */
+    public String getNodeId(String clusterId,HttpServletRequest request) 
+    {
+        // used in Ajp13Parser
+        String worker=request==null?null:(String)request.getAttribute("org.eclipse.jetty.ajp.JVMRoute");
+        if (worker!=null) 
+            return clusterId+'.'+worker; 
+        
+        if (_workerName!=null) 
+            return clusterId+'.'+_workerName;
+       
+        return clusterId;
+    }
+
+    /* ------------------------------------------------------------ */
+    /** Get the session ID without any worker ID.
+     * 
+     * @param nodeId the node id
+     * @return sessionId without any worker ID.
+     */
+    public String getClusterId(String nodeId) 
+    {
+        int dot=nodeId.lastIndexOf('.');
+        return (dot>0)?nodeId.substring(0,dot):nodeId;
+    }
+    
+    /* ------------------------------------------------------------ */
+    @Override
+    protected void doStart() throws Exception
+    {        
+        super.doStart();
+    }
+
+    /* ------------------------------------------------------------ */
+    @Override
+    protected void doStop() throws Exception
+    {
+        _sessions.clear(); 
+        super.doStop();
+    }
+
+    /* ------------------------------------------------------------ */
+    /**
+     * @see SessionIdManager#idInUse(String)
+     */
+    public boolean idInUse(String id)
+    {
+        synchronized (this)
+        {
+            return _sessions.containsKey(id);
+        }
+    }
+
+    /* ------------------------------------------------------------ */
+    /**
+     * @see SessionIdManager#addSession(HttpSession)
+     */
+    public void addSession(HttpSession session)
+    {
+        String id = getClusterId(session.getId());
+        WeakReference<HttpSession> ref = new WeakReference<HttpSession>(session);
+        
+        synchronized (this)
+        {
+            Set<WeakReference<HttpSession>> sessions = _sessions.get(id);
+            if (sessions==null)
+            {
+                sessions=new HashSet<WeakReference<HttpSession>>();
+                _sessions.put(id,sessions);
+            }
+            sessions.add(ref);
+        }
+    }
+
+    /* ------------------------------------------------------------ */
+    /**
+     * @see SessionIdManager#removeSession(HttpSession)
+     */
+    public void removeSession(HttpSession session)
+    {
+        String id = getClusterId(session.getId());
+        
+        synchronized (this)
+        {
+            Collection<WeakReference<HttpSession>> sessions = _sessions.get(id);
+            if (sessions!=null)
+            {
+                for (Iterator<WeakReference<HttpSession>> iter = sessions.iterator(); iter.hasNext();)
+                {
+                    WeakReference<HttpSession> ref = iter.next();
+                    HttpSession s=ref.get();
+                    if (s==null)
+                    {
+                        iter.remove();
+                        continue;
+                    }
+                    if (s==session)
+                    {
+                        iter.remove();
+                        break;
+                    }
+                }
+                if (sessions.isEmpty())
+                    _sessions.remove(id);
+            }
+        }
+    }
+
+    /* ------------------------------------------------------------ */
+    /**
+     * @see SessionIdManager#invalidateAll(String)
+     */
+    public void invalidateAll(String id)
+    {
+        Collection<WeakReference<HttpSession>> sessions;
+        synchronized (this)
+        {
+            sessions = _sessions.remove(id);
+        }
+        
+        if (sessions!=null)
+        {
+            for (WeakReference<HttpSession> ref: sessions)
+            {
+                AbstractSession session=(AbstractSession)ref.get();
+                if (session!=null && session.isValid())
+                    session.invalidate();
+            }
+            sessions.clear();
+        }
+    }
+
+}