--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/eclipse/jetty/server/handler/StatisticsHandler.java	Wed Sep 07 21:15:48 2016 -0600
@@ -0,0 +1,474 @@
+//
+//  ========================================================================
+//  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.handler;
+
+import java.io.IOException;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.eclipse.jetty.continuation.Continuation;
+import org.eclipse.jetty.continuation.ContinuationListener;
+import org.eclipse.jetty.server.AsyncContinuation;
+import org.eclipse.jetty.server.Request;
+import org.eclipse.jetty.server.Response;
+import org.eclipse.jetty.util.statistic.CounterStatistic;
+import org.eclipse.jetty.util.statistic.SampleStatistic;
+
+public class StatisticsHandler extends HandlerWrapper
+{
+    private final AtomicLong _statsStartedAt = new AtomicLong();
+    
+    private final CounterStatistic _requestStats = new CounterStatistic();
+    private final SampleStatistic _requestTimeStats = new SampleStatistic();
+    private final CounterStatistic _dispatchedStats = new CounterStatistic();
+    private final SampleStatistic _dispatchedTimeStats = new SampleStatistic();
+    private final CounterStatistic _suspendStats = new CounterStatistic();
+
+    private final AtomicInteger _resumes = new AtomicInteger();
+    private final AtomicInteger _expires = new AtomicInteger();
+    
+    private final AtomicInteger _responses1xx = new AtomicInteger();
+    private final AtomicInteger _responses2xx = new AtomicInteger();
+    private final AtomicInteger _responses3xx = new AtomicInteger();
+    private final AtomicInteger _responses4xx = new AtomicInteger();
+    private final AtomicInteger _responses5xx = new AtomicInteger();
+    private final AtomicLong _responsesTotalBytes = new AtomicLong();
+
+    private final ContinuationListener _onCompletion = new ContinuationListener()
+    {
+        public void onComplete(Continuation continuation)
+        {
+            final Request request = ((AsyncContinuation)continuation).getBaseRequest();
+            final long elapsed = System.currentTimeMillis()-request.getTimeStamp();
+            
+            _requestStats.decrement();
+            _requestTimeStats.set(elapsed);
+            
+            updateResponse(request);
+            
+            if (!continuation.isResumed())
+                _suspendStats.decrement();
+        }
+
+        public void onTimeout(Continuation continuation)
+        {
+            _expires.incrementAndGet();
+        }
+    };
+    
+    /**
+     * Resets the current request statistics.
+     */
+    public void statsReset()
+    {
+        _statsStartedAt.set(System.currentTimeMillis());
+        
+        _requestStats.reset();
+        _requestTimeStats.reset();
+        _dispatchedStats.reset();
+        _dispatchedTimeStats.reset();
+        _suspendStats.reset();
+
+        _resumes.set(0);
+        _expires.set(0);
+        _responses1xx.set(0);
+        _responses2xx.set(0);
+        _responses3xx.set(0);
+        _responses4xx.set(0);
+        _responses5xx.set(0);
+        _responsesTotalBytes.set(0L);
+    }
+
+    @Override
+    public void handle(String path, Request request, HttpServletRequest httpRequest, HttpServletResponse httpResponse) throws IOException, ServletException
+    {
+        _dispatchedStats.increment();
+
+        final long start;
+        AsyncContinuation continuation = request.getAsyncContinuation();
+        if (continuation.isInitial())
+        {
+            // new request
+            _requestStats.increment();
+            start = request.getTimeStamp();
+        }
+        else
+        {
+            // resumed request
+            start = System.currentTimeMillis();
+            _suspendStats.decrement();
+            if (continuation.isResumed())
+                _resumes.incrementAndGet();
+        }
+
+        try
+        {
+            super.handle(path, request, httpRequest, httpResponse);
+        }
+        finally
+        {
+            final long now = System.currentTimeMillis();
+            final long dispatched=now-start;
+            
+            _dispatchedStats.decrement();
+            _dispatchedTimeStats.set(dispatched);
+            
+            if (continuation.isSuspended())
+            {
+                if (continuation.isInitial())
+                    continuation.addContinuationListener(_onCompletion);
+                _suspendStats.increment();
+            }
+            else if (continuation.isInitial())
+            {
+                _requestStats.decrement();
+                _requestTimeStats.set(dispatched);
+                updateResponse(request);
+            }
+            // else onCompletion will handle it.
+        }
+    }
+
+    private void updateResponse(Request request)
+    {
+        Response response = request.getResponse();
+        switch (response.getStatus() / 100)
+        {
+            case 1:
+                _responses1xx.incrementAndGet();
+                break;
+            case 2:
+                _responses2xx.incrementAndGet();
+                break;
+            case 3:
+                _responses3xx.incrementAndGet();
+                break;
+            case 4:
+                _responses4xx.incrementAndGet();
+                break;
+            case 5:
+                _responses5xx.incrementAndGet();
+                break;
+            default:
+                break;
+        }
+        _responsesTotalBytes.addAndGet(response.getContentCount());
+    }
+
+    @Override
+    protected void doStart() throws Exception
+    {
+        super.doStart();
+        statsReset();
+    }
+
+    /**
+     * @return the number of requests handled by this handler
+     * since {@link #statsReset()} was last called, excluding
+     * active requests
+     * @see #getResumes()
+     */
+    public int getRequests()
+    {
+        return (int)_requestStats.getTotal();
+    }
+
+    /**
+     * @return the number of requests currently active.
+     * since {@link #statsReset()} was last called.
+     */
+    public int getRequestsActive()
+    {
+        return (int)_requestStats.getCurrent();
+    }
+
+    /**
+     * @return the maximum number of active requests
+     * since {@link #statsReset()} was last called.
+     */
+    public int getRequestsActiveMax()
+    {
+        return (int)_requestStats.getMax();
+    }
+
+    /**
+     * @return the maximum time (in milliseconds) of request handling
+     * since {@link #statsReset()} was last called.
+     */
+    public long getRequestTimeMax()
+    {
+        return _requestTimeStats.getMax();
+    }
+
+    /**
+     * @return the total time (in milliseconds) of requests handling
+     * since {@link #statsReset()} was last called.
+     */
+    public long getRequestTimeTotal()
+    {
+        return _requestTimeStats.getTotal();
+    }
+
+    /**
+     * @return the mean time (in milliseconds) of request handling
+     * since {@link #statsReset()} was last called.
+     * @see #getRequestTimeTotal()
+     * @see #getRequests()
+     */
+    public double getRequestTimeMean()
+    {
+        return _requestTimeStats.getMean();
+    }
+
+    /**
+     * @return the standard deviation of time (in milliseconds) of request handling
+     * since {@link #statsReset()} was last called.
+     * @see #getRequestTimeTotal()
+     * @see #getRequests()
+     */
+    public double getRequestTimeStdDev()
+    {
+        return _requestTimeStats.getStdDev();
+    }
+
+    /**
+     * @return the number of dispatches seen by this handler
+     * since {@link #statsReset()} was last called, excluding
+     * active dispatches
+     */
+    public int getDispatched()
+    {
+        return (int)_dispatchedStats.getTotal();
+    }
+
+    /**
+     * @return the number of dispatches currently in this handler
+     * since {@link #statsReset()} was last called, including
+     * resumed requests
+     */
+    public int getDispatchedActive()
+    {
+        return (int)_dispatchedStats.getCurrent();
+    }
+
+    /**
+     * @return the max number of dispatches currently in this handler
+     * since {@link #statsReset()} was last called, including
+     * resumed requests
+     */
+    public int getDispatchedActiveMax()
+    {
+        return (int)_dispatchedStats.getMax();
+    }
+
+    /**
+     * @return the maximum time (in milliseconds) of request dispatch
+     * since {@link #statsReset()} was last called.
+     */
+    public long getDispatchedTimeMax()
+    {
+        return _dispatchedTimeStats.getMax();
+    }
+    
+    /**
+     * @return the total time (in milliseconds) of requests handling
+     * since {@link #statsReset()} was last called.
+     */
+    public long getDispatchedTimeTotal()
+    {
+        return _dispatchedTimeStats.getTotal();
+    }
+
+    /**
+     * @return the mean time (in milliseconds) of request handling
+     * since {@link #statsReset()} was last called.
+     * @see #getRequestTimeTotal()
+     * @see #getRequests()
+     */
+    public double getDispatchedTimeMean()
+    {
+        return _dispatchedTimeStats.getMean();
+    }
+    
+    /**
+     * @return the standard deviation of time (in milliseconds) of request handling
+     * since {@link #statsReset()} was last called.
+     * @see #getRequestTimeTotal()
+     * @see #getRequests()
+     */
+    public double getDispatchedTimeStdDev()
+    {
+        return _dispatchedTimeStats.getStdDev();
+    }
+    
+    /**
+     * @return the number of requests handled by this handler
+     * since {@link #statsReset()} was last called, including
+     * resumed requests
+     * @see #getResumes()
+     */
+    public int getSuspends()
+    {
+        return (int)_suspendStats.getTotal();
+    }
+
+    /**
+     * @return the number of requests currently suspended.
+     * since {@link #statsReset()} was last called.
+     */
+    public int getSuspendsActive()
+    {
+        return (int)_suspendStats.getCurrent();
+    }
+
+    /**
+     * @return the maximum number of current suspended requests
+     * since {@link #statsReset()} was last called.
+     */
+    public int getSuspendsActiveMax()
+    {
+        return (int)_suspendStats.getMax();
+    }
+    
+    /**
+     * @return the number of requests that have been resumed
+     * @see #getExpires()
+     */
+    public int getResumes()
+    {
+        return _resumes.get();
+    }
+
+    /**
+     * @return the number of requests that expired while suspended.
+     * @see #getResumes()
+     */
+    public int getExpires()
+    {
+        return _expires.get();
+    }
+
+    /**
+     * @return the number of responses with a 1xx status returned by this context
+     * since {@link #statsReset()} was last called.
+     */
+    public int getResponses1xx()
+    {
+        return _responses1xx.get();
+    }
+
+    /**
+     * @return the number of responses with a 2xx status returned by this context
+     * since {@link #statsReset()} was last called.
+     */
+    public int getResponses2xx()
+    {
+        return _responses2xx.get();
+    }
+
+    /**
+     * @return the number of responses with a 3xx status returned by this context
+     * since {@link #statsReset()} was last called.
+     */
+    public int getResponses3xx()
+    {
+        return _responses3xx.get();
+    }
+
+    /**
+     * @return the number of responses with a 4xx status returned by this context
+     * since {@link #statsReset()} was last called.
+     */
+    public int getResponses4xx()
+    {
+        return _responses4xx.get();
+    }
+
+    /**
+     * @return the number of responses with a 5xx status returned by this context
+     * since {@link #statsReset()} was last called.
+     */
+    public int getResponses5xx()
+    {
+        return _responses5xx.get();
+    }
+
+    /**
+     * @return the milliseconds since the statistics were started with {@link #statsReset()}.
+     */
+    public long getStatsOnMs()
+    {
+        return System.currentTimeMillis() - _statsStartedAt.get();
+    }
+    
+    /**
+     * @return the total bytes of content sent in responses
+     */
+    public long getResponsesBytesTotal()
+    {
+        return _responsesTotalBytes.get();
+    }
+    
+    public String toStatsHTML()
+    {   
+        StringBuilder sb = new StringBuilder();
+
+        sb.append("<h1>Statistics:</h1>\n");
+        sb.append("Statistics gathering started ").append(getStatsOnMs()).append("ms ago").append("<br />\n");
+
+        sb.append("<h2>Requests:</h2>\n");
+        sb.append("Total requests: ").append(getRequests()).append("<br />\n");
+        sb.append("Active requests: ").append(getRequestsActive()).append("<br />\n");
+        sb.append("Max active requests: ").append(getRequestsActiveMax()).append("<br />\n");
+        sb.append("Total requests time: ").append(getRequestTimeTotal()).append("<br />\n");
+        sb.append("Mean request time: ").append(getRequestTimeMean()).append("<br />\n");
+        sb.append("Max request time: ").append(getRequestTimeMax()).append("<br />\n");
+        sb.append("Request time standard deviation: ").append(getRequestTimeStdDev()).append("<br />\n");
+        
+
+        sb.append("<h2>Dispatches:</h2>\n");
+        sb.append("Total dispatched: ").append(getDispatched()).append("<br />\n");
+        sb.append("Active dispatched: ").append(getDispatchedActive()).append("<br />\n");
+        sb.append("Max active dispatched: ").append(getDispatchedActiveMax()).append("<br />\n");
+        sb.append("Total dispatched time: ").append(getDispatchedTimeTotal()).append("<br />\n");
+        sb.append("Mean dispatched time: ").append(getDispatchedTimeMean()).append("<br />\n");
+        sb.append("Max dispatched time: ").append(getDispatchedTimeMax()).append("<br />\n");
+        sb.append("Dispatched time standard deviation: ").append(getDispatchedTimeStdDev()).append("<br />\n");
+
+
+        sb.append("Total requests suspended: ").append(getSuspends()).append("<br />\n");
+        sb.append("Total requests expired: ").append(getExpires()).append("<br />\n");
+        sb.append("Total requests resumed: ").append(getResumes()).append("<br />\n");
+        
+        sb.append("<h2>Responses:</h2>\n");
+        sb.append("1xx responses: ").append(getResponses1xx()).append("<br />\n");
+        sb.append("2xx responses: ").append(getResponses2xx()).append("<br />\n");
+        sb.append("3xx responses: ").append(getResponses3xx()).append("<br />\n");
+        sb.append("4xx responses: ").append(getResponses4xx()).append("<br />\n");
+        sb.append("5xx responses: ").append(getResponses5xx()).append("<br />\n");
+        sb.append("Bytes sent total: ").append(getResponsesBytesTotal()).append("<br />\n");
+
+        return sb.toString();
+
+    }
+}