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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
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 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
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 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
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 * as provided by Sun in the GPL Version 2 section of the License file that
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package org.glassfish.web.admin.monitor;

import java.util.logging.Level;
import java.util.logging.Logger;
import org.glassfish.external.statistics.CountStatistic;
import org.glassfish.external.statistics.impl.CountStatisticImpl;
import org.glassfish.external.statistics.impl.TimeStatisticImpl;
import org.glassfish.external.probe.provider.annotations.*;
import org.glassfish.gmbal.AMXMetadata;
import org.glassfish.gmbal.Description;
import org.glassfish.gmbal.ManagedObject;
import org.glassfish.gmbal.ManagedAttribute;

/**
 * Provides the monitoring data at the Web container level
 *
 * @author Prashanth Abbagani
 */
@AMXMetadata(type="web-request-mon", group="monitoring")
@ManagedObject
@Description("Web Request Statistics")
public class WebRequestStatsProvider {
    //Provides the longest response time for a request - not a cumulative value, 
    //but the largest response time from among the response times.
    //private Counter maxTime = CounterFactory.createCount();
    //Provides cumulative value of the times taken to process each request. 
    //The processing time is the average of request processing times over the request count.
    //private Counter processingTime = CounterFactory.createCount();
    //Provides cumulative number of the requests processed so far.
    //private Counter requestCount = CounterFactory.createCount();
    //Provides the cumulative value of the error count. The error count represents 
    //the number of cases where the response code was greater than or equal to 400.
    //private CountStatisticImpl requestCount = new CountStatisticImpl("RequestCount", "count", "Cumulative number of requests processed so far");
    private CountStatisticImpl errorCount = new CountStatisticImpl("ErrorCount",
            "count",
            "Cumulative value of the error count, with error count representing the number of cases where the response code was greater than or equal to 400");
    private CountStatisticImpl maxTime = new CountStatisticImpl("MaxTime",
            "milliseconds",
            "Longest response time for a request; not a cumulative value, but the largest response time from among the response times");
    private CountStatisticImpl processingTime = new CountStatisticImpl("ProcessingTime",
            "milliseconds",
            "Cumulative value of the times taken to process each request, with processing time being the average of request processing times over the request count");
    private CountStatisticImpl requestCount = new CountStatisticImpl("RequestCount",
            "count",
            "Cumulative number of requests processed so far");
    
    private TimeStatisticImpl requestProcessTime = new TimeStatisticImpl(0L, 0L, 0L, 0L,
            "", "", "", System.currentTimeMillis(), -1L);
    private Logger logger;
    
    private String virtualServerName = null;
    private String moduleName = null;
    private long requestStartTime = 0;

    public WebRequestStatsProvider(String appName, String vsName, Logger logger) {
        this.logger = logger;
        this.virtualServerName = vsName;
        this.moduleName = appName;
    }

    @ManagedAttribute(id="maxtime")
    @Description( "Longest response time for a request; not a cumulative value, but the largest response time from among the response times" )
    public CountStatistic getMaxTime() {
        maxTime.setCount(requestProcessTime.getMaxTime());
        return maxTime;
    }

    @ManagedAttribute(id="requestcount")
    @Description("Cumulative number of requests processed so far")
    public CountStatistic getRequestCount() {
        requestCount.setCount(requestProcessTime.getCount());
        return requestCount;
    }

    @ManagedAttribute(id="errorcount")
    @Description("Number of responses with a status code that is greater than or equal to 400")
    public CountStatistic getErrorCount() {
        return errorCount;
    }

    @ManagedAttribute(id="processingtime")
    @Description("Cumulative value of the times taken to process each request, with processing time being the average of request processing times over the request count")
    public CountStatistic getProcessingTime() {
        processingTime.setCount(this.getProcessTime());
        return processingTime;
    }

    @ProbeListener("glassfish:web:http-service:requestStartEvent")
    public void requestStartEvent(
            @ProbeParam("appName") String appName,
            @ProbeParam("hostName") String hostName,
            @ProbeParam("serverName") String serverName,
            @ProbeParam("serverPort") int serverPort,
            @ProbeParam("contextPath") String contextPath,
            @ProbeParam("servletPath") String servletPath) {
        if (logger.isLoggable(Level.FINEST)) {
            logger.finest(
                "[TM]requestStartEvent Unprocessed received - virtual-server = " +
                serverName + ":" + serverPort + 
                ": application = " + contextPath +
                " : servlet = " + servletPath +
                " : Expecting (vsName, appName) = (" +
                virtualServerName + ", " + moduleName + ")");
        }
        if ((virtualServerName != null) && (moduleName != null)) {
            //String vs = WebTelemetryBootstrap.getVirtualServerName(
            //    hostName, String.valueOf(request.getServerPort()));
            if ((appName != null && hostName != null) &&
                    hostName.equals(virtualServerName) &&
                    appName.equals(moduleName)){
                
                requestStartTime = System.currentTimeMillis();
                if (logger.isLoggable(Level.FINEST)) {
                    logger.finest(
                        "[TM]requestStartEvent resolved - virtual-server = " +
                        serverName + ": application = " +
                        contextPath + " :appName = " + appName +
                        " : servlet = " + servletPath + " : port = " +
                        serverPort);
                }
            }
        }
        else {
            requestStartTime = System.currentTimeMillis();
            if (logger.isLoggable(Level.FINEST)) {
                logger.finest(
                    "[TM]requestStartEvent resolved - virtual-server = " +
                    serverName + ": application = " + contextPath +
                    " : servlet = " + servletPath);
            }
        }
    }

    @ProbeListener("glassfish:web:http-service:requestEndEvent")
    public void requestEndEvent(
            @ProbeParam("appName") String appName,
            @ProbeParam("hostName") String hostName,
            @ProbeParam("serverName") String serverName,
            @ProbeParam("serverPort") int serverPort,
            @ProbeParam("contextPath") String contextPath,
            @ProbeParam("servletPath") String servletPath,
            @ProbeParam("statusCode") int statusCode) {
        if (logger.isLoggable(Level.FINEST)) {
            logger.finest(
                "[TM]requestEndEvent Unprocessed received - virtual-server = " +
                serverName + ": application = " +
                contextPath + " : servlet = " +
                servletPath + " :Response code = " +
                statusCode + " : Expecting (vsName, appName) = (" +
                virtualServerName + ", " + moduleName + ")");
        }
        if ((virtualServerName != null) && (moduleName != null)) {
            //String vs = WebTelemetryBootstrap.getVirtualServerName(
            //    hostName, String.valueOf(request.getServerPort()));
            if ((appName != null && hostName != null) &&
                    hostName.equals(virtualServerName) &&
                    appName.equals(moduleName)){
                //increment counts
                long requestTime = System.currentTimeMillis() - requestStartTime;
                requestProcessTime.incrementCount(requestTime);
                if (statusCode >= 400) {
                    errorCount.increment();
                }
                if (logger.isLoggable(Level.FINEST)) {
                    logger.finest(
                        "[TM]requestEndEvent resolved - virtual-server = " +
                        serverName + ": application = " + contextPath +
                        " :appName = " + appName +
                        " : servlet = " + servletPath +
                        " : port = " + serverPort +
                        " :Response code = " + statusCode +
                        " :Response time = " +
                        requestTime);
                }
            }
        }
        else {
            long requestTime = System.currentTimeMillis() - requestStartTime;
            requestProcessTime.incrementCount(requestTime);
            if (statusCode >= 400) {
                errorCount.increment();
            }
            if (logger.isLoggable(Level.FINEST)) {
                logger.finest(
                    "[TM]requestEndEvent resolved - virtual-server = " +
                    serverName + ": application = " +
                    contextPath + " : servlet = " +
                    servletPath + " : port = " +
                    serverPort  + " :Response code = " +
                    statusCode + " :Response time = " +
                    requestTime);
            }
    }
        }

    
    private long getProcessTime() {
        long count = requestProcessTime.getCount();
        long processTime = -1L;
        if (count != 0) {
            processTime = requestProcessTime.getTotalTime()/count;
        }
        return processTime;
    }

    public String getModuleName() {
        return moduleName;
    }
    
    public String getVSName() {
        return virtualServerName;
    }

}