/*

 * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package sun.tools.jstat;

import java.util.*;

import java.io.*;

import sun.jvmstat.monitor.*;

import sun.jvmstat.monitor.event.*;

import java.util.regex.PatternSyntaxException;

/**

 * Class to sample and output various jvmstat statistics for a target Java

 * a target Java Virtual Machine.

 *

 * @author Brian Doherty

 * @since 1.5

 */

public class JStatLogger {

    private MonitoredVm monitoredVm;

    private volatile boolean active = true;

    public JStatLogger(MonitoredVm monitoredVm) {

        this.monitoredVm = monitoredVm;

    }

    /**

     * print the monitors that match the given monitor name pattern string.

     */

    public void printNames(String names, Comparator<Monitor> comparator,

                           boolean showUnsupported, PrintStream out)

                throws MonitorException, PatternSyntaxException {

        // get the set of all monitors

        List<Monitor> items = monitoredVm.findByPattern(names);

        Collections.sort(items, comparator);

        for (Monitor m: items) {

            if (!(m.isSupported() || showUnsupported)) {

                continue;

            }

            out.println(m.getName());

        }

    }

    /**

     * print name=value pairs for the given list of monitors.

     */

    public void printSnapShot(String names, Comparator<Monitor> comparator,

                              boolean verbose, boolean showUnsupported,

                              PrintStream out)

                throws MonitorException, PatternSyntaxException {

        // get the set of all monitors

        List<Monitor> items = monitoredVm.findByPattern(names);

        Collections.sort(items, comparator);

        printList(items, verbose, showUnsupported, out);

    }

    /**

     * print name=value pairs for the given list of monitors.

     */

    public void printList(List<Monitor> list, boolean verbose, boolean showUnsupported,

                          PrintStream out)

                throws MonitorException {

        // print out the name of each available counter

        for (Monitor m: list ) {

            if (!(m.isSupported() || showUnsupported)) {

                continue;

            }

            StringBuilder buffer = new StringBuilder();

            buffer.append(m.getName()).append("=");

            if (m instanceof StringMonitor) {

                buffer.append("\"").append(m.getValue()).append("\"");

            } else {

                buffer.append(m.getValue());

            }

            if (verbose) {

                buffer.append(" ").append(m.getUnits());

                buffer.append(" ").append(m.getVariability());

                buffer.append(" ").append(m.isSupported() ? "Supported"

                                                          : "Unsupported");

            }

            out.println(buffer);

        }

    }

    /**

     * method to for asynchronous termination of sampling loops

     */

    public void stopLogging() {

        active = false;

    }

    /**

     * print samples according to the given format.

     */

    public void logSamples(OutputFormatter formatter, int headerRate,

                           int sampleInterval, int sampleCount, PrintStream out)

                throws MonitorException {

        long iterationCount = 0;

        int printHeaderCount = 0;

        // if printHeader == 0, then only an initial column header is desired.

        int printHeader = headerRate;

        if (printHeader == 0) {

            // print the column header once, disable future printing

            out.println(formatter.getHeader());

            printHeader = -1;

        }

        while (active) {

          // check if it's time to print another column header

          if (printHeader > 0 && --printHeaderCount <= 0) {

              printHeaderCount = printHeader;

              out.println(formatter.getHeader());

          }

          out.println(formatter.getRow());

          // check if we've hit the specified sample count

          if (sampleCount > 0 && ++iterationCount >= sampleCount) {

              break;

          }

          try { Thread.sleep(sampleInterval); } catch (Exception e) { };

        }

    }

}