/*

 * Copyright (c) 2014, 2015, 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.

 *

 * 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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 */

/*

 * @test SpaceUtilizationCheck

 * @summary Check if the space utilization for shared spaces is adequate

 * @library /testlibrary

 * @modules java.base/sun.misc

 *          java.management

 * @run main SpaceUtilizationCheck

 */

import jdk.test.lib.*;

import java.util.regex.Pattern;

import java.util.regex.Matcher;

import java.util.ArrayList;

import java.lang.Integer;

public class SpaceUtilizationCheck {

    // Minimum allowed utilization value (percent)

    // The goal is to have this number to be 50% for RO and RW regions

    // Once that feature is implemented, increase the MIN_UTILIZATION to 50

    private static final int MIN_UTILIZATION = 30;

    // Only RO and RW regions are considered for this check, since they

    // currently account for the bulk of the shared space

    private static final int NUMBER_OF_CHECKED_SHARED_REGIONS = 2;

    public static void main(String[] args) throws Exception {

        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(

           "-XX:+UnlockDiagnosticVMOptions",

           "-XX:SharedArchiveFile=./SpaceUtilizationCheck.jsa",

           "-Xshare:dump");

        OutputAnalyzer output = new OutputAnalyzer(pb.start());

        String stdout = output.getStdout();

        ArrayList<String> utilization = findUtilization(stdout);

        if (utilization.size() != NUMBER_OF_CHECKED_SHARED_REGIONS )

            throw new RuntimeException("The output format of sharing summary has changed");

        for(String str : utilization) {

            int value = Integer.parseInt(str);

            if (value < MIN_UTILIZATION) {

                System.out.println(stdout);

                throw new RuntimeException("Utilization for one of the regions" +

                    "is below a threshold of " + MIN_UTILIZATION + "%");

            }

        }

    }

    public static ArrayList<String> findUtilization(String input) {

        ArrayList<String> regions = filterRegionsOfInterest(input.split("\n"));

        return filterByPattern(filterByPattern(regions, "bytes \\[.*% used\\]"), "\\d+");

    }

    private static ArrayList<String> filterByPattern(Iterable<String> input, String pattern) {

        ArrayList<String> result = new ArrayList<String>();

        for (String str : input) {

            Matcher matcher = Pattern.compile(pattern).matcher(str);

            if (matcher.find()) {

                result.add(matcher.group());

            }

        }

        return result;

    }

    private static ArrayList<String> filterRegionsOfInterest(String[] inputLines) {

        ArrayList<String> result = new ArrayList<String>();

        for (String str : inputLines) {

            if (str.contains("ro space:") || str.contains("rw space:")) {

                result.add(str);

            }

        }

        return result;

    }

}