/*
 * Copyright (c) 2014, 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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 * questions.
 */

/*
 * @test SpaceUtilizationCheck
 * @summary Check if the space utilization for shared spaces is adequate
 * @library /testlibrary
 * @run main SpaceUtilizationCheck
 */

import com.oracle.java.testlibrary.*;

import java.util.regex.Pattern;
import java.util.regex.Matcher;
import java.util.ArrayList;
import java.lang.Integer;

public class SpaceUtilizationCheck {
    private static final int NUMBER_OF_SHARED_REGIONS = 4;
    
    // Minimum allowed utilization value (percent)
    // The goal is to have this number to be 75% for RO and RW regions
    // Once that feature is implemented, increase the MIN_UTILIZATION to 75  
    // The utilization for MC region is less important since the size of the region is small 
    private static final int MIN_UTILIZATION = 25;

    public static void main(String[] args) throws Exception {
        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
           "-XX:+UnlockDiagnosticVMOptions", 
           "-XX:SharedArchiveFile=./test.jsa",
           "-Xshare:dump");
 
        OutputAnalyzer output = new OutputAnalyzer(pb.start());
        String stdout = output.getStdout();        
        ArrayList<String> utilization = findUtilization(stdout);
        
        if (utilization.size() != (NUMBER_OF_SHARED_REGIONS + 1) )
            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> result = new ArrayList<String>();
    
        String dm = "\\d"; // digit matcher
        // matching "[dd.d% used]"
        String regex = "\\[" + dm + dm + "\\." + dm + "% used" + "\\]";
        Matcher m = Pattern.compile(regex, Pattern.MULTILINE).matcher(input);
        
        while (m.find())
            result.add(input.substring(m.start() + 1, m.start() + 3 ));
            
        return result;
    }

}