/*

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * @test

 *

 * @build ClassLoaderStatsTest DcmdUtil

 * @run main ClassLoaderStatsTest

 */

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.StringReader;

import java.nio.ByteBuffer;

import java.nio.channels.FileChannel;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class ClassLoaderStatsTest {

    // ClassLoader         Parent              CLD*               Classes   ChunkSz   BlockSz  Type

    // 0x00000007c0215928  0x0000000000000000  0x0000000000000000       0         0         0  org.eclipse.osgi.baseadaptor.BaseAdaptor$1

    // 0x00000007c0009868  0x0000000000000000  0x00007fc52aebcc80       1      6144      3768  sun.reflect.DelegatingClassLoader

    // 0x00000007c0009868  0x0000000000000000  0x00007fc52b8916d0       1      6144      3688  sun.reflect.DelegatingClassLoader

    // 0x00000007c0009868  0x00000007c0038ba8  0x00007fc52afb8760       1      6144      3688  sun.reflect.DelegatingClassLoader

    // 0x00000007c0009868  0x0000000000000000  0x00007fc52afbb1a0       1      6144      3688  sun.reflect.DelegatingClassLoader

    // 0x0000000000000000  0x0000000000000000  0x00007fc523416070    5019  30060544  29956216  <boot classloader>

    //                                                                455   1210368    672848   + unsafe anonymous classes

    // 0x00000007c016b5c8  0x00000007c0038ba8  0x00007fc52a995000       5      8192      5864  org.netbeans.StandardModule$OneModuleClassLoader

    // 0x00000007c0009868  0x00000007c016b5c8  0x00007fc52ac13640       1      6144      3896  sun.reflect.DelegatingClassLoader

    // ...

    static Pattern clLine = Pattern.compile("0x\\p{XDigit}*\\s*0x\\p{XDigit}*\\s*0x\\p{XDigit}*\\s*(\\d*)\\s*(\\d*)\\s*(\\d*)\\s*(.*)");

    static Pattern anonLine = Pattern.compile("\\s*(\\d*)\\s*(\\d*)\\s*(\\d*)\\s*.*");

    public static DummyClassLoader dummyloader;

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

        // create a classloader and load our special class

        dummyloader = new DummyClassLoader();

        Class<?> c = Class.forName("TestClass", true, dummyloader);

        if (c.getClassLoader() != dummyloader) {

            throw new RuntimeException("TestClass defined by wrong classloader: " + c.getClassLoader());

        }

        String result = DcmdUtil.executeDcmd("VM.classloader_stats");

        BufferedReader r = new BufferedReader(new StringReader(result));

        String line;

        while((line = r.readLine()) != null) {

            Matcher m = clLine.matcher(line);

            if (m.matches()) {

                // verify that DummyClassLoader has loaded 1 class and 1 anonymous class

                if (m.group(4).equals("ClassLoaderStatsTest$DummyClassLoader")) {

                    System.out.println("line: " + line);

                    if (!m.group(1).equals("1")) {

                        throw new Exception("Should have loaded 1 class: " + line);

                    }

                    checkPositiveInt(m.group(2));

                    checkPositiveInt(m.group(3));

                    String next = r.readLine();

                    System.out.println("next: " + next);

                    Matcher m1 = anonLine.matcher(next);

                    m1.matches();

                    if (!m1.group(1).equals("1")) {

                        throw new Exception("Should have loaded 1 anonymous class, but found : " + m1.group(1));

                    }

                    checkPositiveInt(m1.group(2));

                    checkPositiveInt(m1.group(3));

                }

            }

        }

    }

    private static void checkPositiveInt(String s) throws Exception {

        if (Integer.parseInt(s) <= 0) {

            throw new Exception("Value should have been > 0: " + s);

        }

    }

    public static class DummyClassLoader extends ClassLoader {

        public static final String CLASS_NAME = "TestClass";

        static ByteBuffer readClassFile(String name)

        {

            File f = new File(System.getProperty("test.classes", "."),

                              name);

            try (FileInputStream fin = new FileInputStream(f);

                 FileChannel fc = fin.getChannel())

            {

                return fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());

            } catch (IOException e) {

                throw new RuntimeException("Can't open file: " + name, e);

            }

        }

        protected Class<?> loadClass(String name, boolean resolve)

            throws ClassNotFoundException

        {

            Class<?> c;

            if (!"TestClass".equals(name)) {

                c = super.loadClass(name, resolve);

            } else {

                // should not delegate to the system class loader

                c = findClass(name);

                if (resolve) {

                    resolveClass(c);

                }

            }

            return c;

        }

        protected Class<?> findClass(String name)

            throws ClassNotFoundException

        {

            if (!"TestClass".equals(name)) {

                throw new ClassNotFoundException("Unexpected class: " + name);

            }

            return defineClass(name, readClassFile(name + ".class"), null);

        }

    } /* DummyClassLoader */

}

class TestClass {

    static {

        // force creation of anonymous class (for the lambdaform)

        Runnable r = () -> System.out.println("Hello");

        r.run();

    }

}