/*

 * Copyright (c) 2008, 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.

 *

 * 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.

 *

 */

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.OutputStream;

import java.io.PrintWriter;

import java.io.StringWriter;

import java.lang.reflect.Method;

import java.net.URI;

import java.util.Arrays;

import java.util.Vector;

import javax.tools.Diagnostic;

import javax.tools.DiagnosticCollector;

import javax.tools.FileObject;

import javax.tools.ForwardingJavaFileManager;

import javax.tools.JavaCompiler;

import javax.tools.JavaCompiler.CompilationTask;

import javax.tools.JavaFileManager;

import javax.tools.JavaFileObject;

import javax.tools.JavaFileObject.Kind;

import javax.tools.SimpleJavaFileObject;

import javax.tools.StandardJavaFileManager;

import javax.tools.ToolProvider;

/*

 * @test SortMethodsTest

 * @bug 6925573

 * @summary verify that class loading does not need quadratic time with regard to the number of class

methods.

 * @run main SortMethodsTest

 * @author volker.simonis@gmail.com

*/

public class SortMethodsTest {

  static String createClass(String name, int nrOfMethods) {

    StringWriter sw = new StringWriter();

    PrintWriter pw = new PrintWriter(sw);

    pw.println("public class " + name + "{");

    for (int i = 0; i < nrOfMethods; i++) {

      pw.println("  public void m" + i + "() {}");

    }

    pw.println("  public static String sayHello() {");

    pw.println("    return \"Hello from class \" + " + name +

               ".class.getName() + \" with \" + " + name +

               ".class.getDeclaredMethods().length + \" methods\";");

    pw.println("  }");

    pw.println("}");

    pw.close();

    return sw.toString();

  }

  public static void main(String args[]) {

    JavaCompiler comp = ToolProvider.getSystemJavaCompiler();

    DiagnosticCollector<JavaFileObject> diags = new DiagnosticCollector<JavaFileObject>();

    final String cName = new String("ManyMethodsClass");

    Vector<Long> results = new Vector<Long>();

    for (int i = 6; i < 600000; i*=10) {

      String klass =  createClass(cName, i);

      JavaMemoryFileObject file = new JavaMemoryFileObject(cName, klass);

      MemoryFileManager mfm = new MemoryFileManager(comp.getStandardFileManager(diags, null, null), file);

      CompilationTask task = comp.getTask(null, mfm, diags, null, null, Arrays.asList(file));

      if (task.call()) {

        try {

          MemoryClassLoader mcl = new MemoryClassLoader(file);

          long start = System.nanoTime();

          Class<? extends Object> c = Class.forName(cName, true, mcl);

          long end = System.nanoTime();

          results.add(end - start);

          Method m = c.getDeclaredMethod("sayHello", new Class[0]);

          String ret = (String)m.invoke(null, new Object[0]);

          System.out.println(ret + " (loaded and resloved in " + (end - start) + "ns)");

        } catch (Exception e) {

          System.err.println(e);

        }

      }

      else {

        System.out.println(klass);

        System.out.println();

        for (Diagnostic diag : diags.getDiagnostics()) {

          System.out.println(diag.getCode() + "\n" + diag.getKind() + "\n" + diag.getPosition());

          System.out.println(diag.getSource() + "\n" + diag.getMessage(null));

        }

      }

    }

    long lastRatio = 0;

    for (int i = 2; i < results.size(); i++) {

      long normalized1 = Math.max(results.get(i-1) - results.get(0), 1);

      long normalized2 = Math.max(results.get(i) - results.get(0), 1);

      long ratio = normalized2/normalized1;

      lastRatio = ratio;

      System.out.println("10 x more methods requires " + ratio + " x more time");

    }

    // The following is just vague estimation but seems to work on current x86_64 and sparcv9 machines

    if (lastRatio > 80) {

      throw new RuntimeException("ATTENTION: it seems that class loading needs quadratic time with regard to the number of class methods!!!");

    }

  }

}

class JavaMemoryFileObject extends SimpleJavaFileObject {

  private final String code;

  private ByteArrayOutputStream byteCode;

  JavaMemoryFileObject(String name, String code) {

    super(URI.create("string:///" + name.replace('.','/') + Kind.SOURCE.extension), Kind.SOURCE);

    this.code = code;

  }

  @Override

  public CharSequence getCharContent(boolean ignoreEncodingErrors) {

    return code;

  }

  @Override

  public OutputStream openOutputStream() {

    byteCode = new ByteArrayOutputStream();

    return byteCode;

  }

  byte[] getByteCode() {

    return byteCode.toByteArray();

   }

}

class MemoryClassLoader extends ClassLoader {

  private final JavaMemoryFileObject jfo;

  public MemoryClassLoader(JavaMemoryFileObject jfo) {

    this.jfo = jfo;

  }

  public Class findClass(String name) {

    byte[] b = jfo.getByteCode();

    return defineClass(name, b, 0, b.length);

  }

}

class MemoryFileManager extends ForwardingJavaFileManager<JavaFileManager> {

  private final JavaFileObject jfo;

  public MemoryFileManager(StandardJavaFileManager jfm, JavaFileObject jfo) {

    super(jfm);

    this.jfo = jfo;

  }

  @Override

  public FileObject getFileForInput(Location location, String packageName,

                                    String relativeName) throws IOException {

    return jfo;

  }

  @Override

  public JavaFileObject getJavaFileForOutput(Location location, String qualifiedName,

                                             Kind kind, FileObject outputFile) throws IOException {

    return jfo;

  }

}