HumongousClassGen.java

/*
 * Copyright (c) 2015, 2018, 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.
 */
package metaspace.stressHierarchy.common;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

/**
 *  This class is compiled and invoke due the build to produce
 *  HumongousClass.java. The size of generated file is
 *  too large to store it in the repository.
 */

public class HumongousClassGen {

private static final String CLASS_NAME = "HumongousClass";
private static final String PKG_NAME = "metaspace.stressHierarchy.common";
private static final String PKG_DIR_NAME = PKG_NAME.replace(".",
        File.separator);
private static final int ITERATIONS = 65300;
private static final double MG = (Math.pow(1024, 2));
private static final int RECORD_COUNT = ITERATIONS + 10;

public static void addFileHeader(List<String> records) {
    records.add("package " + PKG_NAME + ";\n");
    records.add("\n");
    records.add("public class " + CLASS_NAME + " {\n");
    records.add("\n");
}

public static void main(String[] args) throws Exception {
    if (args.length < 1) {
        System.out.println("Usage: HumongousClassGen "
                        + "<vm-testbase_src_folder>");
        throw new RuntimeException("Can't generate " + PKG_NAME + "." + CLASS_NAME);
    }

    List<String> records = new ArrayList<String>(RECORD_COUNT);
    addFileHeader(records);
    for (int i = 1; i <= ITERATIONS; i++) {
        records.add("public long long" + i + ";\n");
    }
    records.add("}");
    writeBuffered(records, (int) (MG * 1), args[0]);
}

private static void writeBuffered(List<String> records, int bufSize,
        String srcDir) throws IOException {
    String path = srcDir + File.separator + PKG_DIR_NAME + File.separator
            + CLASS_NAME + ".java";
    System.out.println("Path="+path);
    File file = new File (path);
    file.getParentFile().mkdirs();
    file.createNewFile();
    long start = System.currentTimeMillis();
    FileWriter writer = new FileWriter(file);
    BufferedWriter bufferedWriter = new BufferedWriter(writer, bufSize);

    for (String record: records) {
       bufferedWriter.write(record);
    }
    bufferedWriter.flush();
    bufferedWriter.close();
    long end = System.currentTimeMillis();
    System.out.println((end - start) / 1000f + " seconds");
}
}