/*

 * 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 sun.hotspot.tools.ctw;

import com.sun.management.HotSpotDiagnosticMXBean;

import java.io.File;

import java.util.regex.Pattern;

/**

 * Auxiliary methods.

 */

public class Utils {

    /**

     * Value of {@code -XX:CompileThreshold}

     */

    public static final boolean TIERED_COMPILATION

            = Boolean.parseBoolean(getVMOption("TieredCompilation", "false"));

    /**

     * Value of {@code -XX:BackgroundCompilation}

     */

    public static final boolean BACKGROUND_COMPILATION

            = Boolean.parseBoolean(getVMOption("BackgroundCompilation",

            "false"));

    /**

     * Value of {@code -XX:TieredStopAtLevel}

     */

    public static final int TIERED_STOP_AT_LEVEL;

    /**

     * Value of {@code -XX:CICompilerCount}

     */

    public static final Integer CI_COMPILER_COUNT

            = Integer.valueOf(getVMOption("CICompilerCount", "1"));

    /**

     * Initial compilation level.

     */

    public static final int INITIAL_COMP_LEVEL;

    /**

     * Compiled path-separator regexp.

     */

    public static final Pattern PATH_SEPARATOR = Pattern.compile(

            File.pathSeparator, Pattern.LITERAL);

    /**

     * Value of {@code -DDeoptimizeAllClassesRate}. Frequency of

     * {@code WB.deoptimizeAll()} invocation If it less that {@code 0},

     * {@code WB.deoptimizeAll()} will not be invoked.

     */

    public static final int DEOPTIMIZE_ALL_CLASSES_RATE

            = Integer.getInteger("DeoptimizeAllClassesRate", -1);

    /**

     * Value of {@code -DCompileTheWorldStopAt}. Last class to consider.

     */

    public static final long COMPILE_THE_WORLD_STOP_AT

            = Long.getLong("CompileTheWorldStopAt", Long.MAX_VALUE);

    /**

     * Value of {@code -DCompileTheWorldStartAt}. First class to consider.

     */

    public static final long COMPILE_THE_WORLD_START_AT

            = Long.getLong("CompileTheWorldStartAt", 1);

    /**

     * Value of {@code -DCompileTheWorldPreloadClasses}. Preload all classes

     * used by a class before start loading.

     */

    public static final boolean COMPILE_THE_WORLD_PRELOAD_CLASSES;

    /**

     * Value of {@code -Dsun.hotspot.tools.ctw.verbose}. Verbose output,

     * adds additional information about compilation.

     */

    public static final boolean IS_VERBOSE

            = Boolean.getBoolean("sun.hotspot.tools.ctw.verbose");

    /**

     * Value of {@code -Dsun.hotspot.tools.ctw.logfile}.Path to logfile, if

     * it's null, cout will be used.

     */

    public static final String LOG_FILE

            = System.getProperty("sun.hotspot.tools.ctw.logfile");

    static {

        if (Utils.TIERED_COMPILATION) {

            INITIAL_COMP_LEVEL = 1;

        } else {

            String vmName = System.getProperty("java.vm.name");

            if (Utils.endsWithIgnoreCase(vmName, " Server VM")) {

                INITIAL_COMP_LEVEL = 4;

            } else if (Utils.endsWithIgnoreCase(vmName, " Client VM")

                    || Utils.endsWithIgnoreCase(vmName, " Minimal VM")) {

                INITIAL_COMP_LEVEL = 1;

            } else {

                throw new RuntimeException("Unknown VM: " + vmName);

            }

        }

        TIERED_STOP_AT_LEVEL = Integer.parseInt(getVMOption("TieredStopAtLevel",

                String.valueOf(INITIAL_COMP_LEVEL)));

    }

    static {

        String tmp = System.getProperty("CompileTheWorldPreloadClasses");

        if (tmp == null) {

            COMPILE_THE_WORLD_PRELOAD_CLASSES = true;

        } else {

            COMPILE_THE_WORLD_PRELOAD_CLASSES = Boolean.parseBoolean(tmp);

        }

    }

    public static final String CLASSFILE_EXT = ".class";

    private Utils() {

    }

    /**

     * Tests if the string ends with the suffix, ignoring case

     * considerations

     *

     * @param string the tested string

     * @param suffix the suffix

     * @return {@code true} if {@code string} ends with the {@code suffix}

     * @see String#endsWith(String)

     */

    public static boolean endsWithIgnoreCase(String string, String suffix) {

        if (string == null || suffix == null) {

            return false;

        }

        int length = suffix.length();

        int toffset = string.length() - length;

        if (toffset < 0) {

            return false;

        }

        return string.regionMatches(true, toffset, suffix, 0, length);

    }

    /**

     * Returns value of VM option.

     *

     * @param name option's name

     * @return value of option or {@code null}, if option doesn't exist

     * @throws NullPointerException if name is null

     */

    public static String getVMOption(String name) {

        String result;

        HotSpotDiagnosticMXBean diagnostic

        result = diagnostic.getVMOption(name).getValue();

        return result;

    }

    /**

     * Returns value of VM option or default value.

     *

     * @param name         option's name

     * @param defaultValue default value

     * @return value of option or {@code defaultValue}, if option doesn't exist

     * @throws NullPointerException if name is null

     * @see #getVMOption(String)

     */

    public static String getVMOption(String name, String defaultValue) {

        String result;

        try {

            result = getVMOption(name);

        } catch (NoClassDefFoundError e) {

            // compact1, compact2 support

            result = defaultValue;

        }

        return result == null ? defaultValue : result;

    }

    /**

     * Tests if the filename is valid filename for class file.

     *

     * @param filename tested filename

     */

    public static boolean isClassFile(String filename) {

        // If the filename has a period after removing '.class', it's not valid class file

        return endsWithIgnoreCase(filename, CLASSFILE_EXT)

                && (filename.indexOf('.')

                == (filename.length() - CLASSFILE_EXT.length()));

    }

    /**

     * Converts the filename to classname.

     *

     * @param filename filename to convert

     * @return corresponding classname.

     * @throws AssertionError if filename isn't valid filename for class file -

     *                        {@link #isClassFile(String)}

     */

    public static String fileNameToClassName(String filename) {

        assert isClassFile(filename);

        return filename.substring(0, filename.length() - CLASSFILE_EXT.length())

                       .replace(File.separatorChar, '.');

    }

}