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import java.util.regex.Matcher;

import java.util.regex.Pattern;

import java.util.ArrayList;

import java.util.Arrays;

import jdk.test.lib.process.ProcessTools;

import jdk.test.lib.process.OutputAnalyzer;

import sun.hotspot.WhiteBox;

class ErgoArgsPrinter {

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

    WhiteBox wb = WhiteBox.getWhiteBox();

    wb.printHeapSizes();

  }

}

final class MinInitialMaxValues {

  public long minHeapSize;

  public long initialHeapSize;

  public long maxHeapSize;

  public long spaceAlignment;

  public long heapAlignment;

}

class TestMaxHeapSizeTools {

  public static void checkMinInitialMaxHeapFlags(String gcflag) throws Exception {

    checkInvalidMinInitialHeapCombinations(gcflag);

    checkValidMinInitialHeapCombinations(gcflag);

    checkInvalidInitialMaxHeapCombinations(gcflag);

    checkValidInitialMaxHeapCombinations(gcflag);

  }

  public static void checkMinInitialErgonomics(String gcflag) throws Exception {

    // heap sizing ergonomics use the value NewSize + OldSize as default values

    // for ergonomics calculation. Retrieve these values.

    long[] values = new long[2];

    getNewOldSize(gcflag, values);

    // we check cases with values smaller and larger than this default value.

    long newPlusOldSize = values[0] + values[1];

    long smallValue = newPlusOldSize / 2;

    long largeValue = newPlusOldSize * 2;

    long maxHeapSize = largeValue + (2 * 1024 * 1024);

    // -Xms is not set

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize }, values, -1, -1);

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-XX:InitialHeapSize=" + smallValue }, values, -1, smallValue);

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-XX:InitialHeapSize=" + largeValue }, values, -1, largeValue);

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-XX:InitialHeapSize=0" }, values, -1, -1);

    // -Xms is set to zero

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-Xms0" }, values, -1, -1);

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-Xms0", "-XX:InitialHeapSize=" + smallValue }, values, -1, smallValue);

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-Xms0", "-XX:InitialHeapSize=" + largeValue }, values, -1, largeValue);

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-Xms0", "-XX:InitialHeapSize=0" }, values, -1, -1);

    // -Xms is set to small value

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-Xms" + smallValue }, values, -1, -1);

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-Xms" + smallValue, "-XX:InitialHeapSize=" + smallValue }, values, smallValue, smallValue);

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-Xms" + smallValue, "-XX:InitialHeapSize=" + largeValue }, values, smallValue, largeValue);

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-Xms" + smallValue, "-XX:InitialHeapSize=0" }, values, smallValue, -1);

    // -Xms is set to large value

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-Xms" + largeValue }, values, largeValue, largeValue);

    checkErgonomics(new String[] { gcflag, "-Xmx" + maxHeapSize, "-Xms" + largeValue, "-XX:InitialHeapSize=0" }, values, largeValue, -1);

  }

  private static long align_up(long value, long alignment) {

    long alignmentMinusOne = alignment - 1;

    return (value + alignmentMinusOne) & ~alignmentMinusOne;

  }

  private static void getNewOldSize(String gcflag, long[] values) throws Exception {

    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(gcflag,

      "-XX:+PrintFlagsFinal", "-version");

    OutputAnalyzer output = new OutputAnalyzer(pb.start());

    output.shouldHaveExitValue(0);

    String stdout = output.getStdout();

    values[0] = getFlagValue(" NewSize", stdout);

    values[1] = getFlagValue(" OldSize", stdout);

  }

  public static void checkGenMaxHeapErgo(String gcflag) throws Exception {

    TestMaxHeapSizeTools.checkGenMaxHeapSize(gcflag, 4);

    TestMaxHeapSizeTools.checkGenMaxHeapSize(gcflag, 5);

  }

  private static void checkInvalidMinInitialHeapCombinations(String gcflag) throws Exception {

    expectError(new String[] { gcflag, "-XX:InitialHeapSize=1023K", "-version" });

    expectError(new String[] { gcflag, "-Xms64M", "-XX:InitialHeapSize=32M", "-version" });

  }

  private static void checkValidMinInitialHeapCombinations(String gcflag) throws Exception {

    expectValid(new String[] { gcflag, "-XX:InitialHeapSize=1024K", "-version" });

    expectValid(new String[] { gcflag, "-XX:InitialHeapSize=8M", "-Xms4M", "-version" });

    expectValid(new String[] { gcflag, "-Xms4M", "-XX:InitialHeapSize=8M", "-version" });

    expectValid(new String[] { gcflag, "-XX:InitialHeapSize=8M", "-Xms8M", "-version" });

    // the following is not an error as -Xms sets both minimal and initial heap size

    expectValid(new String[] { gcflag, "-XX:InitialHeapSize=4M", "-Xms8M", "-version" });

  }

  private static void checkInvalidInitialMaxHeapCombinations(String gcflag) throws Exception {

    expectError(new String[] { gcflag, "-XX:MaxHeapSize=2047K", "-version" });

    expectError(new String[] { gcflag, "-XX:MaxHeapSize=4M", "-XX:InitialHeapSize=8M", "-version" });

    expectError(new String[] { gcflag, "-XX:InitialHeapSize=8M", "-XX:MaxHeapSize=4M", "-version" });

  }

  private static void checkValidInitialMaxHeapCombinations(String gcflag) throws Exception {

    expectValid(new String[] { gcflag, "-XX:InitialHeapSize=4M", "-XX:MaxHeapSize=8M", "-version" });

    expectValid(new String[] { gcflag, "-XX:MaxHeapSize=8M", "-XX:InitialHeapSize=4M", "-version" });

    expectValid(new String[] { gcflag, "-XX:MaxHeapSize=4M", "-XX:InitialHeapSize=4M", "-version" });

    // a value of "0" for initial heap size means auto-detect

    expectValid(new String[] { gcflag, "-XX:MaxHeapSize=4M", "-XX:InitialHeapSize=0M", "-version" });

  }

  private static long valueAfter(String source, String match) {

    int start = source.indexOf(match) + match.length();

    String tail = source.substring(start).split(" ")[0];

    return Long.parseLong(tail);

  }

  /**

   * Executes a new VM process with the given class and parameters.

   * @param vmargs Arguments to the VM to run

   * @param classname Name of the class to run

   * @param arguments Arguments to the class

   * @param useTestDotJavaDotOpts Use test.java.opts as part of the VM argument string

   * @return The OutputAnalyzer with the results for the invocation.

   */

  public static OutputAnalyzer runWhiteBoxTest(String[] vmargs, String classname, String[] arguments, boolean useTestDotJavaDotOpts) throws Exception {

    ArrayList<String> finalargs = new ArrayList<String>();

    String[] whiteboxOpts = new String[] {

      "-Xbootclasspath/a:.",

      "-XX:+UnlockDiagnosticVMOptions", "-XX:+WhiteBoxAPI",

      "-cp", System.getProperty("java.class.path"),

    };

    if (useTestDotJavaDotOpts) {

      // System.getProperty("test.java.opts") is '' if no options is set,

      // we need to skip such a result

      String[] externalVMOpts = new String[0];

      if (System.getProperty("test.java.opts") != null && System.getProperty("test.java.opts").length() != 0) {

        externalVMOpts = System.getProperty("test.java.opts").split(" ");

      }

      finalargs.addAll(Arrays.asList(externalVMOpts));

    }

    finalargs.addAll(Arrays.asList(vmargs));

    finalargs.addAll(Arrays.asList(whiteboxOpts));

    finalargs.add(classname);

    finalargs.addAll(Arrays.asList(arguments));

    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(finalargs.toArray(new String[0]));

    OutputAnalyzer output = new OutputAnalyzer(pb.start());

    output.shouldHaveExitValue(0);

    return output;

  }

  private static void getMinInitialMaxHeap(String[] args, MinInitialMaxValues val) throws Exception {

    OutputAnalyzer output = runWhiteBoxTest(args, ErgoArgsPrinter.class.getName(), new String[] {}, false);

    // the output we watch for has the following format:

    //

    // "Minimum heap X Initial heap Y Maximum heap Z Min alignment A Max Alignment B"

    //

    // where A, B, X, Y and Z are sizes in bytes.

    // Unfortunately there is no other way to retrieve the minimum heap size and

    // the alignments.

    Matcher m = Pattern.compile("Minimum heap \\d+ Initial heap \\d+ Maximum heap \\d+ Space alignment \\d+ Heap alignment \\d+").

      matcher(output.getStdout());

    if (!m.find()) {

      throw new RuntimeException("Could not find heap size string.");

    }

    String match = m.group();

    // actual values

    val.minHeapSize = valueAfter(match, "Minimum heap ");

    val.initialHeapSize = valueAfter(match, "Initial heap ");

    val.maxHeapSize = valueAfter(match, "Maximum heap ");

    val.spaceAlignment = valueAfter(match, "Space alignment ");

    val.heapAlignment = valueAfter(match, "Heap alignment ");

  }

  /**

   * Verify whether the VM automatically synchronizes minimum and initial heap size if only

   * one is given for the GC specified.

   */

  public static void checkErgonomics(String[] args, long[] newoldsize,

    long expectedMin, long expectedInitial) throws Exception {

    MinInitialMaxValues v = new MinInitialMaxValues();

    getMinInitialMaxHeap(args, v);

    if ((expectedMin != -1) && (align_up(expectedMin, v.heapAlignment) != v.minHeapSize)) {

      throw new RuntimeException("Actual minimum heap size of " + v.minHeapSize +

        " differs from expected minimum heap size of " + expectedMin);

    }

    if ((expectedInitial != -1) && (align_up(expectedInitial, v.heapAlignment) != v.initialHeapSize)) {

      throw new RuntimeException("Actual initial heap size of " + v.initialHeapSize +

        " differs from expected initial heap size of " + expectedInitial);

    }

    // always check the invariant min <= initial <= max heap size

    if (!(v.minHeapSize <= v.initialHeapSize && v.initialHeapSize <= v.maxHeapSize)) {

      throw new RuntimeException("Inconsistent min/initial/max heap sizes, they are " +

        v.minHeapSize + "/" + v.initialHeapSize + "/" + v.maxHeapSize);

    }

  }

  /**

   * Verify whether the VM respects the given maximum heap size in MB for the

   * GC specified.

   * @param gcflag The garbage collector to test as command line flag. E.g. -XX:+UseG1GC

   * @param maxHeapSize the maximum heap size to verify, in MB.

   */

  public static void checkGenMaxHeapSize(String gcflag, long maxHeapsize) throws Exception {

    final long K = 1024;

    MinInitialMaxValues v = new MinInitialMaxValues();

    getMinInitialMaxHeap(new String[] { gcflag, "-XX:MaxHeapSize=" + maxHeapsize + "M" }, v);

    long expectedHeapSize = align_up(maxHeapsize * K * K, v.heapAlignment);

    long actualHeapSize = v.maxHeapSize;

    if (actualHeapSize > expectedHeapSize) {

      throw new RuntimeException("Heap has " + actualHeapSize  +

        " bytes, expected to be less than " + expectedHeapSize);

    }

  }

  private static long getFlagValue(String flag, String where) {

    Matcher m = Pattern.compile(flag + "\\s+:?=\\s+\\d+").matcher(where);

    if (!m.find()) {

      throw new RuntimeException("Could not find value for flag " + flag + " in output string");

    }

    String match = m.group();

    return Long.parseLong(match.substring(match.lastIndexOf(" ") + 1, match.length()));

  }

  private static void shouldContainOrNot(OutputAnalyzer output, boolean contains, String message) throws Exception {

    if (contains) {

      output.shouldContain(message);

    } else {

      output.shouldNotContain(message);

    }

  }

  private static void expect(String[] flags, boolean hasWarning, boolean hasError, int errorcode) throws Exception {

    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(flags);

    OutputAnalyzer output = new OutputAnalyzer(pb.start());

    shouldContainOrNot(output, hasWarning, "Warning");

    shouldContainOrNot(output, hasError, "Error");

    output.shouldHaveExitValue(errorcode);

  }

  private static void expectError(String[] flags) throws Exception {

    expect(flags, false, true, 1);

  }

  private static void expectValid(String[] flags) throws Exception {

    expect(flags, false, false, 0);

  }

}