/*

 * Copyright (c) 2005, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.tools.jmap;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.io.UnsupportedEncodingException;

import java.util.Collection;

import com.sun.tools.attach.VirtualMachine;

import com.sun.tools.attach.VirtualMachineDescriptor;

import com.sun.tools.attach.AttachNotSupportedException;

import sun.tools.attach.HotSpotVirtualMachine;

import sun.tools.common.ProcessArgumentMatcher;

/*

 * This class is the main class for the JMap utility. It parses its arguments

 * and decides if the command should be satisfied using the VM attach mechanism

 * or an SA tool. At this time the only option that uses the VM attach mechanism

 * is the -dump option to get a heap dump of a running application. All other

 * options are mapped to SA tools.

 */

public class JMap {

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

        if (args.length == 0) {

            usage(1); // no arguments

        }

        checkForUnsupportedOptions(args);

        // the chosen option

        String option = null;

        // First iterate over the options (arguments starting with -).  There should be

        // one.

        int optionCount = 0;

        while (optionCount < args.length) {

            String arg = args[optionCount];

            if (!arg.startsWith("-")) {

                break;

            }

            if (arg.equals("-?") ||

                arg.equals("-h") ||

                arg.equals("--help") ||

                // -help: legacy. Undocumented.

                arg.equals("-help")) {

                usage(0);

            } else {

                if (option != null) {

                    usage(1);  // option already specified

                }

                option = arg;

            }

            optionCount++;

        }

        // if no option provided then use default.

        if (option == null) {

            usage(0);

        }

        // Next we check the parameter count.

        int paramCount = args.length - optionCount;

        if (paramCount != 1) {

            usage(1);

        }

        String pidArg = args[1];

        // Here we handle the built-in options

        // As more options are added we should create an abstract tool class and

        // have a table to map the options

        ProcessArgumentMatcher ap = new ProcessArgumentMatcher(pidArg);

        Collection<String> pids = ap.getVirtualMachinePids(JMap.class);

        if (pids.isEmpty()) {

            System.err.println("Could not find any processes matching : '" + pidArg + "'");

            System.exit(1);

        }

        for (String pid : pids) {

            if (pids.size() > 1) {

                System.out.println("Pid:" + pid);

            }

            if (option.equals("-histo")) {

                histo(pid, "");

            } else if (option.startsWith("-histo:")) {

                histo(pid, option.substring("-histo:".length()));

            } else if (option.startsWith("-dump:")) {

                dump(pid, option.substring("-dump:".length()));

            } else if (option.equals("-finalizerinfo")) {

                executeCommandForPid(pid, "jcmd", "GC.finalizer_info");

            } else if (option.equals("-clstats")) {

                executeCommandForPid(pid, "jcmd", "GC.class_stats");

            } else {

              usage(1);

            }

        }

    }

    private static void executeCommandForPid(String pid, String command, Object ... args)

        throws AttachNotSupportedException, IOException,

               UnsupportedEncodingException {

        VirtualMachine vm = VirtualMachine.attach(pid);

        // Cast to HotSpotVirtualMachine as this is an

        // implementation specific method.

        HotSpotVirtualMachine hvm = (HotSpotVirtualMachine) vm;

        try (InputStream in = hvm.executeCommand(command, args)) {

          // read to EOF and just print output

          byte b[] = new byte[256];

          int n;

          do {

              n = in.read(b);

              if (n > 0) {

                  String s = new String(b, 0, n, "UTF-8");

                  System.out.print(s);

              }

          } while (n > 0);

        }

        vm.detach();

    }

    private static void histo(String pid, String options)

        throws AttachNotSupportedException, IOException,

               UnsupportedEncodingException {

        String liveopt = "-all";

            //  pass

        }

        else if (options.equals("live")) {

            liveopt = "-live";

        }

        else {

            usage(1);

        }

        // inspectHeap is not the same as jcmd GC.class_histogram

        executeCommandForPid(pid, "inspectheap", liveopt);

    }

    private static void dump(String pid, String options)

        throws AttachNotSupportedException, IOException,

               UnsupportedEncodingException {

        String subopts[] = options.split(",");

        String filename = null;

        String liveopt = "-all";

        for (int i = 0; i < subopts.length; i++) {

            String subopt = subopts[i];

            if (subopt.equals("live")) {

                liveopt = "-live";

            } else if (subopt.startsWith("file=")) {

                // file=<file> - check that <file> is specified

                if (subopt.length() > 5) {

                    filename = subopt.substring(5);

                }

            }

        }

        if (filename == null) {

            usage(1);  // invalid options or no filename

        }

        // get the canonical path - important to avoid just passing

        // a "heap.bin" and having the dump created in the target VM

        // working directory rather than the directory where jmap

        // is executed.

        filename = new File(filename).getCanonicalPath();

        // dumpHeap is not the same as jcmd GC.heap_dump

        executeCommandForPid(pid, "dumpheap", filename, liveopt);

    }

    private static void checkForUnsupportedOptions(String[] args) {

        // Check arguments for -F, -m, and non-numeric value

        // and warn the user that SA is not supported anymore

        int paramCount = 0;

        for (String s : args) {

            if (s.equals("-F")) {

                SAOptionError("-F option used");

            }

            if (s.equals("-heap")) {

                SAOptionError("-heap option used");

            }

            /* Reimplemented using jcmd, output format is different

               from original one

            if (s.equals("-clstats")) {

                warnSA("-clstats option used");

            }

            if (s.equals("-finalizerinfo")) {

                warnSA("-finalizerinfo option used");

            }

            */

            if (! s.startsWith("-")) {

                paramCount += 1;

            }

        }

        if (paramCount > 1) {

            SAOptionError("More than one non-option argument");

        }

    }

    private static void SAOptionError(String msg) {

        System.err.println("Error: " + msg);

        System.err.println("Cannot connect to core dump or remote debug server. Use jhsdb jmap instead");

        System.exit(1);

    }

    // print usage message

    private static void usage(int exit) {

        System.err.println("Usage:");

        System.err.println("    jmap -clstats <pid>");

        System.err.println("        to connect to running process and print class loader statistics");

        System.err.println("    jmap -finalizerinfo <pid>");

        System.err.println("        to connect to running process and print information on objects awaiting finalization");

        System.err.println("    jmap -histo[:live] <pid>");

        System.err.println("        to connect to running process and print histogram of java object heap");

        System.err.println("        if the \"live\" suboption is specified, only count live objects");

        System.err.println("    jmap -dump:<dump-options> <pid>");

        System.err.println("        to connect to running process and dump java heap");

        System.err.println("    jmap -? -h --help");

        System.err.println("        to print this help message");

        System.err.println("");

        System.err.println("    dump-options:");

        System.err.println("      live         dump only live objects; if not specified,");

        System.err.println("                   all objects in the heap are dumped.");

        System.err.println("      format=b     binary format");

        System.err.println("      file=<file>  dump heap to <file>");

        System.err.println("");

        System.err.println("    Example: jmap -dump:live,format=b,file=heap.bin <pid>");

        System.exit(exit);

    }

}