SSHD: Add support for generic commands

Change-Id: I5a60710323ca674d70e34f7451422ec167105429

5 files changed, 933 insertions, 0 deletions

diff --git a/src/main/java/com/gitblit/utils/IdGenerator.java b/src/main/java/com/gitblit/utils/IdGenerator.java
new file mode 100644
index 00000000..d2c1cb23
--- /dev/null
+++ b/src/main/java/com/gitblit/utils/IdGenerator.java
@@ -0,0 +1,91 @@
+// Copyright (C) 2009 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.gitblit.utils;
+
+import java.util.Random;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import javax.inject.Inject;
+
+/** Simple class to produce 4 billion keys randomly distributed. */
+public class IdGenerator {
+  /** Format an id created by this class as a hex string. */
+  public static String format(int id) {
+    final char[] r = new char[8];
+    for (int p = 7; 0 <= p; p--) {
+      final int h = id & 0xf;
+      r[p] = h < 10 ? (char) ('0' + h) : (char) ('a' + (h - 10));
+      id >>= 4;
+    }
+    return new String(r);
+  }
+
+  private final AtomicInteger gen;
+
+  @Inject
+  public IdGenerator() {
+    gen = new AtomicInteger(new Random().nextInt());
+  }
+
+  /** Produce the next identifier. */
+  public int next() {
+    return mix(gen.getAndIncrement());
+  }
+
+  private static final int salt = 0x9e3779b9;
+
+  static int mix(int in) {
+    return mix(salt, in);
+  }
+
+  /** A very simple bit permutation to mask a simple incrementer. */
+  public static int mix(final int salt, final int in) {
+    short v0 = hi16(in);
+    short v1 = lo16(in);
+    v0 += ((v1 << 2) + 0 ^ v1) + (salt ^ (v1 >>> 3)) + 1;
+    v1 += ((v0 << 2) + 2 ^ v0) + (salt ^ (v0 >>> 3)) + 3;
+    return result(v0, v1);
+  }
+
+  /* For testing only. */
+  static int unmix(final int in) {
+    short v0 = hi16(in);
+    short v1 = lo16(in);
+    v1 -= ((v0 << 2) + 2 ^ v0) + (salt ^ (v0 >>> 3)) + 3;
+    v0 -= ((v1 << 2) + 0 ^ v1) + (salt ^ (v1 >>> 3)) + 1;
+    return result(v0, v1);
+  }
+
+  private static short hi16(final int in) {
+    return (short) ( //
+    ((in >>> 24 & 0xff)) | //
+    ((in >>> 16 & 0xff) << 8) //
+    );
+  }
+
+  private static short lo16(final int in) {
+    return (short) ( //
+    ((in >>> 8 & 0xff)) | //
+    ((in & 0xff) << 8) //
+    );
+  }
+
+  private static int result(final short v0, final short v1) {
+    return ((v0 & 0xff) << 24) | //
+        (((v0 >>> 8) & 0xff) << 16) | //
+        ((v1 & 0xff) << 8) | //
+        ((v1 >>> 8) & 0xff);
+  }
+}
diff --git a/src/main/java/com/gitblit/utils/TaskInfoFactory.java b/src/main/java/com/gitblit/utils/TaskInfoFactory.java
new file mode 100644
index 00000000..111af27b
--- /dev/null
+++ b/src/main/java/com/gitblit/utils/TaskInfoFactory.java
@@ -0,0 +1,19 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.gitblit.utils;
+
+public interface TaskInfoFactory<T> {
+  T getTaskInfo(WorkQueue.Task<?> task);
+}
diff --git a/src/main/java/com/gitblit/utils/WorkQueue.java b/src/main/java/com/gitblit/utils/WorkQueue.java
new file mode 100644
index 00000000..778e754c
--- /dev/null
+++ b/src/main/java/com/gitblit/utils/WorkQueue.java
@@ -0,0 +1,340 @@
+// Copyright (C) 2009 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.gitblit.utils;
+
+import com.google.common.collect.Lists;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.lang.Thread.UncaughtExceptionHandler;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Date;
+import java.util.List;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.Delayed;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.RunnableScheduledFuture;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import javax.inject.Inject;
+
+/** Delayed execution of tasks using a background thread pool. */
+public class WorkQueue {
+  private static final Logger log = LoggerFactory.getLogger(WorkQueue.class);
+  private static final UncaughtExceptionHandler LOG_UNCAUGHT_EXCEPTION =
+      new UncaughtExceptionHandler() {
+        @Override
+        public void uncaughtException(Thread t, Throwable e) {
+          log.error("WorkQueue thread " + t.getName() + " threw exception", e);
+        }
+      };
+
+  private Executor defaultQueue;
+  private final IdGenerator idGenerator;
+  private final CopyOnWriteArrayList<Executor> queues;
+
+  @Inject
+  public WorkQueue(final IdGenerator idGenerator) {
+    this.idGenerator = idGenerator;
+    this.queues = new CopyOnWriteArrayList<Executor>();
+  }
+
+  /** Get the default work queue, for miscellaneous tasks. */
+  public synchronized Executor getDefaultQueue() {
+    if (defaultQueue == null) {
+      defaultQueue = createQueue(1, "WorkQueue");
+    }
+    return defaultQueue;
+  }
+
+  /** Create a new executor queue with one thread. */
+  public Executor createQueue(final int poolsize, final String prefix) {
+    final Executor r = new Executor(poolsize, prefix);
+    r.setContinueExistingPeriodicTasksAfterShutdownPolicy(false);
+    r.setExecuteExistingDelayedTasksAfterShutdownPolicy(false);
+    queues.add(r);
+    return r;
+  }
+
+  /** Get all of the tasks currently scheduled in any work queue. */
+  public List<Task<?>> getTasks() {
+    final List<Task<?>> r = new ArrayList<Task<?>>();
+    for (final Executor e : queues) {
+      e.addAllTo(r);
+    }
+    return r;
+  }
+
+  public <T> List<T> getTaskInfos(TaskInfoFactory<T> factory) {
+    List<T> taskInfos = Lists.newArrayList();
+    for (Executor exe : queues) {
+      for (Task<?> task : exe.getTasks()) {
+        taskInfos.add(factory.getTaskInfo(task));
+      }
+    }
+    return taskInfos;
+  }
+
+  /** Locate a task by its unique id, null if no task matches. */
+  public Task<?> getTask(final int id) {
+    Task<?> result = null;
+    for (final Executor e : queues) {
+      final Task<?> t = e.getTask(id);
+      if (t != null) {
+        if (result != null) {
+          // Don't return the task if we have a duplicate. Lie instead.
+          return null;
+        } else {
+          result = t;
+        }
+      }
+    }
+    return result;
+  }
+
+  public void stop() {
+    for (final Executor p : queues) {
+      p.shutdown();
+      boolean isTerminated;
+      do {
+        try {
+          isTerminated = p.awaitTermination(10, TimeUnit.SECONDS);
+        } catch (InterruptedException ie) {
+          isTerminated = false;
+        }
+      } while (!isTerminated);
+    }
+    queues.clear();
+  }
+
+  /** An isolated queue. */
+  public class Executor extends ScheduledThreadPoolExecutor {
+    private final ConcurrentHashMap<Integer, Task<?>> all;
+
+    Executor(final int corePoolSize, final String prefix) {
+      super(corePoolSize, new ThreadFactory() {
+        private final ThreadFactory parent = Executors.defaultThreadFactory();
+        private final AtomicInteger tid = new AtomicInteger(1);
+
+        @Override
+        public Thread newThread(final Runnable task) {
+          final Thread t = parent.newThread(task);
+          t.setName(prefix + "-" + tid.getAndIncrement());
+          t.setUncaughtExceptionHandler(LOG_UNCAUGHT_EXCEPTION);
+          return t;
+        }
+      });
+
+      all = new ConcurrentHashMap<Integer, Task<?>>( //
+          corePoolSize << 1, // table size
+          0.75f, // load factor
+          corePoolSize + 4 // concurrency level
+          );
+    }
+
+    public void unregisterWorkQueue() {
+      queues.remove(this);
+    }
+
+    @Override
+    protected <V> RunnableScheduledFuture<V> decorateTask(
+        final Runnable runnable, RunnableScheduledFuture<V> r) {
+      r = super.decorateTask(runnable, r);
+      for (;;) {
+        final int id = idGenerator.next();
+
+        Task<V> task;
+        task = new Task<V>(runnable, r, this, id);
+
+        if (all.putIfAbsent(task.getTaskId(), task) == null) {
+          return task;
+        }
+      }
+    }
+
+    @Override
+    protected <V> RunnableScheduledFuture<V> decorateTask(
+        final Callable<V> callable, final RunnableScheduledFuture<V> task) {
+      throw new UnsupportedOperationException("Callable not implemented");
+    }
+
+    void remove(final Task<?> task) {
+      all.remove(task.getTaskId(), task);
+    }
+
+    Task<?> getTask(final int id) {
+      return all.get(id);
+    }
+
+    void addAllTo(final List<Task<?>> list) {
+      list.addAll(all.values()); // iterator is thread safe
+    }
+
+    Collection<Task<?>> getTasks() {
+      return all.values();
+    }
+  }
+
+  /** Runnable needing to know it was canceled. */
+  public interface CancelableRunnable extends Runnable {
+    /** Notifies the runnable it was canceled. */
+    public void cancel();
+  }
+
+  /** A wrapper around a scheduled Runnable, as maintained in the queue. */
+  public static class Task<V> implements RunnableScheduledFuture<V> {
+    /**
+     * Summarized status of a single task.
+     * <p>
+     * Tasks have the following state flow:
+     * <ol>
+     * <li>{@link #SLEEPING}: if scheduled with a non-zero delay.</li>
+     * <li>{@link #READY}: waiting for an available worker thread.</li>
+     * <li>{@link #RUNNING}: actively executing on a worker thread.</li>
+     * <li>{@link #DONE}: finished executing, if not periodic.</li>
+     * </ol>
+     */
+    public static enum State {
+      // Ordered like this so ordinal matches the order we would
+      // prefer to see tasks sorted in: done before running,
+      // running before ready, ready before sleeping.
+      //
+      DONE, CANCELLED, RUNNING, READY, SLEEPING, OTHER
+    }
+
+    private final Runnable runnable;
+    private final RunnableScheduledFuture<V> task;
+    private final Executor executor;
+    private final int taskId;
+    private final AtomicBoolean running;
+    private final Date startTime;
+
+    Task(Runnable runnable, RunnableScheduledFuture<V> task, Executor executor,
+        int taskId) {
+      this.runnable = runnable;
+      this.task = task;
+      this.executor = executor;
+      this.taskId = taskId;
+      this.running = new AtomicBoolean();
+      this.startTime = new Date();
+    }
+
+    public int getTaskId() {
+      return taskId;
+    }
+
+    public State getState() {
+      if (isCancelled()) {
+        return State.CANCELLED;
+      } else if (isDone() && !isPeriodic()) {
+        return State.DONE;
+      } else if (running.get()) {
+        return State.RUNNING;
+      }
+
+      final long delay = getDelay(TimeUnit.MILLISECONDS);
+      if (delay <= 0) {
+        return State.READY;
+      } else if (0 < delay) {
+        return State.SLEEPING;
+      }
+
+      return State.OTHER;
+    }
+
+    public Date getStartTime() {
+      return startTime;
+    }
+
+    public boolean cancel(boolean mayInterruptIfRunning) {
+      if (task.cancel(mayInterruptIfRunning)) {
+        // Tiny abuse of running: if the task needs to know it was
+        // canceled (to clean up resources) and it hasn't started
+        // yet the task's run method won't execute. So we tag it
+        // as running and allow it to clean up. This ensures we do
+        // not invoke cancel twice.
+        //
+        if (runnable instanceof CancelableRunnable
+            && running.compareAndSet(false, true)) {
+          ((CancelableRunnable) runnable).cancel();
+        }
+        executor.remove(this);
+        executor.purge();
+        return true;
+
+      } else {
+        return false;
+      }
+    }
+
+    public int compareTo(Delayed o) {
+      return task.compareTo(o);
+    }
+
+    public V get() throws InterruptedException, ExecutionException {
+      return task.get();
+    }
+
+    public V get(long timeout, TimeUnit unit) throws InterruptedException,
+        ExecutionException, TimeoutException {
+      return task.get(timeout, unit);
+    }
+
+    public long getDelay(TimeUnit unit) {
+      return task.getDelay(unit);
+    }
+
+    public boolean isCancelled() {
+      return task.isCancelled();
+    }
+
+    public boolean isDone() {
+      return task.isDone();
+    }
+
+    public boolean isPeriodic() {
+      return task.isPeriodic();
+    }
+
+    public void run() {
+      if (running.compareAndSet(false, true)) {
+        try {
+          task.run();
+        } finally {
+          if (isPeriodic()) {
+            running.set(false);
+          } else {
+            executor.remove(this);
+          }
+        }
+      }
+    }
+
+    @Override
+    public String toString() {
+      return runnable.toString();
+    }
+  }
+}
diff --git a/src/main/java/com/gitblit/utils/cli/CmdLineParser.java b/src/main/java/com/gitblit/utils/cli/CmdLineParser.java
new file mode 100644
index 00000000..def76df4
--- /dev/null
+++ b/src/main/java/com/gitblit/utils/cli/CmdLineParser.java
@@ -0,0 +1,440 @@
+/*
+ * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
+ *
+ * (Taken from JGit org.eclipse.jgit.pgm.opt.CmdLineParser.)
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * - Neither the name of the Git Development Community nor the names of its
+ * contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package com.gitblit.utils.cli;
+
+import java.io.StringWriter;
+import java.io.Writer;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.AnnotatedElement;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.ResourceBundle;
+
+import org.kohsuke.args4j.Argument;
+import org.kohsuke.args4j.CmdLineException;
+import org.kohsuke.args4j.IllegalAnnotationError;
+import org.kohsuke.args4j.NamedOptionDef;
+import org.kohsuke.args4j.Option;
+import org.kohsuke.args4j.OptionDef;
+import org.kohsuke.args4j.spi.BooleanOptionHandler;
+import org.kohsuke.args4j.spi.EnumOptionHandler;
+import org.kohsuke.args4j.spi.FieldSetter;
+import org.kohsuke.args4j.spi.OptionHandler;
+import org.kohsuke.args4j.spi.Setter;
+
+import com.google.common.base.Strings;
+import com.google.common.collect.LinkedHashMultimap;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Multimap;
+
+/**
+ * Extended command line parser which handles --foo=value arguments.
+ * <p>
+ * The args4j package does not natively handle --foo=value and instead prefers
+ * to see --foo value on the command line. Many users are used to the GNU style
+ * --foo=value long option, so we convert from the GNU style format to the
+ * args4j style format prior to invoking args4j for parsing.
+ */
+public class CmdLineParser {
+  public interface Factory {
+    CmdLineParser create(Object bean);
+  }
+
+  private final MyParser parser;
+
+  @SuppressWarnings("rawtypes")
+  private Map<String, OptionHandler> options;
+
+  /**
+   * Creates a new command line owner that parses arguments/options and set them
+   * into the given object.
+   *
+   * @param bean instance of a class annotated by
+   *        {@link org.kohsuke.args4j.Option} and
+   *        {@link org.kohsuke.args4j.Argument}. this object will receive
+   *        values.
+   *
+   * @throws IllegalAnnotationError if the option bean class is using args4j
+   *         annotations incorrectly.
+   */
+  public CmdLineParser(Object bean)
+      throws IllegalAnnotationError {
+    this.parser = new MyParser(bean);
+  }
+
+  public void addArgument(Setter<?> setter, Argument a) {
+    parser.addArgument(setter, a);
+  }
+
+  public void addOption(Setter<?> setter, Option o) {
+    parser.addOption(setter, o);
+  }
+
+  public void printSingleLineUsage(Writer w, ResourceBundle rb) {
+    parser.printSingleLineUsage(w, rb);
+  }
+
+  public void printUsage(Writer out, ResourceBundle rb) {
+    parser.printUsage(out, rb);
+  }
+
+  public void printDetailedUsage(String name, StringWriter out) {
+    out.write(name);
+    printSingleLineUsage(out, null);
+    out.write('\n');
+    out.write('\n');
+    printUsage(out, null);
+    out.write('\n');
+  }
+
+  public void printQueryStringUsage(String name, StringWriter out) {
+    out.write(name);
+
+    char next = '?';
+    List<NamedOptionDef> booleans = new ArrayList<NamedOptionDef>();
+    for (@SuppressWarnings("rawtypes") OptionHandler handler : parser.options) {
+      if (handler.option instanceof NamedOptionDef) {
+        NamedOptionDef n = (NamedOptionDef) handler.option;
+
+        if (handler instanceof BooleanOptionHandler) {
+          booleans.add(n);
+          continue;
+        }
+
+        if (!n.required()) {
+          out.write('[');
+        }
+        out.write(next);
+        next = '&';
+        if (n.name().startsWith("--")) {
+          out.write(n.name().substring(2));
+        } else if (n.name().startsWith("-")) {
+          out.write(n.name().substring(1));
+        } else {
+          out.write(n.name());
+        }
+        out.write('=');
+
+        out.write(metaVar(handler, n));
+        if (!n.required()) {
+          out.write(']');
+        }
+        if (n.isMultiValued()) {
+          out.write('*');
+        }
+      }
+    }
+    for (NamedOptionDef n : booleans) {
+      if (!n.required()) {
+        out.write('[');
+      }
+      out.write(next);
+      next = '&';
+      if (n.name().startsWith("--")) {
+        out.write(n.name().substring(2));
+      } else if (n.name().startsWith("-")) {
+        out.write(n.name().substring(1));
+      } else {
+        out.write(n.name());
+      }
+      if (!n.required()) {
+        out.write(']');
+      }
+    }
+  }
+
+  private static String metaVar(OptionHandler<?> handler, NamedOptionDef n) {
+    String var = n.metaVar();
+    if (Strings.isNullOrEmpty(var)) {
+      var = handler.getDefaultMetaVariable();
+      if (handler instanceof EnumOptionHandler) {
+        var = var.substring(1, var.length() - 1).replace(" ", "");
+      }
+    }
+    return var;
+  }
+
+  public boolean wasHelpRequestedByOption() {
+    return parser.help.value;
+  }
+
+  public void parseArgument(final String... args) throws CmdLineException {
+    List<String> tmp = Lists.newArrayListWithCapacity(args.length);
+    for (int argi = 0; argi < args.length; argi++) {
+      final String str = args[argi];
+      if (str.equals("--")) {
+        while (argi < args.length)
+          tmp.add(args[argi++]);
+        break;
+      }
+
+      if (str.startsWith("--")) {
+        final int eq = str.indexOf('=');
+        if (eq > 0) {
+          tmp.add(str.substring(0, eq));
+          tmp.add(str.substring(eq + 1));
+          continue;
+        }
+      }
+
+      tmp.add(str);
+    }
+    parser.parseArgument(tmp.toArray(new String[tmp.size()]));
+  }
+
+  public void parseOptionMap(Map<String, String[]> parameters)
+      throws CmdLineException {
+    Multimap<String, String> map = LinkedHashMultimap.create();
+    for (Map.Entry<String, String[]> ent : parameters.entrySet()) {
+      for (String val : ent.getValue()) {
+        map.put(ent.getKey(), val);
+      }
+    }
+    parseOptionMap(map);
+  }
+
+  public void parseOptionMap(Multimap<String, String> params)
+      throws CmdLineException {
+    List<String> tmp = Lists.newArrayListWithCapacity(2 * params.size());
+    for (final String key : params.keySet()) {
+      String name = makeOption(key);
+
+      if (isBoolean(name)) {
+        boolean on = false;
+        for (String value : params.get(key)) {
+          on = toBoolean(key, value);
+        }
+        if (on) {
+          tmp.add(name);
+        }
+      } else {
+        for (String value : params.get(key)) {
+          tmp.add(name);
+          tmp.add(value);
+        }
+      }
+    }
+    parser.parseArgument(tmp.toArray(new String[tmp.size()]));
+  }
+
+  public boolean isBoolean(String name) {
+    return findHandler(makeOption(name)) instanceof BooleanOptionHandler;
+  }
+
+  private String makeOption(String name) {
+    if (!name.startsWith("-")) {
+      if (name.length() == 1) {
+        name = "-" + name;
+      } else {
+        name = "--" + name;
+      }
+    }
+    return name;
+  }
+
+  @SuppressWarnings("rawtypes")
+  private OptionHandler findHandler(String name) {
+    if (options == null) {
+      options = index(parser.options);
+    }
+    return options.get(name);
+  }
+
+  @SuppressWarnings("rawtypes")
+  private static Map<String, OptionHandler> index(List<OptionHandler> in) {
+    Map<String, OptionHandler> m = Maps.newHashMap();
+    for (OptionHandler handler : in) {
+      if (handler.option instanceof NamedOptionDef) {
+        NamedOptionDef def = (NamedOptionDef) handler.option;
+        if (!def.isArgument()) {
+          m.put(def.name(), handler);
+          for (String alias : def.aliases()) {
+            m.put(alias, handler);
+          }
+        }
+      }
+    }
+    return m;
+  }
+
+  private boolean toBoolean(String name, String value) throws CmdLineException {
+    if ("true".equals(value) || "t".equals(value)
+        || "yes".equals(value) || "y".equals(value)
+        || "on".equals(value)
+        || "1".equals(value)
+        || value == null || "".equals(value)) {
+      return true;
+    }
+
+    if ("false".equals(value) || "f".equals(value)
+        || "no".equals(value) || "n".equals(value)
+        || "off".equals(value)
+        || "0".equals(value)) {
+      return false;
+    }
+
+    throw new CmdLineException(parser, String.format(
+        "invalid boolean \"%s=%s\"", name, value));
+  }
+
+  private class MyParser extends org.kohsuke.args4j.CmdLineParser {
+    @SuppressWarnings("rawtypes")
+    private List<OptionHandler> options;
+    private HelpOption help;
+
+    MyParser(final Object bean) {
+      super(bean);
+      ensureOptionsInitialized();
+    }
+
+    @SuppressWarnings({"unchecked", "rawtypes"})
+    @Override
+    protected OptionHandler createOptionHandler(final OptionDef option,
+        final Setter setter) {
+      if (isHandlerSpecified(option) || isEnum(setter) || isPrimitive(setter)) {
+        return add(super.createOptionHandler(option, setter));
+      }
+
+//      OptionHandlerFactory<?> factory = handlers.get(setter.getType());
+//      if (factory != null) {
+//        return factory.create(this, option, setter);
+//      }
+      return add(super.createOptionHandler(option, setter));
+    }
+
+    @SuppressWarnings("rawtypes")
+    private OptionHandler add(OptionHandler handler) {
+      ensureOptionsInitialized();
+      options.add(handler);
+      return handler;
+    }
+
+    private void ensureOptionsInitialized() {
+      if (options == null) {
+        help = new HelpOption();
+        options = Lists.newArrayList();
+        addOption(help, help);
+      }
+    }
+
+    private boolean isHandlerSpecified(final OptionDef option) {
+      return option.handler() != OptionHandler.class;
+    }
+
+    private <T> boolean isEnum(Setter<T> setter) {
+      return Enum.class.isAssignableFrom(setter.getType());
+    }
+
+    private <T> boolean isPrimitive(Setter<T> setter) {
+      return setter.getType().isPrimitive();
+    }
+  }
+
+  private static class HelpOption implements Option, Setter<Boolean> {
+    private boolean value;
+
+    @Override
+    public String name() {
+      return "--help";
+    }
+
+    @Override
+    public String[] aliases() {
+      return new String[] {"-h"};
+    }
+
+    @Override
+    public String[] depends() {
+      return new String[] {};
+    }
+
+    @Override
+    public boolean hidden() {
+      return false;
+    }
+
+    @Override
+    public String usage() {
+      return "display this help text";
+    }
+
+    @Override
+    public void addValue(Boolean val) {
+      value = val;
+    }
+
+    @Override
+    public Class<? extends OptionHandler<Boolean>> handler() {
+      return BooleanOptionHandler.class;
+    }
+
+    @Override
+    public String metaVar() {
+      return "";
+    }
+
+    @Override
+    public boolean required() {
+      return false;
+    }
+
+    @Override
+    public Class<? extends Annotation> annotationType() {
+      return Option.class;
+    }
+
+    @Override
+    public FieldSetter asFieldSetter() {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public AnnotatedElement asAnnotatedElement() {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public Class<Boolean> getType() {
+      return Boolean.class;
+    }
+
+    @Override
+    public boolean isMultiValued() {
+      return false;
+    }
+  }
+}
diff --git a/src/main/java/com/gitblit/utils/cli/SubcommandHandler.java b/src/main/java/com/gitblit/utils/cli/SubcommandHandler.java
new file mode 100644
index 00000000..b1ace324
--- /dev/null
+++ b/src/main/java/com/gitblit/utils/cli/SubcommandHandler.java
@@ -0,0 +1,43 @@
+// Copyright (C) 2010 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.gitblit.utils.cli;
+
+import org.kohsuke.args4j.CmdLineException;
+import org.kohsuke.args4j.CmdLineParser;
+import org.kohsuke.args4j.OptionDef;
+import org.kohsuke.args4j.spi.OptionHandler;
+import org.kohsuke.args4j.spi.Parameters;
+import org.kohsuke.args4j.spi.Setter;
+
+public class SubcommandHandler extends OptionHandler<String> {
+
+  public SubcommandHandler(CmdLineParser parser,
+      OptionDef option, Setter<String> setter) {
+    super(parser, option, setter);
+  }
+
+  @Override
+  public final int parseArguments(final Parameters params)
+      throws CmdLineException {
+    setter.addValue(params.getParameter(0));
+    owner.stopOptionParsing();
+    return 1;
+  }
+
+  @Override
+  public final String getDefaultMetaVariable() {
+    return "COMMAND";
+  }
+}