Line data    Source code

       1             : // Copyright (C) 2009 The Android Open Source Project
       2             : //
       3             : // Licensed under the Apache License, Version 2.0 (the "License");
       4             : // you may not use this file except in compliance with the License.
       5             : // You may obtain a copy of the License at
       6             : //
       7             : // http://www.apache.org/licenses/LICENSE-2.0
       8             : //
       9             : // Unless required by applicable law or agreed to in writing, software
      10             : // distributed under the License is distributed on an "AS IS" BASIS,
      11             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             : // See the License for the specific language governing permissions and
      13             : // limitations under the License.
      14             : 
      15             : package com.google.gerrit.sshd;
      16             : 
      17             : import com.google.common.collect.Maps;
      18             : import com.google.gerrit.extensions.registration.RegistrationHandle;
      19             : import com.google.inject.Binding;
      20             : import com.google.inject.Inject;
      21             : import com.google.inject.Injector;
      22             : import com.google.inject.Provider;
      23             : import com.google.inject.TypeLiteral;
      24             : import java.lang.annotation.Annotation;
      25             : import java.util.List;
      26             : import java.util.concurrent.ConcurrentMap;
      27             : import org.apache.sshd.server.command.Command;
      28             : 
      29             : /** Creates DispatchCommand using commands registered by {@link CommandModule}. */
      30             : public class DispatchCommandProvider implements Provider<DispatchCommand> {
      31             :   @Inject private Injector injector;
      32             : 
      33             :   @Inject private DispatchCommand.Factory factory;
      34             : 
      35             :   private final CommandName parent;
      36             :   private volatile ConcurrentMap<String, CommandProvider> map;
      37             : 
      38          17 :   public DispatchCommandProvider(CommandName cn) {
      39          17 :     this.parent = cn;
      40          17 :   }
      41             : 
      42             :   @Override
      43             :   public DispatchCommand get() {
      44           9 :     return factory.create(getMap());
      45             :   }
      46             : 
      47             :   public RegistrationHandle register(CommandName name, Provider<Command> cmd) {
      48           0 :     final ConcurrentMap<String, CommandProvider> m = getMap();
      49           0 :     final CommandProvider commandProvider = new CommandProvider(cmd, null);
      50           0 :     if (m.putIfAbsent(name.value(), commandProvider) != null) {
      51           0 :       throw new IllegalArgumentException(name.value() + " exists");
      52             :     }
      53           0 :     return () -> m.remove(name.value(), commandProvider);
      54             :   }
      55             : 
      56             :   public RegistrationHandle replace(CommandName name, Provider<Command> cmd) {
      57           0 :     final ConcurrentMap<String, CommandProvider> m = getMap();
      58           0 :     final CommandProvider commandProvider = new CommandProvider(cmd, null);
      59           0 :     m.put(name.value(), commandProvider);
      60           0 :     return () -> m.remove(name.value(), commandProvider);
      61             :   }
      62             : 
      63             :   ConcurrentMap<String, CommandProvider> getMap() {
      64           9 :     if (map == null) {
      65           9 :       synchronized (this) {
      66           9 :         if (map == null) {
      67           9 :           map = createMap();
      68             :         }
      69           9 :       }
      70             :     }
      71           9 :     return map;
      72             :   }
      73             : 
      74             :   @SuppressWarnings("unchecked")
      75             :   private ConcurrentMap<String, CommandProvider> createMap() {
      76           9 :     ConcurrentMap<String, CommandProvider> m = Maps.newConcurrentMap();
      77           9 :     for (Binding<?> b : allCommands()) {
      78           9 :       final Annotation annotation = b.getKey().getAnnotation();
      79           9 :       if (annotation instanceof CommandName) {
      80           9 :         final CommandName n = (CommandName) annotation;
      81           9 :         if (!Commands.CMD_ROOT.equals(n) && Commands.isChild(parent, n)) {
      82           9 :           String descr = null;
      83           9 :           if (annotation instanceof Commands.NestedCommandNameImpl) {
      84           5 :             Commands.NestedCommandNameImpl impl = ((Commands.NestedCommandNameImpl) annotation);
      85           5 :             descr = impl.descr();
      86             :           }
      87           9 :           m.put(n.value(), new CommandProvider((Provider<Command>) b.getProvider(), descr));
      88             :         }
      89             :       }
      90           9 :     }
      91           9 :     return m;
      92             :   }
      93             : 
      94          17 :   private static final TypeLiteral<Command> type = new TypeLiteral<>() {};
      95             : 
      96             :   private List<Binding<Command>> allCommands() {
      97           9 :     return injector.findBindingsByType(type);
      98             :   }
      99             : }