Rewrite our build as modular maven components

This refactoring splits the code up into different components, with
their own per-component CLASSPATH.  By moving all of our classes
into isolated components we can better isolate the classpaths and
try to avoid unexpected dependency problems.  It also allows us to
more clearly define which components are used by the GWT UI and
thus must be compiled under GWT, and which components are run on
the server and can therefore use more of the J2SE API.

Change-Id: I833cc22bacc5655d1c9099ed7c2b0e0a5b08855a
Signed-off-by: Shawn O. Pearce <sop@google.com>

gerrit-sshd/src/main/java/com/google/gerrit/sshd/SshModule.java

@@ -0,0 +1,128 @@
+// 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.google.gerrit.sshd;
+
+import static com.google.inject.Scopes.SINGLETON;
+
+import com.google.gerrit.reviewdb.Account;
+import com.google.gerrit.reviewdb.AccountGroup;
+import com.google.gerrit.reviewdb.PatchSet;
+import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.RemotePeer;
+import com.google.gerrit.server.config.FactoryModule;
+import com.google.gerrit.server.config.GerritRequestModule;
+import com.google.gerrit.server.project.ProjectControl;
+import com.google.gerrit.server.ssh.SshInfo;
+import com.google.gerrit.sshd.args4j.AccountGroupIdHandler;
+import com.google.gerrit.sshd.args4j.AccountIdHandler;
+import com.google.gerrit.sshd.args4j.PatchSetIdHandler;
+import com.google.gerrit.sshd.args4j.ProjectControlHandler;
+import com.google.gerrit.sshd.commands.DefaultCommandModule;
+import com.google.gerrit.util.cli.CmdLineParser;
+import com.google.gerrit.util.cli.OptionHandlerFactory;
+import com.google.gerrit.util.cli.OptionHandlerUtil;
+import com.google.inject.Key;
+import com.google.inject.Provider;
+import com.google.inject.TypeLiteral;
+import com.google.inject.assistedinject.FactoryProvider;
+import com.google.inject.servlet.RequestScoped;
+import com.google.inject.servlet.SessionScoped;
+
+import org.apache.sshd.common.KeyPairProvider;
+import org.apache.sshd.common.session.AbstractSession;
+import org.apache.sshd.server.CommandFactory;
+import org.apache.sshd.server.PublickeyAuthenticator;
+import org.apache.sshd.server.session.ServerSession;
+import org.kohsuke.args4j.spi.OptionHandler;
+
+import java.net.SocketAddress;
+
+/** Configures standard dependencies for {@link SshDaemon}. */
+public class SshModule extends FactoryModule {
+  private static final String NAME = "Gerrit Code Review";
+
+  @Override
+  protected void configure() {
+    bindScope(SessionScoped.class, SshScopes.SESSION);
+    bindScope(RequestScoped.class, SshScopes.REQUEST);
+
+    configureSessionScope();
+    configureRequestScope();
+    configureCmdLineParser();
+
+    install(SshKeyCacheImpl.module());
+    bind(SshInfo.class).to(SshDaemon.class).in(SINGLETON);
+    factory(DispatchCommand.Factory.class);
+
+    bind(DispatchCommandProvider.class).annotatedWith(Commands.CMD_ROOT)
+        .toInstance(new DispatchCommandProvider(NAME, Commands.CMD_ROOT));
+    bind(CommandFactoryProvider.class);
+    bind(CommandFactory.class).toProvider(CommandFactoryProvider.class);
+
+    bind(PublickeyAuthenticator.class).to(DatabasePubKeyAuth.class);
+    bind(KeyPairProvider.class).toProvider(HostKeyProvider.class).in(SINGLETON);
+
+    install(new DefaultCommandModule());
+  }
+
+  private void configureSessionScope() {
+    bind(ServerSession.class).toProvider(new Provider<ServerSession>() {
+      @Override
+      public ServerSession get() {
+        return SshScopes.getContext().session;
+      }
+    }).in(SshScopes.SESSION);
+    bind(AbstractSession.class).to(ServerSession.class).in(SshScopes.SESSION);
+
+    bind(SocketAddress.class).annotatedWith(RemotePeer.class).toProvider(
+        new Provider<SocketAddress>() {
+          @Override
+          public SocketAddress get() {
+            return SshScopes.getContext().session
+                .getAttribute(SshUtil.REMOTE_PEER);
+          }
+        }).in(SshScopes.SESSION);
+  }
+
+  private void configureRequestScope() {
+    install(new GerritRequestModule());
+    bind(IdentifiedUser.class).toProvider(SshCurrentUserProvider.class).in(
+        SshScopes.REQUEST);
+    bind(CurrentUser.class).to(IdentifiedUser.class);
+  }
+
+  private void configureCmdLineParser() {
+    factory(CmdLineParser.Factory.class);
+
+    registerOptionHandler(Account.Id.class, AccountIdHandler.class);
+    registerOptionHandler(AccountGroup.Id.class, AccountGroupIdHandler.class);
+    registerOptionHandler(PatchSet.Id.class, PatchSetIdHandler.class);
+    registerOptionHandler(ProjectControl.class, ProjectControlHandler.class);
+  }
+
+  private <T> void registerOptionHandler(Class<T> type,
+      Class<? extends OptionHandler<T>> impl) {
+    final Key<OptionHandlerFactory<T>> key = OptionHandlerUtil.keyFor(type);
+
+    final TypeLiteral<OptionHandlerFactory<T>> factoryType =
+        new TypeLiteral<OptionHandlerFactory<T>>() {};
+
+    final TypeLiteral<? extends OptionHandler<T>> implType =
+        TypeLiteral.get(impl);
+
+    bind(key).toProvider(FactoryProvider.newFactory(factoryType, implType));
+  }
+}