Add a ChangeIdHandler

Add an args4j ChangeId handler, which given a project,branch,change-id
triplet, produces a valid Change.Id.

This will be useful for the "changes" commands, `abandon` and
`restore`.

Eventually, the meat of this will have to be moved somewhere to where
the http servlet will be able to tap into it as well.

Change-Id: Ib6d34fcbf0f20190ff3847fc7aba0d41f7fcadcc

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

@@ -19,6 +19,7 @@ import static com.google.inject.Scopes.SINGLETON;
 import com.google.gerrit.lifecycle.LifecycleModule;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.AccountGroup;
+import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
@@ -36,6 +37,7 @@ import com.google.gerrit.server.util.RequestScopePropagator;
 import com.google.gerrit.sshd.args4j.AccountGroupIdHandler;
 import com.google.gerrit.sshd.args4j.AccountGroupUUIDHandler;
 import com.google.gerrit.sshd.args4j.AccountIdHandler;
+import com.google.gerrit.sshd.args4j.ChangeIdHandler;
 import com.google.gerrit.sshd.args4j.ObjectIdHandler;
 import com.google.gerrit.sshd.args4j.PatchSetIdHandler;
 import com.google.gerrit.sshd.args4j.ProjectControlHandler;
@@ -120,6 +122,7 @@ public class SshModule extends FactoryModule {
     registerOptionHandler(Account.Id.class, AccountIdHandler.class);
     registerOptionHandler(AccountGroup.Id.class, AccountGroupIdHandler.class);
     registerOptionHandler(AccountGroup.UUID.class, AccountGroupUUIDHandler.class);
+    registerOptionHandler(Change.Id.class, ChangeIdHandler.class);
     registerOptionHandler(ObjectId.class, ObjectIdHandler.class);
     registerOptionHandler(PatchSet.Id.class, PatchSetIdHandler.class);
     registerOptionHandler(ProjectControl.class, ProjectControlHandler.class);

gerrit-sshd/src/main/java/com/google/gerrit/sshd/args4j/ChangeIdHandler.java

@@ -0,0 +1,77 @@
+// Copyright (C) 2012 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.args4j;
+
+import com.google.gerrit.reviewdb.client.Branch;
+import com.google.gerrit.reviewdb.client.Change;
+import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Inject;
+import com.google.inject.assistedinject.Assisted;
+
+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 ChangeIdHandler extends OptionHandler<Change.Id> {
+
+  @Inject
+  private ReviewDb db;
+
+  @Inject
+  public ChangeIdHandler(
+      final ReviewDb db,
+      @Assisted final CmdLineParser parser, @Assisted final OptionDef option,
+      @Assisted final Setter<Change.Id> setter) {
+    super(parser, option, setter);
+    this.db = db;
+  }
+
+  @Override
+  public final int parseArguments(final Parameters params)
+      throws CmdLineException {
+    final String token = params.getParameter(0);
+    final String[] tokens = token.split(",");
+    if (tokens.length != 3) {
+      throw new CmdLineException(owner, "change should be specified as "
+                                 + "<project>,<branch>,<change-id>");
+    }
+
+    try {
+      final Change.Key key = Change.Key.parse(tokens[2]);
+      final Project.NameKey project = new Project.NameKey(tokens[0]);
+      final Branch.NameKey branch = new Branch.NameKey(project, tokens[1]);
+      for (final Change change : db.changes().byBranchKey(branch, key)) {
+        setter.addValue(change.getId());
+        return 1;
+      }
+    } catch (IllegalArgumentException e) {
+      throw new CmdLineException(owner, "Change-Id is not valid");
+    } catch (OrmException e) {
+      throw new CmdLineException(owner, "Database error: " + e.getMessage());
+    }
+
+    throw new CmdLineException(owner, "\"" + token + "\": change not found");
+  }
+
+  @Override
+  public final String getDefaultMetaVariable() {
+    return "CHANGE";
+  }
+}