Add ssh command to set new sequence value

Change-Id: I9e7f1d79939a52f44e72a6823fe9ca4c8a5064c6

Documentation/cmd-sequence-set.txt

@@ -0,0 +1,54 @@
+= gerrit sequence set
+
+== NAME
+gerrit sequence set - Set new sequence value.
+
+== SYNOPSIS
+[verse]
+--
+_ssh_ -p <port> <host> _gerrit sequence set_ <NAME> <VALUE>
+--
+
+== DESCRIPTION
+Gerrit maintains the generation of the next available sequence numbers for
+account, group and change entities. The sequences are stored as UTF-8 text in
+a blob pointed to by the `refs/sequences/accounts`, `refs/sequences/groups`
+and `refs/sequences/changes` refs. Those refs are stored in `All-Users` and
+`All-Projects` git repositories correspondingly.
+
+This command allows to set a new sequence value for those sequences.
+
+The link:cmd-sequence-show.html[sequence-show] command displays current
+sequence value.
+
+== ACCESS
+Caller must be a member of the privileged 'Administrators' group.
+
+== SCRIPTING
+This command is intended to be used in scripts.
+
+== OPTIONS
+<NAME>::
+  Sequence name to set a new value for.
+  Currently supported values:
+    * accounts
+    * groups
+    * changes
+
+<VALUE>::
+  New value for the sequence.
+
+== EXAMPLES
+Set a new value for the 'changes' sequence:
+
+----
+$ ssh -p 29418 review.example.com gerrit sequence set changes 42
+The value for the changes sequence was set to 42.
+----
+
+GERRIT
+------
+Part of link:index.html[Gerrit Code Review]
+
+SEARCHBOX
+---------

Documentation/cmd-sequence-show.txt

@@ -18,6 +18,9 @@ and `refs/sequences/changes` refs. Those refs are stored in `All-Users` and
 
 This command allows to display the current sequence value for those sequences.
 
+The link:cmd-sequence-set.html[sequence-set] command allows to set a new
+sequence value.
+
 == ACCESS
 Caller must be a member of the privileged 'Administrators' group.
 

java/com/google/gerrit/server/notedb/RepoSequence.java

@@ -292,6 +292,31 @@ public class RepoSequence {
     return new ReceiveCommand(ObjectId.zeroId(), newId, RefNames.REFS_SEQUENCES + name);
   }
 
+  public void storeNew(int value) {
+    counterLock.lock();
+    try (Repository repo = repoManager.openRepository(projectName);
+        RevWalk rw = new RevWalk(repo)) {
+      Optional<IntBlob> blob = IntBlob.parse(repo, refName, rw);
+      afterReadRef.run();
+      ObjectId oldId;
+      if (!blob.isPresent()) {
+        oldId = ObjectId.zeroId();
+      } else {
+        oldId = blob.get().id();
+      }
+      RefUpdate refUpdate =
+          IntBlob.tryStore(repo, rw, projectName, refName, oldId, value, gitRefUpdated);
+      RefUpdateUtil.checkResult(refUpdate);
+      counter = value;
+      limit = counter + batchSize;
+      acquireCount++;
+    } catch (IOException e) {
+      throw new StorageException(e);
+    } finally {
+      counterLock.unlock();
+    }
+  }
+
   public int current() {
     counterLock.lock();
     try (Repository repo = repoManager.openRepository(projectName);

java/com/google/gerrit/server/notedb/Sequences.java

@@ -140,4 +140,16 @@ public class Sequences {
   public int currentGroupId() {
     return groupSeq.current();
   }
+
+  public void setChangeIdValue(int value) {
+    changeSeq.storeNew(value);
+  }
+
+  public void setAccountIdValue(int value) {
+    accountSeq.storeNew(value);
+  }
+
+  public void setGroupIdValue(int value) {
+    groupSeq.storeNew(value);
+  }
 }

java/com/google/gerrit/sshd/commands/SequenceCommandsModule.java

@@ -26,6 +26,7 @@ public class SequenceCommandsModule extends CommandModule {
     CommandName gerrit = Commands.named("gerrit");
     CommandName sequence = Commands.named(gerrit, "sequence");
     command(sequence).toProvider(new DispatchCommandProvider(sequence));
+    command(sequence, SequenceSetCommand.class);
     command(sequence, SequenceShowCommand.class);
   }
 }

java/com/google/gerrit/sshd/commands/SequenceSetCommand.java

@@ -0,0 +1,56 @@
+// Copyright (C) 2019 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.commands;
+
+import com.google.gerrit.common.data.GlobalCapability;
+import com.google.gerrit.extensions.annotations.RequiresCapability;
+import com.google.gerrit.server.notedb.Sequences;
+import com.google.gerrit.sshd.CommandMetaData;
+import com.google.gerrit.sshd.SshCommand;
+import com.google.inject.Inject;
+import org.kohsuke.args4j.Argument;
+
+/** Set sequence value. */
+@RequiresCapability(GlobalCapability.ADMINISTRATE_SERVER)
+@CommandMetaData(name = "set", description = "Set the sequence value")
+final class SequenceSetCommand extends SshCommand {
+  @Argument(index = 0, metaVar = "NAME", required = true, usage = "sequence name")
+  private String name;
+
+  @Argument(index = 1, metaVar = "VALUE", required = true, usage = "sequence value")
+  private int value;
+
+  @Inject Sequences sequences;
+
+  @Override
+  public void run() throws Exception {
+    switch (name) {
+      case "changes":
+        sequences.setChangeIdValue(value);
+        break;
+      case "accounts":
+        sequences.setAccountIdValue(value);
+        break;
+      case "groups":
+        sequences.setGroupIdValue(value);
+        break;
+      default:
+        throw die("Unknown sequence name: " + name);
+    }
+    stdout.print("The value for the " + name + " sequence was set to " + value + ".");
+    stdout.print('\n');
+    stdout.flush();
+  }
+}

javatests/com/google/gerrit/acceptance/ssh/SshCommandsIT.java

@@ -97,7 +97,7 @@ public class SshCommandsIT extends AbstractDaemonTest {
               "gerrit plugin",
               ImmutableList.of("add", "enable", "install", "ls", "reload", "remove", "rm"))
           .put("gerrit test-submit", ImmutableList.of("rule", "type"))
-          .put("gerrit sequence", ImmutableList.of("show"))
+          .put("gerrit sequence", ImmutableList.of("set", "show"))
           .build();
 
   private static final ImmutableMap<String, List<String>> SLAVE_COMMANDS =