Create change ref from ChangeInserter

Reduce some duplicated code. However, there are still a few special
snowflakes, so leave a flag to turn this off:
 - ReceiveCommits manages its own BatchRefUpdate. (It also doesn't
   even use PatchSetInserter for the new patch set case.)
 - ReviewProjectAccess updates the ref using VersionedMetaData, which
   I'm not going to touch for now.

Change-Id: I6f4f9fb8a6364627a737698d1001ad29ce8a981a

gerrit-server/src/main/java/com/google/gerrit/server/change/ChangeInserter.java

@@ -59,6 +59,7 @@ import com.google.inject.Provider;
 import com.google.inject.assistedinject.Assisted;
 
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.notes.NoteMap;
 import org.eclipse.jgit.revwalk.RevCommit;
@@ -114,10 +115,10 @@ public class ChangeInserter {
   private RequestScopePropagator requestScopePropagator;
   private boolean runHooks;
   private boolean sendMail;
+  private boolean updateRef;
 
   // Fields set during the insertion process.
   private ChangeMessage changeMessage;
-  private boolean validated; // TODO(dborowitz): Remove; see validate().
 
   @Inject
   ChangeInserter(Provider<ReviewDb> dbProvider,
@@ -162,6 +163,7 @@ public class ChangeInserter {
     this.hashtags = Collections.emptySet();
     this.runHooks = true;
     this.sendMail = true;
+    this.updateRef = true;
 
     user = checkUser(projectControl);
     patchSet =
@@ -243,6 +245,11 @@ public class ChangeInserter {
     return this;
   }
 
+  public ChangeInserter setUpdateRef(boolean updateRef) {
+    this.updateRef = updateRef;
+    return this;
+  }
+
   public PatchSetInfo getPatchSetInfo() {
     return patchSetInfo;
   }
@@ -260,6 +267,8 @@ public class ChangeInserter {
       throws OrmException, IOException, InvalidChangeOperationException {
     validate();
 
+    updateRef();
+
     ReviewDb db = dbProvider.get();
     ProjectControl projectControl = refControl.getProjectControl();
     ChangeControl ctl = projectControl.controlFor(change);
@@ -350,11 +359,23 @@ public class ChangeInserter {
     return change;
   }
 
-  // TODO(dborowitz): This is only public because callers expect validation to
-  // happen before updating any refs, and they are still updating refs manually.
-  // Make private once we have migrated ref updates into this class.
-  public void validate() throws IOException, InvalidChangeOperationException {
-    if (validated || validatePolicy == CommitValidators.Policy.NONE) {
+  private void updateRef() throws IOException {
+    if (!updateRef) {
+      return;
+    }
+    RefUpdate ru = git.updateRef(patchSet.getRefName());
+    ru.setExpectedOldObjectId(ObjectId.zeroId());
+    ru.setNewObjectId(commit);
+    ru.disableRefLog();
+    if (ru.update(revWalk) != RefUpdate.Result.NEW) {
+      throw new IOException(String.format(
+          "Failed to create ref %s in %s: %s", ru.getRef().getName(),
+          change.getDest().getParentKey().get(), ru.getResult()));
+    }
+  }
+
+  private void validate() throws IOException, InvalidChangeOperationException {
+    if (validatePolicy == CommitValidators.Policy.NONE) {
       return;
     }
     CommitValidators cv =
@@ -386,6 +407,5 @@ public class ChangeInserter {
     } catch (CommitValidationException e) {
       throw new InvalidChangeOperationException(e.getMessage());
     }
-    validated = true;
   }
 }