Convert PatchSetInserter to use a builder pattern

Instead of multiplying methods based on various parameters, store the
parameters as instance variables in the PatchSetInserter object, and
use a single insert() method with no arguments to do the insertion.
Writing setter methods for each of the "optional arguments" increases
boilerplate slightly, but allows us to do per-argument validation in a
cleanly separated way.

Change-Id: I694c8a1f381d6ba01a31acf904802ea99e8f50e8

gerrit-httpd/src/main/java/com/google/gerrit/httpd/rpc/changedetail/EditCommitMessageHandler.java

@@ -25,7 +25,6 @@ import com.google.gerrit.server.ChangeUtil;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.change.PatchSetInserter;
-import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.git.validators.CommitValidators;
 import com.google.gerrit.server.mail.CommitMessageEditedSender;
@@ -65,7 +64,7 @@ class EditCommitMessageHandler extends Handler<ChangeDetail> {
   private final CommitValidators.Factory commitValidatorsFactory;
   private final GitRepositoryManager gitManager;
   private final PersonIdent myIdent;
-  private final PatchSetInserter patchSetInserter;
+  private final PatchSetInserter.Factory patchSetInserterFactory;
 
   @Inject
   EditCommitMessageHandler(final ChangeControl.Factory changeControlFactory,
@@ -77,7 +76,7 @@ class EditCommitMessageHandler extends Handler<ChangeDetail> {
       final CommitValidators.Factory commitValidatorsFactory,
       final GitRepositoryManager gitManager,
       @GerritPersonIdent final PersonIdent myIdent,
-      final PatchSetInserter patchSetInserter) {
+      final PatchSetInserter.Factory patchSetInserterFactory) {
     this.changeControlFactory = changeControlFactory;
     this.db = db;
     this.currentUser = currentUser;
@@ -88,7 +87,7 @@ class EditCommitMessageHandler extends Handler<ChangeDetail> {
     this.commitValidatorsFactory = commitValidatorsFactory;
     this.gitManager = gitManager;
     this.myIdent = myIdent;
-    this.patchSetInserter = patchSetInserter;
+    this.patchSetInserterFactory = patchSetInserterFactory;
   }
 
   @Override
@@ -114,8 +113,9 @@ class EditCommitMessageHandler extends Handler<ChangeDetail> {
       CommitValidators commitValidators =
           commitValidatorsFactory.create(control.getRefControl(), new NoSshInfo(), git);
 
-      ChangeUtil.editCommitMessage(patchSetId, control.getRefControl(), commitValidators, currentUser, message, db,
+      ChangeUtil.editCommitMessage(patchSetId, control.getRefControl(),
-          commitMessageEditedSenderFactory, git, myIdent, patchSetInserter);
+          commitValidators, currentUser, message, db,
+          commitMessageEditedSenderFactory, git, myIdent, patchSetInserterFactory);
 
       return changeDetailFactory.create(changeId).call();
     } finally {

gerrit-server/src/main/java/com/google/gerrit/server/ChangeUtil.java

@@ -314,7 +314,8 @@ public class ChangeUtil {
       final RefControl refControl, CommitValidators commitValidators,
       final IdentifiedUser user, final String message, final ReviewDb db,
       final CommitMessageEditedSender.Factory commitMessageEditedSenderFactory,
-      Repository git, PersonIdent myIdent, PatchSetInserter patchSetInserter)
+      Repository git, PersonIdent myIdent,
+      PatchSetInserter.Factory patchSetInserterFactory)
       throws NoSuchChangeException, EmailException, OrmException,
       MissingObjectException, IncorrectObjectTypeException, IOException,
       InvalidChangeOperationException, PatchSetInfoNotAvailableException {
@@ -384,8 +385,12 @@ public class ChangeUtil {
           "Patch Set " + newPatchSet.getPatchSetId()
               + ": Commit message was updated";
 
-      change = patchSetInserter.insertPatchSet(git, revWalk, change,
+      change = patchSetInserterFactory
-          newPatchSet, newCommit, refControl, msg, true);
+          .create(git, revWalk, refControl, change, newCommit)
+          .setPatchSet(newPatchSet)
+          .setMessage(msg)
+          .setCopyLabels(true)
+          .insert();
 
       return change.getId();
     } finally {

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

@@ -74,7 +74,7 @@ public class CherryPickChange {
   private final IdentifiedUser currentUser;
   private final CommitValidators.Factory commitValidatorsFactory;
   private final ChangeInserter changeInserter;
-  private final PatchSetInserter patchSetInserter;
+  private final PatchSetInserter.Factory patchSetInserterFactory;
   final MergeUtil.Factory mergeUtilFactory;
 
   @Inject
@@ -83,7 +83,7 @@ public class CherryPickChange {
       final GitRepositoryManager gitManager, final IdentifiedUser currentUser,
       final CommitValidators.Factory commitValidatorsFactory,
       final ChangeInserter changeInserter,
-      final PatchSetInserter patchSetInserter,
+      final PatchSetInserter.Factory patchSetInserterFactory,
       final MergeUtil.Factory mergeUtilFactory) {
     this.patchSetInfoFactory = patchSetInfoFactory;
     this.db = db;
@@ -92,7 +92,7 @@ public class CherryPickChange {
     this.currentUser = currentUser;
     this.commitValidatorsFactory = commitValidatorsFactory;
     this.changeInserter = changeInserter;
-    this.patchSetInserter = patchSetInserter;
+    this.patchSetInserterFactory = patchSetInserterFactory;
     this.mergeUtilFactory = mergeUtilFactory;
   }
 
@@ -223,9 +223,11 @@ public class CherryPickChange {
     } catch (CommitValidationException e) {
       throw new InvalidChangeOperationException(e.getMessage());
     }
-    patchSetInserter.insertPatchSet(git, revWalk, change, newPatchSet,
+    patchSetInserterFactory
-        cherryPickCommit, refControl, buildChangeMessage(patchSetId, change),
+        .create(git, revWalk, refControl, change, cherryPickCommit)
-        false);
+        .setPatchSet(newPatchSet)
+        .setMessage(buildChangeMessage(patchSetId, change))
+        .insert();
     return change.getId();
   }
 

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

@@ -93,6 +93,7 @@ public class Module extends RestApiModule {
         factory(ReviewerResource.Factory.class);
         factory(AccountInfo.Loader.Factory.class);
         factory(EmailReviewComments.Factory.class);
+        factory(PatchSetInserter.Factory.class);
       }
     });
   }

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

@@ -14,6 +14,9 @@
 
 package com.google.gerrit.server.change;
 
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkState;
+
 import com.google.gerrit.common.ChangeHooks;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.ChangeMessage;
@@ -26,11 +29,11 @@ import com.google.gerrit.server.config.TrackingFooters;
 import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
 import com.google.gerrit.server.patch.PatchSetInfoFactory;
 import com.google.gerrit.server.project.InvalidChangeOperationException;
-import com.google.gerrit.server.project.NoSuchChangeException;
 import com.google.gerrit.server.project.RefControl;
 import com.google.gwtorm.server.AtomicUpdate;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.assistedinject.Assisted;
 
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.RefUpdate;
@@ -44,6 +47,11 @@ import java.util.Collections;
 import java.util.List;
 
 public class PatchSetInserter {
+  public static interface Factory {
+    PatchSetInserter create(Repository git, RevWalk revWalk, RefControl refControl,
+        Change change, RevCommit commit);
+  }
+
   private final ChangeHooks hooks;
   private final TrackingFooters trackingFooters;
   private final PatchSetInfoFactory patchSetInfoFactory;
@@ -51,40 +59,75 @@ public class PatchSetInserter {
   private final IdentifiedUser user;
   private final GitReferenceUpdated gitRefUpdated;
 
+  private final Repository git;
+  private final RevWalk revWalk;
+  private final RevCommit commit;
+  private final Change change;
+  private final RefControl refControl;
+
+  private PatchSet patchSet;
+  private ChangeMessage changeMessage;
+  private boolean copyLabels;
+
   @Inject
   public PatchSetInserter(ChangeHooks hooks,
       TrackingFooters trackingFooters,
       ReviewDb db,
       PatchSetInfoFactory patchSetInfoFactory,
       IdentifiedUser user,
-      GitReferenceUpdated gitRefUpdated) {
+      GitReferenceUpdated gitRefUpdated,
+      @Assisted Repository git,
+      @Assisted RevWalk revWalk,
+      @Assisted RefControl refControl,
+      @Assisted Change change,
+      @Assisted RevCommit commit) {
     this.hooks = hooks;
     this.trackingFooters = trackingFooters;
     this.db = db;
     this.patchSetInfoFactory = patchSetInfoFactory;
     this.user = user;
     this.gitRefUpdated = gitRefUpdated;
+
+    this.git = git;
+    this.revWalk = revWalk;
+    this.refControl = refControl;
+    this.change = change;
+    this.commit = commit;
   }
 
-  public Change insertPatchSet(Repository git, RevWalk revWalk,
+  public PatchSetInserter setPatchSet(PatchSet patchSet) {
-      Change change, PatchSet patchSet, RevCommit commit, RefControl refControl,
+    PatchSet.Id psid = patchSet.getId();
-      String message, boolean copyLabels) throws OrmException,
+    checkArgument(psid.getParentKey().equals(change.getId()),
-      InvalidChangeOperationException, NoSuchChangeException, IOException {
+        "patch set %s not for change %s", psid, change.getId());
-    final ChangeMessage cmsg =
+    checkArgument(psid.get() > change.currentPatchSetId().get(),
-        new ChangeMessage(new ChangeMessage.Key(change.getId(),
+        "new patch set ID %s is not greater than current patch set ID %s",
+        psid.get(), change.currentPatchSetId().get());
+    this.patchSet = patchSet;
+    return this;
+  }
+
+  public PatchSetInserter setMessage(String message) throws OrmException {
+    changeMessage = new ChangeMessage(new ChangeMessage.Key(change.getId(),
         ChangeUtil.messageUUID(db)), user.getAccountId(), patchSet.getId());
-    cmsg.setMessage(message);
+    changeMessage.setMessage(message);
-
+    return this;
-    return insertPatchSet(git, revWalk, change, patchSet, commit, refControl,
-        cmsg, copyLabels);
   }
 
-  public Change insertPatchSet(Repository git, RevWalk revWalk,
+  public PatchSetInserter setMessage(ChangeMessage changeMessage) throws OrmException {
-      Change change, final PatchSet patchSet, final RevCommit commit,
+    this.changeMessage = changeMessage;
-      RefControl refControl, ChangeMessage changeMessage, boolean copyLabels)
+    return this;
-      throws OrmException, InvalidChangeOperationException,
+  }
-      NoSuchChangeException, IOException {
 
+  public PatchSetInserter setCopyLabels(boolean copyLabels) {
+    this.copyLabels = copyLabels;
+    return this;
+  }
+
+  public Change insert() throws InvalidChangeOperationException, OrmException,
+      IOException {
+    checkState(patchSet != null, "patch set not set");
+
+    Change updatedChange;
     RefUpdate ru = git.updateRef(patchSet.getRefName());
     ru.setExpectedOldObjectId(ObjectId.zeroId());
     ru.setNewObjectId(commit);
@@ -98,13 +141,6 @@ public class PatchSetInserter {
 
     final PatchSet.Id currentPatchSetId = change.currentPatchSetId();
 
-    if (patchSet.getId().get() <= currentPatchSetId.get()) {
-      throw new InvalidChangeOperationException("New Patch Set ID ["
-          + patchSet.getId().get()
-          + "] is not greater than the current Patch Set ID ["
-          + currentPatchSetId.get() + "]");
-    }
-
     db.changes().beginTransaction(change.getId());
     try {
       if (!db.changes().get(change.getId()).getStatus().isOpen()) {
@@ -115,7 +151,7 @@ public class PatchSetInserter {
       ChangeUtil.insertAncestors(db, patchSet.getId(), commit);
       db.patchSets().insert(Collections.singleton(patchSet));
 
-      Change updatedChange =
+      updatedChange =
           db.changes().atomicUpdate(change.getId(), new AtomicUpdate<Change>() {
             @Override
             public Change update(Change change) {
@@ -135,9 +171,7 @@ public class PatchSetInserter {
               return change;
             }
           });
-      if (updatedChange != null) {
+      if (updatedChange == null) {
-        change = updatedChange;
-      } else {
         throw new ChangeModifiedException(String.format(
             "Change %s was modified", change.getId()));
       }
@@ -159,7 +193,7 @@ public class PatchSetInserter {
     } finally {
       db.rollback();
     }
-    return change;
+    return updatedChange;
   }
 
   public class ChangeModifiedException extends InvalidChangeOperationException {