Merge changes Ibc646fc9,I206f84f3

* changes:
  Use repo from BatchUpdate.Context directly more often
  BatchUpdate: Make repo and RevWalk available to all phases

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

@@ -84,7 +84,6 @@ public class ChangeInserter extends BatchUpdate.InsertChangeOp {
 
   private final RefControl refControl;
   private final IdentifiedUser user;
-  private final Change change;
   private final PatchSet patchSet;
   private final RevCommit commit;
 
@@ -101,6 +100,7 @@ public class ChangeInserter extends BatchUpdate.InsertChangeOp {
   private boolean updateRef;
 
   // Fields set during the insertion process.
+  private Change change;
   private ChangeMessage changeMessage;
   private PatchSetInfo patchSetInfo;
 
@@ -230,9 +230,6 @@ public class ChangeInserter extends BatchUpdate.InsertChangeOp {
   public void updateRepo(RepoContext ctx)
       throws ResourceConflictException, IOException {
     validate(ctx);
-    patchSetInfo = patchSetInfoFactory.get(
-        ctx.getRevWalk(), commit, patchSet.getId());
-    change.setCurrentPatchSet(patchSetInfo);
     if (!updateRef) {
       return;
     }
@@ -242,9 +239,14 @@ public class ChangeInserter extends BatchUpdate.InsertChangeOp {
 
   @Override
   public void updateChange(ChangeContext ctx) throws OrmException, IOException {
+    change = ctx.getChange(); // Use defensive copy created by ChangeControl.
     ReviewDb db = ctx.getDb();
     ChangeControl ctl = ctx.getChangeControl();
     ChangeUpdate update = ctx.getChangeUpdate();
+    patchSetInfo = patchSetInfoFactory.get(
+        ctx.getRevWalk(), commit, patchSet.getId());
+    ctx.getChange().setCurrentPatchSet(patchSetInfo);
+
     if (patchSet.getGroups() == null) {
       patchSet.setGroups(GroupCollector.getDefaultGroups(patchSet));
     }

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

@@ -200,14 +200,13 @@ public class PatchSetInserter extends BatchUpdate.Op {
       throws ResourceConflictException, IOException {
     init();
     validate(ctx);
-    patchSetInfo = patchSetInfoFactory.get(ctx.getRevWalk(), commit, psId);
     ctx.addRefUpdate(new ReceiveCommand(ObjectId.zeroId(),
         commit, getPatchSetId().toRefName(), ReceiveCommand.Type.CREATE));
   }
 
   @Override
   public void updateChange(ChangeContext ctx) throws OrmException,
-      InvalidChangeOperationException {
+      InvalidChangeOperationException, IOException {
     ChangeControl ctl = ctx.getChangeControl();
 
     change = ctx.getChange();
@@ -242,6 +241,7 @@ public class PatchSetInserter extends BatchUpdate.Op {
       changeMessage.setMessage(message);
     }
 
+    patchSetInfo = patchSetInfoFactory.get(ctx.getRevWalk(), commit, psId);
     // TODO(dborowitz): Throw ResourceConflictException instead of using
     // AtomicUpdate.
     change = db.changes().atomicUpdate(id, new AtomicUpdate<Change>() {

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

@@ -42,7 +42,6 @@ import com.google.gerrit.server.change.PublishDraftPatchSet.Input;
 import com.google.gerrit.server.git.BatchUpdate;
 import com.google.gerrit.server.git.BatchUpdate.ChangeContext;
 import com.google.gerrit.server.git.BatchUpdate.Context;
-import com.google.gerrit.server.git.BatchUpdate.RepoContext;
 import com.google.gerrit.server.git.UpdateException;
 import com.google.gerrit.server.mail.CreateChangeSender;
 import com.google.gerrit.server.mail.MailUtil.MailRecipients;
@@ -155,7 +154,6 @@ public class PublishDraftPatchSet implements RestModifyView<RevisionResource, In
     private PatchSet patchSet;
     private Change change;
     private boolean wasDraftChange;
-    private RevCommit commit;
     private PatchSetInfo patchSetInfo;
     private MailRecipients recipients;
 
@@ -164,29 +162,18 @@ public class PublishDraftPatchSet implements RestModifyView<RevisionResource, In
       this.patchSet = patchSet;
     }
 
-    @Override
-    public void updateRepo(RepoContext ctx)
-        throws RestApiException, OrmException, IOException {
-      PatchSet ps = patchSet;
-      if (ps == null) {
-        // Don't save in patchSet, since we're not in a transaction. Here we
-        // just need the revision, which is immutable.
-        ps = ctx.getDb().patchSets().get(psId);
-        if (ps == null) {
-          throw new ResourceNotFoundException(psId.toString());
-        }
-      }
-      commit = ctx.getRevWalk().parseCommit(
-          ObjectId.fromString(ps.getRevision().get()));
-      patchSetInfo = patchSetInfoFactory.get(ctx.getRevWalk(), commit, psId);
-    }
-
     @Override
     public void updateChange(ChangeContext ctx)
-        throws RestApiException, OrmException {
+        throws RestApiException, OrmException, IOException {
       if (!ctx.getChangeControl().canPublish(ctx.getDb())) {
         throw new AuthException("Cannot publish this draft patch set");
       }
+      if (patchSet == null) {
+        patchSet = ctx.getDb().patchSets().get(psId);
+        if (patchSet == null) {
+          throw new ResourceNotFoundException(psId.toString());
+        }
+      }
       saveChange(ctx);
       savePatchSet(ctx);
       addReviewers(ctx);
@@ -204,7 +191,6 @@ public class PublishDraftPatchSet implements RestModifyView<RevisionResource, In
 
     private void savePatchSet(ChangeContext ctx)
         throws RestApiException, OrmException {
-      patchSet = ctx.getDb().patchSets().get(psId);
       if (!patchSet.isDraft()) {
         throw new ResourceConflictException("Patch set is not a draft");
       }
@@ -217,10 +203,15 @@ public class PublishDraftPatchSet implements RestModifyView<RevisionResource, In
       ctx.getDb().patchSets().update(Collections.singleton(patchSet));
     }
 
-    private void addReviewers(ChangeContext ctx) throws OrmException {
+    private void addReviewers(ChangeContext ctx)
+        throws OrmException, IOException {
       LabelTypes labelTypes = ctx.getChangeControl().getLabelTypes();
       Collection<Account.Id> oldReviewers = approvalsUtil.getReviewers(
           ctx.getDb(), ctx.getChangeNotes()).values();
+      RevCommit commit = ctx.getRevWalk().parseCommit(
+          ObjectId.fromString(patchSet.getRevision().get()));
+      patchSetInfo = patchSetInfoFactory.get(ctx.getRevWalk(), commit, psId);
+
       List<FooterLine> footerLines = commit.getFooterLines();
       recipients =
           getRecipientsFromFooters(accountResolver, patchSet, footerLines);

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

@@ -144,7 +144,7 @@ public class RebaseChangeOp extends BatchUpdate.Op {
 
   @Override
   public void updateChange(ChangeContext ctx)
-      throws OrmException, InvalidChangeOperationException {
+      throws OrmException, InvalidChangeOperationException, IOException {
     patchSetInserter.updateChange(ctx);
     rebasedPatchSet = patchSetInserter.getPatchSet();
   }

gerrit-server/src/main/java/com/google/gerrit/server/git/BatchUpdate.java

@@ -102,6 +102,19 @@ public class BatchUpdate implements AutoCloseable {
   }
 
   public class Context {
+    private Repository repoWrapper;
+
+    public Repository getRepository() throws IOException {
+      if (repoWrapper == null) {
+        repoWrapper = new ReadOnlyRepository(BatchUpdate.this.getRepository());
+      }
+      return repoWrapper;
+    }
+
+    public RevWalk getRevWalk() throws IOException {
+      return BatchUpdate.this.getRevWalk();
+    }
+
     public Project.NameKey getProject() {
       return project;
     }
@@ -124,19 +137,13 @@ public class BatchUpdate implements AutoCloseable {
   }
 
   public class RepoContext extends Context {
+    @Override
     public Repository getRepository() throws IOException {
-      initRepository();
-      return repo;
-    }
-
-    public RevWalk getRevWalk() throws IOException {
-      initRepository();
-      return revWalk;
+      return BatchUpdate.this.getRepository();
     }
 
     public ObjectInserter getInserter() throws IOException {
-      initRepository();
-      return inserter;
+      return BatchUpdate.this.getObjectInserter();
     }
 
     public BatchRefUpdate getBatchRefUpdate() throws IOException {

gerrit-server/src/main/java/com/google/gerrit/server/git/ReadOnlyRepository.java

@@ -0,0 +1,170 @@
+// Copyright (C) 2015 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.server.git;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import org.eclipse.jgit.lib.BaseRepositoryBuilder;
+import org.eclipse.jgit.lib.ObjectDatabase;
+import org.eclipse.jgit.lib.ObjectInserter;
+import org.eclipse.jgit.lib.ObjectReader;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.RefDatabase;
+import org.eclipse.jgit.lib.RefRename;
+import org.eclipse.jgit.lib.RefUpdate;
+import org.eclipse.jgit.lib.ReflogReader;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.StoredConfig;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+
+class ReadOnlyRepository extends Repository {
+  private static final String MSG =
+      "Cannot modify a " + ReadOnlyRepository.class.getSimpleName();
+
+  private static BaseRepositoryBuilder<?, ?> builder(Repository r) {
+    checkNotNull(r);
+    return new BaseRepositoryBuilder<>()
+        .setFS(r.getFS())
+        .setGitDir(r.getDirectory())
+        .setWorkTree(r.getWorkTree())
+        .setIndexFile(r.getIndexFile());
+  }
+
+  private final Repository delegate;
+  private final RefDb refdb;
+  private final ObjDb objdb;
+
+  ReadOnlyRepository(Repository delegate) {
+    super(builder(delegate));
+    this.delegate = delegate;
+    this.refdb = new RefDb(delegate.getRefDatabase());
+    this.objdb = new ObjDb(delegate.getObjectDatabase());
+  }
+
+  @Override
+  public void create(boolean bare) throws IOException {
+    throw new UnsupportedOperationException(MSG);
+  }
+
+  @Override
+  public ObjectDatabase getObjectDatabase() {
+    return objdb;
+  }
+
+  @Override
+  public RefDatabase getRefDatabase() {
+    return refdb;
+  }
+
+  @Override
+  public StoredConfig getConfig() {
+    return delegate.getConfig();
+  }
+
+  @Override
+  public void scanForRepoChanges() throws IOException {
+    delegate.scanForRepoChanges();
+  }
+
+  @Override
+  public void notifyIndexChanged() {
+    delegate.notifyIndexChanged();
+  }
+
+  @Override
+  public ReflogReader getReflogReader(String refName) throws IOException {
+    return delegate.getReflogReader(refName);
+  }
+
+  private static class RefDb extends RefDatabase {
+    private final RefDatabase delegate;
+
+    private RefDb(RefDatabase delegate) {
+      this.delegate = checkNotNull(delegate);
+    }
+
+    @Override
+    public void create() throws IOException {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public void close() {
+      delegate.close();
+    }
+
+    @Override
+    public boolean isNameConflicting(String name) throws IOException {
+      return delegate.isNameConflicting(name);
+    }
+
+    @Override
+    public RefUpdate newUpdate(String name, boolean detach) throws IOException {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public RefRename newRename(String fromName, String toName)
+        throws IOException {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public Ref getRef(String name) throws IOException {
+      return delegate.getRef(name);
+    }
+
+    @Override
+    public Map<String, Ref> getRefs(String prefix) throws IOException {
+      return delegate.getRefs(prefix);
+    }
+
+    @Override
+    public List<Ref> getAdditionalRefs() throws IOException {
+      return delegate.getAdditionalRefs();
+    }
+
+    @Override
+    public Ref peel(Ref ref) throws IOException {
+      return delegate.peel(ref);
+    }
+  }
+
+  private static class ObjDb extends ObjectDatabase {
+    private final ObjectDatabase delegate;
+
+    private ObjDb(ObjectDatabase delegate) {
+      this.delegate = checkNotNull(delegate);
+    }
+
+    @Override
+    public ObjectInserter newInserter() {
+      throw new UnsupportedOperationException(MSG);
+    }
+
+    @Override
+    public ObjectReader newReader() {
+      return delegate.newReader();
+    }
+
+    @Override
+    public void close() {
+      delegate.close();
+    }
+  }
+}