Make MergeSuperSet not a singleton

The plan is to add per-instance caching to improve performance.

Change-Id: I5f086adf4cc24eb2075091641d24f751d8f816be

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/change/SubmitResolvingMergeCommitIT.java

@@ -30,6 +30,7 @@ import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gerrit.testutil.ConfigSuite;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Provider;
 
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
@@ -47,7 +48,7 @@ import java.util.List;
 @NoHttpd
 public class SubmitResolvingMergeCommitIT extends AbstractDaemonTest {
   @Inject
-  private MergeSuperSet mergeSuperSet;
+  private Provider<MergeSuperSet> mergeSuperSet;
 
   @Inject
   private Submit submit;
@@ -293,7 +294,7 @@ public class SubmitResolvingMergeCommitIT extends AbstractDaemonTest {
       throws MissingObjectException, IncorrectObjectTypeException, IOException,
       OrmException {
     ChangeSet cs =
-        mergeSuperSet.completeChangeSet(db, change.change(), user(admin));
+        mergeSuperSet.get().completeChangeSet(db, change.change(), user(admin));
     assertThat(submit.unmergeableChanges(cs).isEmpty()).isEqualTo(expected);
   }
 

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

@@ -134,7 +134,7 @@ public class Submit implements RestModifyView<RevisionResource, SubmitInput>,
   private final ChangeMessagesUtil cmUtil;
   private final ChangeNotes.Factory changeNotesFactory;
   private final Provider<MergeOp> mergeOpProvider;
-  private final MergeSuperSet mergeSuperSet;
+  private final Provider<MergeSuperSet> mergeSuperSet;
   private final AccountsCollection accounts;
   private final ChangesCollection changes;
   private final String label;
@@ -154,7 +154,7 @@ public class Submit implements RestModifyView<RevisionResource, SubmitInput>,
       ChangeMessagesUtil cmUtil,
       ChangeNotes.Factory changeNotesFactory,
       Provider<MergeOp> mergeOpProvider,
-      MergeSuperSet mergeSuperSet,
+      Provider<MergeSuperSet> mergeSuperSet,
       AccountsCollection accounts,
       ChangesCollection changes,
       @GerritServerConfig Config cfg,
@@ -345,7 +345,7 @@ public class Submit implements RestModifyView<RevisionResource, SubmitInput>,
 
     ChangeSet cs;
     try {
-      cs = mergeSuperSet.completeChangeSet(
+      cs = mergeSuperSet.get().completeChangeSet(
           db, cd.change(), resource.getControl().getUser());
     } catch (OrmException | IOException e) {
       throw new OrmRuntimeException("Could not determine complete set of " +

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

@@ -54,7 +54,7 @@ public class SubmittedTogether implements RestReadView<ChangeResource> {
   private final ChangeJson.Factory json;
   private final Provider<ReviewDb> dbProvider;
   private final Provider<InternalChangeQuery> queryProvider;
-  private final MergeSuperSet mergeSuperSet;
+  private final Provider<MergeSuperSet> mergeSuperSet;
   private final Provider<WalkSorter> sorter;
 
   @Option(name = "-o", usage = "Output options")
@@ -66,7 +66,7 @@ public class SubmittedTogether implements RestReadView<ChangeResource> {
   SubmittedTogether(ChangeJson.Factory json,
       Provider<ReviewDb> dbProvider,
       Provider<InternalChangeQuery> queryProvider,
-      MergeSuperSet mergeSuperSet,
+      Provider<MergeSuperSet> mergeSuperSet,
       Provider<WalkSorter> sorter) {
     this.json = json;
     this.dbProvider = dbProvider;
@@ -96,7 +96,7 @@ public class SubmittedTogether implements RestReadView<ChangeResource> {
 
       if (c.getStatus().isOpen()) {
         ChangeSet cs =
-            mergeSuperSet.completeChangeSet(
+            mergeSuperSet.get().completeChangeSet(
                 dbProvider.get(), c, resource.getControl().getUser());
         cds = cs.changes().asList();
         hidden = cs.nonVisibleChanges().size();

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

@@ -39,7 +39,6 @@ import com.google.gerrit.server.query.change.InternalChangeQuery;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
-import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
@@ -69,7 +68,6 @@ import java.util.Set;
  * If change.submitWholeTopic is enabled, also all changes of the topic
  * and their parents are included.
  */
-@Singleton
 public class MergeSuperSet {
   private static final Logger log = LoggerFactory.getLogger(MergeOp.class);