Remove NotesMigration from AbstractChangeNotes.Args

Eliminate non-NoteDb conditions from subclasses. The only remaining
thing that's not quite related to the NoteDb migration is the
failOnLoadForTest mechanism, which was wedged into the NotesMigration
since it was a convenient piece of global state. Replace this with an
equally ugly piece of global state, a simple AtomicBoolean, punting for
now on a better approach.

Change-Id: I186744413ef9b263c5c6cabe19c3e5297230974f

java/com/google/gerrit/acceptance/AbstractDaemonTest.java

@@ -112,6 +112,7 @@ import com.google.gerrit.server.index.change.ChangeIndex;
 import com.google.gerrit.server.index.change.ChangeIndexCollection;
 import com.google.gerrit.server.index.change.ChangeIndexer;
 import com.google.gerrit.server.index.group.GroupIndexer;
+import com.google.gerrit.server.notedb.AbstractChangeNotes;
 import com.google.gerrit.server.notedb.ChangeNoteUtil;
 import com.google.gerrit.server.notedb.ChangeNotes;
 import com.google.gerrit.server.notedb.MutableNotesMigration;
@@ -293,6 +294,7 @@ public abstract class AbstractDaemonTest {
   @Inject private AccountIndexer accountIndexer;
   @Inject private Groups groups;
   @Inject private GroupIndexer groupIndexer;
+  @Inject private AbstractChangeNotes.Args changeNotesArgs;
 
   private ProjectResetter resetter;
   private List<Repository> toClose;
@@ -837,12 +839,12 @@ public abstract class AbstractDaemonTest {
   }
 
   protected Context disableDb() {
-    notesMigration.setFailOnLoadForTest(true);
+    changeNotesArgs.failOnLoadForTest.set(true);
     return atrScope.disableDb();
   }
 
   protected void enableDb(Context preDisableContext) {
-    notesMigration.setFailOnLoadForTest(false);
+    changeNotesArgs.failOnLoadForTest.set(false);
     atrScope.set(preDisableContext);
   }
 

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

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.server.notedb;
 
-import static com.google.common.base.Preconditions.checkState;
 import static com.google.gerrit.server.notedb.NoteDbTable.CHANGES;
 import static java.util.Objects.requireNonNull;
 
@@ -34,6 +33,7 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
+import java.util.concurrent.atomic.AtomicBoolean;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Ref;
@@ -44,8 +44,10 @@ public abstract class AbstractChangeNotes<T> {
   @VisibleForTesting
   @Singleton
   public static class Args {
+    // TODO(dborowitz): Some less smelly way of disabling NoteDb in tests.
+    public final AtomicBoolean failOnLoadForTest;
+
     final GitRepositoryManager repoManager;
-    final NotesMigration migration;
     final AllUsersName allUsers;
     final ChangeNoteJson changeNoteJson;
     final LegacyChangeNoteRead legacyChangeNoteRead;
@@ -60,15 +62,14 @@ public abstract class AbstractChangeNotes<T> {
     @Inject
     Args(
         GitRepositoryManager repoManager,
-        NotesMigration migration,
         AllUsersName allUsers,
         ChangeNoteJson changeNoteJson,
         LegacyChangeNoteRead legacyChangeNoteRead,
         NoteDbMetrics metrics,
         Provider<ReviewDb> db,
         Provider<ChangeNotesCache> cache) {
+      this.failOnLoadForTest = new AtomicBoolean();
       this.repoManager = repoManager;
-      this.migration = migration;
       this.allUsers = allUsers;
       this.legacyChangeNoteRead = legacyChangeNoteRead;
       this.changeNoteJson = changeNoteJson;
@@ -132,8 +133,7 @@ public abstract class AbstractChangeNotes<T> {
       return self();
     }
 
-    checkState(args.migration.readChanges(), "NoteDb is required to read changes");
+    if (args.failOnLoadForTest.get()) {
-    if (args.migration.failOnLoadForTest()) {
       throw new OrmException("Reading from NoteDb is disabled");
     }
     try (Timer1.Context timer = args.metrics.readLatency.start(CHANGES);
@@ -181,8 +181,6 @@ public abstract class AbstractChangeNotes<T> {
   public ObjectId loadRevision() throws OrmException {
     if (loaded) {
       return getRevision();
-    } else if (!args.migration.readChanges()) {
-      return null;
     }
     try (Repository repo = args.repoManager.openRepository(getProjectName())) {
       Ref ref = repo.getRefDatabase().exactRef(getRefName());

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

@@ -120,9 +120,6 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
         throws OrmException {
       Change change = readOneReviewDbChange(db, changeId);
       if (change == null) {
-        if (!args.migration.readChanges()) {
-          throw new NoSuchChangeException(changeId);
-        }
         // Change isn't in ReviewDb, but its primary storage might be in NoteDb.
         // Prepopulate the change exists with proper noteDbState field.
         change = newNoteDbOnlyChange(project, changeId);
@@ -159,10 +156,7 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
       Change change = readOneReviewDbChange(db, changeId);
 
       if (change == null) {
-        if (args.migration.readChanges()) {
+        return newNoteDbOnlyChange(project, changeId);
-          return newNoteDbOnlyChange(project, changeId);
-        }
-        throw new NoSuchChangeException(changeId);
       }
       checkArgument(
           change.getProject().equals(project),
@@ -198,33 +192,15 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
       return new ChangeNotes(args, change, true, refs).load();
     }
 
-    // TODO(ekempin): Remove when database backend is deleted
-    /**
-     * Instantiate ChangeNotes for a change that has been loaded by a batch read from the database.
-     */
-    private ChangeNotes createFromChangeOnlyWhenNoteDbDisabled(Change change) throws OrmException {
-      checkState(
-          !args.migration.readChanges(),
-          "do not call createFromChangeWhenNoteDbDisabled when NoteDb is enabled");
-      return new ChangeNotes(args, change).load();
-    }
-
     public List<ChangeNotes> create(ReviewDb db, Collection<Change.Id> changeIds)
         throws OrmException {
       List<ChangeNotes> notes = new ArrayList<>();
-      if (args.migration.readChanges()) {
+      for (Change.Id changeId : changeIds) {
-        for (Change.Id changeId : changeIds) {
+        try {
-          try {
+          notes.add(createChecked(changeId));
-            notes.add(createChecked(changeId));
+        } catch (NoSuchChangeException e) {
-          } catch (NoSuchChangeException e) {
+          // Ignore missing changes to match Access#get(Iterable) behavior.
-            // Ignore missing changes to match Access#get(Iterable) behavior.
-          }
         }
-        return notes;
-      }
-
-      for (Change c : ReviewDbUtil.unwrapDb(db).changes().get(changeIds)) {
-        notes.add(createFromChangeOnlyWhenNoteDbDisabled(c));
       }
       return notes;
     }
@@ -236,28 +212,16 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
         Predicate<ChangeNotes> predicate)
         throws OrmException {
       List<ChangeNotes> notes = new ArrayList<>();
-      if (args.migration.readChanges()) {
+      for (Change.Id cid : changeIds) {
-        for (Change.Id cid : changeIds) {
+        try {
-          try {
+          ChangeNotes cn = create(db, project, cid);
-            ChangeNotes cn = create(db, project, cid);
+          if (cn.getChange() != null && predicate.test(cn)) {
-            if (cn.getChange() != null && predicate.test(cn)) {
-              notes.add(cn);
-            }
-          } catch (NoSuchChangeException e) {
-            // Match ReviewDb behavior, returning not found; maybe the caller learned about it from
-            // a dangling patch set ref or something.
-            continue;
-          }
-        }
-        return notes;
-      }
-
-      for (Change c : ReviewDbUtil.unwrapDb(db).changes().get(changeIds)) {
-        if (c != null && project.equals(c.getDest().getParentKey())) {
-          ChangeNotes cn = createFromChangeOnlyWhenNoteDbDisabled(c);
-          if (predicate.test(cn)) {
             notes.add(cn);
           }
+        } catch (NoSuchChangeException e) {
+          // Match ReviewDb behavior, returning not found; maybe the caller learned about it from
+          // a dangling patch set ref or something.
+          continue;
         }
       }
       return notes;
@@ -267,22 +231,13 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
         ReviewDb db, Predicate<ChangeNotes> predicate) throws IOException, OrmException {
       ListMultimap<Project.NameKey, ChangeNotes> m =
           MultimapBuilder.hashKeys().arrayListValues().build();
-      if (args.migration.readChanges()) {
+      for (Project.NameKey project : projectCache.all()) {
-        for (Project.NameKey project : projectCache.all()) {
+        try (Repository repo = args.repoManager.openRepository(project)) {
-          try (Repository repo = args.repoManager.openRepository(project)) {
+          scan(repo, project)
-            scan(repo, project)
+              .filter(r -> !r.error().isPresent())
-                .filter(r -> !r.error().isPresent())
+              .map(ChangeNotesResult::notes)
-                .map(ChangeNotesResult::notes)
+              .filter(predicate)
-                .filter(predicate)
+              .forEach(n -> m.put(n.getProjectName(), n));
-                .forEach(n -> m.put(n.getProjectName(), n));
-          }
-        }
-      } else {
-        for (Change change : ReviewDbUtil.unwrapDb(db).changes().all()) {
-          ChangeNotes notes = createFromChangeOnlyWhenNoteDbDisabled(change);
-          if (predicate.test(notes)) {
-            m.put(change.getProject(), notes);
-          }
         }
       }
       return ImmutableListMultimap.copyOf(m);
@@ -594,9 +549,7 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
   protected void onLoad(LoadHandle handle) throws NoSuchChangeException, IOException {
     ObjectId rev = handle.id();
     if (rev == null) {
-      if (args.migration.readChanges()
+      if (PrimaryStorage.of(change) == PrimaryStorage.NOTE_DB && shouldExist) {
-          && PrimaryStorage.of(change) == PrimaryStorage.NOTE_DB
-          && shouldExist) {
         throw new NoSuchChangeException(getChangeId());
       }
       loadDefaults();