Add verbose statistics for Schema 130 & 131

Migration to Schemas 130 and 131 are quite heavy and may take
a long time to complete. With extra statistics on the number of
repositories actually impacted is going to be easier to plan
the migration up-front.

Change-Id: I5586c912001122bee61ef1ec4e03a46334bb5c10

gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_131.java

@@ -30,6 +30,9 @@ import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Repository;
 
 import java.io.IOException;
+import java.util.SortedSet;
+import java.util.TreeSet;
+import java.util.stream.Collectors;
 
 public class Schema_131 extends SchemaVersion {
   private static final String COMMIT_MSG =
@@ -49,7 +52,10 @@ public class Schema_131 extends SchemaVersion {
 
   @Override
   protected void migrateData(ReviewDb db, UpdateUI ui) throws OrmException {
-    for (Project.NameKey projectName : repoManager.list()) {
+    SortedSet<Project.NameKey> repoList = repoManager.list();
+    SortedSet<Project.NameKey> repoUpgraded = new TreeSet<>();
+    ui.message("\tMigrating " + repoList.size() + " repositories ...");
+    for (Project.NameKey projectName : repoList) {
       try (Repository git = repoManager.openRepository(projectName);
           MetaDataUpdate md = new MetaDataUpdate(GitReferenceUpdated.DISABLED,
               projectName, git)) {
@@ -59,10 +65,16 @@ public class Schema_131 extends SchemaVersion {
           md.getCommitBuilder().setCommitter(serverUser);
           md.setMessage(COMMIT_MSG);
           config.commit(md);
+          repoUpgraded.add(projectName);
         }
       } catch (ConfigInvalidException | IOException ex) {
         throw new OrmException("Cannot migrate project " + projectName, ex);
       }
     }
+    ui.message("\tMigration completed:  " + repoUpgraded.size()
+        + " repositories updated:");
+    ui.message("\t"
+        + repoUpgraded.stream().map(n -> n.get())
+            .collect(Collectors.joining(" ")));
   }
 }