Replace non-trivial uses of RefDatabase.getRefs with getRefsByPrefix

getRefs returns Map<String, Ref> where the key is the ref name with the
given prefix stripped off. However, getRefsByPrefix returns a list of
Refs with the full refname.

Therefore, when converting to getRefsByPrefix, we have to explicitly
remove the ref prefix from each ref name before using it.

Change-Id: I9a3ecf942ea47325fffa27596265fde217c2af0c

java/com/google/gerrit/server/StarredChangesUtil.java

@@ -296,7 +296,11 @@ public class StarredChangesUtil {
 
   private static Set<String> getRefNames(Repository repo, String prefix) throws IOException {
     RefDatabase refDb = repo.getRefDatabase();
-    return refDb.getRefs(prefix).keySet();
+    return refDb
+        .getRefsByPrefix(prefix)
+        .stream()
+        .map(r -> r.getName().substring(prefix.length()))
+        .collect(toSet());
   }
 
   public ObjectId getObjectId(Account.Id accountId, Change.Id changeId) {

java/com/google/gerrit/server/query/change/ChangeData.java

@@ -1042,12 +1042,12 @@ public class ChangeData {
       editsByUser = new HashMap<>();
       Change.Id id = checkNotNull(change.getId());
       try (Repository repo = repoManager.openRepository(project())) {
-        for (Map.Entry<String, Ref> e :
+        for (Ref ref : repo.getRefDatabase().getRefsByPrefix(RefNames.REFS_USERS)) {
-            repo.getRefDatabase().getRefs(RefNames.REFS_USERS).entrySet()) {
+          String name = ref.getName().substring(RefNames.REFS_USERS.length());
-          if (id.equals(Change.Id.fromEditRefPart(e.getKey()))) {
+          if (id.equals(Change.Id.fromEditRefPart(name))) {
-            Account.Id accountId = Account.Id.fromRefPart(e.getKey());
+            Account.Id accountId = Account.Id.fromRefPart(name);
             if (accountId != null) {
-              editsByUser.put(accountId, e.getValue());
+              editsByUser.put(accountId, ref);
             }
           }
         }

java/com/google/gerrit/server/update/RepoView.java

@@ -16,12 +16,11 @@ package com.google.gerrit.server.update;
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
+import static java.util.stream.Collectors.toMap;
 
-import com.google.common.collect.Maps;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import java.io.IOException;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
 import org.eclipse.jgit.lib.Config;
@@ -133,14 +132,15 @@ public class RepoView {
    *
    * @param prefix ref prefix; must end in '/' or else be empty.
    * @return a map of ref suffixes to SHA-1s. The refs are all under {@code prefix} and have the
-   *     prefix stripped; this matches the behavior of {@link
+   *     prefix stripped.
-   *     org.eclipse.jgit.lib.RefDatabase#getRefs(String)}.
    * @throws IOException if an error occurred.
    */
   public Map<String, ObjectId> getRefs(String prefix) throws IOException {
     Map<String, ObjectId> result =
-        new HashMap<>(
+        repo.getRefDatabase()
-            Maps.transformValues(repo.getRefDatabase().getRefs(prefix), Ref::getObjectId));
+            .getRefsByPrefix(prefix)
+            .stream()
+            .collect(toMap(r -> r.getName().substring(prefix.length()), Ref::getObjectId));
 
     // First, overwrite any cached reads from the underlying RepoRefCache. If any of these differ,
     // it's because a ref was updated after the RepoRefCache read it. It feels a little odd to