From f6e56309ca2c0f857a671aadf26e0a8a3a1b95e6 Mon Sep 17 00:00:00 2001
From: Dave Borowitz <dborowitz@google.com>
Date: Tue, 17 Mar 2015 14:08:25 -0700
Subject: [PATCH] ListBranches: Handle HEAD and refs/meta/config in the
 Comparator

This simplifies the loop body somewhat as we can just add these refs
wherever. It also avoids extra copying inherent in adding to the front
of the ArrayList.

Factor out a Comparator class as well.

Change-Id: I21b0ca0b4840349cc833f9f6166c1743d80aedcc
---
 .../gerrit/server/project/ListBranches.java   | 49 +++++++++----------
 1 file changed, 24 insertions(+), 25 deletions(-)

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/project/ListBranches.java b/gerrit-server/src/main/java/com/google/gerrit/server/project/ListBranches.java
index 4af0f0af89..689e25fb85 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/project/ListBranches.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/project/ListBranches.java
@@ -16,6 +16,7 @@ package com.google.gerrit.server.project;
 
 import com.google.common.base.Predicate;
 import com.google.common.base.Strings;
+import com.google.common.collect.ComparisonChain;
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.Sets;
 import com.google.gerrit.extensions.common.ActionInfo;
@@ -83,9 +84,6 @@ public class ListBranches implements RestReadView<ProjectResource> {
   public List<BranchInfo> apply(ProjectResource rsrc)
       throws ResourceNotFoundException, IOException, BadRequestException {
     List<BranchInfo> branchList;
-    BranchInfo headBranch = null;
-    BranchInfo configBranch = null;
-
     try (Repository db = repoManager.openRepository(rsrc.getNameKey())) {
       Collection<Ref> heads =
           db.getRefDatabase().getRefs(Constants.R_HEADS).values();
@@ -117,41 +115,23 @@ public class ListBranches implements RestReadView<ProjectResource> {
           }
 
           BranchInfo b = new BranchInfo(ref.getName(), target, false);
+          branchList.add(b);
 
-          if (Constants.HEAD.equals(ref.getName())) {
-            headBranch = b;
-          } else {
+          if (!Constants.HEAD.equals(ref.getName())) {
             b.setCanDelete(targetRefControl.canDelete());
-            branchList.add(b);
           }
           continue;
         }
 
         RefControl refControl = rsrc.getControl().controlForRef(ref.getName());
         if (refControl.isVisible()) {
-          if (RefNames.REFS_CONFIG.equals(ref.getName())) {
-            configBranch = createBranchInfo(ref, refControl, targets);
-          } else {
-            branchList.add(createBranchInfo(ref, refControl, targets));
-          }
+          branchList.add(createBranchInfo(ref, refControl, targets));
         }
       }
     } catch (RepositoryNotFoundException noGitRepository) {
       throw new ResourceNotFoundException();
     }
-    Collections.sort(branchList, new Comparator<BranchInfo>() {
-      @Override
-      public int compare(BranchInfo a, BranchInfo b) {
-        return a.ref.compareTo(b.ref);
-      }
-    });
-    if (configBranch != null) {
-      branchList.add(0, configBranch);
-    }
-    if (headBranch != null) {
-      branchList.add(0, headBranch);
-    }
-
+    Collections.sort(branchList, new BranchComparator());
     FluentIterable<BranchInfo> branches = filterBranches(branchList);
     if (start > 0) {
       branches = branches.skip(start);
@@ -162,6 +142,25 @@ public class ListBranches implements RestReadView<ProjectResource> {
     return branches.toList();
   }
 
+  private static class BranchComparator implements Comparator<BranchInfo> {
+    @Override
+    public int compare(BranchInfo a, BranchInfo b) {
+      return ComparisonChain.start()
+          .compareTrueFirst(isHead(a), isHead(b))
+          .compareTrueFirst(isConfig(a), isConfig(b))
+          .compare(a.ref, b.ref)
+          .result();
+    }
+
+    private static boolean isHead(BranchInfo i) {
+      return Constants.HEAD.equals(i.ref);
+    }
+
+    private static boolean isConfig(BranchInfo i) {
+      return RefNames.REFS_CONFIG.equals(i.ref);
+    }
+  }
+
   private static void addRef(Repository db, List<Ref> refs, String name)
       throws IOException {
     Ref ref = db.getRef(name);