enhance: calculate the merge state for history commits in background thread instead of UIThread

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/ViewModels/Histories.cs

@@ -75,7 +75,6 @@ public List<Models.Commit> Commits
             get => _commits;
             set
             {
-                RecalculateMergeState(value);
                 GenerateGraph(value);
                 if (SetProperty(ref _commits, value))
                     PostCommitsChanged();
@@ -511,23 +510,6 @@ private void PostSelectedCommitsChanged()
                 GenerateGraph(_commits);
         }
 
-        private void RecalculateMergeState(List<Models.Commit> commits)
-        {
-            var merged = new HashSet<string>();
-
-            foreach (var commit in commits)
-            {
-                if (merged.Remove(commit.SHA))
-                    commit.IsMerged = true;
-
-                if (commit.IsMerged)
-                {
-                    foreach (var p in commit.Parents)
-                        merged.Add(p);
-                }
-            }
-        }
-
         private void GenerateGraph(List<Models.Commit> commits)
         {
             var firstParentOnly = _repo.UIStates.HistoryShowFlags.HasFlag(Models.HistoryShowFlags.FirstParentOnly);

src/ViewModels/Repository.cs

@@ -1242,6 +1242,19 @@ public void RefreshCommits()
                     .GetResultAsync()
                     .ConfigureAwait(false);
 
+                var merged = new HashSet<string>();
+                foreach (var c in commits)
+                {
+                    if (merged.Remove(c.SHA))
+                        c.IsMerged = true;
+
+                    if (c.IsMerged)
+                    {
+                        foreach (var p in c.Parents)
+                            merged.Add(p);
+                    }
+                }
+
                 Dispatcher.UIThread.Invoke(() =>
                 {
                     if (token.IsCancellationRequested)