1 files changed, 34 insertions, 0 deletions
diff --git a/format/packfile/ingest/thin_unresolved.go b/format/packfile/ingest/thin_unresolved.go
new file mode 100644
index 00000000..757cc0e2
--- /dev/null
+++ b/format/packfile/ingest/thin_unresolved.go
@@ -0,0 +1,34 @@
+package ingest
+
+import (
+	"bytes"
+	"slices"
+
+	objectid "codeberg.org/lindenii/furgit/object/id"
+	objecttype "codeberg.org/lindenii/furgit/object/type"
+)
+
+// unresolvedThinBaseIDs returns sorted unique unresolved ref base IDs.
+func unresolvedThinBaseIDs(state *ingestState) []objectid.ObjectID {
+	seen := make(map[objectid.ObjectID]struct{})
+
+	for _, idx := range state.unresolvedRefDeltas {
+		record := state.records[idx]
+		if record.packedType != objecttype.TypeRefDelta {
+			continue
+		}
+
+		seen[record.baseObject] = struct{}{}
+	}
+
+	out := make([]objectid.ObjectID, 0, len(seen))
+	for id := range seen {
+		out = append(out, id)
+	}
+
+	slices.SortFunc(out, func(a, b objectid.ObjectID) int {
+		return bytes.Compare(a.RawBytes(), b.RawBytes())
+	})
+
+	return out
+}