format: Move commitgraph and packfile here

1 files changed, 27 insertions, 0 deletions

diff --git a/format/packfile/ingest/hash.go b/format/packfile/ingest/hash.go
new file mode 100644
index 00000000..4b739c20
--- /dev/null
+++ b/format/packfile/ingest/hash.go
@@ -0,0 +1,27 @@
+package ingest
+
+import (
+	"fmt"
+
+	objectheader "codeberg.org/lindenii/furgit/object/header"
+	objectid "codeberg.org/lindenii/furgit/object/id"
+	objecttype "codeberg.org/lindenii/furgit/object/type"
+)
+
+// hashCanonicalObject hashes canonical object bytes (header+content).
+func hashCanonicalObject(algo objectid.Algorithm, ty objecttype.Type, content []byte) (objectid.ObjectID, error) {
+	header, ok := objectheader.Encode(ty, int64(len(content)))
+	if !ok {
+		return objectid.ObjectID{}, fmt.Errorf("packfile/ingest: encode object header for type %d", ty)
+	}
+
+	hashImpl, err := algo.New()
+	if err != nil {
+		return objectid.ObjectID{}, err
+	}
+
+	_, _ = hashImpl.Write(header)
+	_, _ = hashImpl.Write(content)
+
+	return objectid.FromBytes(algo, hashImpl.Sum(nil))
+}