Add database and FUSE mapping

trovedb/db.py

@@ -86,6 +86,13 @@ class Sqlite3Trove:
     # CRUD operations
     # ------------------------------------------------------------------
 
+    def get_object_type(self, object_id: int) -> str | None:
+        """Return the type column for an object, or None if not found."""
+        row = self._con.execute(
+            "SELECT type FROM objects WHERE id = ?", (object_id,)
+        ).fetchone()
+        return row["type"] if row else None
+
     def read_object(self, object_id: int) -> bytes | None:
         """Return raw data for a blob object, or None if not found."""
         row = self._con.execute(
@@ -104,6 +111,14 @@ class Sqlite3Trove:
             return None
         return bytes(row["value"]) if row["value"] is not None else b""
 
+    def write_metadata(self, object_id: int, key: str, value: bytes) -> None:
+        """Upsert a metadata row. db.py has no write_metadata, so we go direct."""
+        self._con.execute(
+            "INSERT OR REPLACE INTO metadata (id, key, value) VALUES (?, ?, ?)",
+            (object_id, key, value),
+        )
+        self._con.commit()
+
     def _write_object(self, data: bytes, dtype: str, object_id: int | None = None) -> int:
         """
         Insert or replace an object. Returns the id.
@@ -117,6 +132,7 @@ class Sqlite3Trove:
                 (dtype, data, modified)
             )
             self._con.commit()
+            assert cur.lastrowid is not None
             return cur.lastrowid
         else:
             self._con.execute(
@@ -126,12 +142,16 @@ class Sqlite3Trove:
             self._con.commit()
             return object_id
 
-    def write_blob(self, data: bytes, existing_id: int | None = None) -> int:
+    def write_blob(self, data: bytes, object_id: int | None = None) -> int:
         """
         Insert or replace a blob. Returns the id.
-        Pass existing_id to update an existing object.
+        Pass object_id to update an existing object.
         """
-        return self._write_object(data, "blob", existing_id)
+        return self._write_object(data, "blob", object_id)
+
+    def write_tree(self, data: bytes, object_id: int | None = None) -> int:
+        """Write a tree-typed object. Returns the assigned id."""
+        return self._write_object(data, "tree", object_id)
 
     def delete_object(self, object_id: int) -> bool:
         """