add load from file

src/asset.ml

@@ -0,0 +1,25 @@
+open! Import
+include (val Ohlog.sublogs logger "asset")
+
+exception Error of string * string
+
+let load_file path =
+  trace (fun m -> m "open text file %S" path);
+  let abspath =
+    Unix.realpath
+      (Printf.sprintf "assets/%s" path)
+  in
+  let fd =
+    try Unix.openfile abspath [O_RDONLY] 0
+    with Unix.Unix_error (ENOENT, _, _) ->
+      raise (Error (path, "not found"))
+  in
+  let len = (Unix.fstat fd).st_size in
+  let buf = Bytes.create len in
+  trace (fun m -> m "length=%d" len);
+  let rec read i =
+    match Unix.read fd buf i (len - i) with
+    | 0 -> Unix.close fd; i
+    | n -> read (i + n)
+  in
+  Bytes.sub_string buf 0 (read 0)