ocaml calls

file: crc32.ml

(* C implementation *)
external crc32fast : Unix.file_descr -> int -> Int32.t = "caml_crc32"

file: testcrc.ml

		| "fast" ->
			fun file ->
				let fd = Unix.openfile file [Unix.O_RDONLY] 0o644 in
				let sum = Crc32.crc32fast fd p.size in
				Unix.close fd;
				sum