From 4fa77b12785e591a6f463af40d5f6f3adb653968 Mon Sep 17 00:00:00 2001
From: Vincent Bernardoff <vb@luminar.eu.org>
Date: Mon, 24 Oct 2016 19:12:57 +0200
Subject: [PATCH] + Utils.{finalize,read_file,write_file}

---
 src/utils/utils.ml  | 20 ++++++++++++++++++++
 src/utils/utils.mli |  3 +++
 2 files changed, 23 insertions(+)

diff --git a/src/utils/utils.ml b/src/utils/utils.ml
index ef2fe1f48..60988ac6e 100644
--- a/src/utils/utils.ml
+++ b/src/utils/utils.ml
@@ -121,3 +121,23 @@ let rec remove_elem_from_list nb = function
   | [] -> []
   | l when nb <= 0 -> l
   | _ :: tl -> remove_elem_from_list (nb - 1) tl
+
+let finalize f g = try let res = f () in g (); res with exn -> g (); raise exn
+
+let read_file ?(bin=false) fn =
+  let ic = (if bin then open_in_bin else open_in) fn in
+  finalize (fun () ->
+      let len = in_channel_length ic in
+      let buf = Bytes.create len in
+      let nb_read = input ic buf 0 len in
+      if nb_read <> len then failwith (Printf.sprintf "read_file: read %d, expected %d" nb_read len)
+      else Bytes.unsafe_to_string buf)
+    (fun () -> close_in ic)
+
+let write_file ?(bin=false) fn contents =
+  let oc = (if bin then open_out_bin else open_out) fn in
+  finalize (fun () ->
+      let contents = Bytes.unsafe_of_string contents in
+      output oc contents 0 @@ Bytes.length contents
+    )
+    (fun () -> close_out oc)
diff --git a/src/utils/utils.mli b/src/utils/utils.mli
index a027b783f..7cff8939d 100644
--- a/src/utils/utils.mli
+++ b/src/utils/utils.mli
@@ -38,3 +38,6 @@ val remove_elem_from_list: int -> 'a list -> 'a list
 
 val filter_map: ('a -> 'b option) -> 'a list -> 'b list
 
+val finalize: (unit -> 'a) -> (unit -> unit) -> 'a
+val read_file: ?bin:bool -> string -> string
+val write_file: ?bin:bool -> string -> string -> unit