From 9b09e70f5e9896fa74563fbfaa4f385836d0dbb7 Mon Sep 17 00:00:00 2001
From: Benjamin Canou <benjamin@canou.fr>
Date: Thu, 7 Dec 2017 14:31:28 +0100
Subject: [PATCH] Utils: add `Ring.clear`

---
 src/lib_stdlib/ring.ml  | 6 ++++++
 src/lib_stdlib/ring.mli | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/src/lib_stdlib/ring.ml b/src/lib_stdlib/ring.ml
index f57d98f33..a7a633652 100644
--- a/src/lib_stdlib/ring.ml
+++ b/src/lib_stdlib/ring.ml
@@ -40,6 +40,12 @@ let add_and_return_erased r v =
           None in
   add r v ; replaced
 
+let clear r =
+  match !r with
+  | Empty _ -> ()
+  | Inited { data ; _ } ->
+      r := Empty (Array.length data)
+
 let add_list r l = List.iter (add r) l
 
 let last r =
diff --git a/src/lib_stdlib/ring.mli b/src/lib_stdlib/ring.mli
index e67670f19..69b684588 100644
--- a/src/lib_stdlib/ring.mli
+++ b/src/lib_stdlib/ring.mli
@@ -27,6 +27,9 @@ val add_and_return_erased : 'a t -> 'a -> 'a option
 (** Adds the values of a list, in order. *)
 val add_list : 'a t -> 'a list -> unit
 
+(** Removes all values in the ring buffer. *)
+val clear : 'a t -> unit
+
 (** Retrieves the most recent value, or [None] when empty. *)
 val last : 'a t -> 'a option