unikernel/duniverse/mirage-flow/src/mirage_flow.ml

@@ -0,0 +1,41 @@
+(*
+ * Copyright (C) 2016-present David Scott <dave.scott@docker.com>
+ * Copyright (c) 2011-present Anil Madhavapeddy <anil@recoil.org>
+ * Copyright (c) 2013-present Thomas Gazagnaire <thomas@gazagnaire.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *)
+
+type write_error = [ `Closed ]
+
+let pp_write_error ppf = function
+  | `Closed -> Fmt.pf ppf "attempted to write to a closed flow"
+
+type 'a or_eof = [`Data of 'a | `Eof ]
+
+let pp_or_eof d ppf = function
+  | `Data a -> d ppf a
+  | `Eof    -> Fmt.string ppf "End-of-file"
+
+module type S = sig
+  type error
+  val pp_error: error Fmt.t
+  type nonrec write_error = private [> write_error ]
+  val pp_write_error: write_error Fmt.t
+  type flow
+  val read: flow -> (Cstruct.t or_eof, error) result Lwt.t
+  val write: flow -> Cstruct.t -> (unit, write_error) result Lwt.t
+  val writev: flow -> Cstruct.t list -> (unit, write_error) result Lwt.t
+  val shutdown : flow -> [ `read | `write | `read_write ] -> unit Lwt.t
+  val close: flow -> unit Lwt.t
+end