Merge pull request #103 from avsm/fsync-op

add Uring.fsync and Uring.fdatasync ops

Author: avsm

lib/uring/uring.ml

@@ -333,6 +333,8 @@ module Uring = struct
   external submit_unlinkat : t -> id -> Unix.file_descr -> Sketch.ptr -> bool -> bool = "ocaml_uring_submit_unlinkat" [@@noalloc]
   external submit_send_msg : t -> id -> Unix.file_descr -> Msghdr.t -> Sketch.ptr -> bool = "ocaml_uring_submit_send_msg" [@@noalloc]
   external submit_recv_msg : t -> id -> Unix.file_descr -> Msghdr.t -> Sketch.ptr -> bool = "ocaml_uring_submit_recv_msg" [@@noalloc]
+  external submit_fsync : t -> id -> Unix.file_descr -> int64 -> int -> bool = "ocaml_uring_submit_fsync" [@@noalloc]
+  external submit_fdatasync : t -> id -> Unix.file_descr -> int64 -> int -> bool = "ocaml_uring_submit_fdatasync" [@@noalloc]
 
   type cqe_option = private
     | Cqe_none
@@ -555,6 +557,12 @@ let recv_msg t fd msghdr user_data =
       let iovec = Sketch.Iovec.alloc t.sketch buffers in
       Uring.submit_recv_msg t.uring id fd msghdr iovec) user_data ~extra_data:msghdr
 
+let fsync t ?(off=0L) ?(len=0) fd user_data =
+  with_id t (fun id -> Uring.submit_fsync t.uring id fd off len) user_data
+
+let fdatasync t ?(off=0L) ?(len=0) fd user_data =
+  with_id t (fun id -> Uring.submit_fdatasync t.uring id fd off len) user_data
+
 let cancel t job user_data =
   ignore (Heap.ptr job : Uring.id);  (* Check it's still valid *)
   with_id t (fun id -> Uring.submit_cancel t.uring id (Heap.ptr job)) user_data

lib/uring/uring.mli

@@ -607,6 +607,16 @@ val recv_msg : 'a t -> Unix.file_descr -> Msghdr.t -> 'a -> 'a job option
 (** [recv_msg t fd msghdr d] will submit a [recvmsg(2)] request. If the request is
     successful then the [msghdr] will contain the sender address and the data received. *)
 
+val fsync : 'a t -> ?off:int64 -> ?len:int -> Unix.file_descr -> 'a -> 'a job option
+(** [fsync t ?off ?len fd d] will submit an [fsync(2)] request, with the optional
+    offset [off] and length [len] specifying the subset of the file to perform the
+    synchronisation on. *)
+
+val fdatasync : 'a t -> ?off:int64 -> ?len:int -> Unix.file_descr -> 'a -> 'a job option
+(** [fdatasync t ?off ?len fd d] will submit an [fdatasync(2)] request, with the optional
+    offset [off] and length [len] specifying the subset of the file to perform the
+    synchronisation on. *)
+
 (** {2 Probing}
 
     You can check which operations are supported by the running kernel. *)

lib/uring/uring_stubs.c

@@ -849,6 +849,32 @@ ocaml_uring_submit_unlinkat(value v_uring, value v_id, value v_fd, value v_sketc
   return (Val_true);
 }
 
+value /* noalloc */
+ocaml_uring_submit_fsync(value v_uring, value v_id, value v_fd, value v_off, value v_len)
+{
+  struct io_uring *ring = Ring_val(v_uring);
+  struct io_uring_sqe *sqe = io_uring_get_sqe(ring);
+  if (!sqe) return (Val_false);
+  io_uring_prep_fsync(sqe, Int_val(v_fd), 0);
+  sqe->off = Int64_val(v_off);
+  sqe->len = Int_val(v_len);
+  io_uring_sqe_set_data(sqe, (void *)Long_val(v_id));
+  return (Val_true);
+}
+
+value /* noalloc */
+ocaml_uring_submit_fdatasync(value v_uring, value v_id, value v_fd, value v_off, value v_len)
+{
+  struct io_uring *ring = Ring_val(v_uring);
+  struct io_uring_sqe *sqe = io_uring_get_sqe(ring);
+  if (!sqe) return (Val_false);
+  io_uring_prep_fsync(sqe, Int_val(v_fd), IORING_FSYNC_DATASYNC);
+  sqe->off = Int64_val(v_off);
+  sqe->len = Int_val(v_len);
+  io_uring_sqe_set_data(sqe, (void *)Long_val(v_id));
+  return (Val_true);
+}
+
 value /* noalloc */
 ocaml_uring_submit_cancel(value v_uring, value v_id, value v_target) {
   struct io_uring *ring = Ring_val(v_uring);

tests/main.md

@@ -184,6 +184,22 @@ val fd : Unix.file_descr = <abstr>
   x.st_kind, Printf.sprintf "0o%o" x.st_perm, x.st_size;;
 - : Unix.file_kind * string * int = (Unix.S_REG, "0o600", 9)
 
+# Uring.fsync t fd `Create;;
+- : [ `Create ] Uring.job option = Some <abstr>
+# Uring.submit t;;
+- : int = 1
+# let v, read = consume t;;
+val v : [ `Create ] = `Create
+val read : int = 0
+
+# Uring.fdatasync t ~off:1L ~len:5 fd `Create;;
+- : [ `Create ] Uring.job option = Some <abstr>
+# Uring.submit t;;
+- : int = 1
+# let v, read = consume t;;
+val v : [ `Create ] = `Create
+val read : int = 0
+
 # let fd : unit = Unix.close fd;;
 val fd : unit = ()