src/timestamp.ml

@@ -0,0 +1,46 @@
+type t = Ptime.t option
+
+(* microseconds since the UNIX Epoch, or "never" if None *)
+let jsont =
+  let number_or_never_jsont =
+    let never =
+      let dec s =
+        match s with
+        | "never" -> None
+        | _ -> Jsont.Error.msg Jsont.Meta.none "unexpected string value"
+      in
+      let enc = function None -> "never" | _ -> assert false in
+      Jsont.map ~dec ~enc Jsont.string
+    in
+    let number =
+      let dec n = Ptime.of_float_s n in
+      let enc = function Some n -> Ptime.to_float_s n | _ -> assert false in
+      Jsont.map ~dec ~enc Jsont.number
+    in
+    let enc = function None -> never | Some _ -> number in
+    Jsont.any ~dec_string:never ~dec_number:number ~enc ()
+  in
+  let make t = t in
+  Jsont.Object.map ~kind:"Timestamp" make
+  |> Jsont.Object.mem "t_s" number_or_never_jsont ~enc:Fun.id
+  |> Jsont.Object.finish
+
+(* TODO exn *)
+let ptime_to_int64 ptime = ptime |> Ptime.to_float_s |> Int64.of_float
+
+let ptime_of_int64 i =
+  match Ptime.of_float_s (Int64.to_float i) with
+  | None -> Fmt.failwith "ptime_of_int64 error: `%Ld` is not a valid ptime" i
+  | Some ts -> ts
+
+let encode_int64 = function None -> Int64.max_int | Some p -> ptime_to_int64 p
+let decode_int64 i = if i = Int64.max_int then None else Some (ptime_of_int64 i)
+
+(* UINT64_MAX represents "never". *)
+let bin = Bin.map Bin.neint64 decode_int64 encode_int64
+let bin_nbo = Bin.map Bin.beint64 decode_int64 encode_int64
+
+let caqti : Ptime.t option Caqti_type.t =
+  let encode v = Ok (encode_int64 v) in
+  let decode v = Ok (decode_int64 v) in
+  Caqti_type.custom ~encode ~decode Caqti_type.int64