(*****************************************************************************)
(* *)
(* Open Source License *)
(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com> *)
(* *)
(* Permission is hereby granted, free of charge, to any person obtaining a *)
(* copy of this software and associated documentation files (the "Software"),*)
(* to deal in the Software without restriction, including without limitation *)
(* the rights to use, copy, modify, merge, publish, distribute, sublicense, *)
(* and/or sell copies of the Software, and to permit persons to whom the *)
(* Software is furnished to do so, subject to the following conditions: *)
(* *)
(* The above copyright notice and this permission notice shall be included *)
(* in all copies or substantial portions of the Software. *)
(* *)
(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *)
(* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *)
(* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*)
(* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *)
(* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *)
(* DEALINGS IN THE SOFTWARE. *)
(* *)
(*****************************************************************************)
module type QTY = sig
val id : string
end
module type S = sig
type qty
type error +=
| Addition_overflow of qty * qty (* `Temporary *)
| Subtraction_underflow of qty * qty (* `Temporary *)
| Multiplication_overflow of qty * int64 (* `Temporary *)
| Negative_multiplicator of qty * int64 (* `Temporary *)
| Invalid_divisor of qty * int64
(* `Temporary *)
val id : string
val zero : qty
val one_mutez : qty
val one_cent : qty
val fifty_cents : qty
val one : qty
val ( -? ) : qty -> qty -> qty tzresult
val ( +? ) : qty -> qty -> qty tzresult
val ( *? ) : qty -> int64 -> qty tzresult
val ( /? ) : qty -> int64 -> qty tzresult
val to_mutez : qty -> int64
(** [of_mutez n] (micro tez) is None if n is negative *)
val of_mutez : int64 -> qty option
(** [of_mutez_exn n] fails if n is negative.
It should only be used at toplevel for constants. *)
val of_mutez_exn : int64 -> qty
(** It should only be used at toplevel for constants. *)
val add_exn : qty -> qty -> qty
(** It should only be used at toplevel for constants. *)
val mul_exn : qty -> int -> qty
val encoding : qty Data_encoding.t
val to_int64 : qty -> int64
include Compare.S with type t := qty
val pp : Format.formatter -> qty -> unit
val of_string : string -> qty option
val to_string : qty -> string
end
module Make (T : QTY) : S = struct
type qty = int64 (* invariant: positive *)
type error +=
| Addition_overflow of qty * qty (* `Temporary *)
| Subtraction_underflow of qty * qty (* `Temporary *)
| Multiplication_overflow of qty * int64 (* `Temporary *)
| Negative_multiplicator of qty * int64 (* `Temporary *)
| Invalid_divisor of qty * int64
(* `Temporary *)
include Compare.Int64
let zero = 0L
(* all other constant are defined from the value of one micro tez *)
let one_mutez = 1L
let one_cent = Int64.mul one_mutez 10_000L
let fifty_cents = Int64.mul one_cent 50L
(* 1 tez = 100 cents = 1_000_000 mutez *)
let one = Int64.mul one_cent 100L
let id = T.id
let of_string s =
let triplets = function
| hd :: tl ->
let len = String.length hd in
Compare.Int.(
len <= 3 && len > 0
&& List.for_all (fun s -> String.length s = 3) tl)
| [] ->
false
in
let integers s = triplets (String.split_on_char ',' s) in
let decimals s =
let l = String.split_on_char ',' s in
if Compare.Int.(List.length l > 2) then false else triplets (List.rev l)
in
let parse left right =
let remove_commas s = String.concat "" (String.split_on_char ',' s) in
let pad_to_six s =
let len = String.length s in
String.init 6 (fun i -> if Compare.Int.(i < len) then s.[i] else '0')
in
try
Some
(Int64.of_string
(remove_commas left ^ pad_to_six (remove_commas right)))
with _ -> None
in
match String.split_on_char '.' s with
| [left; right] ->
if String.contains s ',' then
if integers left && decimals right then parse left right else None
else if
Compare.Int.(String.length right > 0)
&& Compare.Int.(String.length right <= 6)
then parse left right
else None
| [left] ->
if (not (String.contains s ',')) || integers left then parse left ""
else None
| _ ->
None
let pp ppf amount =
let mult_int = 1_000_000L in
let rec left ppf amount =
let (d, r) = (Int64.(div amount 1000L), Int64.(rem amount 1000L)) in
if d > 0L then Format.fprintf ppf "%a%03Ld" left d r
else Format.fprintf ppf "%Ld" r
in
let right ppf amount =
let triplet ppf v =
if Compare.Int.(v mod 10 > 0) then Format.fprintf ppf "%03d" v
else if Compare.Int.(v mod 100 > 0) then
Format.fprintf ppf "%02d" (v / 10)
else Format.fprintf ppf "%d" (v / 100)
in
let (hi, lo) = (amount / 1000, amount mod 1000) in
if Compare.Int.(lo = 0) then Format.fprintf ppf "%a" triplet hi
else Format.fprintf ppf "%03d%a" hi triplet lo
in
let (ints, decs) =
(Int64.(div amount mult_int), Int64.(to_int (rem amount mult_int)))
in
Format.fprintf ppf "%a" left ints ;
if Compare.Int.(decs > 0) then Format.fprintf ppf ".%a" right decs
let to_string t = Format.asprintf "%a" pp t
let ( - ) t1 t2 = if t2 <= t1 then Some (Int64.sub t1 t2) else None
let ( -? ) t1 t2 =
match t1 - t2 with
| None ->
error (Subtraction_underflow (t1, t2))
| Some v ->
ok v
let ( +? ) t1 t2 =
let t = Int64.add t1 t2 in
if t < t1 then error (Addition_overflow (t1, t2)) else ok t
let ( *? ) t m =
let open Compare.Int64 in
let open Int64 in
let rec step cur pow acc =
if cur = 0L then ok acc
else
pow +? pow
>>? fun npow ->
if logand cur 1L = 1L then
acc +? pow >>? fun nacc -> step (shift_right_logical cur 1) npow nacc
else step (shift_right_logical cur 1) npow acc
in
if m < 0L then error (Negative_multiplicator (t, m))
else
match step m t 0L with
| Ok res ->
Ok res
| Error ([Addition_overflow _] as errs) ->
Error (Multiplication_overflow (t, m) :: errs)
| Error errs ->
Error errs
let ( /? ) t d =
if d <= 0L then error (Invalid_divisor (t, d)) else ok (Int64.div t d)
let add_exn t1 t2 =
let t = Int64.add t1 t2 in
if t <= 0L then invalid_arg "add_exn" else t
let mul_exn t m =
match t *? Int64.(of_int m) with
| Ok v ->
v
| Error _ ->
invalid_arg "mul_exn"
let of_mutez t = if t < 0L then None else Some t
let of_mutez_exn x =
match of_mutez x with None -> invalid_arg "Qty.of_mutez" | Some v -> v
let to_int64 t = t
let to_mutez t = t
let encoding =
let open Data_encoding in
check_size 10 (conv Z.of_int64 (Json.wrap_error Z.to_int64) n)
let () =
let open Data_encoding in
register_error_kind
`Temporary
~id:(T.id ^ ".addition_overflow")
~title:("Overflowing " ^ T.id ^ " addition")
~pp:(fun ppf (opa, opb) ->
Format.fprintf
ppf
"Overflowing addition of %a %s and %a %s"
pp
opa
T.id
pp
opb
T.id)
~description:("An addition of two " ^ T.id ^ " amounts overflowed")
(obj1 (req "amounts" (tup2 encoding encoding)))
(function Addition_overflow (a, b) -> Some (a, b) | _ -> None)
(fun (a, b) -> Addition_overflow (a, b)) ;
register_error_kind
`Temporary
~id:(T.id ^ ".subtraction_underflow")
~title:("Underflowing " ^ T.id ^ " subtraction")
~pp:(fun ppf (opa, opb) ->
Format.fprintf
ppf
"Underflowing subtraction of %a %s and %a %s"
pp
opa
T.id
pp
opb
T.id)
~description:("An subtraction of two " ^ T.id ^ " amounts underflowed")
(obj1 (req "amounts" (tup2 encoding encoding)))
(function Subtraction_underflow (a, b) -> Some (a, b) | _ -> None)
(fun (a, b) -> Subtraction_underflow (a, b)) ;
register_error_kind
`Temporary
~id:(T.id ^ ".multiplication_overflow")
~title:("Overflowing " ^ T.id ^ " multiplication")
~pp:(fun ppf (opa, opb) ->
Format.fprintf
ppf
"Overflowing multiplication of %a %s and %Ld"
pp
opa
T.id
opb)
~description:
("A multiplication of a " ^ T.id ^ " amount by an integer overflowed")
(obj2 (req "amount" encoding) (req "multiplicator" int64))
(function Multiplication_overflow (a, b) -> Some (a, b) | _ -> None)
(fun (a, b) -> Multiplication_overflow (a, b)) ;
register_error_kind
`Temporary
~id:(T.id ^ ".negative_multiplicator")
~title:("Negative " ^ T.id ^ " multiplicator")
~pp:(fun ppf (opa, opb) ->
Format.fprintf
ppf
"Multiplication of %a %s by negative integer %Ld"
pp
opa
T.id
opb)
~description:
("Multiplication of a " ^ T.id ^ " amount by a negative integer")
(obj2 (req "amount" encoding) (req "multiplicator" int64))
(function Negative_multiplicator (a, b) -> Some (a, b) | _ -> None)
(fun (a, b) -> Negative_multiplicator (a, b)) ;
register_error_kind
`Temporary
~id:(T.id ^ ".invalid_divisor")
~title:("Invalid " ^ T.id ^ " divisor")
~pp:(fun ppf (opa, opb) ->
Format.fprintf
ppf
"Division of %a %s by non positive integer %Ld"
pp
opa
T.id
opb)
~description:
("Multiplication of a " ^ T.id ^ " amount by a non positive integer")
(obj2 (req "amount" encoding) (req "divisor" int64))
(function Invalid_divisor (a, b) -> Some (a, b) | _ -> None)
(fun (a, b) -> Invalid_divisor (a, b))
end