57 lines
1.4 KiB
OCaml
57 lines
1.4 KiB
OCaml
module Nat = struct
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include Nativeint
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let ( lxor ) = Nativeint.logxor
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end
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module type BUFFER = sig
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type t
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val length : t -> int
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val sub : t -> int -> int -> t
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val copy : t -> t
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val benat_to_cpu : t -> int -> nativeint
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val cpu_to_benat : t -> int -> nativeint -> unit
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end
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let imin (a : int) (b : int) = if a < b then a else b
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module Make (B : BUFFER) = struct
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let size_of_long = Sys.word_size / 8
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(* XXX(dinosaure): I'm not sure about this code. May be we don't need the
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first loop and the _optimization_ is irrelevant. *)
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let xor_into src src_off dst dst_off n =
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let n = ref n in
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let i = ref 0 in
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while !n >= size_of_long do
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B.cpu_to_benat dst (dst_off + !i)
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Nat.(
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B.benat_to_cpu dst (dst_off + !i)
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lxor B.benat_to_cpu src (src_off + !i)) ;
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n := !n - size_of_long ;
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i := !i + size_of_long
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done ;
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while !n > 0 do
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B.cpu_to_benat dst (dst_off + !i)
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Nat.(
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B.benat_to_cpu src (src_off + !i)
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lxor B.benat_to_cpu dst (dst_off + !i)) ;
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incr i ;
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decr n
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done
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let xor_into a b n =
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if n > imin (B.length a) (B.length b)
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then raise (Invalid_argument "Baijiu.Xor.xor_inrot: buffers to small")
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else xor_into a 0 b 0 n
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let xor a b =
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let l = imin (B.length a) (B.length b) in
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let r = B.copy (B.sub b 0 l) in
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xor_into a r l ;
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r
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end
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module Bytes = Make (Digestif_by)
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module Bigstring = Make (Digestif_bi)
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