Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

improves the peformance of the byte patterns matcher (1/3) #1404

Merged
merged 1 commit into from
Jan 15, 2022
Merged

improves the peformance of the byte patterns matcher (1/3) #1404

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
36 changes: 17 additions & 19 deletions plugins/patterns/patterns_main.ml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -658,17 +658,13 @@ end

module Pattern : sig
type t
type field

val create : string -> t
val empty : t
val equal : t -> t -> bool
val concat : t -> t -> t
val length : t -> int
val weight : t -> int
val nth : field -> t -> int -> int
val bits : field
val mask : field
val matches : t -> pos:int -> int -> bool
val pp : Format.formatter -> t -> unit
end = struct
Expand Down Expand Up @@ -744,22 +740,30 @@ end = struct

type t = {
repr : string;
bits : Z.t;
mask : Z.t;
bits : int array;
mask : int array;
pops : int;
size : int;
} [@@deriving equal]

type field = t -> Z.t

let nth_byte size x n =
let off = (size / 8 - n - 1) * 8 in
Z.to_int @@
Z.(x asr off land of_int 0xff)

let create repr =
let {Parser.size; bits; mask} = Parser.run repr in
{bits; mask; size; pops = Z.popcount mask; repr}
let pops = Z.popcount mask in
let bits = Array.init (size/8) ~f:(nth_byte size bits) in
let mask = Array.init (size/8) ~f:(nth_byte size mask) in
{bits; mask; size; pops; repr}

let empty = {
repr = "";
bits = Z.zero;
mask = Z.zero;
bits = [||];
mask = [||];
pops = 0;
size = 0;
}
Expand All @@ -772,21 +776,15 @@ end = struct

let concat x y = {
repr = x.repr ^ y.repr;
bits = Z.(x.bits lsl y.size lor y.bits);
mask = Z.(x.mask lsl y.size lor y.mask);
bits = Array.append x.bits y.bits;
mask = Array.append x.mask y.mask;
pops = x.pops + y.pops;
size = x.size + y.size;
}

let nth what x n =
let off = (x.size / 8 - n - 1) * 8 in
Z.to_int @@
Z.(what x asr off land of_int 0xff)

let matches x ~pos:n data =
let mask = nth mask x n
and bits = nth bits x n in
data land mask = bits
let matches {mask; bits} ~pos:n data =
data land mask.(n) = bits.(n)

let pp ppf {repr} =
Format.fprintf ppf "%s" repr
Expand Down