hash.mli

(*
 *	Copyright (C) 2017 Christopher Zimmermann <christopher@gmerlin.de>
 *	Copyright (C) 2006-2009 Vincent Hanquez <tab@snarc.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; version 2.1 or version 3.0 only.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 *)

(** SHA OCaml bindings *)

(** buffer type *)
type buf = (char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t

(** Functor building a complete Digest implementation from Stub functions. *)
module type Stubs =
sig
  (** context type - opaque *)
  type ctx

  (** digest type - opaque *)
  type t

  (** return a binary representation of the given digest *)
  val to_bin : t -> string

  (** length of digest in bits *)
  val digest_length: int

  (** Create a new context *)
  val init: unit -> ctx

  (** unsafe_update_substring ctx s ofs len updates the context
      with the substring of s starting at character number ofs and
      containing len characters. Unsafe: No range checking! *)
  val unsafe_update_substring: ctx -> string -> int -> int -> unit

  val unsafe_update_bigstring: ctx -> buf -> int -> int -> unit

  val update_fd: ctx -> Unix.file_descr -> int -> int

  val file_fast : string -> t

  (** Finalize the context and return digest *)
  val finalize: ctx -> t
end

module type S =
sig
  include Stubs

  (** The zero digest *)
  val zero : t

  (** update_substring ctx s ofs len updates the context with the
      substring of s starting at character number ofs and containing len
      characters. *)
  val update_substring: ctx -> string -> int -> int -> unit

  (** update_string ctx s updates the context with s. *)
  val update_string: ctx -> string -> unit

  val update_bigstring: ctx -> ?pos:int -> ?len:int -> buf -> unit

  (** update_buffer ctx a updates the context with a.
      Runs parallel to other threads if any exist. *)
  val update_buffer: ctx -> buf -> unit

  (** Return an copy of the context *)
  val copy: ctx -> ctx

  (** Return the digest of the given string. *)
  val string : string -> t

  (** substring s ofs len returns the digest of the substring of s starting
      at character number ofs and containing len characters. *)
  val substring : string -> int -> int -> t

  (** Return the digest of the given buffer. *)
  val buffer : buf -> t

  (** If len is nonnegative, channel ic len reads len characters from
      channel ic and returns their digest, or raises End_of_file if end-of-file is
      reached before len characters are read. If len is negative, channel ic
      len reads all characters from ic until end-of-file is reached and return their
      digest. *)
  val channel : in_channel -> int -> t

  (** Return the digest of the file whose name is given. *)
  val file : string -> t

  (** Return the digest of the file whose name is given using fast C function *)
  val file_unbuffered : string -> t

  (** Write a digest on the given output channel. *)
  val output : out_channel -> t -> unit

  (** Read a digest from the given input channel. *)
  val input : in_channel -> t

  (** return a binary representation of the given digest *)
  val to_bin : t -> string

  (** return a printable hexadecimal representation of the given digest *)
  val to_hex : t -> string
end


module Make (Stubs : Stubs) : S with type t = Stubs.t