File : adagio-network-endian.adb
------------------------------------------------------------------------------
-- ADAGIO - ADALID - AENEA. --
-- --
-- Copyright (C) 2003 --
-- A. Mosteo. --
-- --
-- Authors: A. Mosteo. (adagio@mosteo.com) --
-- --
-- If you have any questions in regard to this software, please address --
-- them to the above email. --
-- --
-- This program is free software; you can redistribute it and/or modify --
-- it under the terms of the GNU General Public License as published by --
-- the Free Software Foundation; either version 2 of the License, or (at --
-- your option) any later version. --
-- --
-- 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. --
-- --
-- You should have received a copy of the GNU General Public License --
-- along with this library; if not, write to the Free Software Foundation, --
-- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. --
-- --
-- You are not allowed to use any part of this code to develop a program --
-- whose output would be used to harass or prosecute other users of the --
-- networks Adagio connects with. All data collected with Adagio or a tool --
-- containing Adagio code about other network users must remain --
-- confidential and cannot be made public by any mean, nor be used to --
-- harass or legally prosecute these users. --
------------------------------------------------------------------------------
-- $Id: adagio-network-endian.adb,v 1.3 2004/01/21 21:05:37 Jano Exp $
with Ada.Unchecked_conversion; use Ada;
with Interfaces; use Interfaces;
package body Adagio.Network.Endian is
function to_Unsigned_32 is new Unchecked_conversion (Integer, Unsigned_32);
function to_Integer is new Unchecked_conversion (Unsigned_32, Integer);
function Is_little_endian return boolean is
use type Interfaces.Unsigned_8;
var1: Interfaces.Unsigned_16:= 16#abcd#;
var2: Array(1..2) of Interfaces.Unsigned_8;
for var2'address use var1'address;
pragma Import (Ada, var2);
begin
return var2(1) = 16#cd#;
end Is_little_endian;
-- Convert an arbitrary long byte array to integer in the local endingness
-- May raise Constraint_error if array lengths exceedes integer capacity.
function Convert (
From : Byte_array;
Big_endian : Boolean := true) return Integer is
Aux : Unsigned_32 := 0;
begin
if From'length > 4 then
raise Constraint_error;
end if;
if not Big_endian then
-- If little endian:
for n in reverse From'Range loop
Aux := Shift_left (Aux, 8) or Unsigned_32 (From (n));
end loop;
else
-- Reverse positions:
for n in From'Range loop
Aux := Shift_left (Aux, 8) or Unsigned_32 (From (n));
end loop;
end if;
return Integer (Aux);
end Convert;
function Convert_L (
From : Byte_array;
Big_endian : Boolean := true) return Long_Long_Integer is
Aux : Unsigned_64 := 0;
begin
if From'length > 8 then
raise Constraint_error;
end if;
if not Big_endian then
-- If little endian:
for n in reverse From'Range loop
Aux := Shift_left (Aux, 8) or Unsigned_64 (From (n));
end loop;
else
-- Reverse positions:
for n in From'Range loop
Aux := Shift_left (Aux, 8) or Unsigned_64 (From (n));
end loop;
end if;
return Long_Long_Integer (Aux);
end Convert_L;
-- Converts an integer to an array of bytes, in the desired endianness.
function Convert (
From : Long_Long_Integer;
Big_endian : Boolean := false) return Byte_array is
Aux : Unsigned_64 := Unsigned_64 (From);
Size : Natural := 0;
Result : Byte_array (1 .. 8);
Invert : Byte_array (1 .. 8);
begin
while Aux /= 0 loop
Size := Size + 1;
Result (Size) := Byte (Aux and 16#ff#);
Aux := Shift_right (Aux, 8);
end loop;
if Big_endian then
for N in 1 .. Size loop
Invert (Size + 1 - N) := Result (N);
end loop;
return Invert (1 .. Size);
end if;
return Result (1 .. Size);
end;
-- Converts an integer to an array of bytes, in the desired endianness.
-- Size specified (in bytes):
function Convert (
From : Long_Long_Integer;
Size : Natural;
Big_endian : Boolean := false) return Byte_array is
Aux : Byte_array (1 .. Size) := (others => 0);
Result : Byte_array := Convert (From, Big_endian);
begin
-- Pad if necessary :
if Result'Length < Size then
if Big_endian then
return Aux (1 .. Size - Result'Length) & Result;
else
return Result & Aux (1 .. Size - Result'Length);
end if;
else
return Result;
end if;
end Convert;
-- Converts an integer to an array of bytes, in the desired endianness.
-- Optimally returns the shortest possible array:
function Convert (
From : Integer;
Big_endian : Boolean := false) return Byte_array is
begin
return Convert (Long_long_integer (From), Big_endian);
end Convert;
-- Converts an integer to an array of bytes, in the desired endianness.
-- Size specified (in bytes):
function Convert (
From : Integer;
Size : Natural;
Big_endian : Boolean := false) return Byte_array is
begin
return Convert (Long_long_integer (From), Size, Big_endian);
end Convert;
-- Converts a byte array into a string of same bytes:
function To_string (From : Byte_array) return String is
S : String (From'First .. From'Last);
begin
for N in S'Range loop
S (N) := Character'Val (From (N));
end loop;
return S;
end To_string;
-- Inverse of the previous:
function To_byte_array (From : String) return Byte_array is
B : Byte_array (From'Range);
begin
for N in B'Range loop
B (N) := Byte (Character'Pos (From (N)));
end loop;
return B;
end To_byte_array;
-- Invert a byte_array order
function Invert (From : Byte_array) return Byte_array is
To : Byte_array (From'Range);
Pos : Integer := From'Last;
begin
for N in To'Range loop
To (N) := From (Pos);
Pos := Pos - 1;
end loop;
return To;
end;
begin
Little_endian:= Is_little_endian;
end Adagio.Network.Endian;