Remove loc() called with a variable.
unit Adler32;
{ZLib - Adler32 checksum function}
interface
(*************************************************************************
DESCRIPTION : ZLib - Adler32 checksum function
REQUIREMENTS : TP5-7, D1-D7/D9-D10/D12, FPC, VP
EXTERNAL DATA : ---
MEMORY USAGE : ---
DISPLAY MODE : ---
REFERENCES : RFC 1950 (http://tools.ietf.org/html/rfc1950)
Version Date Author Modification
------- -------- ------- ------------------------------------------
0.10 30.08.03 W.Ehrhardt Initial version based on MD5 layout
2.10 30.08.03 we Common vers., XL versions for Win32
2.20 27.09.03 we FPC/go32v2
2.30 05.10.03 we STD.INC, TP5.0
2.40 10.10.03 we common version, english comments
3.00 01.12.03 we Common version 3.0
3.01 22.05.05 we Adler32UpdateXL (i,n: integer)
3.02 17.12.05 we Force $I- in Adler32File
3.03 07.08.06 we $ifdef BIT32: (const fname: shortstring...)
3.04 10.02.07 we Adler32File: no eof, XL and filemode via $ifdef
3.05 04.07.07 we BASM16: speed-up factor 15
3.06 12.11.08 we uses BTypes, Ptr2Inc and/or Str255
3.07 25.04.09 we updated RFC URL(s)
3.08 19.07.09 we D12 fix: assign with typecast string(fname)
**************************************************************************)
(*-------------------------------------------------------------------------
(C) Copyright 2002-2009 Wolfgang Ehrhardt
This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from
the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software in
a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
----------------------------------------------------------------------------*)
(*
As per the license above, noting that this implementation of adler32 was stripped of everything we didn't need.
That means no btypes, file loading, and the assembly version disabled.
Also, the structure was removed to simplify C conversion
*)
function Adler32Update (var adler : longint; Msg :Pointer; Len :longint ) : longint;
implementation
(*
$ifdef BASM16
procedure Adler32Update(var adler: longint; Msg: pointer; Len: longint);
//-update Adler32 with Msg data
const
BASE = 65521; // max. prime < 65536
NMAX = 5552; // max. n with 255n(n+1)/2 + (n+1)(BASE-1) < 2^32
type
LH = packed record
L,H: word;
end;
var
s1,s2: longint;
n: integer;
begin
s1 := LH(adler).L;
s2 := LH(adler).H;
while Len > 0 do
begin
if Len<NMAX then
n := Len
else
n := NMAX;
//BASM increases speed from about 52 cyc/byte to about 3.7 cyc/byte
asm
mov cx,[n]
db $66; mov ax,word ptr [s1]
db $66; mov di,word ptr [s2]
les si,[msg]
@@1: db $66, $26, $0f, $b6, $1c // movzx ebx,es:[si]
inc si
db $66; add ax,bx // inc(s1, pByte(Msg)^)
db $66; add di,ax // inc(s2, s1
dec cx
jnz @@1
db $66; sub cx,cx
mov cx,BASE
db $66; sub dx,dx
db $66; div cx
db $66; mov word ptr [s1],dx // s1 := s1 mod BASE
db $66; sub dx,dx
db $66; mov ax,di
db $66; div cx
db $66; mov word ptr [s2],dx // s2 := s2 mod BASE
mov word ptr [msg],si // save offset for next chunk
end;
dec(len, n);
end;
LH(adler).L := word(s1);
LH(adler).H := word(s2);
end;
*)
function Adler32Update(var adler:longint; Msg: Pointer; Len :longint) : longint;
{-update Adler32 with Msg data}
const
BASE = 65521; {max. prime < 65536 }
NMAX = 3854; {max. n with 255n(n+1)/2 + (n+1)(BASE-1) < 2^31}
var
s1, s2 : longint;
i, n : integer;
m : PByte;
begin
m := PByte(Msg);
s1 := Longword(adler) and $FFFF;
s2 := Longword(adler) shr 16;
while Len>0 do
begin
if Len<NMAX then
n := Len
else
n := NMAX;
for i := 1 to n do
begin
inc(s1, m^);
inc(m);
inc(s2, s1);
end;
s1 := s1 mod BASE;
s2 := s2 mod BASE;
dec(len, n);
end;
Adler32Update:= (s2 shl 16) or s1;
end;
end.