--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hedgewars/adler32.pas Sun Jun 20 22:35:10 2010 -0400
@@ -0,0 +1,152 @@
+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 $ifdef
+ 3.05 04.07.07 we BASM16: speed-up factor 15
+ 3.06 12.11.08 we uses BTypes, Ptr2Inc and/or Str255
+ 3.07 25.04.09 we updated RFC URL(s)
+ 3.08 19.07.09 we D12 fix: assign with typecast string(fname)
+**************************************************************************)
+
+(*-------------------------------------------------------------------------
+ (C) Copyright 2002-2009 Wolfgang Ehrhardt
+
+ This software is provided 'as-is', without any express or implied warranty.
+ In no event will the authors be held liable for any damages arising from
+ the use of this software.
+
+ Permission is granted to anyone to use this software for any purpose,
+ including commercial applications, and to alter it and redistribute it
+ freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software in
+ a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+
+ 2. Altered source versions must be plainly marked as such, and must not be
+ misrepresented as being the original software.
+
+ 3. This notice may not be removed or altered from any source distribution.
+----------------------------------------------------------------------------*)
+
+(*
+As per the license above, noting that this implementation of adler32 was stripped of everything we didn't need.
+That means no btypes, file loading, and the assembly version disabled.
+*)
+
+procedure Adler32Update(var adler: longint; Msg: pointer; Len: longint);
+
+implementation
+
+(*
+$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;
+*)
+
+procedure Adler32Update(var adler: longint; Msg: pointer; Len: 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}
+type
+ LH = packed record
+ L,H: word;
+ end;
+var
+ s1,s2: longint;
+ i,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;
+ for i:=1 to n do begin
+ inc(s1, pByte(Msg)^);
+ inc(Msg);
+ inc(s2, s1);
+ end;
+ s1 := s1 mod BASE;
+ s2 := s2 mod BASE;
+ dec(len, n);
+ end;
+ LH(adler).L := word(s1);
+ LH(adler).H := word(s2);
+end;
+
+end.