Mega Code Archive
Using minilzo in delphi
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How to use the miniLZO library written in ANSI C in your delphi application without a dll
Introduction
LZO is a lossless compression algorithm that offers EXTREMELY fast decompression speed while giving you a decent compression ratio. I've read that LZO is twice as fast as ZLib at decompressing while only have about 5% less compression ratio.
miniLZO
Is a library from the author of LZO that includes LZO1X_1 compression and LZO1x decompression. I've compiled it to an .obj file that can be linked into a delphi unit using the {$LINK}/{$L} compiler directive. Below you'll find the complete unit. miniLZO is distributed under the GNU Public License, so naturally this code is GNU licensed too. Note, for detailed instructions on how to USE these functions please visit the official LZO homepage at http://www.oberhumer.com/opensource/lzo/.
//------------------------- BEGIN UNIT -------------------------//
unit Lzo;
interface
// "C" routines needed by the linked LZO OBJ file
function _memcmp (s1,s2: Pointer; numBytes: LongWord): integer; cdecl;
procedure _memcpy (s1, s2: Pointer; n: Integer); cdecl;
procedure _memmove(dstP, srcP: pointer; numBytes: LongWord); cdecl;
procedure _memset (s: Pointer; c: Byte; n: Integer); cdecl;
{$LINK 'minilzo.obj'}
function lzo1x_1_compress(const Source: Pointer; SourceLength: LongWord; Dest: Pointer; var DestLength: LongWord; WorkMem: Pointer): integer; stdcall; external;
function lzo1x_decompress(const Source: Pointer; SourceLength: LongWord; Dest: Pointer; var DestLength: LongWord; WorkMem: Pointer (* NOT USED! *)): Integer; stdcall; external;
function lzo1x_decompress_safe(const Source: Pointer; SourceLength: LongWord; Dest: Pointer; var DestLength: LongWord; WorkMem: Pointer (* NOT USED! *)): Integer; stdcall; external;
function lzo_adler32(Adler: LongWord; const Buf: Pointer; Len: LongWord): LongWord; stdcall; external;
function lzo_version: word; stdcall; external;
function lzo_version_string: PChar; stdcall; external;
function lzo_version_date: PChar; stdcall; external;
implementation
procedure _memset(s: Pointer; c: Byte; n: Integer); cdecl;
begin
FillChar(s^, n, c);
end;
procedure _memcpy(s1, s2: Pointer; n: Integer); cdecl;
begin
Move(s2^, s1^, n);
end;
function _memcmp (s1, s2: Pointer; numBytes: LongWord): integer; cdecl;
var
i: integer;
p1, p2: ^byte;
begin
p1 := s1;
p2 := s2;
for i := 0 to numBytes -1 do
begin
if p1^ <> p2^ then
begin
if p1^ < p2^ then
Result := -1
else
Result := 1;
exit;
end;
inc(p1);
inc(p2);
end;
Result := 0;
end;
procedure _memmove(dstP, srcP: pointer; numBytes: LongWord); cdecl;
begin
Move(srcP^, dstP^, numBytes);
FreeMem(srcP, numBytes);
end;
end.
//------------------------- END UNIT -------------------------//
The C miniLZO source, minilzo.obj and this unit can be downloade from here.
That's it! I appologize for my somtimes bad english and writing style
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