[lazarus] PasZlib still

[A.J. Venter]

I am still unable to get paszlib to work. 

I have since gone to some pretty big lengths toward my goal, but I am afraid I 
am stuck.
I think the ideal way would be to be able to read the file into a TMemstream, 
decompress it into another Tmemstream and then write that out, but I must 
admit I have no idea how to go about achieving that.

So considering that, for the moment I decided that I may have made a mistake 
in my code conversions, so I fell back on minigz's own code virtually 
unaltered, but wrapped inside a component.

All I get is that when I call the extract method - the program throws:
TApplication.HandleException Access violation
  Stack trace:
  $40489AE0  GZ_EXTRACT_finalize_implicit,  line 54 of gtkglobals.pp

What does an error in finalize MEAN ?

I did an strace on the program, and it certainly reads and writes a LOT of 
data once you trigger the method, so SOMETHING is happening before the crash.

I attach my full source code this time, if somebody would like to see the 
trace I will mail that offlist as it is likely to be huge.

I urgently need to get this working to do transparent decompression for 
OpenBook on windows (calling gunzip only works where gunzip works well).

Ciao
A.J.
-- 
A.J. Venter
Chief Software Architext
OpenLab International
www.getopenlab.com
www.silentcoder.co.za
+27 82 726 5103

{ Copyright (C) 2006 A.J. Venter

  This library is free software; you can redistribute it and/or modify it
  under the terms of the GNU Library 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 Library General Public License
  for more details.

  You should have received a copy of the GNU Library 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.
}
unit gz_extract;
{Note - you must add turbopoweripro to your project requirements for
this to work}
{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils,Process,zutil,gzIo, Forms, Controls, Graphics, Dialogs;
  
Type
    TGZ_Extractor = class(TComponent)
                private
                FInputFile : String;
                FOutPutFile : String;
                public
                destructor destroy; override;
                Procedure Extract;
                published
                property InputFile : String write FInputFile;
                property OutPutFile : String write FOutPutFile;
                constructor create(AOwner: TComponent); override;
     end;

procedure register;

Implementation
{TGZ_Extractor}

const
  BUFLEN       = 16384 ;
  GZ_SUFFIX    = '.gz' ;
  
{$DEFINE MAXSEF_64K}

var
  buf  : packed array [0..BUFLEN-1] of byte; { Global uses BSS instead of stack }
  prog : string;


procedure error (msg:string);
begin
showMessage(msg);
end;


procedure Register;
begin
  RegisterComponents('OLPack',[TGZ_Extractor]);
end;


procedure gz_uncompress (infile:gzFile; var outfile:file);
var
  len     : int;
  written : uInt;
  ioerr   : integer;
  err     : int;
begin
  while true do begin

    len := gzread (infile, @buf, BUFLEN);
    if (len < 0)
      then error (gzerror (infile, err));
    if (len = 0)
      then break;

    {$I-}
    blockwrite (outfile, buf, len, written);
    {$I+}
    if (written <> len)
      then error ('write error');

  end; {WHILE}

  {$I-}
  close (outfile);
  {$I+}
  ioerr := IOResult;
  if (ioerr <> 0) then begin
    writeln ('close error: ',ioerr);
    halt(1);
  end;

  if (gzclose (infile) <> 0{Z_OK})
    then error ('gzclose error');
end;

procedure file_uncompress (filename,outname:String);
var
  inname  : string;
  infile  : gzFile;
  outfile : file;
  ioerr   : integer;
  len     : integer;
begin
  len := Length(filename);

    inname := filename;

  infile := gzopen (inname, 'r');
  if (infile = NIL) then begin
    writeln (prog,': can''t gzopen ',inname);
    halt(1);
  end;

  Assign (outfile, outname);
  {$I-}
  Rewrite (outfile,1);
  {$I+}
  ioerr := IOResult;
  if (ioerr <> 0) then begin
    writeln ('open error: ',ioerr);
    halt(1);
  end;

  gz_uncompress (infile, outfile);

end;


Procedure TGZ_Extractor.Extract;
Begin
   File_UnCompress(FInputFile,FOutPutFile);
end;



destructor TGZ_Extractor.destroy;
Begin

end;

constructor TGZ_Extractor.create(AOwner: TComponent);
begin
  inherited create(AOwner);
end;

end.