apLib.pas

(*
 * aPLib compression library  -  the smaller the better :)
 *
 * Delphi aPLib wrapper for example
 *
 * Copyright (c) 1998-2004 by Joergen Ibsen / Jibz
 * All Rights Reserved
 *
 * http://www.ibsensoftware.com/
 *
 * -> Delphi by Solodovnikov Alexey 21.03.1999 (alenka@mail.line.ru)
 *)

unit aPLib;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
//(*$IFDEF DYNAMIC_VERSION*)
//  aPLibud;
//(*$ELSE*)
  aPLibu;
//(*$ENDIF*)

const
  aP_pack_break    : DWORD = 0;
  aP_pack_continue : DWORD = 1;

  aPLib_Error      : DWORD = DWORD(-1); (* indicates error compressing/decompressing *)

type

  TaPLib = class(TComponent)
  private
    FWorkMem      : Pointer;
    FLength       : DWORD;
    FSource       : Pointer;
    FDestination  : Pointer;

  protected

  public

    CallBack      : TaPack_Status;

    procedure Pack;
    procedure DePack;

    property  Source      : Pointer  read FSource       write FSource;
    property  Destination : Pointer  read FDestination  write FDestination;
    property  Length      : DWORD    read FLength       write FLength;

  published

  end;

  procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('Samples', [TaPLib]);
end;

procedure TaPLib.Pack;
begin
  if FDestination <> nil then
  begin
     FreeMem(FDestination);
     FDestination := nil;
  end;

  if FWorkMem <> nil then
  begin
     FreeMem(FWorkMem);
     FWorkMem := nil;
  end;

  GetMem(FDestination,_aP_max_packed_size(FLength));
  if FDestination = nil then raise Exception.Create('Out of memory');

  GetMem(FWorkMem,_aP_workmem_size(FLength));
  if FWorkMem = nil then raise Exception.Create('Out of memory');

  FLength := _aPsafe_pack(FSource^, FDestination^, FLength, FWorkMem^, CallBack, nil);

  if FLength = aPLib_Error then raise Exception.Create('Compression error');
end;

procedure TaPLib.DePack;
var
  DLength : DWORD;
begin
  if FDestination <> nil then
  begin
     FreeMem(FDestination);
     FDestination := nil;
  end;

  DLength := _aPsafe_get_orig_size(FSource^);
  if DLength = aPLib_Error then raise Exception.Create('File is not packed with aPLib');

  Getmem(FDestination, DLength);
  if FDestination = nil then raise Exception.Create('Out of memory');

  FLength := _aPsafe_depack(FSource^, FLength, FDestination^, DLength);

  if FLength = aPLib_Error then raise Exception.Create('Decompression error');
end;

end.