File : adagio-zutil.adb


------------------------------------------------------------------------------

--                         ADAGIO - ADALID - AENEA.                         --

--                                                                          --

--                            Copyright (C) 2003                            --

--                                 A. Mosteo.                               --

--                                                                          --

--  Authors: A. Mosteo. (adagio@mosteo.com)                                 --

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--  them to the above email.                                                --

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--  This program is free software; you can redistribute it and/or modify    --

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--  the Free Software Foundation; either version 2 of the License, or (at   --

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--  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       --

--  General Public License for more details.                                --

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--  You should have received a copy of the GNU 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.          --

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--  You are not allowed to use any part of this code to develop a program   --

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--  networks Adagio connects with. All data collected with Adagio or a tool --

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------------------------------------------------------------------------------

--  $Id: adagio-zutil.adb,v 1.3 2004/01/21 21:05:43 Jano Exp $


with Ada.Streams; use Ada.Streams;

package body Adagio.Zutil is

   ------------------------------------------------------------------------

   -- Inflate                                                            --

   ------------------------------------------------------------------------

   -- Well try to translate inbound data, and if not enough resulting space,

   -- iteratively will increase the result buffer.

   function Inflate (
      this     : in Stream_element_array; 
      Max_size : in Stream_element_offset := Max_Initial_Size) 
   return Stream_element_array is
      Z : Zlib.Filter_type;

      Result   : Stream_element_array (1 .. Max_size);
      Last_in  : Stream_element_offset;
      Last_out : Stream_element_offset;
   begin
      Zlib.Inflate_init (Z);
      Zlib.Translate (Z, this, Last_in, Result, Last_out, Zlib.Finish); 
      if Last_out = Result'Last then
         Zlib.Close (Z);
         return Inflate (this, Max_size + Increment_Size);
      else
         Zlib.Close (Z);
         return Result (1 .. Last_out);
      end if;
   end Inflate;

   ------------------------------------------------------------------------

   -- Deflate                                                            --

   ------------------------------------------------------------------------

   function Deflate (this : in Stream_element_array) 
      return Stream_element_array is
      Z : Zlib.Filter_type;

      Result   : Stream_element_array (this'Range);
      Last_in  : Stream_element_offset;
      Last_out : Stream_element_offset;
   begin
      Zlib.Deflate_init (Z);
      Zlib.Translate (Z, this, Last_in, Result, Last_out, Zlib.Finish);
      if Last_out = Result'Last then
         raise Cannot_deflate;
         return this;
      else
         Zlib.Close (Z);
         return Result (1 .. Last_out);
      end if;
   exception
      when others =>
         Zlib.Close (Z);
         raise;
   end Deflate;

   procedure Deflate (
      From   : in     Stream_element_array;
      To     : in out Stream_element_array;
      Last   :    out Stream_element_offset) 
   is
      Z : Zlib.Filter_type;
      Last_in  : Stream_element_offset;
   begin
      Zlib.Deflate_init (Z);
      Zlib.Translate (Z, From, Last_in, To, Last, Zlib.Finish);
      if Last = To'Last then
         raise Cannot_deflate;
      else
         Zlib.Close (Z);
      end if;
   exception
      when others =>
         Zlib.Close (Z);
         raise;
   end Deflate;

end Adagio.Zutil;