File : adagio-upload-resource.ads


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--                         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    --

--  it under the terms of the GNU General Public License as published by    --

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

--  your option) any later version.                                         --

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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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--  $Id: adagio-upload-resource.ads,v 1.3 2004/01/21 21:05:51 Jano Exp $


--  Uploadable resources.


with Adagio.Safe_access;

with Ada.Finalization;
with Ada.Streams; use Ada.Streams;
use  Ada;

package Adagio.Upload.Resource is

   type Stream_access is access all Root_stream_type'Class;

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

   -- Exceptions                                                         --

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

   -- Some exceptions for resources:

   Malformed_request : exception; -- Recognized but malformed.

   Unavailable       : exception; -- Recognized but not found.

   Unknown           : exception; -- Request with unknown method.


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

   -- Object                                                             --

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

   type Object is abstract new Finalization.Limited_controlled with private;
   type Object_access is access all Object'Class;

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

   -- Handle                                                             --

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

   -- Use this private type to hold Object'Class without need to control it.

   type Handle is private;
   function Create (This : access Object) return Handle;
   function V      (This : in Handle) return Object_access;
   function "+"    (This : in Handle) return Object_access renames V;

   Null_handle : constant Handle;

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

   -- Id                                                                 --

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

   -- Unique id for the resource, will identify it in queues.

   function Id (This : in Object) return String is abstract;

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

   -- Set_position                                                       --

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

   -- Set the starting position for its data. Call it before Stream.

   -- First byte is at 1.

   procedure Set_position (This : in out Object; Position : in Natural) 
      is abstract;

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

   -- Stream                                                             --

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

   -- Get an stream for the resource binary data

   procedure Stream (This : in out Object; Result : out Stream_access) 
   is abstract;

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

   -- Content_type                                                       --

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

   -- Get the corresponding Content-Type: http header for the resource.

   function Content_type (This : in Object) return String is abstract;
      
   ------------------------------------------------------------------------

   -- Name                                                               --

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

   -- Descriptive name of the resource.

   function Name (This : in Object) return String is abstract;

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

   -- Size                                                               --

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

   -- Size in bytes of the resource.

   function Size (This : in Object) return Natural is abstract;
      
   ------------------------------------------------------------------------

   -- Qualify                                                            --

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

   -- Say if a resource qualifies according a criteria string:

   function Qualify (This : in Object; Criteria : in String) return Boolean
   is abstract;

private 

   type Object is abstract new 
      Finalization.Limited_controlled with null record;

   package Safe_object is new Safe_access (
      Object'Class, Object_access, "Upload.Resource");
   type Handle is record
      Internal_handle : Safe_object.Object;
   end record;

   Null_handle : constant Handle := (
      Internal_handle => Safe_object.Null_access);

end Adagio.Upload.Resource;