File : src/aws-response.ads
------------------------------------------------------------------------------
-- Ada Web Server --
-- --
-- Copyright (C) 2000-2003 --
-- ACT-Europe --
-- --
-- Authors: Dmitriy Anisimkov - Pascal Obry --
-- --
-- This library 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. --
-- --
-- This library 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. --
-- --
-- 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. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
------------------------------------------------------------------------------
-- $Id: aws-response.ads,v 1.57 2003/10/08 08:26:40 obry Exp $
-- This package is to be used to build answer to be sent to the client
-- browser. It is also used as the object returned from the client API. So
-- it is either a response built on the server side or the response received
-- on the client side.
with Ada.Strings.Unbounded;
with Ada.Streams;
with Ada.Finalization;
with Ada.Unchecked_Deallocation;
with AWS.Headers;
with AWS.Messages;
with AWS.MIME;
with AWS.Net;
with AWS.Resources.Streams;
with AWS.Status;
package AWS.Response is
use Ada;
type Data is private;
-- Note that this type use a reference counter which is not thread safe.
type Callback is access function (Request : in Status.Data) return Data;
-- This is the Web Server Callback procedure. A client must declare and
-- pass such procedure to the HTTP record.
type Data_Mode is (Header, Message, File, Stream, Socket_Taken, No_Data);
type Authentication_Mode is (Any, Basic, Digest);
-- The authentication mode.
-- "Basic" and "Digest" mean that server must accept the requested
-- authentication mode. "Any" mean that server could accept any
-- authentication from client.
-- Note the order here should not be changed as it is used in AWS.Client.
subtype Content_Length_Type is Integer range -1 .. Integer'Last;
Undefined_Length : constant Content_Length_Type;
-- Undefined length could be used when we do not know the message length
-- at the start of transfer. The end of message could be determined by the
-- chunked transfer-encoding in the HTTP/1.1, or by the closing connection
-- in the HTTP/1.0.
Default_Moved_Message : constant String;
-- This is a template message, _@_ will be replaced by the Location (see
-- function Build with Location below).
Default_Authenticate_Message : constant String;
-- This is the message that will be displayed on the Web Browser if the
-- authentication process fails or is cancelled.
-----------------------
-- Data Constructors --
-----------------------
function Build
(Content_Type : in String;
Message_Body : in String;
Status_Code : in Messages.Status_Code := Messages.S200;
Cache_Control : in Messages.Cache_Option := Messages.Unspecified;
Encoding : in Messages.Content_Encoding := Messages.Identity)
return Data;
function Build
(Content_Type : in String;
UString_Message : in Strings.Unbounded.Unbounded_String;
Status_Code : in Messages.Status_Code := Messages.S200;
Cache_Control : in Messages.Cache_Option := Messages.Unspecified;
Encoding : in Messages.Content_Encoding := Messages.Identity)
return Data;
-- Return a message whose body is passed into Message_Body. The
-- Content_Type parameter is the MIME type for the message
-- body. Status_Code is the response status (see Messages.Status_Code
-- definition).
function Build
(Content_Type : in String;
Message_Body : in Streams.Stream_Element_Array;
Status_Code : in Messages.Status_Code := Messages.S200;
Cache_Control : in Messages.Cache_Option := Messages.Unspecified;
Encoding : in Messages.Content_Encoding := Messages.Identity)
return Data;
-- Idem above, but the message body is a stream element array.
function File
(Content_Type : in String;
Filename : in String;
Status_Code : in Messages.Status_Code := Messages.S200;
Cache_Control : in Messages.Cache_Option := Messages.Unspecified;
Encoding : in Messages.Content_Encoding := Messages.Identity)
return Data;
-- Returns a message whose message body is the content of the file. The
-- Content_Type must indicate the MIME type for the file.
function Stream
(Content_Type : in String;
Handle : access Resources.Streams.Stream_Type'Class;
Status_Code : in Messages.Status_Code := Messages.S200;
Cache_Control : in Messages.Cache_Option := Messages.No_Cache;
Encoding : in Messages.Content_Encoding := Messages.Identity)
return Data;
-- Returns a message whose message body is the content of the user
-- defined stream. The Content_Type must indicate the MIME type for
-- the data stream, Stream_Size the total number of bytes and Status_Code
-- the header status code which should be send back to client's browser.
procedure Create_Resource
(D : in Data;
File : out AWS.Resources.File_Type);
pragma Inline (Create_Resource);
-- Creates the resource object (either a file or in-memory object) for
-- the data to be sent to the client. The resource should be closed after
-- use.
------------------------------
-- Redirection Constructors --
------------------------------
function URL (Location : in String) return Data;
-- This ask the server for a redirection to the specified URL.
function Moved
(Location : in String;
Message : in String := Default_Moved_Message)
return Data;
-- This send back a moved message (Messages.S301) with the specified
-- message body.
------------------------
-- Other Constructors --
------------------------
function Acknowledge
(Status_Code : in Messages.Status_Code;
Message_Body : in String := "";
Content_Type : in String := MIME.Text_HTML)
return Data;
-- Returns a message to the Web browser. This routine must be used to
-- send back an error message to the Web browser. For example if a
-- requested resource cannot be served a message with status code S404
-- must be sent.
function Authenticate
(Realm : in String;
Mode : in Authentication_Mode := Basic;
Stale : in Boolean := False;
Message : in String := Default_Authenticate_Message)
return Data;
-- Returns an authentification message (Messages.S401), the Web browser
-- will then ask for an authentification. Realm string will be displayed
-- by the Web Browser in the authentification dialog box.
function Socket_Taken return Data;
-- Must be used to say that the connection socket has been taken by user
-- inside of user callback. No operations should be performed on this
-- socket, and associated slot should be released for further operations.
function Empty return Data;
-- Returns an empty message (Data_Mode = No_Data and Status_Code is 204).
-- It is used to say that user's handlers were not able to do something
-- with the request. This is used by the callback's chain in the
-- dispatcher and should not be used by users.
--
-- API to retrieve response data
--
------------
-- Header --
------------
function Header
(D : in Data;
Name : in String;
N : in Positive)
return String;
pragma Inline (Header);
-- Return the N-th value for header Name.
function Header
(D : in Data;
Name : in String)
return String;
pragma Inline (Header);
-- Return all values as a comma-separated string for header Name.
-- See [RFC 2616 - 4.2] last paragraph.
procedure Send_Header (Socket : in Net.Socket_Type'Class; D : in Data);
pragma Inline (Send_Header);
-- Send all header lines to the socket.
function Status_Code (D : in Data) return Messages.Status_Code;
pragma Inline (Status_Code);
-- Returns the status code.
function Content_Length (D : in Data) return Content_Length_Type;
pragma Inline (Content_Length);
-- Returns the content length (i.e. the message body length). A value of 0
-- indicate that there is no message body.
function Content_Type (D : in Data) return String;
pragma Inline (Content_Type);
-- Returns the MIME type for the message body.
function Cache_Control (D : in Data) return Messages.Cache_Option;
pragma Inline (Cache_Control);
-- Returns the cache control specified for the response
function Location (D : in Data) return String;
pragma Inline (Location);
-- Returns the location for the new page in the case of a moved
-- message. See Moved constructor above.
----------
-- Data --
----------
function Mode (D : in Data) return Data_Mode;
pragma Inline (Mode);
-- Returns the data mode, either Header, Message or File.
function Message_Body (D : in Data) return String;
pragma Inline (Message_Body);
-- Returns the message body content as a string.
-- Message_Body routines could not be used with user defined streams
-- (see. Stream routine in this package). Constraint_Error would be raised
-- on try to get data by the Message_Body from the user defined streams.
-- For get data from user defined streams routine Create_Resource should
-- be used.
function Message_Body
(D : in Data)
return Strings.Unbounded.Unbounded_String;
-- Returns message body content as an unbounded_string.
function Message_Body (D : in Data) return Streams.Stream_Element_Array;
-- Returns message body as a binary content.
function Filename (D : in Data) return String;
pragma Inline (Filename);
-- Returns the filename which should be sent back.
--------------------
-- Authentication --
--------------------
function Realm (D : in Data) return String;
pragma Inline (Realm);
-- Returns the Realm for the current authentification request.
function Authentication (D : in Data) return Authentication_Mode;
pragma Inline (Authentication);
-- Returns the authentication mode requested by server.
function Authentication_Stale (D : in Data) return Boolean;
pragma Inline (Authentication_Stale);
-- Returns the stale parameter for authentication.
private
use Ada.Strings.Unbounded;
Default_Moved_Message : constant String
:= "Page moved<br><a href=""_@_"">Click here</a>";
CRLF : constant String := ASCII.CR & ASCII.LF;
Default_Authenticate_Message : constant String
:= "<HTML><HEAD>" & CRLF
& "<TITLE>401 Authorization Required</TITLE>" & CRLF
& "</HEAD><BODY>" & CRLF
& "<H1>Authorization Required</H1>" & CRLF
& "This server could not verify that you" & CRLF
& "are authorized to access the document you" & CRLF
& "requested. Either you supplied the wrong" & CRLF
& "credentials (e.g., bad password), or your" & CRLF
& "browser doesn't understand how to supply" & CRLF
& "the credentials required.<P>" & CRLF
& "</BODY></HTML>" & CRLF;
Undefined_Length : constant Content_Length_Type
:= Content_Length_Type (Resources.Undefined_Length);
type Release_Controller is record
Counter : Natural := 1;
-- Data object's Reference counter.
Stream_Taken : Boolean := False;
-- Set to True after Create_Resource routine call to not free stream
-- on finalization.
end record;
type Release_Controller_Access is access all Release_Controller;
type Data is new Ada.Finalization.Controlled with record
Ref_Counter : Release_Controller_Access;
Mode : Data_Mode := No_Data;
Status_Code : Messages.Status_Code := Messages.S200;
Filename : Unbounded_String;
Stream : Resources.Streams.Stream_Access;
Header : AWS.Headers.List;
end record;
procedure Initialize (Object : in out Data);
procedure Adjust (Object : in out Data);
procedure Finalize (Object : in out Data);
procedure Free is new Ada.Unchecked_Deallocation
(Resources.Streams.Stream_Type'Class, Resources.Streams.Stream_Access);
end AWS.Response;