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251 | ------------------------------------------------------------------------------
-- --
-- Matreshka Project --
-- --
-- SQL Database Access --
-- --
-- Runtime Library Component --
-- --
------------------------------------------------------------------------------
-- --
-- Copyright © 2011-2013, Vadim Godunko <vgodunko@gmail.com> --
-- All rights reserved. --
-- --
-- Redistribution and use in source and binary forms, with or without --
-- modification, are permitted provided that the following conditions --
-- are met: --
-- --
-- * Redistributions of source code must retain the above copyright --
-- notice, this list of conditions and the following disclaimer. --
-- --
-- * Redistributions in binary form must reproduce the above copyright --
-- notice, this list of conditions and the following disclaimer in the --
-- documentation and/or other materials provided with the distribution. --
-- --
-- * Neither the name of the Vadim Godunko, IE nor the names of its --
-- contributors may be used to endorse or promote products derived from --
-- this software without specific prior written permission. --
-- --
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS --
-- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT --
-- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR --
-- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT --
-- HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, --
-- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED --
-- TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR --
-- PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF --
-- LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING --
-- NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS --
-- SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. --
-- --
------------------------------------------------------------------------------
-- $Revision: 3753 $ $Date: 2013-02-11 09:50:52 +0400 (Пн, 11 фев 2013) $
------------------------------------------------------------------------------
with Ada.Containers.Hashed_Maps;
with Ada.Unchecked_Deallocation;
with League.Strings.Hash;
with Matreshka.Internals.SQL_Drivers.Dummy;
package body Matreshka.Internals.SQL_Drivers is
package Maps is
new Ada.Containers.Hashed_Maps
(League.Strings.Universal_String,
Factory_Access,
League.Strings.Hash,
League.Strings."=");
Factories : Maps.Map;
------------
-- Create --
------------
function Create
(Driver : League.Strings.Universal_String)
return not null Database_Access is
begin
if Factories.Contains (Driver) then
return Factories.Element (Driver).Create;
else
return Dummy.Empty_Database'Access;
end if;
end Create;
-----------------
-- Dereference --
-----------------
procedure Dereference (Self : in out Database_Access) is
procedure Free is
new Ada.Unchecked_Deallocation
(Abstract_Database'Class, Database_Access);
begin
if Self /= Dummy.Empty_Database'Access
and then Matreshka.Atomics.Counters.Decrement (Self.Counter)
then
Self.Finalize;
Free (Self);
else
Self := null;
end if;
end Dereference;
-----------------
-- Dereference --
-----------------
procedure Dereference (Self : in out Query_Access) is
procedure Free is
new Ada.Unchecked_Deallocation (Abstract_Query'Class, Query_Access);
begin
if Self /= Dummy.Empty_Query'Access
and then Matreshka.Atomics.Counters.Decrement (Self.Counter)
then
Self.Finalize;
Free (Self);
else
Self := null;
end if;
end Dereference;
--------------
-- Finalize --
--------------
not overriding procedure Finalize (Self : not null access Abstract_Query) is
begin
Abstract_Query'Class (Self.all).Invalidate;
end Finalize;
----------------
-- Initialize --
----------------
procedure Initialize
(Self : not null access Abstract_Query'Class;
Database : not null Database_Access) is
begin
Self.Database := Database;
Reference (Self.Database);
if Self.Database.Head = null then
-- Insert first item into the list.
Self.Previous := null;
Self.Next := null;
Self.Database.Head := Query_Access (Self);
Self.Database.Tail := Query_Access (Self);
else
-- Insert into the not empty list.
Self.Previous := Self.Database.Tail;
Self.Next := null;
Self.Database.Tail.Next := Query_Access (Self);
Self.Database.Tail := Query_Access (Self);
end if;
end Initialize;
----------------
-- Invalidate --
----------------
not overriding procedure Invalidate
(Self : not null access Abstract_Query) is
begin
if Self.Database /= null then
if Self.Database.Head = Self then
-- Correct list's head.
Self.Database.Head := Self.Next;
end if;
if Self.Database.Tail = Self then
-- Correct list's tail.
Self.Database.Tail := Self.Previous;
end if;
if Self.Previous /= null then
-- Fix Next member of previous element.
Self.Previous.Next := Self.Next;
end if;
if Self.Next /= null then
-- Fix Previous member of next element.
Self.Next.Previous := Self.Previous;
end if;
-- Release database object.
Dereference (Self.Database);
end if;
end Invalidate;
------------------------
-- Invalidate_Queries --
------------------------
procedure Invalidate_Queries
(Self : not null access Abstract_Database'Class) is
begin
while Self.Head /= null loop
Self.Head.Invalidate;
end loop;
end Invalidate_Queries;
---------------------
-- Is_Object_Valid --
---------------------
function Is_Object_Valid
(Self : not null access Abstract_Query'Class) return Boolean is
begin
return Self.Database /= null;
end Is_Object_Valid;
---------------
-- Reference --
---------------
procedure Reference (Self : not null Database_Access) is
begin
if Self /= Dummy.Empty_Database'Access then
Matreshka.Atomics.Counters.Increment (Self.Counter);
end if;
end Reference;
---------------
-- Reference --
---------------
procedure Reference (Self : not null Query_Access) is
begin
if Self /= Dummy.Empty_Query'Access then
Matreshka.Atomics.Counters.Increment (Self.Counter);
end if;
end Reference;
--------------
-- Register --
--------------
procedure Register
(Name : League.Strings.Universal_String;
Factory : not null Factory_Access) is
begin
Factories.Insert (Name, Factory);
end Register;
end Matreshka.Internals.SQL_Drivers;
|