------------------------------------------------------------------------------ -- -- -- Matreshka Project -- -- -- -- SQL Database Access -- -- -- -- Runtime Library Component -- -- -- ------------------------------------------------------------------------------ -- -- -- Copyright © 2011-2013, Vadim Godunko -- -- 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;