-- SPDX-License-Identifier: Apache-2.0
--
-- Copyright (c) 2018 onox <denkpadje@gmail.com>
--
-- Licensed under the Apache License, Version 2.0 (the "License");
-- you may not use this file except in compliance with the License.
-- You may obtain a copy of the License at
--
-- http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.
with Ada.Unchecked_Deallocation;
package body Orka.Smart_Pointers is
procedure Free is new Ada.Unchecked_Deallocation (Data_Record, Data_Record_Access);
function Is_Null (Object : Abstract_Pointer) return Boolean is (Object.Data = null);
function References (Object : Abstract_Pointer) return Natural is
(Object.Data.References.Count);
procedure Set
(Object : in out Abstract_Pointer;
Value : not null Object_Access) is
begin
if Object.Data /= null then
-- Decrement old reference count
Finalize (Object);
end if;
Object.Data := new Data_Record'(Object => Value, References => <>);
end Set;
function Get (Object : Mutable_Pointer) return Reference is
begin
return Reference'(Value => Object.Data.Object, Hold => Object);
end Get;
function Get (Object : Pointer) return Constant_Reference is
begin
return Constant_Reference'(Value => Object.Data.Object, Hold => Object);
end Get;
overriding
procedure Adjust (Object : in out Abstract_Pointer) is
begin
if Object.Data /= null then
Object.Data.References.Increment;
end if;
end Adjust;
overriding
procedure Finalize (Object : in out Abstract_Pointer) is
Zero : Boolean;
begin
if Object.Data /= null then
Object.Data.References.Decrement (Zero);
if Zero then
Free_Object (Object.Data.Object);
Free (Object.Data);
end if;
end if;
-- Idempotence: next call to Finalize has no effect
Object.Data := null;
end Finalize;
end Orka.Smart_Pointers;