| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT LIBRARY COMPONENTS -- |
| -- -- |
| -- A D A . S T R E A M S . S T O R A G E . B O U N D E D -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 2020-2022, Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 3, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. -- |
| -- -- |
| -- As a special exception under Section 7 of GPL version 3, you are granted -- |
| -- additional permissions described in the GCC Runtime Library Exception, -- |
| -- version 3.1, as published by the Free Software Foundation. -- |
| -- -- |
| -- You should have received a copy of the GNU General Public License and -- |
| -- a copy of the GCC Runtime Library Exception along with this program; -- |
| -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- |
| -- <http://www.gnu.org/licenses/>. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| package body Ada.Streams.Storage.Bounded is |
| |
| ---------- |
| -- Read -- |
| ---------- |
| |
| overriding procedure Read |
| (Stream : in out Stream_Type; Item : out Stream_Element_Array; |
| Last : out Stream_Element_Offset) |
| is |
| EA : Stream_Element_Array renames |
| Stream.Elements (1 .. Element_Count (Stream)); |
| begin |
| if Item'Length = 0 then |
| Last := Item'First - 1; |
| |
| -- If the entire content of the stream fits in Item, then copy it and |
| -- clear the stream. This is likely the usual case. |
| |
| elsif Element_Count (Stream) <= Item'Length then |
| Last := Item'First + Element_Count (Stream) - 1; |
| Item (Item'First .. Last) := EA; |
| Clear (Stream); |
| |
| -- Otherwise, copy as much into Item as will fit. Then slide the |
| -- remaining part of the stream down, and compute the new Count. |
| -- We expect this to be the unusual case, so the cost of copying |
| -- the remaining part probably doesn't matter. |
| |
| else |
| Last := Item'Last; |
| |
| declare |
| New_Count : constant Stream_Element_Count := |
| Element_Count (Stream) - Item'Length; |
| begin |
| Item := EA (1 .. Item'Length); |
| EA (1 .. New_Count) := |
| EA (Element_Count (Stream) - New_Count + 1 .. |
| Element_Count (Stream)); |
| Stream.Count := New_Count; |
| end; |
| end if; |
| end Read; |
| |
| ----------- |
| -- Write -- |
| ----------- |
| |
| overriding procedure Write |
| (Stream : in out Stream_Type; Item : Stream_Element_Array) |
| is |
| begin |
| if Element_Count (Stream) + Item'Length > Stream.Max_Elements then |
| -- That is a precondition in the RM |
| raise Constraint_Error; |
| end if; |
| |
| declare |
| New_Count : constant Stream_Element_Count := |
| Element_Count (Stream) + Item'Length; |
| begin |
| Stream.Elements (Element_Count (Stream) + 1 .. New_Count) := Item; |
| Stream.Count := New_Count; |
| end; |
| end Write; |
| |
| ------------------- |
| -- Element_Count -- |
| ------------------- |
| |
| overriding function Element_Count |
| (Stream : Stream_Type) return Stream_Element_Count |
| is |
| begin |
| return Stream.Count; |
| end Element_Count; |
| |
| ----------- |
| -- Clear -- |
| ----------- |
| |
| overriding procedure Clear (Stream : in out Stream_Type) |
| is |
| begin |
| Stream.Count := 0; |
| end Clear; |
| |
| end Ada.Streams.Storage.Bounded; |
