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------------------------------------------------------------------------------
-- --
-- GNAT RUNTIME COMPONENTS --
-- --
-- S Y S T E M . D I R E C T _ I O --
-- --
-- B o d y --
-- --
-- $Revision: 1.12 $ --
-- --
-- Copyright (C) 1992-1997 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 2, 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. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 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. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with Ada.IO_Exceptions; use Ada.IO_Exceptions;
with Interfaces.C_Streams; use Interfaces.C_Streams;
with System; use System;
with System.File_IO;
with System.Tasking_Soft_Links;
with Unchecked_Deallocation;
package body System.Direct_IO is
package FIO renames System.File_IO;
subtype AP is FCB.AFCB_Ptr;
use type FCB.Shared_Status_Type;
-----------------------
-- Local Subprograms --
-----------------------
procedure Set_Position (File : in File_Type);
-- Sets file position pointer according to value of current index
-------------------
-- AFCB_Allocate --
-------------------
function AFCB_Allocate (Control_Block : Direct_AFCB) return FCB.AFCB_Ptr is
begin
return new Direct_AFCB;
end AFCB_Allocate;
----------------
-- AFCB_Close --
----------------
-- No special processing required for Direct_IO close
procedure AFCB_Close (File : access Direct_AFCB) is
begin
null;
end AFCB_Close;
---------------
-- AFCB_Free --
---------------
procedure AFCB_Free (File : access Direct_AFCB) is
type FCB_Ptr is access all Direct_AFCB;
FT : FCB_Ptr := FCB_Ptr (File);
procedure Free is new
Unchecked_Deallocation (Direct_AFCB, FCB_Ptr);
begin
Free (FT);
end AFCB_Free;
------------
-- Create --
------------
procedure Create
(File : in out File_Type;
Mode : in FCB.File_Mode := FCB.Inout_File;
Name : in String := "";
Form : in String := "")
is
File_Control_Block : Direct_AFCB;
begin
FIO.Open (File_Ptr => AP (File),
Dummy_FCB => File_Control_Block,
Mode => Mode,
Name => Name,
Form => Form,
Amethod => 'D',
Creat => True,
Text => False);
end Create;
-----------------
-- End_Of_File --
-----------------
function End_Of_File (File : in File_Type) return Boolean is
begin
FIO.Check_Read_Status (AP (File));
return Count (File.Index) > Size (File);
end End_Of_File;
-----------
-- Index --
-----------
function Index (File : in File_Type) return Positive_Count is
begin
FIO.Check_File_Open (AP (File));
return Count (File.Index);
end Index;
----------
-- Open --
----------
procedure Open
(File : in out File_Type;
Mode : in FCB.File_Mode;
Name : in String;
Form : in String := "")
is
File_Control_Block : Direct_AFCB;
begin
FIO.Open (File_Ptr => AP (File),
Dummy_FCB => File_Control_Block,
Mode => Mode,
Name => Name,
Form => Form,
Amethod => 'D',
Creat => False,
Text => False);
end Open;
----------
-- Read --
----------
procedure Read
(File : in File_Type;
Item : Address;
Size : in Interfaces.C_Streams.size_t;
From : in Positive_Count)
is
begin
Set_Index (File, From);
Read (File, Item, Size);
end Read;
procedure Read
(File : in File_Type;
Item : Address;
Size : in Interfaces.C_Streams.size_t)
is
begin
FIO.Check_Read_Status (AP (File));
-- If last operation was not a read, or if in file sharing mode,
-- then reset the physical pointer of the file to match the index
-- We lock out task access over the two operations in this case.
if File.Last_Op /= Op_Read
or else File.Shared_Status = FCB.Yes
then
if End_Of_File (File) then
raise End_Error;
end if;
System.Tasking_Soft_Links.Lock_Task.all;
Set_Position (File);
FIO.Read_Buf (AP (File), Item, Size);
System.Tasking_Soft_Links.Unlock_Task.all;
else
FIO.Read_Buf (AP (File), Item, Size);
end if;
File.Index := File.Index + 1;
-- Set last operation to read, unless we did not read a full record
-- (happens with the variant record case) in which case we set the
-- last operation as other, to force the file position to be reset
-- on the next read.
if File.Bytes = Size then
File.Last_Op := Op_Read;
else
File.Last_Op := Op_Other;
end if;
end Read;
-- The following is the required overriding for Stream.Read, which is
-- not used, since we do not do Stream operations on Direct_IO files.
procedure Read
(File : in out Direct_AFCB;
Item : out Ada.Streams.Stream_Element_Array;
Last : out Ada.Streams.Stream_Element_Offset)
is
begin
raise Program_Error;
end Read;
-----------
-- Reset --
-----------
procedure Reset (File : in out File_Type; Mode : in FCB.File_Mode) is
begin
FIO.Reset (AP (File), Mode);
File.Index := 1;
File.Last_Op := Op_Read;
end Reset;
procedure Reset (File : in out File_Type) is
begin
FIO.Reset (AP (File));
File.Index := 1;
File.Last_Op := Op_Read;
end Reset;
---------------
-- Set_Index --
---------------
procedure Set_Index (File : in File_Type; To : in Positive_Count) is
begin
FIO.Check_File_Open (AP (File));
File.Index := Count (To);
File.Last_Op := Op_Other;
end Set_Index;
------------------
-- Set_Position --
------------------
procedure Set_Position (File : in File_Type) is
begin
if fseek
(File.Stream, long (File.Bytes) *
long (File.Index - 1), SEEK_SET) /= 0
then
raise Use_Error;
end if;
end Set_Position;
----------
-- Size --
----------
function Size (File : in File_Type) return Count is
begin
FIO.Check_File_Open (AP (File));
File.Last_Op := Op_Other;
if fseek (File.Stream, 0, SEEK_END) /= 0 then
raise Device_Error;
end if;
return Count (ftell (File.Stream) / long (File.Bytes));
end Size;
-----------
-- Write --
-----------
procedure Write
(File : File_Type;
Item : Address;
Size : in Interfaces.C_Streams.size_t;
Zeroes : System.Storage_Elements.Storage_Array)
is
procedure Do_Write;
-- Do the actual write
procedure Do_Write is
begin
FIO.Write_Buf (AP (File), Item, Size);
-- If we did not write the whole record (happens with the variant
-- record case), then fill out the rest of the record with zeroes.
-- This is cleaner in any case, and is required for the last
-- record, since otherwise the length of the file is wrong.
if File.Bytes > Size then
FIO.Write_Buf (AP (File), Zeroes'Address, File.Bytes - Size);
end if;
end Do_Write;
-- Start of processing for Write
begin
FIO.Check_Write_Status (AP (File));
-- If last operation was not a write, or if in file sharing mode,
-- then reset the physical pointer of the file to match the index
-- We lock out task access over the two operations in this case.
if File.Last_Op /= Op_Write
or else File.Shared_Status = FCB.Yes
then
System.Tasking_Soft_Links.Lock_Task.all;
Set_Position (File);
Do_Write;
System.Tasking_Soft_Links.Unlock_Task.all;
else
Do_Write;
end if;
File.Index := File.Index + 1;
-- Set last operation to write, unless we did not read a full record
-- (happens with the variant record case) in which case we set the
-- last operation as other, to force the file position to be reset
-- on the next write.
if File.Bytes = Size then
File.Last_Op := Op_Write;
else
File.Last_Op := Op_Other;
end if;
end Write;
-- The following is the required overriding for Stream.Write, which is
-- not used, since we do not do Stream operations on Direct_IO files.
procedure Write
(File : in out Direct_AFCB;
Item : in Ada.Streams.Stream_Element_Array)
is
begin
raise Program_Error;
end Write;
end System.Direct_IO;
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