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|
------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- A D A . S T R E A M S . S T R E A M _ I O --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2019, 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/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Interfaces.C_Streams; use Interfaces.C_Streams;
with System; use System;
with System.Communication; use System.Communication;
with System.File_IO;
with System.Soft_Links;
with System.CRTL;
with Ada.Unchecked_Conversion;
with Ada.Unchecked_Deallocation;
package body Ada.Streams.Stream_IO is
package FIO renames System.File_IO;
package SSL renames System.Soft_Links;
subtype AP is FCB.AFCB_Ptr;
function To_FCB is new Ada.Unchecked_Conversion (File_Mode, FCB.File_Mode);
function To_SIO is new Ada.Unchecked_Conversion (FCB.File_Mode, File_Mode);
use type FCB.File_Mode;
use type FCB.Shared_Status_Type;
-----------------------
-- Local Subprograms --
-----------------------
procedure Set_Position (File : File_Type);
-- Sets file position pointer according to value of current index
-------------------
-- AFCB_Allocate --
-------------------
function AFCB_Allocate (Control_Block : Stream_AFCB) return FCB.AFCB_Ptr is
pragma Warnings (Off, Control_Block);
begin
return new Stream_AFCB;
end AFCB_Allocate;
----------------
-- AFCB_Close --
----------------
-- No special processing required for closing Stream_IO file
procedure AFCB_Close (File : not null access Stream_AFCB) is
pragma Warnings (Off, File);
begin
null;
end AFCB_Close;
---------------
-- AFCB_Free --
---------------
procedure AFCB_Free (File : not null access Stream_AFCB) is
type FCB_Ptr is access all Stream_AFCB;
FT : FCB_Ptr := FCB_Ptr (File);
procedure Free is new Ada.Unchecked_Deallocation (Stream_AFCB, FCB_Ptr);
begin
Free (FT);
end AFCB_Free;
-----------
-- Close --
-----------
procedure Close (File : in out File_Type) is
begin
FIO.Close (AP (File)'Unrestricted_Access);
end Close;
------------
-- Create --
------------
procedure Create
(File : in out File_Type;
Mode : File_Mode := Out_File;
Name : String := "";
Form : String := "")
is
Dummy_File_Control_Block : Stream_AFCB;
pragma Warnings (Off, Dummy_File_Control_Block);
-- Yes, we know this is never assigned a value, only the tag
-- is used for dispatching purposes, so that's expected.
begin
FIO.Open (File_Ptr => AP (File),
Dummy_FCB => Dummy_File_Control_Block,
Mode => To_FCB (Mode),
Name => Name,
Form => Form,
Amethod => 'S',
Creat => True,
Text => False);
File.Last_Op := Op_Write;
end Create;
------------
-- Delete --
------------
procedure Delete (File : in out File_Type) is
begin
FIO.Delete (AP (File)'Unrestricted_Access);
end Delete;
-----------------
-- End_Of_File --
-----------------
function End_Of_File (File : File_Type) return Boolean is
begin
FIO.Check_Read_Status (AP (File));
return File.Index > Size (File);
end End_Of_File;
-----------
-- Flush --
-----------
procedure Flush (File : File_Type) is
begin
FIO.Flush (AP (File));
end Flush;
----------
-- Form --
----------
function Form (File : File_Type) return String is
begin
return FIO.Form (AP (File));
end Form;
-----------
-- Index --
-----------
function Index (File : File_Type) return Positive_Count is
begin
FIO.Check_File_Open (AP (File));
return File.Index;
end Index;
-------------
-- Is_Open --
-------------
function Is_Open (File : File_Type) return Boolean is
begin
return FIO.Is_Open (AP (File));
end Is_Open;
----------
-- Mode --
----------
function Mode (File : File_Type) return File_Mode is
begin
return To_SIO (FIO.Mode (AP (File)));
end Mode;
----------
-- Name --
----------
function Name (File : File_Type) return String is
begin
return FIO.Name (AP (File));
end Name;
----------
-- Open --
----------
procedure Open
(File : in out File_Type;
Mode : File_Mode;
Name : String;
Form : String := "")
is
Dummy_File_Control_Block : Stream_AFCB;
pragma Warnings (Off, Dummy_File_Control_Block);
-- Yes, we know this is never assigned a value, only the tag
-- is used for dispatching purposes, so that's expected.
begin
FIO.Open (File_Ptr => AP (File),
Dummy_FCB => Dummy_File_Control_Block,
Mode => To_FCB (Mode),
Name => Name,
Form => Form,
Amethod => 'S',
Creat => False,
Text => False);
-- Ensure that the stream index is set properly (e.g., for Append_File)
Reset (File, Mode);
-- Set last operation. The purpose here is to ensure proper handling
-- of the initial operation. In general, a write after a read requires
-- resetting and doing a seek, so we set the last operation as Read
-- for an In_Out file, but for an Out file we set the last operation
-- to Op_Write, since in this case it is not necessary to do a seek
-- (and furthermore there are situations (such as the case of writing
-- a sequential Posix FIFO file) where the lseek would cause problems.
File.Last_Op := (if Mode = Out_File then Op_Write else Op_Read);
end Open;
----------
-- Read --
----------
procedure Read
(File : File_Type;
Item : out Stream_Element_Array;
Last : out Stream_Element_Offset;
From : Positive_Count)
is
begin
Set_Index (File, From);
Read (File, Item, Last);
end Read;
procedure Read
(File : File_Type;
Item : out Stream_Element_Array;
Last : out Stream_Element_Offset)
is
Nread : size_t;
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
Locked_Processing : begin
SSL.Lock_Task.all;
Set_Position (File);
FIO.Read_Buf (AP (File), Item'Address, Item'Length, Nread);
SSL.Unlock_Task.all;
exception
when others =>
SSL.Unlock_Task.all;
raise;
end Locked_Processing;
else
FIO.Read_Buf (AP (File), Item'Address, Item'Length, Nread);
end if;
File.Index := File.Index + Count (Nread);
File.Last_Op := Op_Read;
Last := Last_Index (Item'First, Nread);
end Read;
-- This version of Read is the primitive operation on the underlying
-- Stream type, used when a Stream_IO file is treated as a Stream
procedure Read
(File : in out Stream_AFCB;
Item : out Ada.Streams.Stream_Element_Array;
Last : out Ada.Streams.Stream_Element_Offset)
is
begin
Read (File'Unchecked_Access, Item, Last);
end Read;
-----------
-- Reset --
-----------
procedure Reset (File : in out File_Type; Mode : File_Mode) is
begin
FIO.Check_File_Open (AP (File));
-- Reset file index to start of file for read/write cases. For
-- the append case, the Set_Mode call repositions the index.
File.Index := 1;
Set_Mode (File, Mode);
end Reset;
procedure Reset (File : in out File_Type) is
begin
Reset (File, To_SIO (File.Mode));
end Reset;
---------------
-- Set_Index --
---------------
procedure Set_Index (File : File_Type; To : Positive_Count) is
begin
FIO.Check_File_Open (AP (File));
File.Index := Count (To);
File.Last_Op := Op_Other;
end Set_Index;
--------------
-- Set_Mode --
--------------
procedure Set_Mode (File : in out File_Type; Mode : File_Mode) is
begin
FIO.Check_File_Open (AP (File));
-- If we are switching from read to write, or vice versa, and
-- we are not already open in update mode, then reopen in update
-- mode now. Note that we can use Inout_File as the mode for the
-- call since File_IO handles all modes for all file types.
if ((File.Mode = FCB.In_File) /= (Mode = In_File))
and then not File.Update_Mode
then
FIO.Reset (AP (File)'Unrestricted_Access, FCB.Inout_File);
File.Update_Mode := True;
end if;
-- Set required mode and position to end of file if append mode
File.Mode := To_FCB (Mode);
FIO.Append_Set (AP (File));
if File.Mode = FCB.Append_File then
if Standard'Address_Size = 64 then
File.Index := Count (ftell64 (File.Stream)) + 1;
else
File.Index := Count (ftell (File.Stream)) + 1;
end if;
end if;
File.Last_Op := Op_Other;
end Set_Mode;
------------------
-- Set_Position --
------------------
procedure Set_Position (File : File_Type) is
use type System.CRTL.int64;
R : int;
begin
R := fseek64 (File.Stream, System.CRTL.int64 (File.Index) - 1, SEEK_SET);
if R /= 0 then
raise Use_Error;
end if;
end Set_Position;
----------
-- Size --
----------
function Size (File : File_Type) return Count is
begin
FIO.Check_File_Open (AP (File));
if File.File_Size = -1 then
File.Last_Op := Op_Other;
if fseek64 (File.Stream, 0, SEEK_END) /= 0 then
raise Device_Error;
end if;
File.File_Size := Stream_Element_Offset (ftell64 (File.Stream));
if File.File_Size = -1 then
raise Use_Error;
end if;
end if;
return Count (File.File_Size);
end Size;
------------
-- Stream --
------------
function Stream (File : File_Type) return Stream_Access is
begin
FIO.Check_File_Open (AP (File));
return Stream_Access (File);
end Stream;
-----------
-- Write --
-----------
procedure Write
(File : File_Type;
Item : Stream_Element_Array;
To : Positive_Count)
is
begin
Set_Index (File, To);
Write (File, Item);
end Write;
procedure Write
(File : File_Type;
Item : Stream_Element_Array)
is
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
Locked_Processing : begin
SSL.Lock_Task.all;
Set_Position (File);
FIO.Write_Buf (AP (File), Item'Address, Item'Length);
SSL.Unlock_Task.all;
exception
when others =>
SSL.Unlock_Task.all;
raise;
end Locked_Processing;
else
FIO.Write_Buf (AP (File), Item'Address, Item'Length);
end if;
File.Index := File.Index + Item'Length;
File.Last_Op := Op_Write;
File.File_Size := -1;
end Write;
-- This version of Write is the primitive operation on the underlying
-- Stream type, used when a Stream_IO file is treated as a Stream
procedure Write
(File : in out Stream_AFCB;
Item : Ada.Streams.Stream_Element_Array)
is
begin
Write (File'Unchecked_Access, Item);
end Write;
end Ada.Streams.Stream_IO;
|