------------------------------------------------------------------------------ -- -- -- GNAT RUNTIME COMPONENTS -- -- -- -- S Y S T E M . D I R E C T _ I O -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2003 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. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Ada.IO_Exceptions; use Ada.IO_Exceptions; with Interfaces.C_Streams; use Interfaces.C_Streams; with System; use System; with System.CRTL; with System.File_IO; with System.Soft_Links; with Unchecked_Deallocation; package body System.Direct_IO is package FIO renames System.File_IO; package SSL renames System.Soft_Links; subtype AP is FCB.AFCB_Ptr; use type FCB.Shared_Status_Type; use type System.CRTL.long; use type System.CRTL.size_t; ----------------------- -- 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 pragma Unreferenced (Control_Block); 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 pragma Unreferenced (File); 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 Dummy_File_Control_Block : Direct_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 => 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 Dummy_File_Control_Block : Direct_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 => 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; Locked_Processing : begin SSL.Lock_Task.all; Set_Position (File); FIO.Read_Buf (AP (File), Item, Size); SSL.Unlock_Task.all; exception when others => SSL.Unlock_Task.all; raise; end Locked_Processing; 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 Locked_Processing : begin SSL.Lock_Task.all; Set_Position (File); Do_Write; SSL.Unlock_Task.all; exception when others => SSL.Unlock_Task.all; raise; end Locked_Processing; 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;