Geek Gadgets 1

home *** CD-ROM | disk | FTP | other *** search

/ Geek Gadgets 1 / ADE-1.bin / ade-bin / lib / gcc-lib / m68k-amigaos / 2.7.2.1 / adainclude / s-direio.adb < prev next >

Wrap

Text File | 1995-10-17 | 8.6 KB | 316 lines

------------------------------------------------------------------------------ -- -- -- GNAT RUNTIME COMPONENTS -- -- -- -- S Y S T E M . D I R E C T _ I O -- -- -- -- B o d y -- -- -- -- $Revision: 1.6 $ -- -- -- -- Copyright (c) 1992,1993,1994 NYU, All Rights Reserved -- -- -- -- The GNAT library is free software; you can redistribute it and/or modify -- -- it under terms of the GNU Library General Public License as published by -- -- the Free Software Foundation; either version 2, or (at your option) any -- -- later version. The GNAT library is distributed in the hope that it will -- -- be useful, but WITHOUT ANY WARRANTY; without even the implied warranty -- -- of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -- -- Library General Public License for more details. You should have -- -- received a copy of the GNU Library General Public License along with -- -- the GNAT library; see the file COPYING.LIB. If not, write to the Free -- -- Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. -- -- -- ------------------------------------------------------------------------------ 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; ----------------------- -- 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 := 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; From : in Positive_Count) is begin Set_Index (File, From); Read (File, Item); end Read; procedure Read (File : in File_Type; Item : Address) 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; Set_Position (File); FIO.Read_Buf (AP (File), Item, File.Bytes); System.Tasking_Soft_Links.Unlock_Task; else FIO.Read_Buf (AP (File), Item, File.Bytes); end if; File.Index := File.Index + 1; File.Last_Op := Op_Read; 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 Positive_Count (ftell (File.Stream) / long (File.Bytes)); end Size; ----------- -- Write -- ----------- procedure Write (File : File_Type; Item : Address; To : Positive_Count) is begin Set_Index (File, To); Write (File, Item); end Write; procedure Write (File : File_Type; Item : Address) 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 System.Tasking_Soft_Links.Lock_Task; Set_Position (File); FIO.Write_Buf (AP (File), Item, File.Bytes); System.Tasking_Soft_Links.Unlock_Task; else FIO.Write_Buf (AP (File), Item, File.Bytes); end if; File.Index := File.Index + 1; File.Last_Op := Op_Write; 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;