| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- S Y S T E M . D I R E C T _ I O -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2014, 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. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This package contains the declaration of the control block used for |
| -- Direct_IO. This must be declared at the outer library level. It also |
| -- contains code that is shared between instances of Direct_IO. |
| |
| with Interfaces.C_Streams; |
| with Ada.Streams; |
| with System.File_Control_Block; |
| with System.Storage_Elements; |
| |
| package System.Direct_IO is |
| |
| package FCB renames System.File_Control_Block; |
| |
| type Operation is (Op_Read, Op_Write, Op_Other); |
| -- Type used to record last operation (to optimize sequential operations) |
| |
| subtype Count is Interfaces.C_Streams.int64; |
| -- The Count type in each instantiation is derived from this type |
| |
| subtype Positive_Count is Count range 1 .. Count'Last; |
| |
| type Direct_AFCB is new FCB.AFCB with record |
| Index : Count := 1; |
| -- Current Index value |
| |
| Bytes : Interfaces.C_Streams.size_t; |
| -- Length of item in bytes (set from inside generic template) |
| |
| Last_Op : Operation := Op_Other; |
| -- Last operation performed on file, used to avoid unnecessary |
| -- repositioning between successive read or write operations. |
| end record; |
| |
| function AFCB_Allocate (Control_Block : Direct_AFCB) return FCB.AFCB_Ptr; |
| |
| procedure AFCB_Close (File : not null access Direct_AFCB); |
| procedure AFCB_Free (File : not null access Direct_AFCB); |
| |
| procedure Read |
| (File : in out Direct_AFCB; |
| Item : out Ada.Streams.Stream_Element_Array; |
| Last : out Ada.Streams.Stream_Element_Offset); |
| -- Required overriding of Read, not actually used for Direct_IO |
| |
| procedure Write |
| (File : in out Direct_AFCB; |
| Item : Ada.Streams.Stream_Element_Array); |
| -- Required overriding of Write, not actually used for Direct_IO |
| |
| type File_Type is access all Direct_AFCB; |
| -- File_Type in individual instantiations is derived from this type |
| |
| procedure Create |
| (File : in out File_Type; |
| Mode : FCB.File_Mode := FCB.Inout_File; |
| Name : String := ""; |
| Form : String := ""); |
| |
| function End_Of_File (File : File_Type) return Boolean; |
| |
| function Index (File : File_Type) return Positive_Count; |
| |
| procedure Open |
| (File : in out File_Type; |
| Mode : FCB.File_Mode; |
| Name : String; |
| Form : String := ""); |
| |
| procedure Read |
| (File : File_Type; |
| Item : System.Address; |
| Size : Interfaces.C_Streams.size_t; |
| From : Positive_Count); |
| |
| procedure Read |
| (File : File_Type; |
| Item : System.Address; |
| Size : Interfaces.C_Streams.size_t); |
| |
| procedure Reset (File : in out File_Type; Mode : FCB.File_Mode); |
| procedure Reset (File : in out File_Type); |
| |
| procedure Set_Index (File : File_Type; To : Positive_Count); |
| |
| function Size (File : File_Type) return Count; |
| |
| procedure Write |
| (File : File_Type; |
| Item : System.Address; |
| Size : Interfaces.C_Streams.size_t; |
| Zeroes : System.Storage_Elements.Storage_Array); |
| -- Note: Zeroes is the buffer of zeroes used to fill out partial records |
| |
| -- The following procedures have a File_Type formal of mode IN OUT because |
| -- they may close the original file. The Close operation may raise an |
| -- exception, but in that case we want any assignment to the formal to |
| -- be effective anyway, so it must be passed by reference (or the caller |
| -- will be left with a dangling pointer). |
| |
| pragma Export_Procedure |
| (Internal => Reset, |
| External => "", |
| Parameter_Types => (File_Type), |
| Mechanism => Reference); |
| pragma Export_Procedure |
| (Internal => Reset, |
| External => "", |
| Parameter_Types => (File_Type, FCB.File_Mode), |
| Mechanism => (File => Reference)); |
| |
| end System.Direct_IO; |
