| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- A D A . S T R E A M S . S T R E A M _ I O -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2012, Free Software Foundation, Inc. -- |
| -- -- |
| -- This specification is derived from the Ada Reference Manual for use with -- |
| -- GNAT. The copyright notice above, and the license provisions that follow -- |
| -- apply solely to the contents of the part following the private keyword. -- |
| -- -- |
| -- 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 Ada.IO_Exceptions; |
| with System.File_Control_Block; |
| |
| package Ada.Streams.Stream_IO is |
| pragma Preelaborate; |
| |
| type Stream_Access is access all Root_Stream_Type'Class; |
| |
| type File_Type is limited private; |
| |
| type File_Mode is (In_File, Out_File, Append_File); |
| |
| -- The following representation clause allows the use of unchecked |
| -- conversion for rapid translation between the File_Mode type |
| -- used in this package and System.File_IO. |
| |
| for File_Mode use |
| (In_File => 0, -- System.File_IO.File_Mode'Pos (In_File) |
| Out_File => 2, -- System.File_IO.File_Mode'Pos (Out_File) |
| Append_File => 3); -- System.File_IO.File_Mode'Pos (Append_File) |
| |
| type Count is new Stream_Element_Offset |
| range 0 .. Stream_Element_Offset'Last; |
| |
| subtype Positive_Count is Count range 1 .. Count'Last; |
| -- Index into file, in stream elements |
| |
| --------------------- |
| -- File Management -- |
| --------------------- |
| |
| procedure Create |
| (File : in out File_Type; |
| Mode : File_Mode := Out_File; |
| Name : String := ""; |
| Form : String := ""); |
| |
| procedure Open |
| (File : in out File_Type; |
| Mode : File_Mode; |
| Name : String; |
| Form : String := ""); |
| |
| procedure Close (File : in out File_Type); |
| procedure Delete (File : in out File_Type); |
| procedure Reset (File : in out File_Type; Mode : File_Mode); |
| procedure Reset (File : in out File_Type); |
| |
| function Mode (File : File_Type) return File_Mode; |
| function Name (File : File_Type) return String; |
| function Form (File : File_Type) return String; |
| |
| function Is_Open (File : File_Type) return Boolean; |
| function End_Of_File (File : File_Type) return Boolean; |
| |
| function Stream (File : File_Type) return Stream_Access; |
| |
| ----------------------------- |
| -- Input-Output Operations -- |
| ----------------------------- |
| |
| procedure Read |
| (File : File_Type; |
| Item : out Stream_Element_Array; |
| Last : out Stream_Element_Offset; |
| From : Positive_Count); |
| |
| procedure Read |
| (File : File_Type; |
| Item : out Stream_Element_Array; |
| Last : out Stream_Element_Offset); |
| |
| procedure Write |
| (File : File_Type; |
| Item : Stream_Element_Array; |
| To : Positive_Count); |
| |
| procedure Write |
| (File : File_Type; |
| Item : Stream_Element_Array); |
| |
| ---------------------------------------- |
| -- Operations on Position within File -- |
| ---------------------------------------- |
| |
| procedure Set_Index (File : File_Type; To : Positive_Count); |
| |
| function Index (File : File_Type) return Positive_Count; |
| function Size (File : File_Type) return Count; |
| |
| procedure Set_Mode (File : in out File_Type; Mode : File_Mode); |
| |
| -- Note: The parameter file is IN OUT in the RM, but this is clearly |
| -- an oversight, and was intended to be IN, see AI95-00057. |
| |
| procedure Flush (File : File_Type); |
| |
| ---------------- |
| -- Exceptions -- |
| ---------------- |
| |
| Status_Error : exception renames IO_Exceptions.Status_Error; |
| Mode_Error : exception renames IO_Exceptions.Mode_Error; |
| Name_Error : exception renames IO_Exceptions.Name_Error; |
| Use_Error : exception renames IO_Exceptions.Use_Error; |
| Device_Error : exception renames IO_Exceptions.Device_Error; |
| End_Error : exception renames IO_Exceptions.End_Error; |
| Data_Error : exception renames IO_Exceptions.Data_Error; |
| |
| private |
| |
| -- 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 => Close, |
| External => "", |
| Mechanism => Reference); |
| pragma Export_Procedure |
| (Internal => Delete, |
| External => "", |
| Mechanism => Reference); |
| pragma Export_Procedure |
| (Internal => Reset, |
| External => "", |
| Parameter_Types => (File_Type), |
| Mechanism => Reference); |
| pragma Export_Procedure |
| (Internal => Reset, |
| External => "", |
| Parameter_Types => (File_Type, File_Mode), |
| Mechanism => (File => Reference)); |
| pragma Export_Procedure |
| (Internal => Set_Mode, |
| External => "", |
| Mechanism => (File => Reference)); |
| |
| package FCB renames System.File_Control_Block; |
| |
| ----------------------------- |
| -- Stream_IO Control Block -- |
| ----------------------------- |
| |
| type Operation is (Op_Read, Op_Write, Op_Other); |
| -- Type used to record last operation (to optimize sequential operations) |
| |
| type Stream_AFCB is new FCB.AFCB with record |
| Index : Count := 1; |
| -- Current Index value |
| |
| File_Size : Stream_Element_Offset := -1; |
| -- Cached value of File_Size, so that we do not keep recomputing it |
| -- when not necessary (otherwise End_Of_File becomes gruesomely slow). |
| -- A value of minus one means that there is no cached value. |
| |
| Last_Op : Operation := Op_Other; |
| -- Last operation performed on file, used to avoid unnecessary |
| -- repositioning between successive read or write operations. |
| |
| Update_Mode : Boolean := False; |
| -- Set if the mode is changed from write to read or vice versa. |
| -- Indicates that the file has been reopened in update mode. |
| |
| end record; |
| |
| type File_Type is access all Stream_AFCB; |
| |
| overriding function AFCB_Allocate |
| (Control_Block : Stream_AFCB) return FCB.AFCB_Ptr; |
| |
| overriding procedure AFCB_Close (File : not null access Stream_AFCB); |
| overriding procedure AFCB_Free (File : not null access Stream_AFCB); |
| |
| overriding procedure Read |
| (File : in out Stream_AFCB; |
| Item : out Ada.Streams.Stream_Element_Array; |
| Last : out Ada.Streams.Stream_Element_Offset); |
| -- Read operation used when Stream_IO file is treated directly as Stream |
| |
| overriding procedure Write |
| (File : in out Stream_AFCB; |
| Item : Ada.Streams.Stream_Element_Array); |
| -- Write operation used when Stream_IO file is treated directly as Stream |
| |
| end Ada.Streams.Stream_IO; |
