1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME COMPONENTS -- 4-- -- 5-- S Y S T E M . D I R E C T _ I O -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2019, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This package contains the declaration of the control block used for 33-- Direct_IO. This must be declared at the outer library level. It also 34-- contains code that is shared between instances of Direct_IO. 35 36with Interfaces.C_Streams; 37with Ada.Streams; 38with System.File_Control_Block; 39with System.Storage_Elements; 40 41package System.Direct_IO is 42 43 package FCB renames System.File_Control_Block; 44 45 type Operation is (Op_Read, Op_Write, Op_Other); 46 -- Type used to record last operation (to optimize sequential operations) 47 48 subtype Count is Interfaces.C_Streams.int64; 49 -- The Count type in each instantiation is derived from this type 50 51 subtype Positive_Count is Count range 1 .. Count'Last; 52 53 type Direct_AFCB is new FCB.AFCB with record 54 Index : Count := 1; 55 -- Current Index value 56 57 Bytes : Interfaces.C_Streams.size_t; 58 -- Length of item in bytes (set from inside generic template) 59 60 Last_Op : Operation := Op_Other; 61 -- Last operation performed on file, used to avoid unnecessary 62 -- repositioning between successive read or write operations. 63 end record; 64 65 function AFCB_Allocate (Control_Block : Direct_AFCB) return FCB.AFCB_Ptr; 66 67 procedure AFCB_Close (File : not null access Direct_AFCB); 68 procedure AFCB_Free (File : not null access Direct_AFCB); 69 70 procedure Read 71 (File : in out Direct_AFCB; 72 Item : out Ada.Streams.Stream_Element_Array; 73 Last : out Ada.Streams.Stream_Element_Offset); 74 -- Required overriding of Read, not actually used for Direct_IO 75 76 procedure Write 77 (File : in out Direct_AFCB; 78 Item : Ada.Streams.Stream_Element_Array); 79 -- Required overriding of Write, not actually used for Direct_IO 80 81 type File_Type is access all Direct_AFCB; 82 -- File_Type in individual instantiations is derived from this type 83 84 procedure Create 85 (File : in out File_Type; 86 Mode : FCB.File_Mode := FCB.Inout_File; 87 Name : String := ""; 88 Form : String := ""); 89 90 function End_Of_File (File : File_Type) return Boolean; 91 92 function Index (File : File_Type) return Positive_Count; 93 94 procedure Open 95 (File : in out File_Type; 96 Mode : FCB.File_Mode; 97 Name : String; 98 Form : String := ""); 99 100 procedure Read 101 (File : File_Type; 102 Item : System.Address; 103 Size : Interfaces.C_Streams.size_t; 104 From : Positive_Count); 105 106 procedure Read 107 (File : File_Type; 108 Item : System.Address; 109 Size : Interfaces.C_Streams.size_t); 110 111 procedure Reset (File : in out File_Type; Mode : FCB.File_Mode); 112 procedure Reset (File : in out File_Type); 113 114 procedure Set_Index (File : File_Type; To : Positive_Count); 115 116 function Size (File : File_Type) return Count; 117 118 procedure Write 119 (File : File_Type; 120 Item : System.Address; 121 Size : Interfaces.C_Streams.size_t; 122 Zeroes : System.Storage_Elements.Storage_Array); 123 -- Note: Zeroes is the buffer of zeroes used to fill out partial records 124 125 -- The following procedures have a File_Type formal of mode IN OUT because 126 -- they may close the original file. The Close operation may raise an 127 -- exception, but in that case we want any assignment to the formal to 128 -- be effective anyway, so it must be passed by reference (or the caller 129 -- will be left with a dangling pointer). 130 131 pragma Export_Procedure 132 (Internal => Reset, 133 External => "", 134 Parameter_Types => (File_Type), 135 Mechanism => Reference); 136 pragma Export_Procedure 137 (Internal => Reset, 138 External => "", 139 Parameter_Types => (File_Type, FCB.File_Mode), 140 Mechanism => (File => Reference)); 141 142end System.Direct_IO; 143