1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME COMPONENTS -- 4-- -- 5-- A D A . S T R E A M S . S T R E A M _ I O -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2012, Free Software Foundation, Inc. -- 10-- -- 11-- This specification is derived from the Ada Reference Manual for use with -- 12-- GNAT. The copyright notice above, and the license provisions that follow -- 13-- apply solely to the contents of the part following the private keyword. -- 14-- -- 15-- GNAT is free software; you can redistribute it and/or modify it under -- 16-- terms of the GNU General Public License as published by the Free Soft- -- 17-- ware Foundation; either version 3, or (at your option) any later ver- -- 18-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 19-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 20-- or FITNESS FOR A PARTICULAR PURPOSE. -- 21-- -- 22-- As a special exception under Section 7 of GPL version 3, you are granted -- 23-- additional permissions described in the GCC Runtime Library Exception, -- 24-- version 3.1, as published by the Free Software Foundation. -- 25-- -- 26-- You should have received a copy of the GNU General Public License and -- 27-- a copy of the GCC Runtime Library Exception along with this program; -- 28-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 29-- <http://www.gnu.org/licenses/>. -- 30-- -- 31-- GNAT was originally developed by the GNAT team at New York University. -- 32-- Extensive contributions were provided by Ada Core Technologies Inc. -- 33-- -- 34------------------------------------------------------------------------------ 35 36with Ada.IO_Exceptions; 37with System.File_Control_Block; 38 39package Ada.Streams.Stream_IO is 40 pragma Preelaborate; 41 42 type Stream_Access is access all Root_Stream_Type'Class; 43 44 type File_Type is limited private; 45 46 type File_Mode is (In_File, Out_File, Append_File); 47 48 -- The following representation clause allows the use of unchecked 49 -- conversion for rapid translation between the File_Mode type 50 -- used in this package and System.File_IO. 51 52 for File_Mode use 53 (In_File => 0, -- System.File_IO.File_Mode'Pos (In_File) 54 Out_File => 2, -- System.File_IO.File_Mode'Pos (Out_File) 55 Append_File => 3); -- System.File_IO.File_Mode'Pos (Append_File) 56 57 type Count is new Stream_Element_Offset 58 range 0 .. Stream_Element_Offset'Last; 59 60 subtype Positive_Count is Count range 1 .. Count'Last; 61 -- Index into file, in stream elements 62 63 --------------------- 64 -- File Management -- 65 --------------------- 66 67 procedure Create 68 (File : in out File_Type; 69 Mode : File_Mode := Out_File; 70 Name : String := ""; 71 Form : String := ""); 72 73 procedure Open 74 (File : in out File_Type; 75 Mode : File_Mode; 76 Name : String; 77 Form : String := ""); 78 79 procedure Close (File : in out File_Type); 80 procedure Delete (File : in out File_Type); 81 procedure Reset (File : in out File_Type; Mode : File_Mode); 82 procedure Reset (File : in out File_Type); 83 84 function Mode (File : File_Type) return File_Mode; 85 function Name (File : File_Type) return String; 86 function Form (File : File_Type) return String; 87 88 function Is_Open (File : File_Type) return Boolean; 89 function End_Of_File (File : File_Type) return Boolean; 90 91 function Stream (File : File_Type) return Stream_Access; 92 93 ----------------------------- 94 -- Input-Output Operations -- 95 ----------------------------- 96 97 procedure Read 98 (File : File_Type; 99 Item : out Stream_Element_Array; 100 Last : out Stream_Element_Offset; 101 From : Positive_Count); 102 103 procedure Read 104 (File : File_Type; 105 Item : out Stream_Element_Array; 106 Last : out Stream_Element_Offset); 107 108 procedure Write 109 (File : File_Type; 110 Item : Stream_Element_Array; 111 To : Positive_Count); 112 113 procedure Write 114 (File : File_Type; 115 Item : Stream_Element_Array); 116 117 ---------------------------------------- 118 -- Operations on Position within File -- 119 ---------------------------------------- 120 121 procedure Set_Index (File : File_Type; To : Positive_Count); 122 123 function Index (File : File_Type) return Positive_Count; 124 function Size (File : File_Type) return Count; 125 126 procedure Set_Mode (File : in out File_Type; Mode : File_Mode); 127 128 -- Note: The parameter file is IN OUT in the RM, but this is clearly 129 -- an oversight, and was intended to be IN, see AI95-00057. 130 131 procedure Flush (File : File_Type); 132 133 ---------------- 134 -- Exceptions -- 135 ---------------- 136 137 Status_Error : exception renames IO_Exceptions.Status_Error; 138 Mode_Error : exception renames IO_Exceptions.Mode_Error; 139 Name_Error : exception renames IO_Exceptions.Name_Error; 140 Use_Error : exception renames IO_Exceptions.Use_Error; 141 Device_Error : exception renames IO_Exceptions.Device_Error; 142 End_Error : exception renames IO_Exceptions.End_Error; 143 Data_Error : exception renames IO_Exceptions.Data_Error; 144 145private 146 147 -- The following procedures have a File_Type formal of mode IN OUT because 148 -- they may close the original file. The Close operation may raise an 149 -- exception, but in that case we want any assignment to the formal to 150 -- be effective anyway, so it must be passed by reference (or the caller 151 -- will be left with a dangling pointer). 152 153 pragma Export_Procedure 154 (Internal => Close, 155 External => "", 156 Mechanism => Reference); 157 pragma Export_Procedure 158 (Internal => Delete, 159 External => "", 160 Mechanism => Reference); 161 pragma Export_Procedure 162 (Internal => Reset, 163 External => "", 164 Parameter_Types => (File_Type), 165 Mechanism => Reference); 166 pragma Export_Procedure 167 (Internal => Reset, 168 External => "", 169 Parameter_Types => (File_Type, File_Mode), 170 Mechanism => (File => Reference)); 171 pragma Export_Procedure 172 (Internal => Set_Mode, 173 External => "", 174 Mechanism => (File => Reference)); 175 176 package FCB renames System.File_Control_Block; 177 178 ----------------------------- 179 -- Stream_IO Control Block -- 180 ----------------------------- 181 182 type Operation is (Op_Read, Op_Write, Op_Other); 183 -- Type used to record last operation (to optimize sequential operations) 184 185 type Stream_AFCB is new FCB.AFCB with record 186 Index : Count := 1; 187 -- Current Index value 188 189 File_Size : Stream_Element_Offset := -1; 190 -- Cached value of File_Size, so that we do not keep recomputing it 191 -- when not necessary (otherwise End_Of_File becomes gruesomely slow). 192 -- A value of minus one means that there is no cached value. 193 194 Last_Op : Operation := Op_Other; 195 -- Last operation performed on file, used to avoid unnecessary 196 -- repositioning between successive read or write operations. 197 198 Update_Mode : Boolean := False; 199 -- Set if the mode is changed from write to read or vice versa. 200 -- Indicates that the file has been reopened in update mode. 201 202 end record; 203 204 type File_Type is access all Stream_AFCB; 205 206 overriding function AFCB_Allocate 207 (Control_Block : Stream_AFCB) return FCB.AFCB_Ptr; 208 209 overriding procedure AFCB_Close (File : not null access Stream_AFCB); 210 overriding procedure AFCB_Free (File : not null access Stream_AFCB); 211 212 overriding procedure Read 213 (File : in out Stream_AFCB; 214 Item : out Ada.Streams.Stream_Element_Array; 215 Last : out Ada.Streams.Stream_Element_Offset); 216 -- Read operation used when Stream_IO file is treated directly as Stream 217 218 overriding procedure Write 219 (File : in out Stream_AFCB; 220 Item : Ada.Streams.Stream_Element_Array); 221 -- Write operation used when Stream_IO file is treated directly as Stream 222 223end Ada.Streams.Stream_IO; 224