1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . S T R E A M S . S T R E A M _ I O --
10 -- Copyright (C) 1992-2001 Free Software Foundation, Inc. --
12 -- This specification is derived from the Ada Reference Manual for use with --
13 -- GNAT. The copyright notice above, and the license provisions that follow --
14 -- apply solely to the contents of the part following the private keyword. --
16 -- GNAT is free software; you can redistribute it and/or modify it under --
17 -- terms of the GNU General Public License as published by the Free Soft- --
18 -- ware Foundation; either version 2, or (at your option) any later ver- --
19 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
20 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
21 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
22 -- for more details. You should have received a copy of the GNU General --
23 -- Public License distributed with GNAT; see file COPYING. If not, write --
24 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
25 -- MA 02111-1307, USA. --
27 -- As a special exception, if other files instantiate generics from this --
28 -- unit, or you link this unit with other files to produce an executable, --
29 -- this unit does not by itself cause the resulting executable to be --
30 -- covered by the GNU General Public License. This exception does not --
31 -- however invalidate any other reasons why the executable file might be --
32 -- covered by the GNU Public License. --
34 -- GNAT was originally developed by the GNAT team at New York University. --
35 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
37 ------------------------------------------------------------------------------
39 with Ada
.IO_Exceptions
;
40 with System
.File_Control_Block
;
42 package Ada
.Streams
.Stream_IO
is
44 type Stream_Access
is access all Root_Stream_Type
'Class;
46 type File_Type
is limited private;
48 type File_Mode
is (In_File
, Out_File
, Append_File
);
50 -- The following representation clause allows the use of unchecked
51 -- conversion for rapid translation between the File_Mode type
52 -- used in this package and System.File_IO.
55 (In_File
=> 0, -- System.FIle_IO.File_Mode'Pos (In_File)
56 Out_File
=> 2, -- System.File_IO.File_Mode'Pos (Out_File)
57 Append_File
=> 3); -- System.File_IO.File_Mode'Pos (Append_File)
59 type Count
is new Stream_Element_Offset
60 range 0 .. Stream_Element_Offset
'Last;
62 subtype Positive_Count
is Count
range 1 .. Count
'Last;
63 -- Index into file, in stream elements
70 (File
: in out File_Type
;
71 Mode
: in File_Mode
:= Out_File
;
72 Name
: in String := "";
73 Form
: in String := "");
76 (File
: in out File_Type
;
79 Form
: in String := "");
81 procedure Close
(File
: in out File_Type
);
82 procedure Delete
(File
: in out File_Type
);
83 procedure Reset
(File
: in out File_Type
; Mode
: in File_Mode
);
84 procedure Reset
(File
: in out File_Type
);
86 function Mode
(File
: in File_Type
) return File_Mode
;
87 function Name
(File
: in File_Type
) return String;
88 function Form
(File
: in File_Type
) return String;
90 function Is_Open
(File
: in File_Type
) return Boolean;
91 function End_Of_File
(File
: in File_Type
) return Boolean;
93 function Stream
(File
: in File_Type
) return Stream_Access
;
95 -----------------------------
96 -- Input-Output Operations --
97 -----------------------------
100 (File
: in File_Type
;
101 Item
: out Stream_Element_Array
;
102 Last
: out Stream_Element_Offset
;
103 From
: in Positive_Count
);
106 (File
: in File_Type
;
107 Item
: out Stream_Element_Array
;
108 Last
: out Stream_Element_Offset
);
111 (File
: in File_Type
;
112 Item
: in Stream_Element_Array
;
113 To
: in Positive_Count
);
116 (File
: in File_Type
;
117 Item
: in Stream_Element_Array
);
119 ----------------------------------------
120 -- Operations on Position within File --
121 ----------------------------------------
123 procedure Set_Index
(File
: in File_Type
; To
: in Positive_Count
);
125 function Index
(File
: in File_Type
) return Positive_Count
;
126 function Size
(File
: in File_Type
) return Count
;
128 procedure Set_Mode
(File
: in out File_Type
; Mode
: in File_Mode
);
130 -- Note: The parameter file is IN OUT in the RM, but this is clearly
131 -- an oversight, and was intended to be IN, see AI95-00057.
133 procedure Flush
(File
: File_Type
);
139 Status_Error
: exception renames IO_Exceptions
.Status_Error
;
140 Mode_Error
: exception renames IO_Exceptions
.Mode_Error
;
141 Name_Error
: exception renames IO_Exceptions
.Name_Error
;
142 Use_Error
: exception renames IO_Exceptions
.Use_Error
;
143 Device_Error
: exception renames IO_Exceptions
.Device_Error
;
144 End_Error
: exception renames IO_Exceptions
.End_Error
;
145 Data_Error
: exception renames IO_Exceptions
.Data_Error
;
148 package FCB
renames System
.File_Control_Block
;
150 -----------------------------
151 -- Stream_IO Control Block --
152 -----------------------------
154 type Operation
is (Op_Read
, Op_Write
, Op_Other
);
155 -- Type used to record last operation (to optimize sequential operations)
157 type Stream_AFCB
is new FCB
.AFCB
with record
159 -- Current Index value
161 File_Size
: Stream_Element_Offset
:= -1;
162 -- Cached value of File_Size, so that we do not keep recomputing it
163 -- when not necessary (otherwise End_Of_File becomes gruesomely slow).
164 -- A value of minus one means that there is no cached value.
166 Last_Op
: Operation
:= Op_Other
;
167 -- Last operation performed on file, used to avoid unnecessary
168 -- repositioning between successive read or write operations.
170 Update_Mode
: Boolean := False;
171 -- Set if the mode is changed from write to read or vice versa.
172 -- Indicates that the file has been reopened in update mode.
176 type File_Type
is access all Stream_AFCB
;
178 function AFCB_Allocate
(Control_Block
: Stream_AFCB
) return FCB
.AFCB_Ptr
;
180 procedure AFCB_Close
(File
: access Stream_AFCB
);
181 procedure AFCB_Free
(File
: access Stream_AFCB
);
184 (File
: in out Stream_AFCB
;
185 Item
: out Ada
.Streams
.Stream_Element_Array
;
186 Last
: out Ada
.Streams
.Stream_Element_Offset
);
187 -- Read operation used when Stream_IO file is treated directly as Stream
190 (File
: in out Stream_AFCB
;
191 Item
: in Ada
.Streams
.Stream_Element_Array
);
192 -- Write operation used when Stream_IO file is treated directly as Stream
194 end Ada
.Streams
.Stream_IO
;