1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
------------------------------------------------------------------------------
-- --
-- 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) 1992-2006, 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 2, 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. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- 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
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
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;
function AFCB_Allocate (Control_Block : Stream_AFCB) return FCB.AFCB_Ptr;
procedure AFCB_Close (File : access Stream_AFCB);
procedure AFCB_Free (File : access Stream_AFCB);
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
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;
|
