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
|
------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- S Y S T E M . D I R E C T _ I O --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
-- --
-- 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. --
-- --
------------------------------------------------------------------------------
-- This package contains the declaration of the control block used for
-- Direct_IO. This must be declared at the outer library level. It also
-- contains code that is shared between instances of Direct_IO.
with Interfaces.C_Streams;
with Ada.Streams;
with System.File_Control_Block;
with System.Storage_Elements;
package System.Direct_IO is
package FCB renames System.File_Control_Block;
type Operation is (Op_Read, Op_Write, Op_Other);
-- Type used to record last operation (to optimize sequential operations)
subtype Count is Interfaces.C_Streams.long;
-- The Count type in each instantiation is derived from this type
subtype Positive_Count is Count range 1 .. Count'Last;
type Direct_AFCB is new FCB.AFCB with record
Index : Count := 1;
-- Current Index value
Bytes : Interfaces.C_Streams.size_t;
-- Length of item in bytes (set from inside generic template)
Last_Op : Operation := Op_Other;
-- Last operation performed on file, used to avoid unnecessary
-- repositioning between successive read or write operations.
end record;
function AFCB_Allocate (Control_Block : Direct_AFCB) return FCB.AFCB_Ptr;
procedure AFCB_Close (File : not null access Direct_AFCB);
procedure AFCB_Free (File : not null access Direct_AFCB);
procedure Read
(File : in out Direct_AFCB;
Item : out Ada.Streams.Stream_Element_Array;
Last : out Ada.Streams.Stream_Element_Offset);
-- Required overriding of Read, not actually used for Direct_IO
procedure Write
(File : in out Direct_AFCB;
Item : Ada.Streams.Stream_Element_Array);
-- Required overriding of Write, not actually used for Direct_IO
type File_Type is access all Direct_AFCB;
-- File_Type in individual instantiations is derived from this type
procedure Create
(File : in out File_Type;
Mode : FCB.File_Mode := FCB.Inout_File;
Name : String := "";
Form : String := "");
function End_Of_File (File : File_Type) return Boolean;
function Index (File : File_Type) return Positive_Count;
procedure Open
(File : in out File_Type;
Mode : FCB.File_Mode;
Name : String;
Form : String := "");
procedure Read
(File : File_Type;
Item : System.Address;
Size : Interfaces.C_Streams.size_t;
From : Positive_Count);
procedure Read
(File : File_Type;
Item : System.Address;
Size : Interfaces.C_Streams.size_t);
procedure Reset (File : in out File_Type; Mode : FCB.File_Mode);
procedure Reset (File : in out File_Type);
procedure Set_Index (File : File_Type; To : Positive_Count);
function Size (File : File_Type) return Count;
procedure Write
(File : File_Type;
Item : System.Address;
Size : Interfaces.C_Streams.size_t;
Zeroes : System.Storage_Elements.Storage_Array);
-- Note: Zeroes is the buffer of zeroes used to fill out partial records
end System.Direct_IO;
|
