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
|
------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- S Y S T E M . D I R E C T _ I O --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2009, 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 3, 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. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- 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
-- The following procedures have a File_Type formal of mode IN OUT because
-- they may close the original file. The Close operation may raise an
-- exception, but in that case we want any assignment to the formal to
-- be effective anyway, so it must be passed by reference (or the caller
-- will be left with a dangling pointer).
pragma Export_Procedure
(Internal => Reset,
External => "",
Parameter_Types => (File_Type),
Mechanism => Reference);
pragma Export_Procedure
(Internal => Reset,
External => "",
Parameter_Types => (File_Type, FCB.File_Mode),
Mechanism => (File => Reference));
end System.Direct_IO;
|
