aboutsummaryrefslogtreecommitdiff
path: root/paludis/util/safe_ifstream.hh
blob: 37803e65d8048584155cf4a28df50ef8b7231470 (plain)
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
/* vim: set sw=4 sts=4 et foldmethod=syntax : */

/*
 * Copyright (c) 2009 Ciaran McCreesh
 *
 * This file is part of the Paludis package manager. Paludis is free software;
 * you can redistribute it and/or modify it under the terms of the GNU General
 * Public License version 2, as published by the Free Software Foundation.
 *
 * Paludis is distributed in the hope that it will be useful, but WITHOUT 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 along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef PALUDIS_GUARD_PALUDIS_UTIL_SAFE_IFSTREAM_HH
#define PALUDIS_GUARD_PALUDIS_UTIL_SAFE_IFSTREAM_HH 1

#include <paludis/util/attributes.hh>
#include <paludis/util/exception.hh>
#include <paludis/util/fs_entry-fwd.hh>
#include <istream>

/** \file
 * Declarations for SafeIFStream.
 *
 * \ingroup g_fs
 *
 * \section Examples
 *
 * - None at this time.
 */

namespace paludis
{
    /**
     * Input stream buffer class that can be opened via an FD, and that doesn't
     * do retarded things when given a non-file.
     *
     * See \ref TCppSL Ch. 13.13 for what we're doing here. The buffer code is
     * based upon the "io/inbuf1.hpp" example in section 13.13.3.
     *
     * \ingroup g_fs
     * \since 0.34.3
     */
    class PALUDIS_VISIBLE SafeIFStreamBuf :
        public std::streambuf
    {
        protected:
            static const int lookbehind_size = 16;
            static const int buffer_size = 512 + lookbehind_size;
            char buffer[buffer_size];

            virtual int_type underflow();
            virtual pos_type seekoff(off_type, std::ios_base::seekdir, std::ios_base::openmode);
            virtual pos_type seekpos(pos_type, std::ios_base::openmode);

        public:
            ///\name Basic operations
            ///\{

            SafeIFStreamBuf(const int f);

            ///\}

            /// Our file descriptor.
            int fd;
    };

    /**
     * Member from base initialisation for SafeIFStream.
     *
     * \ingroup g_fs
     * \since 0.34.3
     */
    class PALUDIS_VISIBLE SafeIFStreamBase
    {
        protected:
            /// Our buffer.
            SafeIFStreamBuf buf;

        public:
            ///\name Basic operations
            ///\{

            SafeIFStreamBase(const int fd);

            ///\}
    };

    /**
     * Input stream buffer class that can be opened via an FD, and that doesn't
     * do retarded things when given a non-file.
     *
     * \ingroup g_fs
     * \since 0.34.3
     */
    class PALUDIS_VISIBLE SafeIFStream :
        protected SafeIFStreamBase,
        public std::istream
    {
        private:
            const bool _close;

        public:
            ///\name Basic operations
            ///\{

            SafeIFStream(const int fd);
            SafeIFStream(const FSEntry &);
            ~SafeIFStream();

            ///\}
    };

    /**
     * Thrown by SafeIFStream if an error occurs.
     *
     * \ingroup g_fs
     * \since 0.34.3
     */
    class PALUDIS_VISIBLE SafeIFStreamError :
        public Exception
    {
        public:
            SafeIFStreamError(const std::string &) throw ();
    };
}

#endif