summaryrefslogtreecommitdiff
path: root/Userland/Libraries/LibCore/IODevice.h
blob: 8223f5d84f109ccba460eb036cfd5770c2e9af95 (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
/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 * Copyright (c) 2022, the SerenityOS developers.
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/EnumBits.h>
#include <AK/Forward.h>
#include <AK/Stream.h>
#include <LibCore/Object.h>

namespace Core {

class IODevice;

// This is not necessarily a valid iterator in all contexts,
// if we had concepts, this would be InputIterator, not Copyable, Movable.
class LineIterator {
    AK_MAKE_NONCOPYABLE(LineIterator);

public:
    explicit LineIterator(IODevice&, bool is_end = false);

    bool operator==(LineIterator const& other) const { return &other == this || (at_end() && other.is_end()) || (other.at_end() && is_end()); }
    bool is_end() const { return m_is_end; }
    bool at_end() const;

    LineIterator& operator++();

    StringView operator*() const { return m_buffer; }

private:
    NonnullRefPtr<IODevice> m_device;
    bool m_is_end { false };
    DeprecatedString m_buffer;
};

class LineRange {
public:
    LineRange() = delete;
    explicit LineRange(IODevice& device)
        : m_device(device)
    {
    }
    LineIterator begin();
    LineIterator end();

private:
    IODevice& m_device;
};

enum class OpenMode : unsigned {
    NotOpen = 0,
    ReadOnly = 1,
    WriteOnly = 2,
    ReadWrite = 3,
    Append = 4,
    Truncate = 8,
    MustBeNew = 16,
    KeepOnExec = 32,
};

AK_ENUM_BITWISE_OPERATORS(OpenMode)

class IODevice : public Object {
    C_OBJECT_ABSTRACT(IODevice)
public:
    virtual ~IODevice() override = default;

    int fd() const { return m_fd; }
    OpenMode mode() const { return m_mode; }
    bool is_open() const { return m_mode != OpenMode::NotOpen; }
    bool eof() const { return m_eof; }

    int error() const { return m_error; }
    char const* error_string() const;

    bool has_error() const { return m_error != 0; }

    int read(u8* buffer, int length);

    ByteBuffer read(size_t max_size);
    ByteBuffer read_all();
    DeprecatedString read_line(size_t max_size = 16384);

    bool write(u8 const*, int size);
    bool write(StringView);

    bool truncate(off_t);

    bool can_read_line() const;

    bool can_read() const;
    bool can_read_only_from_buffer() const { return !m_buffered_data.is_empty() && !can_read_from_fd(); }

    bool seek(i64, SeekMode = SeekMode::SetPosition, off_t* = nullptr);

    virtual bool open(OpenMode) = 0;
    virtual bool close();

    LineIterator line_begin() & { return LineIterator(*this); }
    LineIterator line_end() { return LineIterator(*this, true); }
    LineRange lines()
    {
        return LineRange(*this);
    }

protected:
    explicit IODevice(Object* parent = nullptr);

    void set_fd(int);
    void set_mode(OpenMode mode) { m_mode = mode; }
    void set_error(int error) const { m_error = error; }
    void set_eof(bool eof) const { m_eof = eof; }

    virtual void did_update_fd(int) { }

private:
    bool populate_read_buffer(size_t size = 1024) const;
    bool can_read_from_fd() const;

    int m_fd { -1 };
    OpenMode m_mode { OpenMode::NotOpen };
    mutable int m_error { 0 };
    mutable bool m_eof { false };
    mutable Vector<u8> m_buffered_data;
};

}