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

use axio::{prelude::*, Result, SeekFrom};
use core::fmt;

use crate::fops;

/// A structure representing a type of file with accessors for each file type.
/// It is returned by [`Metadata::file_type`] method.
pub type FileType = fops::FileType;

/// Representation of the various permissions on a file.
pub type Permissions = fops::FilePerm;

/// An object providing access to an open file on the filesystem.
pub struct File {
    inner: fops::File,
}

/// Metadata information about a file.
pub struct Metadata(fops::FileAttr);

/// Options and flags which can be used to configure how a file is opened.
#[derive(Clone, Debug)]
pub struct OpenOptions(fops::OpenOptions);

impl OpenOptions {
    /// Creates a blank new set of options ready for configuration.
    pub const fn new() -> Self {
        OpenOptions(fops::OpenOptions::new())
    }

    /// Sets the option for read access.
    pub fn read(&mut self, read: bool) -> &mut Self {
        self.0.read(read);
        self
    }

    /// Sets the option for write access.
    pub fn write(&mut self, write: bool) -> &mut Self {
        self.0.write(write);
        self
    }

    /// Sets the option for the append mode.
    pub fn append(&mut self, append: bool) -> &mut Self {
        self.0.append(append);
        self
    }

    /// Sets the option for truncating a previous file.
    pub fn truncate(&mut self, truncate: bool) -> &mut Self {
        self.0.truncate(truncate);
        self
    }

    /// Sets the option to create a new file, or open it if it already exists.
    pub fn create(&mut self, create: bool) -> &mut Self {
        self.0.create(create);
        self
    }

    /// Sets the option to create a new file, failing if it already exists.
    pub fn create_new(&mut self, create_new: bool) -> &mut Self {
        self.0.create_new(create_new);
        self
    }

    /// Opens a file at `path` with the options specified by `self`.
    pub fn open(&self, path: &str) -> Result<File> {
        fops::File::open(path, &self.0).map(|inner| File { inner })
    }
}

impl Metadata {
    /// Returns the file type for this metadata.
    pub const fn file_type(&self) -> FileType {
        self.0.file_type()
    }

    /// Returns `true` if this metadata is for a directory. The
    /// result is mutually exclusive to the result of
    /// [`Metadata::is_file`].
    pub const fn is_dir(&self) -> bool {
        self.0.is_dir()
    }

    /// Returns `true` if this metadata is for a regular file. The
    /// result is mutually exclusive to the result of
    /// [`Metadata::is_dir`].
    pub const fn is_file(&self) -> bool {
        self.0.is_file()
    }

    /// Returns the size of the file, in bytes, this metadata is for.
    #[allow(clippy::len_without_is_empty)]
    pub const fn len(&self) -> u64 {
        self.0.size()
    }

    /// Returns the permissions of the file this metadata is for.
    pub const fn permissions(&self) -> Permissions {
        self.0.perm()
    }

    /// Returns the total size of this file in bytes.
    pub const fn size(&self) -> u64 {
        self.0.size()
    }

    /// Returns the number of blocks allocated to the file, in 512-byte units.
    pub const fn blocks(&self) -> u64 {
        self.0.blocks()
    }
}

impl fmt::Debug for Metadata {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("Metadata")
            .field("file_type", &self.file_type())
            .field("is_dir", &self.is_dir())
            .field("is_file", &self.is_file())
            .field("permissions", &self.permissions())
            .finish_non_exhaustive()
    }
}

impl File {
    /// Attempts to open a file in read-only mode.
    pub fn open(path: &str) -> Result<Self> {
        OpenOptions::new().read(true).open(path)
    }

    /// Opens a file in write-only mode.
    pub fn create(path: &str) -> Result<Self> {
        OpenOptions::new()
            .write(true)
            .create(true)
            .truncate(true)
            .open(path)
    }

    /// Creates a new file in read-write mode; error if the file exists.
    pub fn create_new(path: &str) -> Result<Self> {
        OpenOptions::new()
            .read(true)
            .write(true)
            .create_new(true)
            .open(path)
    }

    /// Returns a new OpenOptions object.
    pub fn options() -> OpenOptions {
        OpenOptions::new()
    }

    /// Truncates or extends the underlying file, updating the size of
    /// this file to become `size`.
    pub fn set_len(&self, size: u64) -> Result<()> {
        self.inner.truncate(size)
    }

    /// Queries metadata about the underlying file.
    pub fn metadata(&self) -> Result<Metadata> {
        self.inner.get_attr().map(Metadata)
    }
}

impl Read for File {
    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
        self.inner.read(buf)
    }
}

impl Write for File {
    fn write(&mut self, buf: &[u8]) -> Result<usize> {
        self.inner.write(buf)
    }

    fn flush(&mut self) -> Result<()> {
        self.inner.flush()
    }
}

impl Seek for File {
    fn seek(&mut self, pos: SeekFrom) -> Result<u64> {
        self.inner.seek(pos)
    }
}