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
use magic::{flags, Cookie, MagicError};
use mime::FromStrError;
use std::env::temp_dir;
use std::fs::File;
use std::io::{self, Read, Write};
use std::path::{Path, PathBuf};
use std::{error, fmt};
pub struct MimeDetective {
cookie: Cookie,
}
impl MimeDetective {
pub fn new() -> Result<MimeDetective, DetectiveError> {
let path = Self::magic_file()?;
MimeDetective::load_databases(&[&path])
}
fn magic_file() -> Result<PathBuf, DetectiveError> {
let bytes = include_bytes!("../default_magic.mgc");
let magic_path = temp_dir().join(".mime_detective_magic.mgc");
let mut file = File::create(&magic_path)?;
file.write_all(bytes)?;
Ok(magic_path)
}
pub fn load_databases<P: AsRef<Path>>(path: &[P]) -> Result<MimeDetective, DetectiveError> {
let cookie = Cookie::open(flags::MIME_TYPE)?;
cookie.load(path)?;
Ok(MimeDetective { cookie })
}
pub fn detect_filepath<P: AsRef<Path>>(
&self,
filename: P,
) -> Result<mime::Mime, DetectiveError> {
let mime_str = self.cookie.file(filename)?;
let mime: mime::Mime = mime_str.parse()?;
Ok(mime)
}
pub fn detect_file(&self, file: &mut File) -> Result<mime::Mime, DetectiveError> {
let mut buf: [u8; 2] = [0; 2];
file.read_exact(&mut buf)?;
self.detect_buffer(&buf)
}
pub fn detect_buffer(&self, buffer: &[u8]) -> Result<mime::Mime, DetectiveError> {
let mime_str = self.cookie.buffer(buffer)?;
let mime: mime::Mime = mime_str.parse()?;
Ok(mime)
}
}
#[derive(Debug)]
pub enum DetectiveError {
Magic(MagicError),
Parse(FromStrError),
IO(io::Error),
}
impl error::Error for DetectiveError {
fn source(&self) -> Option<&(dyn error::Error + 'static)> {
match self {
DetectiveError::Magic(err) => err.source(),
DetectiveError::Parse(err) => err.source(),
DetectiveError::IO(err) => err.source(),
}
}
}
impl fmt::Display for DetectiveError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
DetectiveError::Magic(err) => write!(f, "MagicError: {}", err),
DetectiveError::Parse(err) => write!(f, "MimeParseError: {}", err),
DetectiveError::IO(err) => write!(f, "IOError: {}", err),
}
}
}
impl From<MagicError> for DetectiveError {
fn from(err: MagicError) -> Self {
DetectiveError::Magic(err)
}
}
impl From<FromStrError> for DetectiveError {
fn from(err: FromStrError) -> Self {
DetectiveError::Parse(err)
}
}
impl From<io::Error> for DetectiveError {
fn from(err: io::Error) -> Self {
DetectiveError::IO(err)
}
}
#[cfg(test)]
mod tests {
use super::MimeDetective;
use mime;
use std::fs::File;
use std::io::Read;
fn init() -> MimeDetective {
MimeDetective::new().expect("mime db not found")
}
fn read_file() -> File {
File::open("Cargo.toml").unwrap()
}
#[test]
fn detect_filepath() {
let detective = init();
let mime = detective.detect_filepath("Cargo.toml").unwrap();
assert_eq!(mime::TEXT_PLAIN, mime);
}
#[test]
fn detect_file() {
let detective = init();
let mut file = read_file();
let mime = detective.detect_file(&mut file).unwrap();
assert_eq!(mime::TEXT_PLAIN, mime);
}
#[test]
fn detect_buffer() {
let detective = init();
let mut file = read_file();
let mut buf: [u8; 2] = [0; 2];
file.read_exact(&mut buf).unwrap();
let mime = detective.detect_buffer(&buf).unwrap();
assert_eq!(mime::TEXT_PLAIN, mime);
}
}