hierr/
lib.rs

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
//! 包装OS的错误码, 统一错误码的查询和获取接口
//! 1. fn errno() -> i32;
//! 2. fn set_errno(i32);
//! 3. fn errmsg(i32, &mut [u8]) -> &str;
//!
//! 封装i32为Error
//!
//! # Example
//! ```rust
//! use hierr;
//!
//! hierr::set_errno(100);
//! let err = hierr::Error::last();
//!
//! println!("{}", err);
//!
//! let mut buf = [0_u8; 64];
//! println!("{}: {}",  hierr::errno(), hierr::errmsg(hierr::errno(), &mut buf[..]));
//!
//! assert_eq!(err, 100.into());
//! assert_eq!(hierr::errno(), 100);
//!
//! ```

#![no_std]

use core::fmt;
use core::result;
use core::str;

pub type Result<T> = result::Result<T, Error>;

#[derive(Copy, Clone, Eq, Ord, PartialEq, PartialOrd)]
#[repr(transparent)]
pub struct Error {
    pub errno: i32,
}

impl Error {
    pub const fn new(errno: i32) -> Self {
        Self { errno }
    }
    pub fn last() -> Self {
        Self { errno: errno() }
    }
}

impl Default for Error {
    fn default() -> Self {
        Error::new(-1)
    }
}

impl From<i32> for Error {
    fn from(i32: i32) -> Self {
        Self::new(i32)
    }
}

impl From<Error> for Result<()> {
    fn from(err: Error) -> Self {
        if err.errno == 0 {
            Ok(())
        } else {
            Err(err)
        }
    }
}

const ERRMSG_MAX_SIZE: usize = 64;
impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> result::Result<(), fmt::Error> {
        let mut msg = [0_u8; ERRMSG_MAX_SIZE];
        write!(f, "{}: {}", self.errno, errmsg(self.errno, &mut msg[..]))
    }
}

impl fmt::Debug for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> result::Result<(), fmt::Error> {
        let mut msg = [0_u8; ERRMSG_MAX_SIZE];
        write!(f, "{}: {}", self.errno, errmsg(self.errno, &mut msg[..]))
    }
}

#[cfg(any(unix, all(target_os = "windows", target_env = "gnu")))]
fn format_message_utf8<'a>(input: &[u8], output: &'a mut [u8]) -> &'a str {
    let Ok(s) = str::from_utf8(input) else {
        return get_message(output, 0);
    };
    if input.len() <= output.len() {
        output[..input.len()].copy_from_slice(input);
        return str::from_utf8(&output[..input.len()]).unwrap();
    }
    return truncate_message(s, output);
}

#[cfg(any(unix, all(target_os = "windows", target_env = "gnu")))]
fn truncate_message<'a>(input: &str, output: &'a mut [u8]) -> &'a str {
    let mut pos = 0;
    for c in input.chars() {
        if !put_message(output, &mut pos, c) {
            break;
        }
    }
    get_message(output, pos)
}

fn put_message(output: &mut [u8], pos: &mut usize, c: char) -> bool {
    if *pos + c.len_utf8() <= output.len() {
        c.encode_utf8(&mut output[*pos..]);
        *pos += c.len_utf8();
        return true;
    }
    false
}

fn get_message(output: &[u8], len: usize) -> &str {
    if len > 0 {
        str::from_utf8(&output[..len]).unwrap()
    } else {
        "Unknown error"
    }
}

#[cfg(all(target_os = "windows", not(target_env = "gnu")))]
fn format_message_utf16<'a>(input: &[u16], output: &'a mut [u8]) -> &'a str {
    let mut pos = 0;
    char::decode_utf16(input.iter().copied()).any(|c| {
        let Ok(c) = c else {
            pos = 0;
            return true;
        };
        !put_message(output, &mut pos, c)
    });
    get_message(output, pos)
}

#[cfg(any(unix, all(target_os = "windows", target_env = "gnu")))]
mod unix;
#[cfg(any(unix, all(target_os = "windows", target_env = "gnu")))]
pub use unix::*;

#[cfg(all(target_os = "windows", not(target_env = "gnu")))]
mod windows;
#[cfg(all(target_os = "windows", not(target_env = "gnu")))]
pub use windows::*;

#[cfg(test)]
mod test {
    use super::*;
    extern crate std;
    use std::println;

    #[test]
    fn test_errno() {
        set_errno(100);
        assert_eq!(errno(), 100);
    }

    #[test]
    fn test_print() {
        for n in 0..=102 {
            let err = Error::new(n);
            println!("[{}]\n[{:?}]\n", err, err);
        }

        set_errno(4);
        println!("5: {}", errmsg(5, &mut [0_u8; 7]));
    }
}