sysinfo/unix/linux/
utils.rs

1// Take a look at the license at the top of the repository in the LICENSE file.
2
3#[cfg(any(feature = "disk", feature = "system"))]
4use std::fs::File;
5#[cfg(any(feature = "disk", feature = "system"))]
6use std::io::{self, Read, Seek};
7#[cfg(any(feature = "disk", feature = "system"))]
8use std::path::Path;
9
10#[cfg(feature = "system")]
11pub(crate) fn get_all_data_from_file(file: &mut File, size: usize) -> io::Result<Vec<u8>> {
12    let mut buf = Vec::with_capacity(size);
13    file.rewind()?;
14    file.read_to_end(&mut buf)?;
15    Ok(buf)
16}
17
18#[cfg(any(feature = "disk", feature = "system"))]
19pub(crate) fn get_all_utf8_data_from_file(file: &mut File, size: usize) -> io::Result<String> {
20    let mut buf = String::with_capacity(size);
21    file.rewind()?;
22    file.read_to_string(&mut buf)?;
23    Ok(buf)
24}
25
26#[cfg(any(feature = "disk", feature = "system"))]
27pub(crate) fn get_all_utf8_data<P: AsRef<Path>>(file_path: P, size: usize) -> io::Result<String> {
28    let mut file = File::open(file_path.as_ref())?;
29    get_all_utf8_data_from_file(&mut file, size)
30}
31
32#[cfg(feature = "system")]
33#[allow(clippy::useless_conversion)]
34pub(crate) fn realpath(path: &Path) -> Option<std::path::PathBuf> {
35    match std::fs::read_link(path) {
36        Ok(path) => Some(path),
37        Err(_e) => {
38            sysinfo_debug!("failed to get real path for {:?}: {:?}", path, _e);
39            None
40        }
41    }
42}
43
44/// This type is used in `retrieve_all_new_process_info` because we have a "parent" path and
45/// from it, we `pop`/`join` every time because it's more memory efficient than using `Path::join`.
46#[cfg(feature = "system")]
47pub(crate) struct PathHandler(std::path::PathBuf);
48
49#[cfg(feature = "system")]
50impl PathHandler {
51    pub(crate) fn new(path: &Path) -> Self {
52        // `path` is the "parent" for all paths which will follow so we add a fake element at
53        // the end since every `PathHandler::replace_and_join` call will first call `pop`
54        // internally.
55        Self(path.join("a"))
56    }
57
58    pub(crate) fn as_path(&self) -> &Path {
59        &self.0
60    }
61}
62
63#[cfg(feature = "system")]
64pub(crate) trait PathPush {
65    fn replace_and_join(&mut self, p: &str) -> &Path;
66}
67
68#[cfg(feature = "system")]
69impl PathPush for PathHandler {
70    fn replace_and_join(&mut self, p: &str) -> &Path {
71        self.0.pop();
72        self.0.push(p);
73        self.as_path()
74    }
75}
76
77// This implementation allows to skip one allocation that is done in `PathHandler`.
78#[cfg(feature = "system")]
79impl PathPush for std::path::PathBuf {
80    fn replace_and_join(&mut self, p: &str) -> &Path {
81        self.push(p);
82        self.as_path()
83    }
84}
85
86#[cfg(feature = "system")]
87pub(crate) fn to_u64(v: &[u8]) -> u64 {
88    let mut x = 0;
89
90    for c in v {
91        x *= 10;
92        x += u64::from(c - b'0');
93    }
94    x
95}
96
97/// Converts a path to a NUL-terminated `Vec<u8>` suitable for use with C functions.
98#[cfg(feature = "disk")]
99pub(crate) fn to_cpath(path: &std::path::Path) -> Vec<u8> {
100    use std::{ffi::OsStr, os::unix::ffi::OsStrExt};
101
102    let path_os: &OsStr = path.as_ref();
103    let mut cpath = path_os.as_bytes().to_vec();
104    cpath.push(0);
105    cpath
106}
sysinfo/unix/linux/utils.rs

sysinfo/unix/linux/
utils.rs
