rigtop_core/linux/
mod.rs

1//! Linux-specific readers for `/sys` and `/proc`.
2//!
3//! These cover what `sysinfo` does not expose: hwmon sensors, RAPL energy
4//! counters, per-device disk I/O, btrfs, mdadm and ZFS state, failed
5//! systemd units, OOM kills, pending reboots, the containers processes run
6//! in.
7//!
8//! Every reader takes its root directories from [`SysRoots`] instead of
9//! hard-coding `/sys` and `/proc`, so tests can point them at a fixture tree.
10
11pub mod battery;
12pub mod btrfs;
13pub mod containers;
14pub mod diskstats;
15pub mod drm;
16pub mod hwmon;
17pub mod mdstat;
18pub mod meminfo;
19pub mod mounts;
20pub mod net;
21pub mod oom;
22pub mod procstat;
23pub mod rapl;
24pub mod reboot;
25pub mod systemd;
26pub mod zfs;
27
28use std::fs;
29use std::path::{Path, PathBuf};
30
31/// Root directories of the kernel pseudo filesystems.
32#[derive(Debug, Clone)]
33pub struct SysRoots {
34    /// Normally `/sys`.
35    pub sys: PathBuf,
36    /// Normally `/proc`.
37    pub proc: PathBuf,
38}
39
40impl Default for SysRoots {
41    fn default() -> Self {
42        Self {
43            sys: PathBuf::from("/sys"),
44            proc: PathBuf::from("/proc"),
45        }
46    }
47}
48
49/// Reads a sysfs attribute and trims the trailing newline.
50///
51/// Returns `None` on any error: sysfs attributes may disappear at any time
52/// (hot-unplug) or be unreadable without root, and callers treat both as
53/// "not available".
54pub(crate) fn read_trimmed(path: &Path) -> Option<String> {
55    fs::read_to_string(path).ok().map(|s| s.trim().to_owned())
56}
57
58/// Reads a sysfs attribute holding a single unsigned integer.
59pub(crate) fn read_u64(path: &Path) -> Option<u64> {
60    read_trimmed(path)?.parse().ok()
61}
62
63/// Reads a sysfs attribute holding a single signed integer.
64pub(crate) fn read_i64(path: &Path) -> Option<i64> {
65    read_trimmed(path)?.parse().ok()
66}
67
68/// Returns the file names in `dir`, sorted, or an empty list if it cannot be read.
69pub(crate) fn sorted_entries(dir: &Path) -> Vec<String> {
70    let mut names: Vec<String> = match fs::read_dir(dir) {
71        Ok(entries) => entries
72            .filter_map(|e| e.ok())
73            .filter_map(|e| e.file_name().into_string().ok())
74            .collect(),
75        Err(_) => Vec::new(),
76    };
77    names.sort_by(|a, b| natural_cmp(a, b));
78    names
79}
80
81/// Compares strings so that embedded numbers sort numerically
82/// (`hwmon2` < `hwmon10`, `fan2` < `fan10`).
83pub(crate) fn natural_cmp(a: &str, b: &str) -> std::cmp::Ordering {
84    // Split into (non-digit prefix, trailing number). Kernel object names
85    // ("hwmon10", "nvme2", "md127") only carry a number at the end.
86    fn split(s: &str) -> (&str, Option<u64>) {
87        let digits_start = s
88            .char_indices()
89            .rev()
90            .take_while(|(_, c)| c.is_ascii_digit())
91            .last()
92            .map(|(i, _)| i)
93            .unwrap_or(s.len());
94        let (prefix, digits) = s.split_at(digits_start);
95        (prefix, digits.parse().ok())
96    }
97    let (pa, na) = split(a);
98    let (pb, nb) = split(b);
99    pa.cmp(pb).then(na.cmp(&nb)).then_with(|| a.cmp(b))
100}
101
102#[cfg(test)]
103pub(crate) mod testutil {
104    //! Helpers to build fake sysfs/procfs trees in a temporary directory.
105
106    use std::fs;
107    use std::path::Path;
108
109    /// Writes `content` to `root/rel`, creating parent directories.
110    pub fn write(root: &Path, rel: &str, content: &str) {
111        let path = root.join(rel);
112        fs::create_dir_all(path.parent().unwrap()).unwrap();
113        fs::write(path, content).unwrap();
114    }
115
116    /// Creates a symlink at `root/rel` pointing to `target` (absolute or relative).
117    pub fn symlink(root: &Path, rel: &str, target: &Path) {
118        let path = root.join(rel);
119        fs::create_dir_all(path.parent().unwrap()).unwrap();
120        std::os::unix::fs::symlink(target, path).unwrap();
121    }
122}
123
124#[cfg(test)]
125mod tests {
126    use super::natural_cmp;
127
128    #[test]
129    fn natural_order_sorts_numbers_numerically() {
130        let mut names = vec!["hwmon10", "hwmon2", "hwmon1", "fan"];
131        names.sort_by(|a, b| natural_cmp(a, b));
132        assert_eq!(names, vec!["fan", "hwmon1", "hwmon2", "hwmon10"]);
133    }
134}
rigtop_core/linux/mod.rs

rigtop_core/linux/
mod.rs
