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, pressure stall information.
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 pressure;
23pub mod procstat;
24pub mod rapl;
25pub mod reboot;
26pub mod systemd;
27pub mod zfs;
28pub mod zpool;
29
30use std::fs;
31use std::path::{Path, PathBuf};
32
33/// Root directories of the kernel pseudo filesystems.
34#[derive(Debug, Clone)]
35pub struct SysRoots {
36    /// Normally `/sys`.
37    pub sys: PathBuf,
38    /// Normally `/proc`.
39    pub proc: PathBuf,
40}
41
42impl Default for SysRoots {
43    fn default() -> Self {
44        Self {
45            sys: PathBuf::from("/sys"),
46            proc: PathBuf::from("/proc"),
47        }
48    }
49}
50
51/// Reads a sysfs attribute and trims the trailing newline.
52///
53/// Returns `None` on any error: sysfs attributes may disappear at any time
54/// (hot-unplug) or be unreadable without root, and callers treat both as
55/// "not available".
56pub(crate) fn read_trimmed(path: &Path) -> Option<String> {
57    fs::read_to_string(path).ok().map(|s| s.trim().to_owned())
58}
59
60/// Reads a sysfs attribute holding a single unsigned integer.
61pub(crate) fn read_u64(path: &Path) -> Option<u64> {
62    read_trimmed(path)?.parse().ok()
63}
64
65/// Reads a sysfs attribute holding a single signed integer.
66pub(crate) fn read_i64(path: &Path) -> Option<i64> {
67    read_trimmed(path)?.parse().ok()
68}
69
70/// Returns the file names in `dir`, sorted, or an empty list if it cannot be read.
71pub(crate) fn sorted_entries(dir: &Path) -> Vec<String> {
72    let mut names: Vec<String> = match fs::read_dir(dir) {
73        Ok(entries) => entries
74            .filter_map(|e| e.ok())
75            .filter_map(|e| e.file_name().into_string().ok())
76            .collect(),
77        Err(_) => Vec::new(),
78    };
79    names.sort_by(|a, b| natural_cmp(a, b));
80    names
81}
82
83/// Compares strings so that embedded numbers sort numerically
84/// (`hwmon2` < `hwmon10`, `fan2` < `fan10`).
85pub(crate) fn natural_cmp(a: &str, b: &str) -> std::cmp::Ordering {
86    // Split into (non-digit prefix, trailing number). Kernel object names
87    // ("hwmon10", "nvme2", "md127") only carry a number at the end.
88    fn split(s: &str) -> (&str, Option<u64>) {
89        let digits_start = s
90            .char_indices()
91            .rev()
92            .take_while(|(_, c)| c.is_ascii_digit())
93            .last()
94            .map(|(i, _)| i)
95            .unwrap_or(s.len());
96        let (prefix, digits) = s.split_at(digits_start);
97        (prefix, digits.parse().ok())
98    }
99    let (pa, na) = split(a);
100    let (pb, nb) = split(b);
101    pa.cmp(pb).then(na.cmp(&nb)).then_with(|| a.cmp(b))
102}
103
104#[cfg(test)]
105pub(crate) mod testutil {
106    //! Helpers to build fake sysfs/procfs trees in a temporary directory.
107
108    use std::fs;
109    use std::path::Path;
110
111    /// Writes `content` to `root/rel`, creating parent directories.
112    pub fn write(root: &Path, rel: &str, content: &str) {
113        let path = root.join(rel);
114        fs::create_dir_all(path.parent().unwrap()).unwrap();
115        fs::write(path, content).unwrap();
116    }
117
118    /// Creates a symlink at `root/rel` pointing to `target` (absolute or relative).
119    pub fn symlink(root: &Path, rel: &str, target: &Path) {
120        let path = root.join(rel);
121        fs::create_dir_all(path.parent().unwrap()).unwrap();
122        std::os::unix::fs::symlink(target, path).unwrap();
123    }
124}
125
126#[cfg(test)]
127mod tests {
128    use super::natural_cmp;
129
130    #[test]
131    fn natural_order_sorts_numbers_numerically() {
132        let mut names = vec!["hwmon10", "hwmon2", "hwmon1", "fan"];
133        names.sort_by(|a, b| natural_cmp(a, b));
134        assert_eq!(names, vec!["fan", "hwmon1", "hwmon2", "hwmon10"]);
135    }
136}
rigtop_core/linux/mod.rs

rigtop_core/linux/
mod.rs
