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

rigtop_core/linux/
mod.rs
