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

rigtop_core/linux/
mod.rs
