sync cpu time

Cargo.lock

@@ -1059,6 +1059,7 @@ dependencies = [
  "heim",
  "hostname",
  "iai",
+ "libc",
  "once_cell",
  "parse-display",
  "regex",

Cargo.toml

@@ -17,6 +17,7 @@ parse-display = "0.4"
 regex = { version = "1", default-features = false }
 once_cell = "1"
 hostname = "0.3"
+libc = "0.2"
 
 [dev-dependencies]
 iai = "0.1"

src/lib.rs

@@ -11,12 +11,12 @@ use std::collections::HashSet;
 use std::fmt::Write;
 
 pub async fn get_metrics() -> Result<String> {
-    let (cpu, network, disks, disk_usage) = try_join! {
-        cpu_time(),
+    let (network, disks, disk_usage) = try_join! {
         network_stats(),
         disk_stats(),
         disk_usage(),
     }?;
+    let cpu = cpu_time()?;
     let hostname = hostname()?;
     let memory = memory()?;
     let temperatures = temperatures()?;

src/sensors.rs

@@ -1,9 +1,8 @@
 use color_eyre::{Report, Result};
 use futures_util::future;
 use futures_util::stream::{Stream, StreamExt};
-use heim::cpu::time;
 use heim::disk::{FileSystem, Partition};
-use heim::units::{information, time};
+use heim::units::information;
 use once_cell::sync::Lazy;
 use parse_display::Display;
 use regex::Regex;
@@ -110,9 +109,22 @@ pub fn memory() -> Result<Memory> {
     Ok(mem)
 }
 
-pub async fn cpu_time() -> Result<f64> {
-    let time = time().await?;
-    Ok(time.user().get::<time::second>() + time.system().get::<time::second>())
+pub fn cpu_time() -> Result<u64> {
+    let stat = BufReader::new(File::open("/proc/stat")?);
+    let line = stat
+        .lines()
+        .next()
+        .ok_or(Report::msg("Invalid /proc/stat"))??;
+    let mut parts = line.split_ascii_whitespace();
+    if let (_cpu, Some(user), _nice, Some(system)) =
+        (parts.next(), parts.next(), parts.next(), parts.next())
+    {
+        let user: u64 = user.parse()?;
+        let system: u64 = system.parse()?;
+        Ok((user + system) * clock_ticks()?)
+    } else {
+        Err(Report::msg("Invalid /proc/stat"))
+    }
 }
 
 pub async fn network_stats() -> Result<impl Stream<Item = IOStats>> {
@@ -173,3 +185,13 @@ pub async fn disk_usage() -> Result<impl Stream<Item = DiskUsage>> {
             free: usage.free().get::<information::byte>(),
         }))
 }
+
+fn clock_ticks() -> Result<u64> {
+    let result = unsafe { libc::sysconf(libc::_SC_CLK_TCK) };
+
+    if result > 0 {
+        Ok(result as u64)
+    } else {
+        Err(Report::msg("Failed to get clock ticks"))
+    }
+}