v0.1.5 (#40)

Reviewed-on: wrenn/wrenn#40

envd-rs/src/host/metrics.rs

@@ -0,0 +1,73 @@
+use std::ffi::CString;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use serde::Serialize;
+
+#[derive(Serialize)]
+pub struct Metrics {
+    pub ts: i64,
+    pub cpu_count: u32,
+    pub cpu_used_pct: f32,
+    pub mem_total_mib: u64,
+    pub mem_used_mib: u64,
+    pub mem_total: u64,
+    pub mem_used: u64,
+    pub disk_used: u64,
+    pub disk_total: u64,
+}
+
+pub fn get_metrics() -> Result<Metrics, String> {
+    use sysinfo::System;
+
+    let mut sys = System::new();
+    sys.refresh_memory();
+    sys.refresh_cpu_all();
+
+    std::thread::sleep(std::time::Duration::from_millis(100));
+    sys.refresh_cpu_all();
+
+    let cpu_count = sys.cpus().len() as u32;
+    let cpu_used_pct = sys.global_cpu_usage();
+    let cpu_used_pct_rounded = if cpu_used_pct > 0.0 {
+        (cpu_used_pct * 100.0).round() / 100.0
+    } else {
+        0.0
+    };
+
+    let mem_total = sys.total_memory();
+    let mem_used = sys.used_memory();
+
+    let (disk_total, disk_used) = disk_stats("/")?;
+
+    let ts = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap()
+        .as_secs() as i64;
+
+    Ok(Metrics {
+        ts,
+        cpu_count,
+        cpu_used_pct: cpu_used_pct_rounded,
+        mem_total_mib: mem_total / 1024 / 1024,
+        mem_used_mib: mem_used / 1024 / 1024,
+        mem_total,
+        mem_used,
+        disk_used,
+        disk_total,
+    })
+}
+
+fn disk_stats(path: &str) -> Result<(u64, u64), String> {
+    let c_path = CString::new(path).unwrap();
+    let mut stat: libc::statfs = unsafe { std::mem::zeroed() };
+    let ret = unsafe { libc::statfs(c_path.as_ptr(), &mut stat) };
+    if ret != 0 {
+        return Err(format!("statfs failed: {}", std::io::Error::last_os_error()));
+    }
+
+    let block = stat.f_bsize as u64;
+    let total = stat.f_blocks * block;
+    let available = stat.f_bavail * block;
+
+    Ok((total, total - available))
+}