1 files changed, 83 insertions, 0 deletions
diff --git a/third_party/rust/nix/src/sys/sysinfo.rs b/third_party/rust/nix/src/sys/sysinfo.rs
new file mode 100644
index 0000000000..e8aa00b00d
--- /dev/null
+++ b/third_party/rust/nix/src/sys/sysinfo.rs
@@ -0,0 +1,83 @@
+use libc::{self, SI_LOAD_SHIFT};
+use std::time::Duration;
+use std::{cmp, mem};
+
+use crate::errno::Errno;
+use crate::Result;
+
+/// System info structure returned by `sysinfo`.
+#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq)]
+#[repr(transparent)]
+pub struct SysInfo(libc::sysinfo);
+
+// The fields are c_ulong on 32-bit linux, u64 on 64-bit linux; x32's ulong is u32
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "32"))]
+type mem_blocks_t = u64;
+#[cfg(not(all(target_arch = "x86_64", target_pointer_width = "32")))]
+type mem_blocks_t = libc::c_ulong;
+
+impl SysInfo {
+    /// Returns the load average tuple.
+    ///
+    /// The returned values represent the load average over time intervals of
+    /// 1, 5, and 15 minutes, respectively.
+    pub fn load_average(&self) -> (f64, f64, f64) {
+        (
+            self.0.loads[0] as f64 / (1 << SI_LOAD_SHIFT) as f64,
+            self.0.loads[1] as f64 / (1 << SI_LOAD_SHIFT) as f64,
+            self.0.loads[2] as f64 / (1 << SI_LOAD_SHIFT) as f64,
+        )
+    }
+
+    /// Returns the time since system boot.
+    // The cast is not unnecessary on all platforms.
+    #[allow(clippy::unnecessary_cast)]
+    pub fn uptime(&self) -> Duration {
+        // Truncate negative values to 0
+        Duration::from_secs(cmp::max(self.0.uptime, 0) as u64)
+    }
+
+    /// Current number of processes.
+    pub fn process_count(&self) -> u16 {
+        self.0.procs
+    }
+
+    /// Returns the amount of swap memory in Bytes.
+    pub fn swap_total(&self) -> u64 {
+        self.scale_mem(self.0.totalswap)
+    }
+
+    /// Returns the amount of unused swap memory in Bytes.
+    pub fn swap_free(&self) -> u64 {
+        self.scale_mem(self.0.freeswap)
+    }
+
+    /// Returns the total amount of installed RAM in Bytes.
+    pub fn ram_total(&self) -> u64 {
+        self.scale_mem(self.0.totalram)
+    }
+
+    /// Returns the amount of completely unused RAM in Bytes.
+    ///
+    /// "Unused" in this context means that the RAM in neither actively used by
+    /// programs, nor by the operating system as disk cache or buffer. It is
+    /// "wasted" RAM since it currently serves no purpose.
+    pub fn ram_unused(&self) -> u64 {
+        self.scale_mem(self.0.freeram)
+    }
+
+    // The cast is not unnecessary on all platforms.
+    #[allow(clippy::unnecessary_cast)]
+    fn scale_mem(&self, units: mem_blocks_t) -> u64 {
+        units as u64 * self.0.mem_unit as u64
+    }
+}
+
+/// Returns system information.
+///
+/// [See `sysinfo(2)`](https://man7.org/linux/man-pages/man2/sysinfo.2.html).
+pub fn sysinfo() -> Result<SysInfo> {
+    let mut info = mem::MaybeUninit::uninit();
+    let res = unsafe { libc::sysinfo(info.as_mut_ptr()) };
+    Errno::result(res).map(|_| unsafe { SysInfo(info.assume_init()) })
+}