Import nix crate.
Bug: 170784756
Test: mm
Change-Id: Ia7f0f09de3adfa46f04a63c5a65a39bab08a0145
diff --git a/src/sys/sysinfo.rs b/src/sys/sysinfo.rs
new file mode 100644
index 0000000..f4b8279
--- /dev/null
+++ b/src/sys/sysinfo.rs
@@ -0,0 +1,73 @@
+use libc::{self, SI_LOAD_SHIFT};
+use std::{cmp, mem};
+use std::time::Duration;
+
+use crate::Result;
+use crate::errno::Errno;
+
+/// System info structure returned by `sysinfo`.
+#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq)]
+#[repr(transparent)]
+pub struct SysInfo(libc::sysinfo);
+
+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.
+ 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)
+ }
+
+ fn scale_mem(&self, units: libc::c_ulong) -> u64 {
+ units as u64 * self.0.mem_unit as u64
+ }
+}
+
+/// Returns system information.
+///
+/// [See `sysinfo(2)`](http://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()) })
+}