add cpu limit

src/cgroup/cgroup_option.rs

@@ -0,0 +1,6 @@
+use super::cpu_limit::CpuLimit;
+
+#[derive(Debug, Clone, Copy, Default)]
+pub struct CGroupOption {
+    pub cpu_max: Option<CpuLimit>,
+}

src/cgroup/cpu_limit.rs

@@ -0,0 +1,49 @@
+use core::fmt;
+use std::str::FromStr;
+
+use super::limit_value::CGroupLimitValue;
+
+#[derive(Debug, Clone, Copy)]
+pub struct CpuLimit {
+    pub max: CGroupLimitValue<u64>,
+    pub period: u64,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct ParseCpuLimitError;
+
+impl FromStr for CpuLimit {
+    type Err = ParseCpuLimitError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut spl = s.trim().split(" ");
+
+        let max = if let Some(max) = spl.next() {
+            if let Ok(max) = CGroupLimitValue::from_str(max) {
+                max
+            } else {
+                return Err(ParseCpuLimitError);
+            }
+        } else {
+            return Err(ParseCpuLimitError);
+        };
+
+        let period = if let Some(period) = spl.next() {
+            if let Ok(period) = u64::from_str(period) {
+                period
+            } else {
+                return Err(ParseCpuLimitError);
+            }
+        } else {
+            return Err(ParseCpuLimitError);
+        };
+
+        Ok(Self { max, period })
+    }
+}
+
+impl fmt::Display for CpuLimit {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{} {}", self.max, self.period)
+    }
+}