go-sandbox/pkg/cgroup/subcgroup.go

49 lines
1019 B
Go

package cgroup
import (
"errors"
"io/ioutil"
"path"
"strconv"
"strings"
)
// SubCGroup is the sub-cgroup
type SubCGroup struct {
path string
}
// ErrNotInitialized returned when trying to read from not initialized cgroup
var ErrNotInitialized = errors.New("cgroup was not initialized")
// NewSubCGroup creates a sug CGroup
func NewSubCGroup(p string) *SubCGroup {
return &SubCGroup{
path: p,
}
}
// WriteUint writes uint64 into given file
func (c *SubCGroup) WriteUint(filename string, i uint64) error {
if c.path == "" {
return nil
}
return ioutil.WriteFile(path.Join(c.path, filename), []byte(strconv.FormatUint(i, 10)), 644)
}
// ReadUint read uint64 into given file
func (c *SubCGroup) ReadUint(filename string) (uint64, error) {
if c.path == "" {
return 0, ErrNotInitialized
}
b, err := ioutil.ReadFile(path.Join(c.path, filename))
if err != nil {
return 0, err
}
s, err := strconv.ParseUint(strings.TrimSpace(string(b)), 10, 64)
if err != nil {
return 0, err
}
return s, nil
}