80 lines
2.3 KiB
Go
80 lines
2.3 KiB
Go
// Copyright (c) 2017 Uber Technologies, Inc.
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
// of this software and associated documentation files (the "Software"), to deal
|
|
// in the Software without restriction, including without limitation the rights
|
|
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
// copies of the Software, and to permit persons to whom the Software is
|
|
// furnished to do so, subject to the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included in
|
|
// all copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
// THE SOFTWARE.
|
|
|
|
//go:build linux
|
|
// +build linux
|
|
|
|
package cgroups
|
|
|
|
import (
|
|
"bufio"
|
|
"io"
|
|
"os"
|
|
"path/filepath"
|
|
"strconv"
|
|
)
|
|
|
|
// CGroup represents the data structure for a Linux control group.
|
|
type CGroup struct {
|
|
path string
|
|
}
|
|
|
|
// NewCGroup returns a new *CGroup from a given path.
|
|
func NewCGroup(path string) *CGroup {
|
|
return &CGroup{path: path}
|
|
}
|
|
|
|
// Path returns the path of the CGroup*.
|
|
func (cg *CGroup) Path() string {
|
|
return cg.path
|
|
}
|
|
|
|
// ParamPath returns the path of the given cgroup param under itself.
|
|
func (cg *CGroup) ParamPath(param string) string {
|
|
return filepath.Join(cg.path, param)
|
|
}
|
|
|
|
// readFirstLine reads the first line from a cgroup param file.
|
|
func (cg *CGroup) readFirstLine(param string) (string, error) {
|
|
paramFile, err := os.Open(cg.ParamPath(param))
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
defer paramFile.Close()
|
|
|
|
scanner := bufio.NewScanner(paramFile)
|
|
if scanner.Scan() {
|
|
return scanner.Text(), nil
|
|
}
|
|
if err := scanner.Err(); err != nil {
|
|
return "", err
|
|
}
|
|
return "", io.ErrUnexpectedEOF
|
|
}
|
|
|
|
// readInt parses the first line from a cgroup param file as int.
|
|
func (cg *CGroup) readInt(param string) (int, error) {
|
|
text, err := cg.readFirstLine(param)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
return strconv.Atoi(text)
|
|
}
|