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