open-consul/vendor/github.com/shirou/gopsutil/internal/common/common.go

393 lines
8.3 KiB
Go

package common
//
// gopsutil is a port of psutil(http://pythonhosted.org/psutil/).
// This covers these architectures.
// - linux (amd64, arm)
// - freebsd (amd64)
// - windows (amd64)
import (
"bufio"
"bytes"
"context"
"errors"
"fmt"
"io/ioutil"
"net/url"
"os"
"os/exec"
"path"
"path/filepath"
"reflect"
"runtime"
"strconv"
"strings"
"time"
)
var (
Timeout = 3 * time.Second
ErrTimeout = errors.New("command timed out")
)
type Invoker interface {
Command(string, ...string) ([]byte, error)
CommandWithContext(context.Context, string, ...string) ([]byte, error)
}
type Invoke struct{}
func (i Invoke) Command(name string, arg ...string) ([]byte, error) {
ctx, cancel := context.WithTimeout(context.Background(), Timeout)
defer cancel()
return i.CommandWithContext(ctx, name, arg...)
}
func (i Invoke) CommandWithContext(ctx context.Context, name string, arg ...string) ([]byte, error) {
cmd := exec.CommandContext(ctx, name, arg...)
var buf bytes.Buffer
cmd.Stdout = &buf
cmd.Stderr = &buf
if err := cmd.Start(); err != nil {
return buf.Bytes(), err
}
if err := cmd.Wait(); err != nil {
return buf.Bytes(), err
}
return buf.Bytes(), nil
}
type FakeInvoke struct {
Suffix string // Suffix species expected file name suffix such as "fail"
Error error // If Error specfied, return the error.
}
// Command in FakeInvoke returns from expected file if exists.
func (i FakeInvoke) Command(name string, arg ...string) ([]byte, error) {
if i.Error != nil {
return []byte{}, i.Error
}
arch := runtime.GOOS
commandName := filepath.Base(name)
fname := strings.Join(append([]string{commandName}, arg...), "")
fname = url.QueryEscape(fname)
fpath := path.Join("testdata", arch, fname)
if i.Suffix != "" {
fpath += "_" + i.Suffix
}
if PathExists(fpath) {
return ioutil.ReadFile(fpath)
}
return []byte{}, fmt.Errorf("could not find testdata: %s", fpath)
}
func (i FakeInvoke) CommandWithContext(ctx context.Context, name string, arg ...string) ([]byte, error) {
return i.Command(name, arg...)
}
var ErrNotImplementedError = errors.New("not implemented yet")
// ReadLines reads contents from a file and splits them by new lines.
// A convenience wrapper to ReadLinesOffsetN(filename, 0, -1).
func ReadLines(filename string) ([]string, error) {
return ReadLinesOffsetN(filename, 0, -1)
}
// ReadLines reads contents from file and splits them by new line.
// The offset tells at which line number to start.
// The count determines the number of lines to read (starting from offset):
// n >= 0: at most n lines
// n < 0: whole file
func ReadLinesOffsetN(filename string, offset uint, n int) ([]string, error) {
f, err := os.Open(filename)
if err != nil {
return []string{""}, err
}
defer f.Close()
var ret []string
r := bufio.NewReader(f)
for i := 0; i < n+int(offset) || n < 0; i++ {
line, err := r.ReadString('\n')
if err != nil {
break
}
if i < int(offset) {
continue
}
ret = append(ret, strings.Trim(line, "\n"))
}
return ret, nil
}
func IntToString(orig []int8) string {
ret := make([]byte, len(orig))
size := -1
for i, o := range orig {
if o == 0 {
size = i
break
}
ret[i] = byte(o)
}
if size == -1 {
size = len(orig)
}
return string(ret[0:size])
}
func UintToString(orig []uint8) string {
ret := make([]byte, len(orig))
size := -1
for i, o := range orig {
if o == 0 {
size = i
break
}
ret[i] = byte(o)
}
if size == -1 {
size = len(orig)
}
return string(ret[0:size])
}
func ByteToString(orig []byte) string {
n := -1
l := -1
for i, b := range orig {
// skip left side null
if l == -1 && b == 0 {
continue
}
if l == -1 {
l = i
}
if b == 0 {
break
}
n = i + 1
}
if n == -1 {
return string(orig)
}
return string(orig[l:n])
}
// ReadInts reads contents from single line file and returns them as []int32.
func ReadInts(filename string) ([]int64, error) {
f, err := os.Open(filename)
if err != nil {
return []int64{}, err
}
defer f.Close()
var ret []int64
r := bufio.NewReader(f)
// The int files that this is concerned with should only be one liners.
line, err := r.ReadString('\n')
if err != nil {
return []int64{}, err
}
i, err := strconv.ParseInt(strings.Trim(line, "\n"), 10, 32)
if err != nil {
return []int64{}, err
}
ret = append(ret, i)
return ret, nil
}
// Parse to int32 without error
func mustParseInt32(val string) int32 {
vv, _ := strconv.ParseInt(val, 10, 32)
return int32(vv)
}
// Parse to uint64 without error
func mustParseUint64(val string) uint64 {
vv, _ := strconv.ParseInt(val, 10, 64)
return uint64(vv)
}
// Parse to Float64 without error
func mustParseFloat64(val string) float64 {
vv, _ := strconv.ParseFloat(val, 64)
return vv
}
// StringsHas checks the target string slice contains src or not
func StringsHas(target []string, src string) bool {
for _, t := range target {
if strings.TrimSpace(t) == src {
return true
}
}
return false
}
// StringsContains checks the src in any string of the target string slice
func StringsContains(target []string, src string) bool {
for _, t := range target {
if strings.Contains(t, src) {
return true
}
}
return false
}
// IntContains checks the src in any int of the target int slice.
func IntContains(target []int, src int) bool {
for _, t := range target {
if src == t {
return true
}
}
return false
}
// get struct attributes.
// This method is used only for debugging platform dependent code.
func attributes(m interface{}) map[string]reflect.Type {
typ := reflect.TypeOf(m)
if typ.Kind() == reflect.Ptr {
typ = typ.Elem()
}
attrs := make(map[string]reflect.Type)
if typ.Kind() != reflect.Struct {
return nil
}
for i := 0; i < typ.NumField(); i++ {
p := typ.Field(i)
if !p.Anonymous {
attrs[p.Name] = p.Type
}
}
return attrs
}
func PathExists(filename string) bool {
if _, err := os.Stat(filename); err == nil {
return true
}
return false
}
//GetEnv retrieves the environment variable key. If it does not exist it returns the default.
func GetEnv(key string, dfault string, combineWith ...string) string {
value := os.Getenv(key)
if value == "" {
value = dfault
}
switch len(combineWith) {
case 0:
return value
case 1:
return filepath.Join(value, combineWith[0])
default:
all := make([]string, len(combineWith)+1)
all[0] = value
copy(all[1:], combineWith)
return filepath.Join(all...)
}
panic("invalid switch case")
}
func HostProc(combineWith ...string) string {
return GetEnv("HOST_PROC", "/proc", combineWith...)
}
func HostSys(combineWith ...string) string {
return GetEnv("HOST_SYS", "/sys", combineWith...)
}
func HostEtc(combineWith ...string) string {
return GetEnv("HOST_ETC", "/etc", combineWith...)
}
func HostVar(combineWith ...string) string {
return GetEnv("HOST_VAR", "/var", combineWith...)
}
func HostRun(combineWith ...string) string {
return GetEnv("HOST_RUN", "/run", combineWith...)
}
// https://gist.github.com/kylelemons/1525278
func Pipeline(cmds ...*exec.Cmd) ([]byte, []byte, error) {
// Require at least one command
if len(cmds) < 1 {
return nil, nil, nil
}
// Collect the output from the command(s)
var output bytes.Buffer
var stderr bytes.Buffer
last := len(cmds) - 1
for i, cmd := range cmds[:last] {
var err error
// Connect each command's stdin to the previous command's stdout
if cmds[i+1].Stdin, err = cmd.StdoutPipe(); err != nil {
return nil, nil, err
}
// Connect each command's stderr to a buffer
cmd.Stderr = &stderr
}
// Connect the output and error for the last command
cmds[last].Stdout, cmds[last].Stderr = &output, &stderr
// Start each command
for _, cmd := range cmds {
if err := cmd.Start(); err != nil {
return output.Bytes(), stderr.Bytes(), err
}
}
// Wait for each command to complete
for _, cmd := range cmds {
if err := cmd.Wait(); err != nil {
return output.Bytes(), stderr.Bytes(), err
}
}
// Return the pipeline output and the collected standard error
return output.Bytes(), stderr.Bytes(), nil
}
// getSysctrlEnv sets LC_ALL=C in a list of env vars for use when running
// sysctl commands (see DoSysctrl).
func getSysctrlEnv(env []string) []string {
foundLC := false
for i, line := range env {
if strings.HasPrefix(line, "LC_ALL") {
env[i] = "LC_ALL=C"
foundLC = true
}
}
if !foundLC {
env = append(env, "LC_ALL=C")
}
return env
}