go-common/library/stat/sys/cpu/util.go
2019-04-22 18:49:16 +08:00

122 lines
3.0 KiB
Go

package cpu
import (
"bufio"
"io/ioutil"
"os"
"strconv"
"strings"
"github.com/pkg/errors"
)
func readFile(path string) (string, error) {
contents, err := ioutil.ReadFile(path)
if err != nil {
return "", errors.Wrapf(err, "os/stat: read file(%s) failed!", path)
}
return strings.TrimSpace(string(contents)), nil
}
func parseUint(s string) (uint64, error) {
v, err := strconv.ParseUint(s, 10, 64)
if err != nil {
intValue, intErr := strconv.ParseInt(s, 10, 64)
// 1. Handle negative values greater than MinInt64 (and)
// 2. Handle negative values lesser than MinInt64
if intErr == nil && intValue < 0 {
return 0, nil
} else if intErr != nil &&
intErr.(*strconv.NumError).Err == strconv.ErrRange &&
intValue < 0 {
return 0, nil
}
return 0, errors.Wrapf(err, "os/stat: parseUint(%s) failed!", s)
}
return v, nil
}
// ParseUintList parses and validates the specified string as the value
// found in some cgroup file (e.g. cpuset.cpus, cpuset.mems), which could be
// one of the formats below. Note that duplicates are actually allowed in the
// input string. It returns a map[int]bool with available elements from val
// set to true.
// Supported formats:
// 7
// 1-6
// 0,3-4,7,8-10
// 0-0,0,1-7
// 03,1-3 <- this is gonna get parsed as [1,2,3]
// 3,2,1
// 0-2,3,1
func ParseUintList(val string) (map[int]bool, error) {
if val == "" {
return map[int]bool{}, nil
}
availableInts := make(map[int]bool)
split := strings.Split(val, ",")
errInvalidFormat := errors.Errorf("os/stat: invalid format: %s", val)
for _, r := range split {
if !strings.Contains(r, "-") {
v, err := strconv.Atoi(r)
if err != nil {
return nil, errInvalidFormat
}
availableInts[v] = true
} else {
split := strings.SplitN(r, "-", 2)
min, err := strconv.Atoi(split[0])
if err != nil {
return nil, errInvalidFormat
}
max, err := strconv.Atoi(split[1])
if err != nil {
return nil, errInvalidFormat
}
if max < min {
return nil, errInvalidFormat
}
for i := min; i <= max; i++ {
availableInts[i] = true
}
}
}
return availableInts, nil
}
// 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)
}
// ReadLinesOffsetN 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
}