blob: 5ff0a1615048cba54b107c2dcabd3458eabdc6f3 [file] [log] [blame]
// +build linux
package fs
import (
"errors"
"fmt"
"io/ioutil"
"path/filepath"
"strconv"
"strings"
)
var (
ErrNotValidFormat = errors.New("line is not a valid key value format")
)
// Saturates negative values at zero and returns a uint64.
// Due to kernel bugs, some of the memory cgroup stats can be negative.
func parseUint(s string, base, bitSize int) (uint64, error) {
value, err := strconv.ParseUint(s, base, bitSize)
if err != nil {
intValue, intErr := strconv.ParseInt(s, base, bitSize)
// 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 value, err
}
return value, nil
}
// Parses a cgroup param and returns as name, value
// i.e. "io_service_bytes 1234" will return as io_service_bytes, 1234
func getCgroupParamKeyValue(t string) (string, uint64, error) {
parts := strings.Fields(t)
switch len(parts) {
case 2:
value, err := parseUint(parts[1], 10, 64)
if err != nil {
return "", 0, fmt.Errorf("unable to convert param value (%q) to uint64: %v", parts[1], err)
}
return parts[0], value, nil
default:
return "", 0, ErrNotValidFormat
}
}
// Gets a single uint64 value from the specified cgroup file.
func getCgroupParamUint(cgroupPath, cgroupFile string) (uint64, error) {
fileName := filepath.Join(cgroupPath, cgroupFile)
contents, err := ioutil.ReadFile(fileName)
if err != nil {
return 0, err
}
res, err := parseUint(strings.TrimSpace(string(contents)), 10, 64)
if err != nil {
return res, fmt.Errorf("unable to parse %q as a uint from Cgroup file %q", string(contents), fileName)
}
return res, nil
}
// Gets a string value from the specified cgroup file
func getCgroupParamString(cgroupPath, cgroupFile string) (string, error) {
contents, err := ioutil.ReadFile(filepath.Join(cgroupPath, cgroupFile))
if err != nil {
return "", err
}
return strings.TrimSpace(string(contents)), nil
}