79 lines
2.1 KiB
Go
79 lines
2.1 KiB
Go
// +build linux
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package fs
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import (
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"errors"
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"fmt"
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"io/ioutil"
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"path/filepath"
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"strconv"
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"strings"
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)
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var (
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ErrNotSupportStat = errors.New("stats are not supported for subsystem")
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ErrNotValidFormat = errors.New("line is not a valid key value format")
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)
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// Saturates negative values at zero and returns a uint64.
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// Due to kernel bugs, some of the memory cgroup stats can be negative.
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func parseUint(s string, base, bitSize int) (uint64, error) {
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value, err := strconv.ParseUint(s, base, bitSize)
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if err != nil {
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intValue, intErr := strconv.ParseInt(s, base, bitSize)
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// 1. Handle negative values greater than MinInt64 (and)
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// 2. Handle negative values lesser than MinInt64
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if intErr == nil && intValue < 0 {
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return 0, nil
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} else if intErr != nil && intErr.(*strconv.NumError).Err == strconv.ErrRange && intValue < 0 {
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return 0, nil
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}
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return value, err
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}
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return value, nil
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}
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// Parses a cgroup param and returns as name, value
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// i.e. "io_service_bytes 1234" will return as io_service_bytes, 1234
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func getCgroupParamKeyValue(t string) (string, uint64, error) {
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parts := strings.Fields(t)
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switch len(parts) {
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case 2:
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value, err := parseUint(parts[1], 10, 64)
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if err != nil {
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return "", 0, fmt.Errorf("unable to convert param value (%q) to uint64: %v", parts[1], err)
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}
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return parts[0], value, nil
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default:
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return "", 0, ErrNotValidFormat
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}
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}
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// Gets a single uint64 value from the specified cgroup file.
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func getCgroupParamUint(cgroupPath, cgroupFile string) (uint64, error) {
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fileName := filepath.Join(cgroupPath, cgroupFile)
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contents, err := ioutil.ReadFile(fileName)
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if err != nil {
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return 0, err
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}
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res, err := parseUint(strings.TrimSpace(string(contents)), 10, 64)
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if err != nil {
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return res, fmt.Errorf("unable to parse %q as a uint from Cgroup file %q", string(contents), fileName)
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}
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return res, nil
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}
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// Gets a string value from the specified cgroup file
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func getCgroupParamString(cgroupPath, cgroupFile string) (string, error) {
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contents, err := ioutil.ReadFile(filepath.Join(cgroupPath, cgroupFile))
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if err != nil {
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return "", err
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}
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return strings.TrimSpace(string(contents)), nil
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}
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