vendor: github.com/prometheus/client_golang v1.12.1

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/github.com/prometheus/procfs/mountinfo.go

@@ -15,19 +15,13 @@ package procfs
 
 import (
 	"bufio"
+	"bytes"
 	"fmt"
-	"io"
-	"os"
 	"strconv"
 	"strings"
-)
 
-var validOptionalFields = map[string]bool{
-	"shared":         true,
-	"master":         true,
-	"propagate_from": true,
-	"unbindable":     true,
-}
+	"github.com/prometheus/procfs/internal/util"
+)
 
 // A MountInfo is a type that describes the details, options
 // for each mount, parsed from /proc/self/mountinfo.
@@ -35,10 +29,10 @@ var validOptionalFields = map[string]bool{
 // is described in the following man page.
 // http://man7.org/linux/man-pages/man5/proc.5.html
 type MountInfo struct {
-	// Unique Id for the mount
-	MountId int
-	// The Id of the parent mount
-	ParentId int
+	// Unique ID for the mount
+	MountID int
+	// The ID of the parent mount
+	ParentID int
 	// The value of `st_dev` for the files on this FS
 	MajorMinorVer string
 	// The pathname of the directory in the FS that forms
@@ -58,18 +52,10 @@ type MountInfo struct {
 	SuperOptions map[string]string
 }
 
-// Returns part of the mountinfo line, if it exists, else an empty string.
-func getStringSliceElement(parts []string, idx int, defaultValue string) string {
-	if idx >= len(parts) {
-		return defaultValue
-	}
-	return parts[idx]
-}
-
 // Reads each line of the mountinfo file, and returns a list of formatted MountInfo structs.
-func parseMountInfo(r io.Reader) ([]*MountInfo, error) {
+func parseMountInfo(info []byte) ([]*MountInfo, error) {
 	mounts := []*MountInfo{}
-	scanner := bufio.NewScanner(r)
+	scanner := bufio.NewScanner(bytes.NewReader(info))
 	for scanner.Scan() {
 		mountString := scanner.Text()
 		parsedMounts, err := parseMountInfoString(mountString)
@@ -89,58 +75,76 @@ func parseMountInfo(r io.Reader) ([]*MountInfo, error) {
 func parseMountInfoString(mountString string) (*MountInfo, error) {
 	var err error
 
-	// OptionalFields can be zero, hence these checks to ensure we do not populate the wrong values in the wrong spots
-	separatorIndex := strings.Index(mountString, "-")
-	if separatorIndex == -1 {
-		return nil, fmt.Errorf("no separator found in mountinfo string: %s", mountString)
+	mountInfo := strings.Split(mountString, " ")
+	mountInfoLength := len(mountInfo)
+	if mountInfoLength < 10 {
+		return nil, fmt.Errorf("couldn't find enough fields in mount string: %s", mountString)
 	}
-	beforeFields := strings.Fields(mountString[:separatorIndex])
-	afterFields := strings.Fields(mountString[separatorIndex+1:])
-	if (len(beforeFields) + len(afterFields)) < 7 {
-		return nil, fmt.Errorf("too few fields")
+
+	if mountInfo[mountInfoLength-4] != "-" {
+		return nil, fmt.Errorf("couldn't find separator in expected field: %s", mountInfo[mountInfoLength-4])
 	}
 
 	mount := &MountInfo{
-		MajorMinorVer:  getStringSliceElement(beforeFields, 2, ""),
-		Root:           getStringSliceElement(beforeFields, 3, ""),
-		MountPoint:     getStringSliceElement(beforeFields, 4, ""),
-		Options:        mountOptionsParser(getStringSliceElement(beforeFields, 5, "")),
+		MajorMinorVer:  mountInfo[2],
+		Root:           mountInfo[3],
+		MountPoint:     mountInfo[4],
+		Options:        mountOptionsParser(mountInfo[5]),
 		OptionalFields: nil,
-		FSType:         getStringSliceElement(afterFields, 0, ""),
-		Source:         getStringSliceElement(afterFields, 1, ""),
-		SuperOptions:   mountOptionsParser(getStringSliceElement(afterFields, 2, "")),
+		FSType:         mountInfo[mountInfoLength-3],
+		Source:         mountInfo[mountInfoLength-2],
+		SuperOptions:   mountOptionsParser(mountInfo[mountInfoLength-1]),
 	}
 
-	mount.MountId, err = strconv.Atoi(getStringSliceElement(beforeFields, 0, ""))
+	mount.MountID, err = strconv.Atoi(mountInfo[0])
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse mount ID")
 	}
-	mount.ParentId, err = strconv.Atoi(getStringSliceElement(beforeFields, 1, ""))
+	mount.ParentID, err = strconv.Atoi(mountInfo[1])
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse parent ID")
 	}
 	// Has optional fields, which is a space separated list of values.
 	// Example: shared:2 master:7
-	if len(beforeFields) > 6 {
-		mount.OptionalFields = make(map[string]string)
-		optionalFields := beforeFields[6:]
-		for _, field := range optionalFields {
-			optionSplit := strings.Split(field, ":")
-			target, value := optionSplit[0], ""
-			if len(optionSplit) == 2 {
-				value = optionSplit[1]
-			}
-			// Checks if the 'keys' in the optional fields in the mountinfo line are acceptable.
-			// Allowed 'keys' are shared, master, propagate_from, unbindable.
-			if _, ok := validOptionalFields[target]; ok {
-				mount.OptionalFields[target] = value
-			}
+	if mountInfo[6] != "" {
+		mount.OptionalFields, err = mountOptionsParseOptionalFields(mountInfo[6 : mountInfoLength-4])
+		if err != nil {
+			return nil, err
 		}
 	}
 	return mount, nil
 }
 
-// Parses the mount options, superblock options.
+// mountOptionsIsValidField checks a string against a valid list of optional fields keys.
+func mountOptionsIsValidField(s string) bool {
+	switch s {
+	case
+		"shared",
+		"master",
+		"propagate_from",
+		"unbindable":
+		return true
+	}
+	return false
+}
+
+// mountOptionsParseOptionalFields parses a list of optional fields strings into a double map of strings.
+func mountOptionsParseOptionalFields(o []string) (map[string]string, error) {
+	optionalFields := make(map[string]string)
+	for _, field := range o {
+		optionSplit := strings.SplitN(field, ":", 2)
+		value := ""
+		if len(optionSplit) == 2 {
+			value = optionSplit[1]
+		}
+		if mountOptionsIsValidField(optionSplit[0]) {
+			optionalFields[optionSplit[0]] = value
+		}
+	}
+	return optionalFields, nil
+}
+
+// mountOptionsParser parses the mount options, superblock options.
 func mountOptionsParser(mountOptions string) map[string]string {
 	opts := make(map[string]string)
 	options := strings.Split(mountOptions, ",")
@@ -157,22 +161,20 @@ func mountOptionsParser(mountOptions string) map[string]string {
 	return opts
 }
 
-// Retrieves mountinfo information from `/proc/self/mountinfo`.
+// GetMounts retrieves mountinfo information from `/proc/self/mountinfo`.
 func GetMounts() ([]*MountInfo, error) {
-	f, err := os.Open("/proc/self/mountinfo")
+	data, err := util.ReadFileNoStat("/proc/self/mountinfo")
 	if err != nil {
 		return nil, err
 	}
-	defer f.Close()
-	return parseMountInfo(f)
+	return parseMountInfo(data)
 }
 
-// Retrieves mountinfo information from a processes' `/proc/<pid>/mountinfo`.
+// GetProcMounts retrieves mountinfo information from a processes' `/proc/<pid>/mountinfo`.
 func GetProcMounts(pid int) ([]*MountInfo, error) {
-	f, err := os.Open(fmt.Sprintf("/proc/%d/mountinfo", pid))
+	data, err := util.ReadFileNoStat(fmt.Sprintf("/proc/%d/mountinfo", pid))
 	if err != nil {
 		return nil, err
 	}
-	defer f.Close()
-	return parseMountInfo(f)
+	return parseMountInfo(data)
 }