AdGuardHome/internal/home/portsmap.go

64 lines
1.3 KiB
Go

package home
import (
"fmt"
"strconv"
"strings"
"github.com/AdguardTeam/golibs/errors"
"github.com/AdguardTeam/golibs/stringutil"
)
// portsMap is a helper type for mapping a network port to the number of its
// users.
type portsMap map[int]int
// add binds each of ps. Zeroes are skipped.
func (pm portsMap) add(ps ...int) {
for _, p := range ps {
if p == 0 {
continue
}
pm[p]++
}
}
// validate returns an error about all the ports bound several times.
func (pm portsMap) validate() (err error) {
overbound := []int{}
for p, num := range pm {
if num > 1 {
overbound = append(overbound, p)
pm[p] = 1
}
}
switch len(overbound) {
case 0:
return nil
case 1:
return fmt.Errorf("port %d is already used", overbound[0])
default:
b := &strings.Builder{}
// TODO(e.burkov, a.garipov): Add JoinToBuilder helper to stringutil.
stringutil.WriteToBuilder(b, "ports ", strconv.Itoa(overbound[0]))
for _, p := range overbound[1:] {
stringutil.WriteToBuilder(b, ", ", strconv.Itoa(p))
}
stringutil.WriteToBuilder(b, " are already used")
return errors.Error(b.String())
}
}
// validatePorts is a helper function for a single-step ports binding
// validation.
func validatePorts(ps ...int) (err error) {
pm := portsMap{}
pm.add(ps...)
return pm.validate()
}