badguardhome/dnsfilter/helpers.go
2018-12-29 17:37:18 +03:00

61 lines
975 B
Go

package dnsfilter
import (
"strings"
"sync/atomic"
)
func isValidRule(rule string) bool {
if len(rule) < 4 {
return false
}
if rule[0] == '!' {
return false
}
if rule[0] == '#' {
return false
}
if strings.HasPrefix(rule, "[Adblock") {
return false
}
// Filter out all sorts of cosmetic rules:
// https://kb.adguard.com/en/general/how-to-create-your-own-ad-filters#cosmetic-rules
masks := []string{
"##",
"#@#",
"#?#",
"#@?#",
"#$#",
"#@$#",
"#?$#",
"#@?$#",
"$$",
"$@$",
"#%#",
"#@%#",
}
for _, mask := range masks {
if strings.Contains(rule, mask) {
return false
}
}
return true
}
func updateMax(valuePtr *int64, maxPtr *int64) {
for {
current := atomic.LoadInt64(valuePtr)
max := atomic.LoadInt64(maxPtr)
if current <= max {
break
}
swapped := atomic.CompareAndSwapInt64(maxPtr, max, current)
if swapped {
break
}
// swapping failed because value has changed after reading, try again
}
}