lbry.go/ytsync/namer/names.go
2018-10-02 20:53:54 -04:00

79 lines
1.4 KiB
Go

package namer
import (
"crypto/md5"
"encoding/hex"
"fmt"
"regexp"
"strconv"
"strings"
"sync"
)
var titleRegexp = regexp.MustCompile(`[^a-zA-Z0-9]+`)
type Namer struct {
mu *sync.Mutex
names map[string]bool
}
func NewNamer() *Namer {
return &Namer{
mu: &sync.Mutex{},
names: make(map[string]bool),
}
}
func (n *Namer) GetNextName(prefix string) string {
n.mu.Lock()
defer n.mu.Unlock()
attempt := 1
var name string
for {
name = getClaimNameFromTitle(prefix, attempt)
if _, exists := n.names[name]; !exists {
break
}
attempt++
}
//if for some reasons the title can't be converted in a valid claim name (too short or not latin) then we use a hash
if len(name) < 2 {
sum := md5.Sum([]byte(prefix))
name = fmt.Sprintf("%s-%d", hex.EncodeToString(sum[:])[:15], attempt)
}
n.names[name] = true
return name
}
// TODO: clean this up some
func getClaimNameFromTitle(title string, attempt int) string {
suffix := ""
if attempt > 1 {
suffix = "-" + strconv.Itoa(attempt)
}
maxLen := 40 - len(suffix)
chunks := strings.Split(strings.ToLower(strings.Trim(titleRegexp.ReplaceAllString(title, "-"), "-")), "-")
name := chunks[0]
if len(name) > maxLen {
return name[:maxLen]
}
for _, chunk := range chunks[1:] {
tmpName := name + "-" + chunk
if len(tmpName) > maxLen {
if len(name) < 20 {
name = tmpName[:maxLen]
}
break
}
name = tmpName
}
return name + suffix
}