Files

92 lines
1.6 KiB
Go

package transporttoken
import (
"crypto/rand"
"encoding/hex"
"fmt"
"strings"
"sync"
"time"
)
type record struct {
baseRevision int64
digest string
expiresAt time.Time
}
type Store struct {
mu sync.Mutex
ttl time.Duration
records map[string]record
}
func NewStore(ttl time.Duration) *Store {
if ttl <= 0 {
ttl = 10 * time.Minute
}
return &Store{
ttl: ttl,
records: map[string]record{},
}
}
func (s *Store) Issue(prefix string, baseRevision int64, digest string) string {
token := strings.TrimSpace(prefix) + NewTokenHex(10)
now := time.Now()
s.mu.Lock()
defer s.mu.Unlock()
s.cleanupLocked(now)
s.records[token] = record{
baseRevision: baseRevision,
digest: digest,
expiresAt: now.Add(s.ttl),
}
return token
}
func (s *Store) Consume(token string, baseRevision int64, digest string) bool {
token = strings.TrimSpace(token)
if token == "" {
return false
}
now := time.Now()
s.mu.Lock()
defer s.mu.Unlock()
s.cleanupLocked(now)
rec, ok := s.records[token]
if !ok {
return false
}
delete(s.records, token)
if rec.baseRevision != baseRevision {
return false
}
if rec.digest != digest {
return false
}
if now.After(rec.expiresAt) {
return false
}
return true
}
func (s *Store) cleanupLocked(now time.Time) {
for k, rec := range s.records {
if now.After(rec.expiresAt) {
delete(s.records, k)
}
}
}
func NewTokenHex(n int) string {
if n <= 0 {
n = 8
}
buf := make([]byte, n)
if _, err := rand.Read(buf); err != nil {
return fmt.Sprintf("%d", time.Now().UnixNano())
}
return hex.EncodeToString(buf)
}