Function writeUserSessionCache

model/user_session.go:276–356

writeUserSessionCache writes a bounded Session snapshot. Active snapshots must carry a deadline captured immediately before their authoritative database read or mutation. Delayed fills inherit the unspent portion of that window, so a stale active snapshot cannot outlive a short deny tombstone and re

(entry *userSessionCacheEntry, cacheDeadline time.Time)

// reactivate a revoked Session after the tombstone expires. Deny states pass a
// zero deadline because their TTL starts when they are published.
func writeUserSessionCache(entry *userSessionCacheEntry, cacheDeadline time.Time) error {
	if entry == nil || !common.RedisEnabled {
		return nil
	}
	now := time.Now()
	sessionExpiresAt := time.Unix(entry.ExpiresAt, 0)
	sessionTTL := sessionExpiresAt.Sub(now)
	var redisExpiration int64
	if entry.Status == UserSessionStatusActive {
		if cacheDeadline.IsZero() {
			return ErrUserSessionInvalid
		}
		cacheTTL := cacheDeadline.Sub(now)
		if cacheTTL <= 0 {
			return errUserSessionCacheObservationStale
		}
		if sessionTTL <= 0 {
			return ErrUserSessionInactive
		}
		cacheExpiresAt := cacheDeadline
		if sessionExpiresAt.Before(cacheExpiresAt) {
			cacheExpiresAt = sessionExpiresAt
		}
		if cacheExpiresAt.Sub(now) < time.Millisecond {
			return errUserSessionCacheObservationStale
		}
		redisExpiration = cacheExpiresAt.UnixMilli()
	} else {
		ttl := min(sessionTTL, time.Duration(userCacheTTLSeconds())*time.Second)
		if ttl <= 0 {
			ttl = time.Second
		}
		redisExpiration = ttl.Milliseconds()
		if redisExpiration <= 0 {
			redisExpiration = 1
		}
	}
	entry.CacheSchema = userSessionCacheSchema
	const script = `
local current_status = redis.call('HGET', KEYS[1], 'Status')
local current_version = tonumber(redis.call('HGET', KEYS[1], 'Version') or '0')
if ARGV[5] == 'active' and (current_status == 'revoking' or current_status == 'revoked') then
  return 0
end
if current_version > tonumber(ARGV[3]) then
  return 0
end
redis.call('HSET', KEYS[1],
  'SID', ARGV[1], 'UserID', ARGV[2], 'Version', ARGV[3],
  'UserAuthVersion', ARGV[4], 'Status', ARGV[5],
  'LoginMethod', ARGV[6], 'IP', ARGV[7], 'UserAgent', ARGV[8],
  'CreatedAt', ARGV[9], 'LastActiveAt', ARGV[10], 'ExpiresAt', ARGV[11],
  'RevokedAt', ARGV[12], 'RevokedReason', ARGV[13], 'CacheSchema', ARGV[14])
if ARGV[5] == 'active' then
  redis.call('PEXPIREAT', KEYS[1], ARGV[15])
else
  redis.call('PEXPIRE', KEYS[1], ARGV[15])
end