diff options
Diffstat (limited to 'plugin/cache/cache.go')
| -rw-r--r-- | plugin/cache/cache.go | 41 |
1 files changed, 28 insertions, 13 deletions
diff --git a/plugin/cache/cache.go b/plugin/cache/cache.go index 654841b23..9ff43dac2 100644 --- a/plugin/cache/cache.go +++ b/plugin/cache/cache.go @@ -22,13 +22,15 @@ type Cache struct { Next plugin.Handler Zones []string - ncache *cache.Cache - ncap int - nttl time.Duration + ncache *cache.Cache + ncap int + nttl time.Duration + minnttl time.Duration - pcache *cache.Cache - pcap int - pttl time.Duration + pcache *cache.Cache + pcap int + pttl time.Duration + minpttl time.Duration // Prefetch. prefetch int @@ -47,9 +49,11 @@ func New() *Cache { pcap: defaultCap, pcache: cache.New(defaultCap), pttl: maxTTL, + minpttl: minTTL, ncap: defaultCap, ncache: cache.New(defaultCap), nttl: maxNTTL, + minnttl: minNTTL, prefetch: 0, duration: 1 * time.Minute, percentage: 10, @@ -100,6 +104,17 @@ func hash(qname string, qtype uint16, do bool) uint64 { return h.Sum64() } +func computeTTL(msgTTL, minTTL, maxTTL time.Duration) time.Duration { + ttl := msgTTL + if ttl < minTTL { + ttl = minTTL + } + if ttl > maxTTL { + ttl = maxTTL + } + return ttl +} + // ResponseWriter is a response writer that caches the reply message. type ResponseWriter struct { dns.ResponseWriter @@ -154,14 +169,12 @@ func (w *ResponseWriter) WriteMsg(res *dns.Msg) error { // key returns empty string for anything we don't want to cache. hasKey, key := key(res, mt, do) - duration := w.pttl - if mt == response.NameError || mt == response.NoData { - duration = w.nttl - } - msgTTL := dnsutil.MinimalTTL(res, mt) - if msgTTL < duration { - duration = msgTTL + var duration time.Duration + if mt == response.NameError || mt == response.NoData { + duration = computeTTL(msgTTL, w.minnttl, w.nttl) + } else { + duration = computeTTL(msgTTL, w.minpttl, w.pttl) } if hasKey && duration > 0 { @@ -226,7 +239,9 @@ func (w *ResponseWriter) Write(buf []byte) (int, error) { const ( maxTTL = dnsutil.MaximumDefaulTTL + minTTL = dnsutil.MinimalDefaultTTL maxNTTL = dnsutil.MaximumDefaulTTL / 2 + minNTTL = dnsutil.MinimalDefaultTTL defaultCap = 10000 // default capacity of the cache. |