1 files changed, 0 insertions, 167 deletions
diff --git a/middleware/cache/cache.go b/middleware/cache/cache.go
deleted file mode 100644
index 434efa296..000000000
--- a/middleware/cache/cache.go
+++ /dev/null
@@ -1,167 +0,0 @@
-// Package cache implements a cache.
-package cache
-
-import (
-	"encoding/binary"
-	"hash/fnv"
-	"log"
-	"time"
-
-	"github.com/coredns/coredns/middleware"
-	"github.com/coredns/coredns/middleware/pkg/cache"
-	"github.com/coredns/coredns/middleware/pkg/response"
-
-	"github.com/miekg/dns"
-)
-
-// Cache is middleware that looks up responses in a cache and caches replies.
-// It has a success and a denial of existence cache.
-type Cache struct {
-	Next  middleware.Handler
-	Zones []string
-
-	ncache *cache.Cache
-	ncap   int
-	nttl   time.Duration
-
-	pcache *cache.Cache
-	pcap   int
-	pttl   time.Duration
-
-	// Prefetch.
-	prefetch   int
-	duration   time.Duration
-	percentage int
-}
-
-// Return key under which we store the item, -1 will be returned if we don't store the
-// message.
-// Currently we do not cache Truncated, errors zone transfers or dynamic update messages.
-func key(m *dns.Msg, t response.Type, do bool) int {
-	// We don't store truncated responses.
-	if m.Truncated {
-		return -1
-	}
-	// Nor errors or Meta or Update
-	if t == response.OtherError || t == response.Meta || t == response.Update {
-		return -1
-	}
-
-	return int(hash(m.Question[0].Name, m.Question[0].Qtype, do))
-}
-
-var one = []byte("1")
-var zero = []byte("0")
-
-func hash(qname string, qtype uint16, do bool) uint32 {
-	h := fnv.New32()
-
-	if do {
-		h.Write(one)
-	} else {
-		h.Write(zero)
-	}
-
-	b := make([]byte, 2)
-	binary.BigEndian.PutUint16(b, qtype)
-	h.Write(b)
-
-	for i := range qname {
-		c := qname[i]
-		if c >= 'A' && c <= 'Z' {
-			c += 'a' - 'A'
-		}
-		h.Write([]byte{c})
-	}
-
-	return h.Sum32()
-}
-
-// ResponseWriter is a response writer that caches the reply message.
-type ResponseWriter struct {
-	dns.ResponseWriter
-	*Cache
-
-	prefetch bool // When true write nothing back to the client.
-}
-
-// WriteMsg implements the dns.ResponseWriter interface.
-func (w *ResponseWriter) WriteMsg(res *dns.Msg) error {
-	do := false
-	mt, opt := response.Typify(res, time.Now().UTC())
-	if opt != nil {
-		do = opt.Do()
-	}
-
-	// key returns empty string for anything we don't want to cache.
-	key := key(res, mt, do)
-
-	duration := w.pttl
-	if mt == response.NameError || mt == response.NoData {
-		duration = w.nttl
-	}
-
-	msgTTL := minMsgTTL(res, mt)
-	if msgTTL < duration {
-		duration = msgTTL
-	}
-
-	if key != -1 {
-		w.set(res, key, mt, duration)
-
-		cacheSize.WithLabelValues(Success).Set(float64(w.pcache.Len()))
-		cacheSize.WithLabelValues(Denial).Set(float64(w.ncache.Len()))
-	}
-
-	if w.prefetch {
-		return nil
-	}
-
-	return w.ResponseWriter.WriteMsg(res)
-}
-
-func (w *ResponseWriter) set(m *dns.Msg, key int, mt response.Type, duration time.Duration) {
-	if key == -1 {
-		log.Printf("[ERROR] Caching called with empty cache key")
-		return
-	}
-
-	switch mt {
-	case response.NoError, response.Delegation:
-		i := newItem(m, duration)
-		w.pcache.Add(uint32(key), i)
-
-	case response.NameError, response.NoData:
-		i := newItem(m, duration)
-		w.ncache.Add(uint32(key), i)
-
-	case response.OtherError:
-		// don't cache these
-	default:
-		log.Printf("[WARNING] Caching called with unknown classification: %d", mt)
-	}
-}
-
-// Write implements the dns.ResponseWriter interface.
-func (w *ResponseWriter) Write(buf []byte) (int, error) {
-	log.Printf("[WARNING] Caching called with Write: not caching reply")
-	if w.prefetch {
-		return 0, nil
-	}
-	n, err := w.ResponseWriter.Write(buf)
-	return n, err
-}
-
-const (
-	maxTTL  = 1 * time.Hour
-	maxNTTL = 30 * time.Minute
-
-	minTTL = 5 // seconds
-
-	defaultCap = 10000 // default capacity of the cache.
-
-	// Success is the class for caching positive caching.
-	Success = "success"
-	// Denial is the class defined for negative caching.
-	Denial = "denial"
-)