Cache elements of State

Cache the size and the do bit whenever someone asked for it. We can

probably add more:



PASS

BenchmarkStateDo-4  	100000000	        11.9 ns/op

BenchmarkStateSize-4	 5000000	       265 ns/op

ok  	github.com/miekg/coredns/middleware	2.828s



PASS

BenchmarkStateDo-4  	1000000000	         2.86 ns/op

BenchmarkStateSize-4	500000000	         3.10 ns/op

ok  	github.com/miekg/coredns/middleware	5.032s



This PR also includes some testing cleanups as well.

middleware/chaos/chaos_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/miekg/coredns/middleware"
+	coretest "github.com/miekg/coredns/middleware/testing"
 
 	"github.com/miekg/dns"
 	"golang.org/x/net/context"
@@ -57,7 +58,7 @@ func TestChaos(t *testing.T) {
 		req.Question[0].Qclass = dns.ClassCHAOS
 		em.Next = test.next
 
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		code, err := em.ServeDNS(ctx, rec, req)
 
 		if err != test.expectedErr {

middleware/errors/errors_test.go

@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"github.com/miekg/coredns/middleware"
+	coretest "github.com/miekg/coredns/middleware/testing"
 
 	"github.com/miekg/dns"
 	"golang.org/x/net/context"
@@ -46,7 +47,7 @@ func TestErrors(t *testing.T) {
 	for i, test := range tests {
 		em.Next = test.next
 		buf.Reset()
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		code, err := em.ServeDNS(ctx, rec, req)
 
 		if err != test.expectedErr {
@@ -77,7 +78,7 @@ func TestVisibleErrorWithPanic(t *testing.T) {
 	req := new(dns.Msg)
 	req.SetQuestion("example.org.", dns.TypeA)
 
-	rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+	rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 
 	code, err := eh.ServeDNS(ctx, rec, req)
 	if code != 0 {

middleware/etcd/cname_test.go

@@ -23,7 +23,7 @@ func TestCnameLookup(t *testing.T) {
 	for _, tc := range dnsTestCasesCname {
 		m := tc.Msg()
 
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		_, err := etc.ServeDNS(ctx, rec, m)
 		if err != nil {
 			t.Errorf("expected no error, got %v\n", err)

middleware/etcd/group_test.go

@@ -25,7 +25,7 @@ func TestGroupLookup(t *testing.T) {
 	for _, tc := range dnsTestCasesGroup {
 		m := tc.Msg()
 
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		_, err := etc.ServeDNS(ctx, rec, m)
 		if err != nil {
 			t.Errorf("expected no error, got %v\n", err)

middleware/etcd/multi_test.go

@@ -28,7 +28,7 @@ func TestMultiLookup(t *testing.T) {
 	for _, tc := range dnsTestCasesMulti {
 		m := tc.Msg()
 
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		_, err := etcMulti.ServeDNS(ctx, rec, m)
 		if err != nil {
 			t.Errorf("expected no error, got %v\n", err)

middleware/etcd/other_test.go

@@ -27,7 +27,7 @@ func TestOtherLookup(t *testing.T) {
 	for _, tc := range dnsTestCasesOther {
 		m := tc.Msg()
 
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		_, err := etc.ServeDNS(ctx, rec, m)
 		if err != nil {
 			t.Errorf("expected no error, got %v\n", err)

middleware/etcd/setup_test.go

@@ -16,9 +16,9 @@ import (
 	"github.com/miekg/coredns/middleware/etcd/singleflight"
 	"github.com/miekg/coredns/middleware/proxy"
 	coretest "github.com/miekg/coredns/middleware/testing"
-	"github.com/miekg/dns"
 
 	etcdc "github.com/coreos/etcd/client"
+	"github.com/miekg/dns"
 	"golang.org/x/net/context"
 )
 
@@ -67,7 +67,7 @@ func TestLookup(t *testing.T) {
 	for _, tc := range dnsTestCases {
 		m := tc.Msg()
 
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		_, err := etc.ServeDNS(ctx, rec, m)
 		if err != nil {
 			t.Errorf("expected no error, got %v\n", err)

middleware/file/dnssec_test.go

@@ -109,7 +109,7 @@ func TestLookupDNSSEC(t *testing.T) {
 	for _, tc := range dnssecTestCases {
 		m := tc.Msg()
 
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		_, err := fm.ServeDNS(ctx, rec, m)
 		if err != nil {
 			t.Errorf("expected no error, got %v\n", err)
@@ -147,7 +147,7 @@ func BenchmarkLookupDNSSEC(b *testing.B) {
 
 	fm := File{Next: coretest.ErrorHandler(), Zones: Zones{Z: map[string]*Zone{testzone: zone}, Names: []string{testzone}}}
 	ctx := context.TODO()
-	rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+	rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 
 	tc := coretest.Case{
 		Qname: "b.miek.nl.", Qtype: dns.TypeA, Do: true,

middleware/file/ent_test.go

@@ -42,7 +42,7 @@ func TestLookupENT(t *testing.T) {
 	for _, tc := range entTestCases {
 		m := tc.Msg()
 
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		_, err := fm.ServeDNS(ctx, rec, m)
 		if err != nil {
 			t.Errorf("expected no error, got %v\n", err)

middleware/file/lookup_test.go

@@ -77,7 +77,7 @@ func TestLookup(t *testing.T) {
 	for _, tc := range dnsTestCases {
 		m := tc.Msg()
 
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		_, err := fm.ServeDNS(ctx, rec, m)
 		if err != nil {
 			t.Errorf("expected no error, got %v\n", err)
@@ -112,7 +112,7 @@ func TestLookupNil(t *testing.T) {
 	ctx := context.TODO()
 
 	m := dnsTestCases[0].Msg()
-	rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+	rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 	fm.ServeDNS(ctx, rec, m)
 }
 
@@ -124,7 +124,7 @@ func BenchmarkLookup(b *testing.B) {
 
 	fm := File{Next: coretest.ErrorHandler(), Zones: Zones{Z: map[string]*Zone{testzone: zone}, Names: []string{testzone}}}
 	ctx := context.TODO()
-	rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+	rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 
 	tc := coretest.Case{
 		Qname: "www.miek.nl.", Qtype: dns.TypeA,

middleware/file/wildcard_test.go

@@ -56,7 +56,7 @@ func TestLookupWildcard(t *testing.T) {
 	for _, tc := range wildcardTestCases {
 		m := tc.Msg()
 
-		rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+		rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 		_, err := fm.ServeDNS(ctx, rec, m)
 		if err != nil {
 			t.Errorf("expected no error, got %v\n", err)

middleware/loadbalance/loadbalance_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/miekg/coredns/middleware"
+	coretest "github.com/miekg/coredns/middleware/testing"
 
 	"github.com/miekg/dns"
 	"golang.org/x/net/context"
@@ -55,7 +56,7 @@ func TestLoadBalance(t *testing.T) {
 		},
 	}
 
-	rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+	rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 
 	for i, test := range tests {
 		req := new(dns.Msg)

middleware/log/log_test.go

@@ -7,6 +7,8 @@ import (
 	"testing"
 
 	"github.com/miekg/coredns/middleware"
+	coretest "github.com/miekg/coredns/middleware/testing"
+
 	"github.com/miekg/dns"
 	"golang.org/x/net/context"
 )
@@ -35,7 +37,7 @@ func TestLoggedStatus(t *testing.T) {
 	r := new(dns.Msg)
 	r.SetQuestion("example.org.", dns.TypeA)
 
-	rec := middleware.NewResponseRecorder(&middleware.TestResponseWriter{})
+	rec := middleware.NewResponseRecorder(&coretest.ResponseWriter{})
 
 	rcode, _ := logger.ServeDNS(ctx, rec, r)
 	if rcode != 0 {

middleware/proxy/lookup_test.go

@@ -7,6 +7,8 @@ import (
 	"testing"
 
 	"github.com/miekg/coredns/middleware"
+	coretest "github.com/miekg/coredns/middleware/testing"
+
 	"github.com/miekg/dns"
 )
 
@@ -30,5 +32,5 @@ func TestLookupProxy(t *testing.T) {
 }
 
 func fakeState() middleware.State {
-	return middleware.State{W: &middleware.TestResponseWriter{}, Req: new(dns.Msg)}
+	return middleware.State{W: &coretest.ResponseWriter{}, Req: new(dns.Msg)}
 }

middleware/recorder.go

@@ -1,7 +1,6 @@
 package middleware
 
 import (
-	"net"
 	"time"
 
 	"github.com/miekg/dns"
@@ -79,24 +78,3 @@ func (r *ResponseRecorder) Hijack() {
 	r.ResponseWriter.Hijack()
 	return
 }
-
-type TestResponseWriter struct{}
-
-func (t *TestResponseWriter) LocalAddr() net.Addr {
-	ip := net.ParseIP("127.0.0.1")
-	port := 53
-	return &net.UDPAddr{IP: ip, Port: port, Zone: ""}
-}
-
-func (t *TestResponseWriter) RemoteAddr() net.Addr {
-	ip := net.ParseIP("10.240.0.1")
-	port := 40212
-	return &net.UDPAddr{IP: ip, Port: port, Zone: ""}
-}
-
-func (t *TestResponseWriter) WriteMsg(m *dns.Msg) error     { return nil }
-func (t *TestResponseWriter) Write(buf []byte) (int, error) { return len(buf), nil }
-func (t *TestResponseWriter) Close() error                  { return nil }
-func (t *TestResponseWriter) TsigStatus() error             { return nil }
-func (t *TestResponseWriter) TsigTimersOnly(bool)           { return }
-func (t *TestResponseWriter) Hijack()                       { return }

middleware/state.go

@@ -2,36 +2,38 @@ package middleware
 
 import (
 	"net"
-	"net/http"
 	"strings"
 	"time"
 
 	"github.com/miekg/dns"
 )
 
-// This file contains the state nd functions available for use in the templates.
+// This file contains the state functions available for use in the middlewares.
 
 // State contains some connection state and is useful in middleware.
 type State struct {
-	Root http.FileSystem // TODO(miek): needed?
 	Req *dns.Msg
 	W   dns.ResponseWriter
+
+	// Cache size after first call to Size or Do
+	size int
+	do   int // 0: not, 1: true: 2: false
 }
 
 // Now returns the current timestamp in the specified format.
-func (s State) Now(format string) string { return time.Now().Format(format) }
+func (s *State) Now(format string) string { return time.Now().Format(format) }
 
 // NowDate returns the current date/time that can be used in other time functions.
-func (s State) NowDate() time.Time { return time.Now() }
+func (s *State) NowDate() time.Time { return time.Now() }
 
 // Header gets the heaser of the request in State.
-func (s State) Header() *dns.RR_Header {
+func (s *State) Header() *dns.RR_Header {
 	// TODO(miek)
 	return nil
 }
 
 // IP gets the (remote) IP address of the client making the request.
-func (s State) IP() string {
+func (s *State) IP() string {
 	ip, _, err := net.SplitHostPort(s.W.RemoteAddr().String())
 	if err != nil {
 		return s.W.RemoteAddr().String()
@@ -40,7 +42,7 @@ func (s State) IP() string {
 }
 
 // Post gets the (remote) Port of the client making the request.
-func (s State) Port() (string, error) {
+func (s *State) Port() (string, error) {
 	_, port, err := net.SplitHostPort(s.W.RemoteAddr().String())
 	if err != nil {
 		return "0", err
@@ -50,7 +52,7 @@ func (s State) Port() (string, error) {
 
 // Proto gets the protocol used as the transport. This
 // will be udp or tcp.
-func (s State) Proto() string {
+func (s *State) Proto() string {
 	if _, ok := s.W.RemoteAddr().(*net.UDPAddr); ok {
 		return "udp"
 	}
@@ -62,7 +64,7 @@ func (s State) Proto() string {
 
 // Family returns the family of the transport.
 // 1 for IPv4 and 2 for IPv6.
-func (s State) Family() int {
+func (s *State) Family() int {
 	var a net.IP
 	ip := s.W.RemoteAddr()
 	if i, ok := ip.(*net.UDPAddr); ok {
@@ -79,33 +81,56 @@ func (s State) Family() int {
 }
 
 // Do returns if the request has the DO (DNSSEC OK) bit set.
-func (s State) Do() bool {
+func (s *State) Do() bool {
+	if s.do != 0 {
+		return s.do == doTrue
+	}
+
 	if o := s.Req.IsEdns0(); o != nil {
+		if o.Do() {
+			s.do = doTrue
+		} else {
+			s.do = doFalse
+		}
 		return o.Do()
 	}
+	s.do = doFalse
 	return false
 }
 
 // UDPSize returns if UDP buffer size advertised in the requests OPT record.
 // Or when the request was over TCP, we return the maximum allowed size of 64K.
-func (s State) Size() int {
+func (s *State) Size() int {
+	if s.size != 0 {
+		return s.size
+	}
+
 	if s.Proto() == "tcp" {
+		s.size = dns.MaxMsgSize
 		return dns.MaxMsgSize
 	}
 	if o := s.Req.IsEdns0(); o != nil {
-		s := o.UDPSize()
-		if s < dns.MinMsgSize {
-			s = dns.MinMsgSize
+		if o.Do() == true {
+			s.do = doTrue
+		} else {
+			s.do = doFalse
 		}
-		return int(s)
+
+		size := o.UDPSize()
+		if size < dns.MinMsgSize {
+			size = dns.MinMsgSize
 		}
+		s.size = int(size)
+		return int(size)
+	}
+	s.size = dns.MinMsgSize
 	return dns.MinMsgSize
 }
 
 // SizeAndDo returns a ready made OPT record that the reflects the intent from
 // state. This can be added to upstream requests that will then hopefully
 // return a message that is fits the buffer in the client.
-func (s State) SizeAndDo() *dns.OPT {
+func (s *State) SizeAndDo() *dns.OPT {
 	size := s.Size()
 	Do := s.Do()
 
@@ -134,7 +159,7 @@ const (
 // the TC bit will be set regardless of protocol, even TCP message will get the bit, the client
 // should then retry with pigeons.
 // TODO(referral).
-func (s State) Scrub(reply *dns.Msg) (*dns.Msg, Result) {
+func (s *State) Scrub(reply *dns.Msg) (*dns.Msg, Result) {
 	size := s.Size()
 	l := reply.Len()
 	if size >= l {
@@ -150,32 +175,36 @@ func (s State) Scrub(reply *dns.Msg) (*dns.Msg, Result) {
 	// Still?!! does not fit.
 	reply.Truncated = true
 	return reply, ScrubDone
-
 }
 
 // Type returns the type of the question as a string.
-func (s State) Type() string { return dns.Type(s.Req.Question[0].Qtype).String() }
+func (s *State) Type() string { return dns.Type(s.Req.Question[0].Qtype).String() }
 
 // QType returns the type of the question as a uint16.
-func (s State) QType() uint16 { return s.Req.Question[0].Qtype }
+func (s *State) QType() uint16 { return s.Req.Question[0].Qtype }
 
 // Name returns the name of the question in the request. Note
 // this name will always have a closing dot and will be lower cased.
-func (s State) Name() string { return strings.ToLower(dns.Name(s.Req.Question[0].Name).String()) }
+func (s *State) Name() string { return strings.ToLower(dns.Name(s.Req.Question[0].Name).String()) }
 
 // QName returns the name of the question in the request.
-func (s State) QName() string { return dns.Name(s.Req.Question[0].Name).String() }
+func (s *State) QName() string { return dns.Name(s.Req.Question[0].Name).String() }
 
 // Class returns the class of the question in the request.
-func (s State) Class() string { return dns.Class(s.Req.Question[0].Qclass).String() }
+func (s *State) Class() string { return dns.Class(s.Req.Question[0].Qclass).String() }
 
 // QClass returns the class of the question in the request.
-func (s State) QClass() uint16 { return s.Req.Question[0].Qclass }
+func (s *State) QClass() uint16 { return s.Req.Question[0].Qclass }
 
 // ErrorMessage returns an error message suitable for sending
 // back to the client.
-func (s State) ErrorMessage(rcode int) *dns.Msg {
+func (s *State) ErrorMessage(rcode int) *dns.Msg {
 	m := new(dns.Msg)
 	m.SetRcode(s.Req, rcode)
 	return m
 }
+
+const (
+	doTrue  = 1
+	doFalse = 2
+)

middleware/state_test.go

@@ -1,5 +1,46 @@
 package middleware
 
+import (
+	"testing"
+
+	coretest "github.com/miekg/coredns/middleware/testing"
+
+	"github.com/miekg/dns"
+)
+
+func TestStateDo(t *testing.T) {
+	st := testState()
+
+	st.Do()
+	if st.do == 0 {
+		t.Fatalf("expected st.do to be set")
+	}
+}
+
+func BenchmarkStateDo(b *testing.B) {
+	st := testState()
+
+	for i := 0; i < b.N; i++ {
+		st.Do()
+	}
+}
+
+func BenchmarkStateSize(b *testing.B) {
+	st := testState()
+
+	for i := 0; i < b.N; i++ {
+		st.Size()
+	}
+}
+
+func testState() State {
+	m := new(dns.Msg)
+	m.SetQuestion("example.com.", dns.TypeA)
+	m.SetEdns0(4097, true)
+
+	return State{W: &coretest.ResponseWriter{}, Req: m}
+}
+
 /*
 func TestHeader(t *testing.T) {
 	state := getContextOrFail(t)

middleware/testing/helpers.go

@@ -3,8 +3,6 @@ package testing
 import (
 	"testing"
 
-	"github.com/miekg/coredns/middleware"
-
 	"github.com/miekg/dns"
 	"golang.org/x/net/context"
 )
@@ -199,11 +197,27 @@ func Section(t *testing.T, tc Case, sect Sect, rr []dns.RR) bool {
 	return true
 }
 
-func ErrorHandler() middleware.Handler {
-	return middleware.HandlerFunc(func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+func ErrorHandler() Handler {
+	return HandlerFunc(func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 		m := new(dns.Msg)
 		m.SetRcode(r, dns.RcodeServerFailure)
 		w.WriteMsg(m)
 		return dns.RcodeServerFailure, nil
 	})
 }
+
+// Copied here to prevent an import cycle.
+type (
+	// HandlerFunc is a convenience type like dns.HandlerFunc, except
+	// ServeDNS returns an rcode and an error.
+	HandlerFunc func(context.Context, dns.ResponseWriter, *dns.Msg) (int, error)
+
+	Handler interface {
+		ServeDNS(context.Context, dns.ResponseWriter, *dns.Msg) (int, error)
+	}
+)
+
+// ServeDNS implements the Handler interface.
+func (f HandlerFunc) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+	return f(ctx, w, r)
+}

middleware/testing/responsewriter.go

@@ -0,0 +1,28 @@
+package testing
+
+import (
+	"net"
+
+	"github.com/miekg/dns"
+)
+
+type ResponseWriter struct{}
+
+func (t *ResponseWriter) LocalAddr() net.Addr {
+	ip := net.ParseIP("127.0.0.1")
+	port := 53
+	return &net.UDPAddr{IP: ip, Port: port, Zone: ""}
+}
+
+func (t *ResponseWriter) RemoteAddr() net.Addr {
+	ip := net.ParseIP("10.240.0.1")
+	port := 40212
+	return &net.UDPAddr{IP: ip, Port: port, Zone: ""}
+}
+
+func (t *ResponseWriter) WriteMsg(m *dns.Msg) error     { return nil }
+func (t *ResponseWriter) Write(buf []byte) (int, error) { return len(buf), nil }
+func (t *ResponseWriter) Close() error                  { return nil }
+func (t *ResponseWriter) TsigStatus() error             { return nil }
+func (t *ResponseWriter) TsigTimersOnly(bool)           { return }
+func (t *ResponseWriter) Hijack()                       { return }