Use separate DNSRequestContext struct for adding DNS context to connections

resolver/rrcache.go

@@ -2,7 +2,6 @@ package resolver
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"net"
 	"time"
@@ -45,25 +44,6 @@ type RRCache struct {
 	Modified int64
 }
 
-func (rrCache *RRCache) MarshalJSON() ([]byte, error) {
-	var record = struct {
-		RRCache
-
-		Question string
-		RCode    string
-		Modified time.Time
-		Expires  time.Time
-	}{
-		RRCache:  *rrCache,
-		Question: rrCache.Question.String(),
-		RCode:    dns.RcodeToString[rrCache.RCode],
-		Modified: time.Unix(rrCache.Modified, 0),
-		Expires:  time.Unix(rrCache.Expires, 0),
-	}
-
-	return json.Marshal(record)
-}
-
 // ID returns the ID of the RRCache consisting of the domain and question type.
 func (rrCache *RRCache) ID() string {
 	return rrCache.Domain + rrCache.Question.String()