Do not use ristretto

Memory usage is too big

go.mod

 	github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5
 	github.com/babolivier/go-doh-client v0.0.0-20201028162107-a76cff4cb8b6
 	github.com/d4l3k/messagediff v1.2.1 // indirect
-	github.com/dgraph-io/ristretto v0.0.3 // indirect
 	github.com/jarcoal/httpmock v1.0.8
 	github.com/kentik/patricia v0.0.0-20201202224819-f9447a6e25f1
 	github.com/libp2p/go-reuseport v0.0.2
 	github.com/stretchr/testify v1.7.0
 	github.com/tylertreat/BoomFilters v0.0.0-20200520150052-42a7b4300c0c
 	github.com/xeipuuv/gojsonschema v1.2.0
-	golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2 // indirect
+	golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2
 	golang.org/x/net v0.0.0-20210226172049-e18ecbb05110
-	golang.org/x/sys v0.0.0-20210309074719-68d13333faf2 // indirect
+	golang.org/x/sys v0.0.0-20210309074719-68d13333faf2
 )

go.sum

 cloud.google.com/go v0.34.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible/go.mod h1:r7JcOSlj0wfOMncg0iLm8Leh48TZaKVeNIfJntJ2wa0=
-github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/OneOfOne/xxhash v1.2.8 h1:31czK/TI9sNkxIKfaUfGlU47BAxQ0ztGgd9vPyqimf8=
 github.com/OneOfOne/xxhash v1.2.8/go.mod h1:eZbhyaAYD41SGSSsnmcpxVoRiQ/MPUTjUdIIOT9Um7Q=
 github.com/Shopify/sarama v1.19.0/go.mod h1:FVkBWblsNy7DGZRfXLU0O9RCGt5g3g3yEuWXgklEdEo=
 github.com/casbin/casbin/v2 v2.1.2/go.mod h1:YcPU1XXisHhLzuxH9coDNf2FbKpjGlbCg3n9yuLkIJQ=
 github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
-github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
-github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
 github.com/cespare/xxhash/v2 v2.1.1 h1:6MnRN8NT7+YBpUIWxHtefFZOKTAPgGjpQSxqLNn0+qY=
 github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/clbanning/x2j v0.0.0-20191024224557-825249438eec/go.mod h1:jMjuTZXRI4dUb/I5gc9Hdhagfvm9+RyrPryS/auMzxE=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/dgraph-io/ristretto v0.0.3 h1:jh22xisGBjrEVnRZ1DVTpBVQm0Xndu8sMl0CWDzSIBI=
-github.com/dgraph-io/ristretto v0.0.3/go.mod h1:KPxhHT9ZxKefz+PCeOGsrHpl1qZ7i70dGTu2u+Ahh6E=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
-github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2/go.mod h1:SqUrOPUnsFjfmXRMNPybcSiG0BgUW2AuFH8PAnS2iTw=
 github.com/dustin/go-humanize v0.0.0-20171111073723-bb3d318650d4/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/eapache/go-resiliency v1.1.0/go.mod h1:kFI+JgMyC7bLPUVY133qvEBtVayf5mFgVsvEsIPBvNs=
 github.com/eapache/go-xerial-snappy v0.0.0-20180814174437-776d5712da21/go.mod h1:+020luEh2TKB4/GOp8oxxtq0Daoen/Cii55CzbTV6DU=
 github.com/smira/go-statsd v1.3.2/go.mod h1:1srXJ9/pbnN04G8f4F1jUzsGOnwkPKXciyqpewGlkC4=
 github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4kGIyLM=
 github.com/sony/gobreaker v0.4.1/go.mod h1:ZKptC7FHNvhBz7dN2LGjPVBz2sZJmc0/PkyDJOjmxWY=
-github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/spf13/cobra v0.0.3/go.mod h1:1l0Ry5zgKvJasoi3XT1TypsSe7PqH0Sj9dhYf7v3XqQ=
 github.com/spf13/pflag v1.0.1/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/streadway/amqp v0.0.0-20190404075320-75d898a42a94/go.mod h1:AZpEONHx3DKn8O/DFsRAY58/XVQiIPMTMB1SddzLXVw=

network/dns_resolver.go

 
 import (
 	"net/http"
+	"sync"
 	"time"
 
 	doh "github.com/babolivier/go-doh-client"
-	"github.com/dgraph-io/ristretto"
 )
 
-const (
-	dnsResolverSize     = 1024 * 1024 // 1mb
-	dnsResolverKeepTime = 10 * time.Minute
-)
+const dnsResolverKeepTime = 10 * time.Minute
+
+type dnsResolverCacheEntry struct {
+	ips       []string
+	createdAt time.Time
+}
+
+func (c dnsResolverCacheEntry) Ok() bool {
+	return time.Since(c.createdAt) < dnsResolverKeepTime
+}
 
 type dnsResolver struct {
-	resolver doh.Resolver
-	cache    *ristretto.Cache
+	resolver   doh.Resolver
+	cache      map[string]dnsResolverCacheEntry
+	cacheMutex sync.RWMutex
 }
 
-func (d dnsResolver) LookupA(hostname string) []string {
-	key := "\x00." + hostname
+func (d *dnsResolver) LookupA(hostname string) []string {
+	key := "\x00" + hostname
+
+	d.cacheMutex.RLock()
+	entry, ok := d.cache[key]
+	d.cacheMutex.RUnlock()
 
-	if value, ok := d.cache.Get(key); ok {
-		return value.([]string)
+	if ok && entry.Ok() {
+		return entry.ips
 	}
 
 	var ips []string
 			ips = append(ips, v.IP4)
 		}
 
-		d.cache.SetWithTTL(key, ips, 0, dnsResolverKeepTime)
+		d.cacheMutex.Lock()
+		d.cache[key] = dnsResolverCacheEntry{
+			ips:       ips,
+			createdAt: time.Now(),
+		}
+		d.cacheMutex.Unlock()
 	}
 
 	return ips
 }
 
-func (d dnsResolver) LookupAAAA(hostname string) []string {
-	key := "\x01." + hostname
+func (d *dnsResolver) LookupAAAA(hostname string) []string {
+	key := "\x01" + hostname
 
-	if value, ok := d.cache.Get(key); ok {
-		return value.([]string)
+	d.cacheMutex.RLock()
+	entry, ok := d.cache[key]
+	d.cacheMutex.RUnlock()
+
+	if ok && entry.Ok() {
+		return entry.ips
 	}
 
 	var ips []string
 			ips = append(ips, v.IP6)
 		}
 
-		d.cache.SetWithTTL(key, ips, 0, dnsResolverKeepTime)
+		d.cacheMutex.Lock()
+		d.cache[key] = dnsResolverCacheEntry{
+			ips:       ips,
+			createdAt: time.Now(),
+		}
+		d.cacheMutex.Unlock()
 	}
 
 	return ips
 }
 
-func newDNSResolver(hostname string, httpClient *http.Client) dnsResolver {
-	cache, err := ristretto.NewCache(&ristretto.Config{
-		NumCounters: 10 * dnsResolverSize, // nolint: gomnd // taken from official doc as a best practice value
-		MaxCost:     dnsResolverSize,
-		BufferItems: 64, // nolint: gomnd // taken from official doc as a best practice value
-		Cost: func(value interface{}) int64 {
-			var cost int64
-
-			for _, v := range value.([]string) {
-				cost += int64(len([]byte(v)))
-			}
-
-			return cost
-		},
-	})
-	if err != nil {
-		panic(err)
-	}
-
-	return dnsResolver{
+func newDNSResolver(hostname string, httpClient *http.Client) *dnsResolver {
+	return &dnsResolver{
 		resolver: doh.Resolver{
 			Host:       hostname,
 			Class:      doh.IN,
 			HTTPClient: httpClient,
 		},
-		cache: cache,
+		cache: map[string]dnsResolverCacheEntry{},
 	}
 }

network/dns_resolver_internal_test.go

 type DNSResolverTestSuite struct {
 	suite.Suite
 
-	d dnsResolver
+	d *dnsResolver
 }
 
 func (suite *DNSResolverTestSuite) TestLookupA() {

network/network.go

 
 type network struct {
 	dialer      Dialer
-	dns         dnsResolver
 	httpTimeout time.Duration
 	userAgent   string
+	dns         *dnsResolver
 }
 
 func (n *network) Dial(protocol, address string) (net.Conn, error) {