Redis caching

cache.go

@@ -1,15 +1,11 @@
 package main
 
 import (
-	"crypto/md5"
-	"encoding/json"
 	"fmt"
-	"sync"
 	"time"
 
-	"github.com/bradfitz/gomemcache/memcache"
-	"github.com/hoisie/redis"
 	"github.com/miekg/dns"
+	"crypto/md5"
 )
 
 type KeyNotFound struct {
@@ -56,178 +52,10 @@ type Cache interface {
 	Full() bool
 }
 
-type MemoryCache struct {
-	Backend  map[string]Mesg
-	Expire   time.Duration
-	Maxcount int
-	mu       sync.RWMutex
-}
-
-func (c *MemoryCache) Get(key string) (*dns.Msg, error) {
-	c.mu.RLock()
-	mesg, ok := c.Backend[key]
-	c.mu.RUnlock()
-	if !ok {
-		return nil, KeyNotFound{key}
-	}
-
-	if mesg.Expire.Before(time.Now()) {
-		c.Remove(key)
-		return nil, KeyExpired{key}
-	}
-
-	return mesg.Msg, nil
-
-}
-
-func (c *MemoryCache) Set(key string, msg *dns.Msg) error {
-	if c.Full() && !c.Exists(key) {
-		return CacheIsFull{}
-	}
-
-	expire := time.Now().Add(c.Expire)
-	mesg := Mesg{msg, expire}
-	c.mu.Lock()
-	c.Backend[key] = mesg
-	c.mu.Unlock()
-	return nil
-}
-
-func (c *MemoryCache) Remove(key string) error {
-	c.mu.Lock()
-	delete(c.Backend, key)
-	c.mu.Unlock()
-	return nil
-}
-
-func (c *MemoryCache) Exists(key string) bool {
-	c.mu.RLock()
-	_, ok := c.Backend[key]
-	c.mu.RUnlock()
-	return ok
-}
-
-func (c *MemoryCache) Length() int {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-	return len(c.Backend)
-}
-
-func (c *MemoryCache) Full() bool {
-	// if Maxcount is zero. the cache will never be full.
-	if c.Maxcount == 0 {
-		return false
-	}
-	return c.Length() >= c.Maxcount
-}
-
-/*
-Memcached backend
-*/
-
-func NewMemcachedCache(servers []string, expire int32) *MemcachedCache {
-	c := memcache.New(servers...)
-	return &MemcachedCache{
-		backend: c,
-		expire:  expire,
-	}
-}
-
-type MemcachedCache struct {
-	backend *memcache.Client
-	expire  int32
-}
-
-func (m *MemcachedCache) Set(key string, msg *dns.Msg) error {
-	var val []byte
-	var err error
-
-	// handle cases for negacache where it sets nil values
-	if msg == nil {
-		val = []byte("nil")
-	} else {
-		val, err = msg.Pack()
-	}
-	if err != nil {
-		err = SerializerError{err}
-	}
-	return m.backend.Set(&memcache.Item{Key: key, Value: val, Expiration: m.expire})
-}
-
-func (m *MemcachedCache) Get(key string) (*dns.Msg, error) {
-	var msg dns.Msg
-	item, err := m.backend.Get(key)
-	if err != nil {
-		err = KeyNotFound{key}
-		return &msg, err
-	}
-	err = msg.Unpack(item.Value)
-	if err != nil {
-		err = SerializerError{err}
-	}
-	return &msg, err
-}
-
-func (m *MemcachedCache) Exists(key string) bool {
-	_, err := m.backend.Get(key)
-	if err != nil {
-		return true
-	}
-	return false
-}
-
-func (m *MemcachedCache) Remove(key string) error {
-	return m.backend.Delete(key)
-}
-
-func (m *MemcachedCache) Full() bool {
-	// memcache is never full (LRU)
-	return false
-}
-
-/*
-TODO: Redis cache Backend
-*/
-
-type RedisCache struct {
-	Backend    *redis.Client
-	Serializer JsonSerializer
-	Expire     time.Duration
-	Maxcount   int
-}
-
-func (c *RedisCache) Get() {
-
-}
-
-func (c *RedisCache) Set() {
-
-}
-
-func (c *RedisCache) Remove() {
-
-}
-
 func KeyGen(q Question) string {
 	h := md5.New()
 	h.Write([]byte(q.String()))
 	x := h.Sum(nil)
 	key := fmt.Sprintf("%x", x)
 	return key
-}
+}
-
-/* we need to define marsheling to encode and decode
- */
-type JsonSerializer struct {
-}
-
-func (*JsonSerializer) Dumps(mesg *dns.Msg) (encoded []byte, err error) {
-	encoded, err = json.Marshal(*mesg)
-	return
-}
-
-func (*JsonSerializer) Loads(data []byte) (*dns.Msg, error) {
-	var mesg dns.Msg
-	err := json.Unmarshal(data, &mesg)
-	return &mesg, err
-}

cache_memcached.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"github.com/bradfitz/gomemcache/memcache"
+	"github.com/miekg/dns"
+)
+
+func NewMemcachedCache(servers []string, expire int32) *MemcachedCache {
+	c := memcache.New(servers...)
+	return &MemcachedCache{
+		backend: c,
+		expire:  expire,
+	}
+}
+
+type MemcachedCache struct {
+	backend *memcache.Client
+	expire  int32
+}
+
+func (m *MemcachedCache) Set(key string, msg *dns.Msg) error {
+	var val []byte
+	var err error
+
+	// handle cases for negacache where it sets nil values
+	if msg == nil {
+		val = []byte("nil")
+	} else {
+		val, err = msg.Pack()
+	}
+	if err != nil {
+		err = SerializerError{err}
+	}
+	return m.backend.Set(&memcache.Item{Key: key, Value: val, Expiration: m.expire})
+}
+
+func (m *MemcachedCache) Get(key string) (*dns.Msg, error) {
+	var msg dns.Msg
+	item, err := m.backend.Get(key)
+	if err != nil {
+		err = KeyNotFound{key}
+		return &msg, err
+	}
+	err = msg.Unpack(item.Value)
+	if err != nil {
+		err = SerializerError{err}
+	}
+	return &msg, err
+}
+
+func (m *MemcachedCache) Exists(key string) bool {
+	_, err := m.backend.Get(key)
+	if err != nil {
+		return true
+	}
+	return false
+}
+
+func (m *MemcachedCache) Remove(key string) error {
+	return m.backend.Delete(key)
+}
+
+func (m *MemcachedCache) Full() bool {
+	// memcache is never full (LRU)
+	return false
+}

cache_memory.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"time"
+	"sync"
+	"github.com/miekg/dns"
+)
+
+type MemoryCache struct {
+	Cache
+
+	Backend  map[string]Mesg
+	Expire   time.Duration
+	Maxcount int
+	mu       sync.RWMutex
+}
+
+func (c *MemoryCache) Get(key string) (*dns.Msg, error) {
+	c.mu.RLock()
+	mesg, ok := c.Backend[key]
+	c.mu.RUnlock()
+	if !ok {
+		return nil, KeyNotFound{key}
+	}
+
+	if mesg.Expire.Before(time.Now()) {
+		c.Remove(key)
+		return nil, KeyExpired{key}
+	}
+
+	return mesg.Msg, nil
+
+}
+
+func (c *MemoryCache) Set(key string, msg *dns.Msg) error {
+	if c.Full() && !c.Exists(key) {
+		return CacheIsFull{}
+	}
+
+	expire := time.Now().Add(c.Expire)
+	mesg := Mesg{msg, expire}
+	c.mu.Lock()
+	c.Backend[key] = mesg
+	c.mu.Unlock()
+	return nil
+}
+
+func (c *MemoryCache) Remove(key string) error {
+	c.mu.Lock()
+	delete(c.Backend, key)
+	c.mu.Unlock()
+	return nil
+}
+
+func (c *MemoryCache) Exists(key string) bool {
+	c.mu.RLock()
+	_, ok := c.Backend[key]
+	c.mu.RUnlock()
+	return ok
+}
+
+func (c *MemoryCache) Length() int {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return len(c.Backend)
+}
+
+func (c *MemoryCache) Full() bool {
+	// if Maxcount is zero. the cache will never be full.
+	if c.Maxcount == 0 {
+		return false
+	}
+	return c.Length() >= c.Maxcount
+}

cache_redis.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"github.com/hoisie/redis"
+	"github.com/miekg/dns"
+)
+
+func NewRedisCache(c RedisSettings, expire int32) *RedisCache {
+	rc := &redis.Client{Addr: c.Addr(), Db: c.DB, Password: c.Password}
+
+	return &RedisCache{
+		backend: rc,
+		expire:  expire,
+	}
+}
+
+type RedisCache struct {
+	Cache
+
+	backend    *redis.Client
+	expire     int32
+}
+
+func (m *RedisCache) Set(key string, msg *dns.Msg) error {
+	var val []byte
+	var err error
+
+	// handle cases for negacache where it sets nil values
+	if msg == nil {
+		val = []byte("nil")
+	} else {
+		val, err = msg.Pack()
+	}
+	if err != nil {
+		err = SerializerError{err}
+	}
+	return m.backend.Setex(key, int64(m.expire), val)
+}
+
+func (m *RedisCache) Get(key string) (*dns.Msg, error) {
+	var msg dns.Msg
+	item, err := m.backend.Get(key)
+	if err != nil {
+		err = KeyNotFound{key}
+		return &msg, err
+	}
+	err = msg.Unpack(item)
+	if err != nil {
+		err = SerializerError{err}
+	}
+	return &msg, err
+}
+
+func (m *RedisCache) Exists(key string) bool {
+	exists, err := m.backend.Exists(key)
+	if err != nil {
+		return true
+	}
+	return exists
+}
+
+func (m *RedisCache) Remove(key string) error {
+	_, err := m.backend.Del(key)
+	return err
+}
+
+func (m *RedisCache) Full() bool {
+	// memcache is never full (LRU)
+	return false
+}

etc/godns.conf

@@ -16,6 +16,7 @@ port = 53
 # Semicolon separate multiple files.
 server-list-file = "./etc/apple.china.conf;./etc/google.china.conf"
 resolv-file = "/etc/resolv.conf"
+dns-over-https = "https://cloudflare-dns.com/dns-query"
 timeout = 5  # 5 seconds
 # The concurrency interval request upstream recursive server
 # Match the PR15, https://github.com/kenshinx/godns/pull/15

handler.go

@@ -60,13 +60,12 @@ func NewHandler() *GODNSHandler {
 			settings.Memcache.Servers,
 			int32(cacheConfig.Expire/2))
 	case "redis":
-		// cache = &MemoryCache{
+		cache = NewRedisCache(
-		// 	Backend:    make(map[string]*dns.Msg),
+			settings.Redis,
-		//  Expire:   time.Duration(cacheConfig.Expire) * time.Second,
+			int32(cacheConfig.Expire))
-		// 	Serializer: new(JsonSerializer),
+		negCache = NewRedisCache(
-		// 	Maxcount:   cacheConfig.Maxcount,
+			settings.Redis,
-		// }
+			int32(cacheConfig.Expire/2))
-		panic("Redis cache backend not implement yet")
 	default:
 		logger.Error("Invalid cache backend %s", cacheConfig.Backend)
 		panic("Invalid cache backend")