godns/cache_redis.go

71 lines
1.2 KiB
Go

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 {
// redis is never full (LRU)
return false
}