godns/cache_memcached.go

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2018-07-01 15:49:24 +00:00
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
}