func NewLRUCache(size int) LRUCache {
cache := lrucache.New(size)
return &concurrentLruCacheImp{
cache: cache,
}
}
func (p *concurrentLruCacheImp) Clear() {
p.lock.Lock()
defer p.lock.Unlock()
// there is no way to clear the cache. So, just create a new one
p.cache = lrucache.New(p.cache.MaxSize())
}
// DNSCachingDial wraps the given dial function with Caching of DNS
// resolutions. When a hostname is found in the cache it will call the provided
// dial with the IP address instead of the hostname, so no DNS lookup need be
// performed. It will also cache DNS failures.
//
func DNSCachingDial(dial func(network, addr string) (net.Conn, error), maxEntries int) func(network, addr string) (net.Conn, error) {
if dial == nil {
dial = net.Dial
}
c := &dnsCache{
wrappedDial: dial,
cache: lrucache.New(maxEntries),
}
return c.dial
}
func NewCassandraDatastore() (*CassandraDatastore, error) {
ds := &CassandraDatastore{
cf: GetCassandraConfig(),
}
var err error
ds.db, err = ds.cf.CreateSession()
if err != nil {
return nil, fmt.Errorf("Failed to create cassandra datastore: %v", err)
}
ds.addedDomains = lrucache.New(Config.AddedDomainsCacheSize)
u, err := gocql.RandomUUID()
if err != nil {
return ds, err
}
ds.crawlerUuid = u
return ds, nil
}