github.com/mysteriumnetwork/node@v0.0.0-20240516044423-365054f76801/requests/resolver/resolver_cache.go (about)

     1  /*
     2   * Copyright (C) 2021 The "MysteriumNetwork/node" Authors.
     3   *
     4   * This program is free software: you can redistribute it and/or modify
     5   * it under the terms of the GNU General Public License as published by
     6   * the Free Software Foundation, either version 3 of the License, or
     7   * (at your option) any later version.
     8   *
     9   * This program is distributed in the hope that it will be useful,
    10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    12   * GNU General Public License for more details.
    13   *
    14   * You should have received a copy of the GNU General Public License
    15   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    16   */
    17  
    18  package resolver
    19  
    20  import (
    21  	"sync"
    22  )
    23  
    24  var defaultResolveCache = NewResolverCache()
    25  
    26  type resolverCache struct {
    27  	mu    sync.Mutex
    28  	cache map[string][]string
    29  }
    30  
    31  // NewResolverCache caches resolver responses.
    32  func NewResolverCache() *resolverCache {
    33  	return &resolverCache{
    34  		cache: make(map[string][]string),
    35  	}
    36  }
    37  
    38  // CacheDNSRecord add a cached record for the provided name.
    39  func CacheDNSRecord(name string, addrs []string) {
    40  	defaultResolveCache.Add(name, addrs)
    41  }
    42  
    43  // FetchDNSFromCache returns a cached addressed for the provided name.
    44  func FetchDNSFromCache(name string) (addrs []string) {
    45  	return defaultResolveCache.Fetch(name)
    46  }
    47  
    48  func (rc *resolverCache) Fetch(name string) []string {
    49  	rc.mu.Lock()
    50  	defer rc.mu.Unlock()
    51  
    52  	return rc.cache[name]
    53  }
    54  
    55  func (rc *resolverCache) Add(name string, addrs []string) {
    56  	rc.mu.Lock()
    57  	defer rc.mu.Unlock()
    58  
    59  	rc.cache[name] = addrs
    60  }