private IDnsQueryResponse Query(DnsQuestion question)
{
if (question == null)
{
throw new ArgumentNullException(nameof(question));
}
var head = new DnsRequestHeader(GetNextUniqueId(), Recursion, DnsOpCode.Query);
var request = new DnsRequestMessage(head, question);
var handler = UseTcpOnly ? _tcpFallbackHandler : _messageHandler;
if (_cache.Enabled)
{
var cacheKey = ResponseCache.GetCacheKey(question);
var item = _cache.Get(cacheKey);
if (item == null)
{
item = ResolveQuery(handler, request);
_cache.Add(cacheKey, item);
}
return(item);
}
else
{
return(ResolveQuery(handler, request));
}
}
private async Task <IDnsQueryResponse> QueryAsync(DnsQuestion question, CancellationToken cancellationToken)
{
if (question == null)
{
throw new ArgumentNullException(nameof(question));
}
var head = new DnsRequestHeader(GetNextUniqueId(), Recursion, DnsOpCode.Query);
var request = new DnsRequestMessage(head, question);
var handler = UseTcpOnly ? _tcpFallbackHandler : _messageHandler;
if (_cache.Enabled)
{
var cacheKey = ResponseCache.GetCacheKey(question);
var item = _cache.Get(cacheKey);
if (item == null)
{
item = await ResolveQueryAsync(handler, request, cancellationToken).ConfigureAwait(false);
_cache.Add(cacheKey, item);
}
return(item);
}
else
{
return(await ResolveQueryAsync(handler, request, cancellationToken).ConfigureAwait(false));
}
}
private static void DoCleanup(ResponseCache cache)
{
cache._cleanupRunning = true;
var now = DateTimeOffset.UtcNow;
foreach (var entry in cache._cache)
{
if (entry.Value.IsExpiredFor(now))
{
cache._cache.TryRemove(entry.Key, out ResponseEntry o);
}
}
cache._cleanupRunning = false;
}