NewDefaultCrawler creates a new DefaultCrawler.

WithConnectTimeout defines the time for peer connection before timing out.

WithDialAddrExtendDuration sets the duration by which the TTL of dialed address in peer store are extended.

WithMsgTimeout defines the amount of time a single DHT message is allowed to take before it's deemed failed.

WithParallelism defines the number of queries that can be issued in parallel.

WithProtocols defines the ordered set of protocols the crawler will use to talk to other nodes.

HandleQueryFail is a callback on failed peer query.

HandleQueryResult is a callback on successful peer query.

Option DHT Crawler option type.