distribution/vendor/github.com/anacrolix/dht/v2/bootstrap.go

66 lines
1.6 KiB
Go

package dht
import (
"context"
"errors"
"time"
"github.com/anacrolix/dht/v2/krpc"
"github.com/anacrolix/dht/v2/traversal"
)
type TraversalStats = traversal.Stats
// See BootstrapContext.
func (s *Server) Bootstrap() (TraversalStats, error) {
return s.BootstrapContext(context.Background())
}
// Populates the node table.
func (s *Server) BootstrapContext(ctx context.Context) (_ TraversalStats, err error) {
s.mu.Lock()
if s.bootstrappingNow {
s.mu.Unlock()
err = errors.New("already bootstrapping")
return
}
s.bootstrappingNow = true
s.mu.Unlock()
defer func() {
s.mu.Lock()
defer s.mu.Unlock()
s.bootstrappingNow = false
}()
// Track number of responses, for STM use. (It's available via atomic in TraversalStats but that
// won't let wake up STM transactions that are observing the value.)
t := traversal.Start(traversal.OperationInput{
Target: krpc.ID(s.id.AsByteArray()),
K: 16,
DoQuery: func(ctx context.Context, addr krpc.NodeAddr) traversal.QueryResult {
return s.FindNode(NewAddr(addr.UDP()), s.id, QueryRateLimiting{}).TraversalQueryResult(addr)
},
NodeFilter: s.TraversalNodeFilter,
})
nodes, err := s.TraversalStartingNodes()
if err != nil {
return
}
t.AddNodes(nodes)
s.mu.Lock()
s.lastBootstrap = time.Now()
s.mu.Unlock()
select {
case <-ctx.Done():
err = ctx.Err()
case <-t.Stalled():
}
t.Stop()
if err != nil {
// Could test for Stopped and return stats here but the interface doesn't tell the caller if
// we were successful in taking the stats. We could also take a snapshot instead.
return
}
<-t.Stopped()
return *t.Stats(), nil
}