prysm-pulse/beacon-chain/p2p/peers/assigner.go
terence 5a66807989
Update to V5 (#13622)
* First take at updating everything to v5

* Patch gRPC gateway to use prysm v5

Fix patch

* Update go ssz

---------

Co-authored-by: Preston Van Loon <pvanloon@offchainlabs.com>
2024-02-15 05:46:47 +00:00

79 lines
2.9 KiB
Go

package peers
import (
"github.com/libp2p/go-libp2p/core/peer"
"github.com/pkg/errors"
forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
"github.com/prysmaticlabs/prysm/v5/cmd/beacon-chain/flags"
"github.com/prysmaticlabs/prysm/v5/config/params"
"github.com/sirupsen/logrus"
)
// FinalizedCheckpointer describes the minimum capability that Assigner needs from forkchoice.
// That is, the ability to retrieve the latest finalized checkpoint to help with peer evaluation.
type FinalizedCheckpointer interface {
FinalizedCheckpoint() *forkchoicetypes.Checkpoint
}
// NewAssigner assists in the correct construction of an Assigner by code in other packages,
// assuring all the important private member fields are given values.
// The FinalizedCheckpointer is used to retrieve the latest finalized checkpoint each time peers are requested.
// Peers that report an older finalized checkpoint are filtered out.
func NewAssigner(s *Status, fc FinalizedCheckpointer) *Assigner {
return &Assigner{
ps: s,
fc: fc,
}
}
// Assigner uses the "BestFinalized" peer scoring method to pick the next-best peer to receive rpc requests.
type Assigner struct {
ps *Status
fc FinalizedCheckpointer
}
// ErrInsufficientSuitable is a sentinel error, signaling that a peer couldn't be assigned because there are currently
// not enough peers that match our selection criteria to serve rpc requests. It is the responsibility of the caller to
// look for this error and continue to try calling Assign with appropriate backoff logic.
var ErrInsufficientSuitable = errors.New("no suitable peers")
func (a *Assigner) freshPeers() ([]peer.ID, error) {
required := params.BeaconConfig().MaxPeersToSync
if flags.Get().MinimumSyncPeers < required {
required = flags.Get().MinimumSyncPeers
}
_, peers := a.ps.BestFinalized(params.BeaconConfig().MaxPeersToSync, a.fc.FinalizedCheckpoint().Epoch)
if len(peers) < required {
log.WithFields(logrus.Fields{
"suitable": len(peers),
"required": required}).Warn("Unable to assign peer while suitable peers < required ")
return nil, ErrInsufficientSuitable
}
return peers, nil
}
// Assign uses the "BestFinalized" method to select the best peers that agree on a canonical block
// for the configured finalized epoch. At most `n` peers will be returned. The `busy` param can be used
// to filter out peers that we know we don't want to connect to, for instance if we are trying to limit
// the number of outbound requests to each peer from a given component.
func (a *Assigner) Assign(busy map[peer.ID]bool, n int) ([]peer.ID, error) {
best, err := a.freshPeers()
if err != nil {
return nil, err
}
return pickBest(busy, n, best), nil
}
func pickBest(busy map[peer.ID]bool, n int, best []peer.ID) []peer.ID {
ps := make([]peer.ID, 0, n)
for _, p := range best {
if len(ps) == n {
return ps
}
if !busy[p] {
ps = append(ps, p)
}
}
return ps
}