package blockchain
import (
"encoding/hex"
"fmt"
"net/http"
"github.com/emicklei/dot"
"github.com/prysmaticlabs/prysm/config/params"
)
const template = `
`
// TreeHandler is a handler to serve /tree page in metrics.
func (s *Service) TreeHandler(w http.ResponseWriter, r *http.Request) {
headState, err := s.HeadState(r.Context())
if err != nil {
log.WithError(err).Error("Could not get head state")
return
}
if headState == nil || headState.IsNil() {
if _, err := w.Write([]byte("Unavailable during initial syncing")); err != nil {
log.WithError(err).Error("Failed to render p2p info page")
}
}
nodes := s.cfg.ForkChoiceStore.Nodes()
graph := dot.NewGraph(dot.Directed)
graph.Attr("rankdir", "RL")
graph.Attr("labeljust", "l")
dotNodes := make([]*dot.Node, len(nodes))
avgBalance := uint64(averageBalance(headState.Balances()))
for i := len(nodes) - 1; i >= 0; i-- {
// Construct label for each node.
slot := fmt.Sprintf("%d", nodes[i].Slot())
weight := fmt.Sprintf("%d", nodes[i].Weight()/1e9) // Convert unit Gwei to unit ETH.
votes := fmt.Sprintf("%d", nodes[i].Weight()/1e9/avgBalance)
index := fmt.Sprintf("%d", i)
g := nodes[i].Graffiti()
graffiti := hex.EncodeToString(g[:8])
label := "slot: " + slot + "\n votes: " + votes + "\n weight: " + weight + "\n graffiti: " + graffiti
var dotN dot.Node
if nodes[i].Parent() != ^uint64(0) {
dotN = graph.Node(index).Box().Attr("label", label)
}
if nodes[i].Slot() == s.HeadSlot() &&
nodes[i].BestDescendant() == ^uint64(0) &&
nodes[i].Parent() != ^uint64(0) {
dotN = dotN.Attr("color", "green")
}
dotNodes[i] = &dotN
}
for i := len(nodes) - 1; i >= 0; i-- {
if nodes[i].Parent() != ^uint64(0) && nodes[i].Parent() < uint64(len(dotNodes)) {
graph.Edge(*dotNodes[i], *dotNodes[nodes[i].Parent()])
}
}
w.WriteHeader(http.StatusOK)
w.Header().Set("Content-Type", "text/html")
if _, err := fmt.Fprintf(w, template, graph.String()); err != nil {
log.WithError(err).Error("Failed to render p2p info page")
}
}
func averageBalance(balances []uint64) float64 {
total := uint64(0)
for i := 0; i < len(balances); i++ {
total += balances[i]
}
return float64(total) / float64(len(balances)) / float64(params.BeaconConfig().GweiPerEth)
}