package blockchain
import (
"encoding/hex"
"fmt"
"net/http"
"github.com/emicklei/dot"
)
const template = `
`
// TreeHandler is a handler to serve /tree page in metrics.
func (s *Service) TreeHandler(w http.ResponseWriter, r *http.Request) {
if s.headState(r.Context()) == nil {
if _, err := w.Write([]byte("Unavailable during initial syncing")); err != nil {
log.WithError(err).Error("Failed to render p2p info page")
}
}
nodes := s.forkChoiceStore.Nodes()
graph := dot.NewGraph(dot.Directed)
graph.Attr("rankdir", "RL")
graph.Attr("labeljust", "l")
dotNodes := make([]*dot.Node, len(nodes))
avgBalance := uint64(averageBalance(s.headState(r.Context()).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) {
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")
}
}