package blockchain
import (
"bytes"
"encoding/hex"
"fmt"
"net/http"
"sort"
"strconv"
"github.com/emicklei/dot"
"github.com/prysmaticlabs/prysm/shared/bytesutil"
"github.com/sirupsen/logrus"
)
const latestSlotCount = 10
// HeadsHandler is a handler to serve /heads page in metrics.
func (s *Service) HeadsHandler(w http.ResponseWriter, _ *http.Request) {
buf := new(bytes.Buffer)
if _, err := fmt.Fprintf(w, "\n %s\t%s\t", "Head slot", "Head root"); err != nil {
logrus.WithError(err).Error("Failed to render chain heads page")
return
}
if _, err := fmt.Fprintf(w, "\n %s\t%s\t", "---------", "---------"); err != nil {
logrus.WithError(err).Error("Failed to render chain heads page")
return
}
slots := s.latestHeadSlots()
for _, slot := range slots {
r := hex.EncodeToString(bytesutil.Trunc(s.canonicalRoots[uint64(slot)]))
if _, err := fmt.Fprintf(w, "\n %d\t\t%s\t", slot, r); err != nil {
logrus.WithError(err).Error("Failed to render chain heads page")
return
}
}
w.WriteHeader(http.StatusOK)
if _, err := w.Write(buf.Bytes()); err != nil {
log.WithError(err).Error("Failed to render chain heads page")
}
}
const template = `
`
// TreeHandler is a handler to serve /tree page in metrics.
func (s *Service) TreeHandler(w http.ResponseWriter, _ *http.Request) {
if s.headState == 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.Balances()))
for i := len(nodes) - 1; i >= 0; i-- {
// Construct label for each node.
slot := strconv.Itoa(int(nodes[i].Slot))
weight := strconv.Itoa(int(nodes[i].Weight / 1e9)) // Convert unit Gwei to unit ETH.
votes := strconv.Itoa(int(nodes[i].Weight / 1e9 / avgBalance))
bestDescendent := strconv.Itoa(int(nodes[i].BestDescendent))
index := strconv.Itoa(int(i))
label := "slot: " + slot + "\n index: " + index + "\n bestDescendent: " + bestDescendent + "\n votes: " + votes + "\n weight: " + weight
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].BestDescendent == ^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")
}
}
// This returns the latest head slots in a slice and up to latestSlotCount
func (s *Service) latestHeadSlots() []int {
slots := make([]int, 0, len(s.canonicalRoots))
for k := range s.canonicalRoots {
slots = append(slots, int(k))
}
sort.Ints(slots)
if (len(slots)) > latestSlotCount {
return slots[len(slots)-latestSlotCount:]
}
return slots
}