plugeth/cmd/devp2p/nodeset.go

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// Copyright 2019 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package main
import (
"bytes"
"encoding/json"
"fmt"
"os"
"sort"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/p2p/enode"
)
const jsonIndent = " "
// nodeSet is the nodes.json file format. It holds a set of node records
// as a JSON object.
type nodeSet map[enode.ID]nodeJSON
type nodeJSON struct {
Seq uint64 `json:"seq"`
N *enode.Node `json:"record"`
// The score tracks how many liveness checks were performed. It is incremented by one
// every time the node passes a check, and halved every time it doesn't.
Score int `json:"score,omitempty"`
// These two track the time of last successful contact.
FirstResponse time.Time `json:"firstResponse,omitempty"`
LastResponse time.Time `json:"lastResponse,omitempty"`
// This one tracks the time of our last attempt to contact the node.
LastCheck time.Time `json:"lastCheck,omitempty"`
}
func loadNodesJSON(file string) nodeSet {
var nodes nodeSet
if err := common.LoadJSON(file, &nodes); err != nil {
exit(err)
}
return nodes
}
func writeNodesJSON(file string, nodes nodeSet) {
nodesJSON, err := json.MarshalIndent(nodes, "", jsonIndent)
if err != nil {
exit(err)
}
if file == "-" {
os.Stdout.Write(nodesJSON)
return
}
if err := os.WriteFile(file, nodesJSON, 0644); err != nil {
exit(err)
}
}
// nodes returns the node records contained in the set.
func (ns nodeSet) nodes() []*enode.Node {
result := make([]*enode.Node, 0, len(ns))
for _, n := range ns {
result = append(result, n.N)
}
// Sort by ID.
sort.Slice(result, func(i, j int) bool {
return bytes.Compare(result[i].ID().Bytes(), result[j].ID().Bytes()) < 0
})
return result
}
// add ensures the given nodes are present in the set.
func (ns nodeSet) add(nodes ...*enode.Node) {
for _, n := range nodes {
v := ns[n.ID()]
v.N = n
v.Seq = n.Seq()
ns[n.ID()] = v
}
}
// topN returns the top n nodes by score as a new set.
func (ns nodeSet) topN(n int) nodeSet {
if n >= len(ns) {
return ns
}
byscore := make([]nodeJSON, 0, len(ns))
for _, v := range ns {
byscore = append(byscore, v)
}
sort.Slice(byscore, func(i, j int) bool {
return byscore[i].Score >= byscore[j].Score
})
result := make(nodeSet, n)
for _, v := range byscore[:n] {
result[v.N.ID()] = v
}
return result
}
// verify performs integrity checks on the node set.
func (ns nodeSet) verify() error {
for id, n := range ns {
if n.N.ID() != id {
return fmt.Errorf("invalid node %v: ID does not match ID %v in record", id, n.N.ID())
}
if n.N.Seq() != n.Seq {
return fmt.Errorf("invalid node %v: 'seq' does not match seq %d from record", id, n.N.Seq())
}
}
return nil
}