github.com/phillinzzz/newBsc@v1.1.6/les/ulc.go (about) 1 // Copyright 2019 The go-ethereum Authors 2 // This file is part of the go-ethereum library. 3 // 4 // The go-ethereum library is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU Lesser General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // The go-ethereum library is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU Lesser General Public License for more details. 13 // 14 // You should have received a copy of the GNU Lesser General Public License 15 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. 16 17 package les 18 19 import ( 20 "errors" 21 22 "github.com/phillinzzz/newBsc/log" 23 "github.com/phillinzzz/newBsc/p2p/enode" 24 ) 25 26 type ulc struct { 27 keys map[string]bool 28 fraction int 29 } 30 31 // newULC creates and returns an ultra light client instance. 32 func newULC(servers []string, fraction int) (*ulc, error) { 33 keys := make(map[string]bool) 34 for _, id := range servers { 35 node, err := enode.Parse(enode.ValidSchemes, id) 36 if err != nil { 37 log.Warn("Failed to parse trusted server", "id", id, "err", err) 38 continue 39 } 40 keys[node.ID().String()] = true 41 } 42 if len(keys) == 0 { 43 return nil, errors.New("no trusted servers") 44 } 45 return &ulc{ 46 keys: keys, 47 fraction: fraction, 48 }, nil 49 } 50 51 // trusted return an indicator that whether the specified peer is trusted. 52 func (u *ulc) trusted(p enode.ID) bool { 53 return u.keys[p.String()] 54 }