github.com/divan/go-ethereum@v1.8.14-0.20180820134928-1de9ada4016d/les/commons.go (about)

     1  // Copyright 2018 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  	"fmt"
    21  	"math/big"
    22  
    23  	"github.com/ethereum/go-ethereum/common"
    24  	"github.com/ethereum/go-ethereum/core"
    25  	"github.com/ethereum/go-ethereum/eth"
    26  	"github.com/ethereum/go-ethereum/ethdb"
    27  	"github.com/ethereum/go-ethereum/light"
    28  	"github.com/ethereum/go-ethereum/p2p"
    29  	"github.com/ethereum/go-ethereum/p2p/discover"
    30  	"github.com/ethereum/go-ethereum/params"
    31  )
    32  
    33  // lesCommons contains fields needed by both server and client.
    34  type lesCommons struct {
    35  	config                       *eth.Config
    36  	chainDb                      ethdb.Database
    37  	protocolManager              *ProtocolManager
    38  	chtIndexer, bloomTrieIndexer *core.ChainIndexer
    39  }
    40  
    41  // NodeInfo represents a short summary of the Ethereum sub-protocol metadata
    42  // known about the host peer.
    43  type NodeInfo struct {
    44  	Network    uint64                  `json:"network"`    // Ethereum network ID (1=Frontier, 2=Morden, Ropsten=3, Rinkeby=4)
    45  	Difficulty *big.Int                `json:"difficulty"` // Total difficulty of the host's blockchain
    46  	Genesis    common.Hash             `json:"genesis"`    // SHA3 hash of the host's genesis block
    47  	Config     *params.ChainConfig     `json:"config"`     // Chain configuration for the fork rules
    48  	Head       common.Hash             `json:"head"`       // SHA3 hash of the host's best owned block
    49  	CHT        light.TrustedCheckpoint `json:"cht"`        // Trused CHT checkpoint for fast catchup
    50  }
    51  
    52  // makeProtocols creates protocol descriptors for the given LES versions.
    53  func (c *lesCommons) makeProtocols(versions []uint) []p2p.Protocol {
    54  	protos := make([]p2p.Protocol, len(versions))
    55  	for i, version := range versions {
    56  		version := version
    57  		protos[i] = p2p.Protocol{
    58  			Name:     "les",
    59  			Version:  version,
    60  			Length:   ProtocolLengths[version],
    61  			NodeInfo: c.nodeInfo,
    62  			Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
    63  				return c.protocolManager.runPeer(version, p, rw)
    64  			},
    65  			PeerInfo: func(id discover.NodeID) interface{} {
    66  				if p := c.protocolManager.peers.Peer(fmt.Sprintf("%x", id[:8])); p != nil {
    67  					return p.Info()
    68  				}
    69  				return nil
    70  			},
    71  		}
    72  	}
    73  	return protos
    74  }
    75  
    76  // nodeInfo retrieves some protocol metadata about the running host node.
    77  func (c *lesCommons) nodeInfo() interface{} {
    78  	var cht light.TrustedCheckpoint
    79  	sections, _, sectionHead := c.chtIndexer.Sections()
    80  	sections2, _, sectionHead2 := c.bloomTrieIndexer.Sections()
    81  	if sections2 < sections {
    82  		sections = sections2
    83  		sectionHead = sectionHead2
    84  	}
    85  	if sections > 0 {
    86  		sectionIndex := sections - 1
    87  		cht = light.TrustedCheckpoint{
    88  			SectionIdx:  sectionIndex,
    89  			SectionHead: sectionHead,
    90  			CHTRoot:     light.GetChtRoot(c.chainDb, sectionIndex, sectionHead),
    91  			BloomRoot:   light.GetBloomTrieRoot(c.chainDb, sectionIndex, sectionHead),
    92  		}
    93  	}
    94  
    95  	chain := c.protocolManager.blockchain
    96  	head := chain.CurrentHeader()
    97  	hash := head.Hash()
    98  	return &NodeInfo{
    99  		Network:    c.config.NetworkId,
   100  		Difficulty: chain.GetTd(hash, head.Number.Uint64()),
   101  		Genesis:    chain.Genesis().Hash(),
   102  		Config:     chain.Config(),
   103  		Head:       chain.CurrentHeader().Hash(),
   104  		CHT:        cht,
   105  	}
   106  }