go-ethereum/contracts/checkpointoracle/oracle.go
gary rong c6285e6437 les/checkpointoracle: move oracle into its own package (#20508)
* les: move the checkpoint oracle into its own package

It's first step of refactor LES package. LES package
basically can be divided into LES client and LES server.
However both sides will use checkpoint package for
status retrieval and verification. So this PR moves
checkpoint oracle into a separate package

* les: address comments
2020-01-07 11:24:21 +02:00

97 lines
3.5 KiB
Go

// Copyright 2019 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Package checkpointoracle is a an on-chain light client checkpoint oracle.
package checkpointoracle
//go:generate abigen --sol contract/oracle.sol --pkg contract --out contract/oracle.go
import (
"errors"
"math/big"
"github.com/ethereum/go-ethereum/accounts/abi/bind"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/contracts/checkpointoracle/contract"
"github.com/ethereum/go-ethereum/core/types"
)
// CheckpointOracle is a Go wrapper around an on-chain checkpoint oracle contract.
type CheckpointOracle struct {
address common.Address
contract *contract.CheckpointOracle
}
// NewCheckpointOracle binds checkpoint contract and returns a registrar instance.
func NewCheckpointOracle(contractAddr common.Address, backend bind.ContractBackend) (*CheckpointOracle, error) {
c, err := contract.NewCheckpointOracle(contractAddr, backend)
if err != nil {
return nil, err
}
return &CheckpointOracle{address: contractAddr, contract: c}, nil
}
// ContractAddr returns the address of contract.
func (oracle *CheckpointOracle) ContractAddr() common.Address {
return oracle.address
}
// Contract returns the underlying contract instance.
func (oracle *CheckpointOracle) Contract() *contract.CheckpointOracle {
return oracle.contract
}
// LookupCheckpointEvents searches checkpoint event for specific section in the
// given log batches.
func (oracle *CheckpointOracle) LookupCheckpointEvents(blockLogs [][]*types.Log, section uint64, hash common.Hash) []*contract.CheckpointOracleNewCheckpointVote {
var votes []*contract.CheckpointOracleNewCheckpointVote
for _, logs := range blockLogs {
for _, log := range logs {
event, err := oracle.contract.ParseNewCheckpointVote(*log)
if err != nil {
continue
}
if event.Index == section && common.Hash(event.CheckpointHash) == hash {
votes = append(votes, event)
}
}
}
return votes
}
// RegisterCheckpoint registers the checkpoint with a batch of associated signatures
// that are collected off-chain and sorted by lexicographical order.
//
// Notably all signatures given should be transformed to "ethereum style" which transforms
// v from 0/1 to 27/28 according to the yellow paper.
func (oracle *CheckpointOracle) RegisterCheckpoint(opts *bind.TransactOpts, index uint64, hash []byte, rnum *big.Int, rhash [32]byte, sigs [][]byte) (*types.Transaction, error) {
var (
r [][32]byte
s [][32]byte
v []uint8
)
for i := 0; i < len(sigs); i++ {
if len(sigs[i]) != 65 {
return nil, errors.New("invalid signature")
}
r = append(r, common.BytesToHash(sigs[i][:32]))
s = append(s, common.BytesToHash(sigs[i][32:64]))
v = append(v, sigs[i][64])
}
return oracle.contract.SetCheckpoint(opts, rnum, rhash, common.BytesToHash(hash), index, v, r, s)
}