go-ethereum/consensus/consensus.go

131 lines
5.6 KiB
Go

// Copyright 2017 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 consensus implements different Ethereum consensus engines.
package consensus
import (
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/rpc"
)
// ChainHeaderReader defines a small collection of methods needed to access the local
// blockchain during header verification.
type ChainHeaderReader interface {
// Config retrieves the blockchain's chain configuration.
Config() *params.ChainConfig
// CurrentHeader retrieves the current header from the local chain.
CurrentHeader() *types.Header
// GetHeader retrieves a block header from the database by hash and number.
GetHeader(hash common.Hash, number uint64) *types.Header
// GetHeaderByNumber retrieves a block header from the database by number.
GetHeaderByNumber(number uint64) *types.Header
// GetHeaderByHash retrieves a block header from the database by its hash.
GetHeaderByHash(hash common.Hash) *types.Header
// GetTd retrieves the total difficulty from the database by hash and number.
GetTd(hash common.Hash, number uint64) *big.Int
}
// ChainReader defines a small collection of methods needed to access the local
// blockchain during header and/or uncle verification.
type ChainReader interface {
ChainHeaderReader
// GetBlock retrieves a block from the database by hash and number.
GetBlock(hash common.Hash, number uint64) *types.Block
}
// Engine is an algorithm agnostic consensus engine.
type Engine interface {
// Author retrieves the Ethereum address of the account that minted the given
// block, which may be different from the header's coinbase if a consensus
// engine is based on signatures.
Author(header *types.Header) (common.Address, error)
// VerifyHeader checks whether a header conforms to the consensus rules of a
// given engine. Verifying the seal may be done optionally here, or explicitly
// via the VerifySeal method.
VerifyHeader(chain ChainHeaderReader, header *types.Header, seal bool) error
// VerifyHeaders is similar to VerifyHeader, but verifies a batch of headers
// concurrently. The method returns a quit channel to abort the operations and
// a results channel to retrieve the async verifications (the order is that of
// the input slice).
VerifyHeaders(chain ChainHeaderReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error)
// VerifyUncles verifies that the given block's uncles conform to the consensus
// rules of a given engine.
VerifyUncles(chain ChainReader, block *types.Block) error
// Prepare initializes the consensus fields of a block header according to the
// rules of a particular engine. The changes are executed inline.
Prepare(chain ChainHeaderReader, header *types.Header) error
// Finalize runs any post-transaction state modifications (e.g. block rewards
// or process withdrawals) but does not assemble the block.
//
// Note: The state database might be updated to reflect any consensus rules
// that happen at finalization (e.g. block rewards).
Finalize(chain ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction,
uncles []*types.Header, withdrawals []*types.Withdrawal)
// FinalizeAndAssemble runs any post-transaction state modifications (e.g. block
// rewards or process withdrawals) and assembles the final block.
//
// Note: The block header and state database might be updated to reflect any
// consensus rules that happen at finalization (e.g. block rewards).
FinalizeAndAssemble(chain ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction,
uncles []*types.Header, receipts []*types.Receipt, withdrawals []*types.Withdrawal) (*types.Block, error)
// Seal generates a new sealing request for the given input block and pushes
// the result into the given channel.
//
// Note, the method returns immediately and will send the result async. More
// than one result may also be returned depending on the consensus algorithm.
Seal(chain ChainHeaderReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) error
// SealHash returns the hash of a block prior to it being sealed.
SealHash(header *types.Header) common.Hash
// CalcDifficulty is the difficulty adjustment algorithm. It returns the difficulty
// that a new block should have.
CalcDifficulty(chain ChainHeaderReader, time uint64, parent *types.Header) *big.Int
// APIs returns the RPC APIs this consensus engine provides.
APIs(chain ChainHeaderReader) []rpc.API
// Close terminates any background threads maintained by the consensus engine.
Close() error
}
// PoW is a consensus engine based on proof-of-work.
type PoW interface {
Engine
// Hashrate returns the current mining hashrate of a PoW consensus engine.
Hashrate() float64
}