github.com/Elemental-core/elementalcore@v0.0.0-20191206075037-63891242267a/consensus/consensus.go (about)

     1  // Copyright 2017 The elementalcore Authors
     2  // This file is part of the elementalcore library.
     3  //
     4  // The elementalcore 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 elementalcore 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 elementalcore library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  // Package consensus implements different Ethereum consensus engines.
    18  package consensus
    19  
    20  import (
    21  	"github.com/Elemental-core/elementalcore/common"
    22  	"github.com/Elemental-core/elementalcore/core/state"
    23  	"github.com/Elemental-core/elementalcore/core/types"
    24  	"github.com/Elemental-core/elementalcore/params"
    25  	"github.com/Elemental-core/elementalcore/rpc"
    26  )
    27  
    28  // ChainReader defines a small collection of methods needed to access the local
    29  // blockchain during header and/or uncle verification.
    30  type ChainReader interface {
    31  	// Config retrieves the blockchain's chain configuration.
    32  	Config() *params.ChainConfig
    33  
    34  	// CurrentHeader retrieves the current header from the local chain.
    35  	CurrentHeader() *types.Header
    36  
    37  	// GetHeader retrieves a block header from the database by hash and number.
    38  	GetHeader(hash common.Hash, number uint64) *types.Header
    39  
    40  	// GetHeaderByNumber retrieves a block header from the database by number.
    41  	GetHeaderByNumber(number uint64) *types.Header
    42  
    43  	// GetHeaderByHash retrieves a block header from the database by its hash.
    44  	GetHeaderByHash(hash common.Hash) *types.Header
    45  
    46  	// GetBlock retrieves a block from the database by hash and number.
    47  	GetBlock(hash common.Hash, number uint64) *types.Block
    48  }
    49  
    50  // Engine is an algorithm agnostic consensus engine.
    51  type Engine interface {
    52  	// Author retrieves the Ethereum address of the account that minted the given
    53  	// block, which may be different from the header's coinbase if a consensus
    54  	// engine is based on signatures.
    55  	Author(header *types.Header) (common.Address, error)
    56  
    57  	// Coinbase return the benefits owner of the given block
    58  	Coinbase(header *types.Header) (common.Address, error)
    59  
    60  	// VerifyHeader checks whether a header conforms to the consensus rules of a
    61  	// given engine. Verifying the seal may be done optionally here, or explicitly
    62  	// via the VerifySeal method.
    63  	VerifyHeader(chain ChainReader, header *types.Header, seal bool) error
    64  
    65  	// VerifyHeaders is similar to VerifyHeader, but verifies a batch of headers
    66  	// concurrently. The method returns a quit channel to abort the operations and
    67  	// a results channel to retrieve the async verifications (the order is that of
    68  	// the input slice).
    69  	VerifyHeaders(chain ChainReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error)
    70  
    71  	// VerifyUncles verifies that the given block's uncles conform to the consensus
    72  	// rules of a given engine.
    73  	VerifyUncles(chain ChainReader, block *types.Block) error
    74  
    75  	// VerifySeal checks whether the crypto seal on a header is valid according to
    76  	// the consensus rules of the given engine.
    77  	VerifySeal(chain ChainReader, header *types.Header) error
    78  
    79  	// Prepare initializes the consensus fields of a block header according to the
    80  	// rules of a particular engine. The changes are executed inline.
    81  	Prepare(chain ChainReader, header *types.Header) error
    82  
    83  	// Finalize runs any post-transaction state modifications (e.g. block rewards)
    84  	// and assembles the final block.
    85  	// Note: The block header and state database might be updated to reflect any
    86  	// consensus rules that happen at finalization (e.g. block rewards).
    87  	Finalize(chain ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction,
    88  		uncles []*types.Header, receipts []*types.Receipt, dposContext *types.DposContext) (*types.Block, error)
    89  
    90  	// Seal generates a new block for the given input block with the local miner's
    91  	// seal place on top.
    92  	Seal(chain ChainReader, block *types.Block, stop <-chan struct{}) (*types.Block, error)
    93  
    94  	// APIs returns the RPC APIs this consensus engine provides.
    95  	APIs(chain ChainReader) []rpc.API
    96  }
    97  
    98  // PoW is a consensus engine based on proof-of-work.
    99  type PoW interface {
   100  	Engine
   101  
   102  	// Hashrate returns the current mining hashrate of a PoW consensus engine.
   103  	Hashrate() float64
   104  }