github.com/arieschain/arieschain@v0.0.0-20191023063405-37c074544356/consensus/consensus.go (about)

     1  // Package consensus implements different Ethereum consensus engines.
     2  package consensus
     3  
     4  import (
     5  	"math/big"
     6  
     7  	"github.com/quickchainproject/quickchain/common"
     8  	"github.com/quickchainproject/quickchain/core/state"
     9  	"github.com/quickchainproject/quickchain/core/types"
    10  	"github.com/quickchainproject/quickchain/p2p"
    11  	"github.com/quickchainproject/quickchain/params"
    12  	"github.com/quickchainproject/quickchain/rpc"
    13  )
    14  
    15  // ChainReader defines a small collection of methods needed to access the local
    16  // blockchain during header and/or uncle verification.
    17  type ChainReader interface {
    18  	// Config retrieves the blockchain's chain configuration.
    19  	Config() *params.ChainConfig
    20  
    21  	// CurrentHeader retrieves the current header from the local chain.
    22  	CurrentHeader() *types.Header
    23  
    24  	// GetHeader retrieves a block header from the database by hash and number.
    25  	GetHeader(hash common.Hash, number uint64) *types.Header
    26  
    27  	// GetHeaderByNumber retrieves a block header from the database by number.
    28  	GetHeaderByNumber(number uint64) *types.Header
    29  
    30  	// GetHeaderByHash retrieves a block header from the database by its hash.
    31  	GetHeaderByHash(hash common.Hash) *types.Header
    32  
    33  	// GetBlock retrieves a block from the database by hash and number.
    34  	GetBlock(hash common.Hash, number uint64) *types.Block
    35  }
    36  
    37  // Engine is an algorithm agnostic consensus engine.
    38  type Engine interface {
    39  	// Author retrieves the Ethereum address of the account that minted the given
    40  	// block, which may be different from the header's coinbase if a consensus
    41  	// engine is based on signatures.
    42  	Author(header *types.Header) (common.Address, error)
    43  
    44  	// VerifyHeader checks whether a header conforms to the consensus rules of a
    45  	// given engine. Verifying the seal may be done optionally here, or explicitly
    46  	// via the VerifySeal method.
    47  	VerifyHeader(chain ChainReader, header *types.Header, seal bool) error
    48  
    49  	// VerifyHeaders is similar to VerifyHeader, but verifies a batch of headers
    50  	// concurrently. The method returns a quit channel to abort the operations and
    51  	// a results channel to retrieve the async verifications (the order is that of
    52  	// the input slice).
    53  	VerifyHeaders(chain ChainReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error)
    54  
    55  	// VerifyUncles verifies that the given block's uncles conform to the consensus
    56  	// rules of a given engine.
    57  	VerifyUncles(chain ChainReader, block *types.Block) error
    58  
    59  	// VerifySeal checks whether the crypto seal on a header is valid according to
    60  	// the consensus rules of the given engine.
    61  	VerifySeal(chain ChainReader, header *types.Header) error
    62  
    63  	// Prepare initializes the consensus fields of a block header according to the
    64  	// rules of a particular engine. The changes are executed inline.
    65  	Prepare(chain ChainReader, header *types.Header) error
    66  
    67  	// Finalize runs any post-transaction state modifications (e.g. block rewards)
    68  	// and assembles the final block.
    69  	// Note: The block header and state database might be updated to reflect any
    70  	// consensus rules that happen at finalization (e.g. block rewards).
    71  	Finalize(chain ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction,
    72  		uncles []*types.Header, receipts []*types.Receipt, dposContext *types.DposContext) (*types.Block, error)
    73  
    74  	// Seal generates a new block for the given input block with the local miner's
    75  	// seal place on top.
    76  	Seal(chain ChainReader, block *types.Block, stop <-chan struct{}) (*types.Block, error)
    77  
    78  	// CalcDifficulty is the difficulty adjustment algorithm. It returns the difficulty
    79  	// that a new block should have.
    80  	CalcDifficulty(chain ChainReader, time uint64, parent *types.Header) *big.Int
    81  
    82  	// APIs returns the RPC APIs this consensus engine provides.
    83  	APIs(chain ChainReader) []rpc.API
    84  
    85  	// Judge the create contract Transaction from a no authorized account for clique engine.
    86  	JudgeTx(chain ChainReader, header *types.Header, tx *types.Transaction, from common.Address) error
    87  }
    88  
    89  // Handler should be implemented is the consensus needs to handle and send peer's message
    90  type Handler interface {
    91  	// NewChainHead handles a new head block comes
    92  	NewChainHead() error
    93  
    94  	// HandleMsg handles a message from peer
    95  	HandleMsg(address common.Address, data p2p.Msg) (bool, error)
    96  
    97  	// SetBroadcaster sets the broadcaster to send message to peers
    98  	SetBroadcaster(Broadcaster)
    99  }
   100  
   101  // PoW is a consensus engine based on proof-of-work.
   102  type PoW interface {
   103  	Engine
   104  
   105  	// Hashrate returns the current mining hashrate of a PoW consensus engine.
   106  	Hashrate() float64
   107  }
   108  
   109  // BFT is a consensus engine to avoid byzantine failure
   110  type BFT interface {
   111  	Engine
   112  
   113  	// Start starts the engine
   114  	Start(chain ChainReader, currentBlock func() *types.Block, hasBadBlock func(hash common.Hash) bool) error
   115  
   116  	// Stop stops the engine
   117  	Stop() error
   118  }
   119  
   120  // DBFT is a consensus engine to avoid byzantine failure
   121  type DBFT interface {
   122  	Engine
   123  
   124  	// Start starts the engine
   125  	Start(chain ChainReader, currentBlock func() *types.Block, hasBadBlock func(hash common.Hash) bool) error
   126  
   127  	// Stop stops the engine
   128  	Stop() error
   129  }