consensus

Documentation

Overview

Package consensus implements different cpchain consensus engines.

Index

• Variables
• type ChainReadWriter
• type ChainReader
• type ChainWriter
• type Engine
• type PbftEngine
• type PbftStatus
• type Proposer
• type Protocol
• type State
• type Validator

Variables

var (
	// ErrUnknownAncestor is returned when validating a block requires an ancestor
	// that is unknown.
	ErrUnknownAncestor = errors.New("unknown ancestor")

	// ErrPrunedAncestor is returned when validating a block requires an ancestor
	// that is known, but the state of which is not available.
	ErrPrunedAncestor = errors.New("pruned ancestor")

	// ErrFutureBlock is returned when a block's timestamp is in the future according
	// to the current node.
	ErrFutureBlock = errors.New("block in the future")

	// ErrInvalidNumber is returned if a block's number doesn't equal it's parent's
	// plus one.
	ErrInvalidNumber = errors.New("invalid block number")

	// ErrNotEnoughSigs is returned if there is not enough signatures for a block.
	ErrNotEnoughSigs = errors.New("not enough signatures in block")

	// ErrUnauthorized is returned if a header is signed by a non-authorized entity.
	ErrUnauthorized = errors.New("unauthorized leader")

	// ErrNotInProposerCommittee is returned  if the account is not in proposer committee.
	ErrNotInProposerCommittee = errors.New("not in proposer committee")

	// ErrUnknownLbftState is returned if committee handler's state is unknown
	ErrUnknownLbftState = errors.New("unknown lbft state")

	// ErrInvalidSigners is returned if a block contains an invalid extra sigers bytes.
	ErrInvalidSigners = errors.New("invalid signer list on checkpoint block")
)

Types

type ChainReadWriter

type ChainReadWriter interface {
	ChainReader
	ChainWriter
}

ChainReadWriter includes reader and writer

type ChainReader

type ChainReader interface {
	// Config retrieves the blockchain's chain configuration.
	Config() *configs.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

	// GetBlock retrieves a block from the database by hash and number.
	GetBlock(hash common.Hash, number uint64) *types.Block
}

ChainReader defines a small collection of methods needed to access the local blockchain.

type ChainWriter

type ChainWriter interface {

	// InsertChain inserts blocks to chain, returns fail index and error
	InsertChain(chain types.Blocks) (int, error)
}

ChainWriter reads and writes pending block to blockchain

type Engine

type Engine interface {
	// Author retrieves the cpchain 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 sigs may be done optionally here, or explicitly
	// via the VerifySeal method.
	// `refHeader' points to the original header, but `header' only points to a copy.
	VerifyHeader(chain ChainReader, header *types.Header, verifySigs bool, refHeader *types.Header) 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 ChainReader, headers []*types.Header, verifySigs []bool, refHeaders []*types.Header) (chan<- struct{}, <-chan error)

	// VerifySigs checks whether the crypto seal on a header is valid according to
	// the consensus rules of the given engine.
	VerifySigs(chain ChainReader, header *types.Header, refHeader *types.Header) error

	// PrepareBlock initializes the consensus fields of a block header according to the
	// rules of a particular engine. The changes are executed inline.
	PrepareBlock(chain ChainReader, header *types.Header) error

	// Finalize runs any post-transaction state modifications (e.g. block rewards)
	// 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).
	Finalize(chain ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction,
		uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error)

	// Seal generates a new block for the given input block with the local miner's
	// seal place on top.
	Seal(chain ChainReader, block *types.Block, stop <-chan struct{}) (*types.Block, error)

	// CalcDifficulty is the difficulty adjustment algorithm. It returns the difficulty
	// that a new block should have.
	CalcDifficulty(chain ChainReader, time uint64, parent *types.Header) *big.Int

	// APIs returns the RPC APIs this consensus engine provides.
	APIs(chain ChainReader) []rpc.API

	// GAPIs returns the GRPC APIs this consensus engine provides.
	GAPIs(chain ChainReader) []grpc.GApi
}

Engine is an algorithm agnostic consensus engine.

type PbftEngine

type PbftEngine interface {
	Engine

	// State returns current pbft phrase, one of (PrePrepare, Prepare, Commit).
	State() State

	// Start starts engine
	Start() error

	// Stop stops all
	Stop() error

	Protocol() Protocol
}

PbftEngine is a pbft based consensus engine

type PbftStatus

type PbftStatus struct {
	State State
	Head  *types.Header
}

PbftStatus represents a state of a dpor replica

type Proposer

type Proposer interface {
	Engine
}

Proposer is used to produce a block in our PV(Producer-Validator) model.

type Protocol

type Protocol interface {
	Version() uint

	Length() uint64

	Available() bool

	AddPeer(version int, p *p2p.Peer, rw p2p.MsgReadWriter) (string, bool, bool, error)

	RemovePeer(id string)

	HandleMsg(id string, msg p2p.Msg) error

	NodeInfo() interface{}
}

Protocol represents interfaces a protocol can provide

type State

type State uint8

State is the pbft state

const (
	// Idle state is served as the first state in PBFT, ready to receive the proposed block
	Idle State = iota

	// Preprepared state is the second state. The validator can enter this state after receiving proposed block (pre-prepare) message.
	// It is ready to send prepare messages
	Preprepared

	// Prepared state is the third state. The validator can enter it after collecting prepare certificate
	// It is about to broadcast commit messages
	Prepared

	// ImpeachPreprepared The validator transit to impeach pre-prepared state whenever the timer expires
	// It is about to broadcast impeach prepare messages
	ImpeachPreprepared

	// ImpeachPrepared Once a impeach prepare certificate is collected, a validator enters impeach prepared state
	ImpeachPrepared
)

type Validator

type Validator interface {

	// ValidateBlock validates a basic field excepts seal of a block.
	ValidateBlock(chain ChainReader, block *types.Block) error

	// SignHeader signs a header in given state.
	SignHeader(chain ChainReader, header *types.Header, state State) error
}

Validator is used to validate and sign a block