consensus

Documentation

Overview

Package consensus implements different Quai consensus engines.

Index

• Variables
• func DifficultyToTarget(difficulty *big.Int) *big.Int
• func TargetToDifficulty(target *big.Int) *big.Int
• type ChainHeaderReader
• type ChainReader
• type Engine
• type PoW

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 its parent's
	// plus one.
	ErrInvalidNumber = errors.New("invalid block number")
)

Functions

func DifficultyToTarget

func DifficultyToTarget(difficulty *big.Int) *big.Int

func TargetToDifficulty

func TargetToDifficulty(target *big.Int) *big.Int

Types

type ChainHeaderReader

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

	// GetTerminiByHash retrieves the termini for a given header hash
	GetTerminiByHash(hash common.Hash) *types.Termini

	// ProcessingState returns true for slices that are running
	ProcessingState() bool
}

ChainHeaderReader defines a small collection of methods needed to access the local blockchain during header verification.

type ChainReader

type ChainReader interface {
	ChainHeaderReader

	// 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 during header and/or uncle verification.

type Engine

type Engine interface {
	// Author retrieves the Quai 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)

	// IntrinsicLogS returns the logarithm of the intrinsic entropy reduction of a PoW hash
	IntrinsicLogS(powHash common.Hash) *big.Int

	// CalcOrder returns the order of the block within the hierarchy of chains
	CalcOrder(header *types.Header) (*big.Int, int, error)

	// TotalLogS returns the log of the total entropy reduction if the chain since genesis to the given header
	TotalLogS(header *types.Header) *big.Int

	// TotalLogPhS returns the log of the total entropy reduction if the chain since genesis for a pending header
	TotalLogPhS(header *types.Header) *big.Int

	// DeltaLogS returns the log of the entropy delta for a chain since its prior coincidence
	DeltaLogS(header *types.Header) *big.Int

	ComputePowLight(header *types.Header) (mixHash, powHash common.Hash)

	// 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) 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) (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, parent *types.Header) error

	// Finalize runs any post-transaction state modifications (e.g. block rewards)
	// but does not assemble the 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 ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction,
		uncles []*types.Header)

	// FinalizeAndAssemble 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).
	FinalizeAndAssemble(chain ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, etxs []*types.Transaction, manifest types.BlockManifest, receipts []*types.Receipt) (*types.Block, error)

	// Hashrate returns the measured rate of the search invocations
	// per second over the last minute.
	Hashrate() float64

	// 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(header *types.Header, results chan<- *types.Header, stop <-chan struct{}) error

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

	// IsDomCoincident returns true if this block satisfies the difficulty order
	// of a dominant chain. If this node does not have a dominant chain (i.e.
	// if this is a prime node), then the function will always return false.
	//
	// Importantly, this check does NOT mean the block is canonical in the
	// dominant chain, or even that the claimed dominant difficulty is valid.
	IsDomCoincident(chain ChainHeaderReader, header *types.Header) bool

	// VerifySeal computes the PowHash and checks if work meets the difficulty
	// requirement specified in header
	VerifySeal(header *types.Header) (common.Hash, error)

	// 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
}

Engine is an algorithm agnostic consensus engine.

type PoW

type PoW interface {
	Engine

	// Hashrate returns the current mining hashrate of a PoW consensus engine.
	Hashrate() float64
}

PoW is a consensus engine based on proof-of-work.