clique

Documentation

Overview

Package clique implements the proof-of-authority consensus engine.

Index

• Variables
• func CalcDifficulty(snap *Snapshot, signer common.Address) *big.Int
• func CliqueRLP(header *types.Header) []byte
• func SealHash(header *types.Header) (hash common.Hash)
• type API
  • func (api *API) Discard(address common.Address)
  • func (api *API) GetSigners(number *rpc.BlockNumber) ([]common.Address, error)
  • func (api *API) GetSignersAtHash(hash common.Hash) ([]common.Address, error)
  • func (api *API) GetSnapshot(number *rpc.BlockNumber) (*Snapshot, error)
  • func (api *API) GetSnapshotAtHash(hash common.Hash) (*Snapshot, error)
  • func (api *API) Proposals() map[common.Address]bool
  • func (api *API) Propose(address common.Address, auth bool)
• type Clique
  • func New(name string, config *params.CliqueConfig, db ethdb.Database) *Clique
  • func (c *Clique) APIs(chain consensus.ChainReader) []rpc.API
  • func (c *Clique) Author(header *types.Header) (common.Address, error)
  • func (c *Clique) Authorize(signer common.Address, signFn SignerFn)
  • func (c *Clique) CalcDifficulty(chain consensus.ChainReader, time uint64, parent *types.Header) *big.Int
  • func (c *Clique) Close() error
  • func (c *Clique) Finalize(chain consensus.ChainReader, header *types.Header, state *state.StateDB, ...) (*types.Block, error)
  • func (c *Clique) Prepare(chain consensus.ChainReader, header *types.Header) error
  • func (c *Clique) Seal(chain consensus.ChainReader, block *types.Block, ...) error
  • func (c *Clique) SealHash(header *types.Header) common.Hash
  • func (c *Clique) VerifyHeader(chain consensus.ChainReader, header *types.Header, seal bool) error
  • func (c *Clique) VerifyHeaders(chain consensus.ChainReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error)
  • func (c *Clique) VerifySeal(chain consensus.ChainReader, header *types.Header) error
  • func (c *Clique) VerifyUncles(chain consensus.ChainReader, block *types.Block) error
• type SignerFn
• type Snapshot
• type Tally
• type Vote

Variables

var (

	// ErrInvalidTimestamp is returned if the timestamp of a block is lower than
	// the previous block's timestamp + the minimum block period.
	ErrInvalidTimestamp = errors.New("invalid timestamp")
)

Various error messages to mark blocks invalid. These should be private to prevent engine specific errors from being referenced in the remainder of the codebase, inherently breaking if the engine is swapped out. Please put common error types into the consensus package.

Functions

func CalcDifficulty

func CalcDifficulty(snap *Snapshot, signer common.Address) *big.Int

CalcDifficulty is the difficulty adjustment algorithm. It returns the difficulty that a new block should have based on the previous blocks in the chain and the current signer.

func CliqueRLP

func CliqueRLP(header *types.Header) []byte

CliqueRLP returns the rlp bytes which needs to be signed for the proof-of-authority sealing. The RLP to sign consists of the entire header apart from the 65 byte signature contained at the end of the extra data.

Note, the method requires the extra data to be at least 65 bytes, otherwise it panics. This is done to avoid accidentally using both forms (signature present or not), which could be abused to produce different hashes for the same header.

func SealHash

func SealHash(header *types.Header) (hash common.Hash)

SealHash returns the hash of a block prior to it being sealed.

Types

type API

type API struct {
	// contains filtered or unexported fields
}

API is a user facing RPC API to allow controlling the signer and voting mechanisms of the proof-of-authority scheme.

func (*API) Discard

func (api *API) Discard(address common.Address)

Discard drops a currently running proposal, stopping the signer from casting further votes (either for or against).

func (*API) GetSigners

func (api *API) GetSigners(number *rpc.BlockNumber) ([]common.Address, error)

GetSigners retrieves the list of authorized signers at the specified block.

func (*API) GetSignersAtHash

func (api *API) GetSignersAtHash(hash common.Hash) ([]common.Address, error)

GetSignersAtHash retrieves the list of authorized signers at the specified block.

func (*API) GetSnapshot

func (api *API) GetSnapshot(number *rpc.BlockNumber) (*Snapshot, error)

GetSnapshot retrieves the state snapshot at a given block.

func (*API) GetSnapshotAtHash

func (api *API) GetSnapshotAtHash(hash common.Hash) (*Snapshot, error)

GetSnapshotAtHash retrieves the state snapshot at a given block.

func (*API) Proposals

func (api *API) Proposals() map[common.Address]bool

Proposals returns the current proposals the node tries to uphold and vote on.

func (*API) Propose

func (api *API) Propose(address common.Address, auth bool)

Propose injects a new authorization proposal that the signer will attempt to push through.

type Clique

type Clique struct {
	// contains filtered or unexported fields
}

Clique is the proof-of-authority consensus engine proposed to support the Ethereum testnet following the Ropsten attacks.

func New

func New(name string, config *params.CliqueConfig, db ethdb.Database) *Clique

New creates a Clique proof-of-authority consensus engine with the initial signers set to the ones provided by the user.

func (*Clique) APIs

func (c *Clique) APIs(chain consensus.ChainReader) []rpc.API

APIs implements consensus.Engine, returning the user facing RPC API to allow controlling the signer voting.

func (*Clique) Author

func (c *Clique) Author(header *types.Header) (common.Address, error)

Author implements consensus.Engine, returning the Ethereum address recovered from the signature in the header's extra-data section.

func (*Clique) Authorize

func (c *Clique) Authorize(signer common.Address, signFn SignerFn)

Authorize injects a private key into the consensus engine to mint new blocks with.

func (*Clique) CalcDifficulty

func (c *Clique) CalcDifficulty(chain consensus.ChainReader, time uint64, parent *types.Header) *big.Int

CalcDifficulty is the difficulty adjustment algorithm. It returns the difficulty that a new block should have based on the previous blocks in the chain and the current signer.

func (*Clique) Close

func (c *Clique) Close() error

Close implements consensus.Engine. It's a noop for clique as there are no background threads.

func (*Clique) Finalize

func (c *Clique) Finalize(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error)

Finalize implements consensus.Engine, ensuring no uncles are set, nor block rewards given, and returns the final block.

func (*Clique) Prepare

func (c *Clique) Prepare(chain consensus.ChainReader, header *types.Header) error

Prepare implements consensus.Engine, preparing all the consensus fields of the header for running the transactions on top.

func (*Clique) Seal

func (c *Clique) Seal(chain consensus.ChainReader, block *types.Block, results func(block *types.Block)) error

Seal implements consensus.Engine, attempting to create a sealed block using the local signing credentials.

func (*Clique) SealHash

func (c *Clique) SealHash(header *types.Header) common.Hash

SealHash returns the hash of a block prior to it being sealed.

func (*Clique) VerifyHeader

func (c *Clique) VerifyHeader(chain consensus.ChainReader, header *types.Header, seal bool) error

VerifyHeader checks whether a header conforms to the consensus rules.

func (*Clique) VerifyHeaders

func (c *Clique) VerifyHeaders(chain consensus.ChainReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error)

VerifyHeaders is similar to VerifyHeader, but verifies a batch of headers. 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).

func (*Clique) VerifySeal

func (c *Clique) VerifySeal(chain consensus.ChainReader, header *types.Header) error

VerifySeal implements consensus.Engine, checking whether the signature contained in the header satisfies the consensus protocol requirements.

func (*Clique) VerifyUncles

func (c *Clique) VerifyUncles(chain consensus.ChainReader, block *types.Block) error

VerifyUncles implements consensus.Engine, always returning an error for any uncles as this consensus mechanism doesn't permit uncles.

type SignerFn

type SignerFn func(accounts.Account, string, []byte) ([]byte, error)

SignerFn is a signer callback function to request a header to be signed by a backing account.

type Snapshot

type Snapshot struct {
	Number  uint64                      `json:"number"`  // Block number where the snapshot was created
	Hash    common.Hash                 `json:"hash"`    // Block hash where the snapshot was created
	Signers map[common.Address]struct{} `json:"signers"` // Set of authorized signers at this moment
	Recents map[uint64]common.Address   `json:"recents"` // Set of recent signers for spam protections
	Votes   []*Vote                     `json:"votes"`   // List of votes cast in chronological order
	Tally   map[common.Address]Tally    `json:"tally"`   // Current vote tally to avoid recalculating
	// contains filtered or unexported fields
}

Snapshot is the state of the authorization voting at a given point in time.

type Tally

type Tally struct {
	Authorize bool `json:"authorize"` // Whether the vote is about authorizing or kicking someone
	Votes     int  `json:"votes"`     // Number of votes until now wanting to pass the proposal
}

Tally is a simple vote tally to keep the current score of votes. Votes that go against the proposal aren't counted since it's equivalent to not voting.

type Vote

type Vote struct {
	Signer    common.Address `json:"signer"`    // Authorized signer that cast this vote
	Block     uint64         `json:"block"`     // Block number the vote was cast in (expire old votes)
	Address   common.Address `json:"address"`   // Account being voted on to change its authorization
	Authorize bool           `json:"authorize"` // Whether to authorize or deauthorize the voted account
}

Vote represents a single vote that an authorized signer made to modify the list of authorizations.