Documentation ¶
Overview ¶
Package clique implements PoA (Proof of Authority) consensus engine which is mainly for private chains.
Consensus Engine Overview ¶
In clique, only pre-selected nodes can propose a block. The list of these nodes are described in the header's extra field and the list can be changed by calling Propose() API.
The sequence of proposers is decided by the block number and the number of nodes which can propose a block. If a proposer proposes a block in its turn (in-turn), it will have a blockscore(formerly known as difficulty) of 2. If a proposer proposes a block in other node's turn (out-of-turn), it will have a blockscore of 1.
If an in-turn proposer didn't propose a block for some time, other nodes start to propose their block with a blockscore of 1. So the block generation can continue. But there can be a fork because several nodes can propose a block at the same time. In this case, a block reorganization will happen based on total blockscore (the sum of all blockscore from the genesis block to the current one).
Index ¶
- Variables
- func CalcBlockScore(snap *Snapshot, signer common.Address) *big.Int
- 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 (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) CalcBlockScore(chain consensus.ChainReader, time uint64, parent *types.Header) *big.Int
- func (c *Clique) CanVerifyHeadersConcurrently() bool
- func (c *Clique) CreateSnapshot(chain consensus.ChainReader, number uint64, hash common.Hash, ...) 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) PreprocessHeaderVerification(headers []*types.Header) (chan<- struct{}, <-chan error)
- func (c *Clique) Protocol() consensus.Protocol
- func (c *Clique) Seal(chain consensus.ChainReader, block *types.Block, stop <-chan struct{}) (*types.Block, error)
- 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
- type SignerFn
- type Snapshot
- type Tally
- type Vote
Constants ¶
This section is empty.
Variables ¶
var ( ExtraVanity = 32 // Fixed number of extra-data prefix bytes reserved for signer vanity ExtraSeal = crypto.SignatureLength // Fixed number of extra-data suffix bytes reserved for signer seal )
Clique proof-of-authority protocol constants.
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 ¶
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 ¶
Discard drops a currently running proposal, stopping the signer from casting further votes (either for or against).
func (*API) GetSigners ¶
GetSigners retrieves the list of authorized signers at the specified block.
func (*API) GetSignersAtHash ¶
GetSignersAtHash retrieves the state snapshot at a given 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 ¶
GetSnapshotAtHash retrieves the state snapshot at a given block.
type Clique ¶
type Clique struct {
// contains filtered or unexported fields
}
Clique is the proof-of-authority consensus engine proposed to support the Klaytn testnet following the Baobab attacks.
func New ¶
func New(config *params.CliqueConfig, db database.DBManager) *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 ¶
Author implements consensus.Engine, returning the Klaytn address recovered from the signature in the header's extra-data section.
func (*Clique) Authorize ¶
Authorize injects a private key into the consensus engine to mint new blocks with.
func (*Clique) CalcBlockScore ¶
func (c *Clique) CalcBlockScore(chain consensus.ChainReader, time uint64, parent *types.Header) *big.Int
CalcBlockScore is the blockScore adjustment algorithm. It returns the blockScore that a new block should have based on the previous blocks in the chain and the current signer.
func (*Clique) CanVerifyHeadersConcurrently ¶ added in v1.7.0
CanVerifyHeadersConcurrently returns true if concurrent header verification possible, otherwise returns false.
func (*Clique) CreateSnapshot ¶ added in v1.7.3
func (c *Clique) CreateSnapshot(chain consensus.ChainReader, number uint64, hash common.Hash, parents []*types.Header) error
CreateSnapshot does not return a snapshot but creates a new snapshot at a given point in time.
func (*Clique) Finalize ¶
func (c *Clique) Finalize(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, receipts []*types.Receipt) (*types.Block, error)
Finalize implements consensus.Engine and returns the final block.
func (*Clique) Prepare ¶
Prepare implements consensus.Engine, preparing all the consensus fields of the header for running the transactions on top.
func (*Clique) PreprocessHeaderVerification ¶ added in v1.7.0
func (c *Clique) PreprocessHeaderVerification(headers []*types.Header) (chan<- struct{}, <-chan error)
PreprocessHeaderVerification prepares header verification for heavy computation before synchronous header verification such as ecrecover.
func (*Clique) Seal ¶
func (c *Clique) Seal(chain consensus.ChainReader, block *types.Block, stop <-chan struct{}) (*types.Block, error)
Seal implements consensus.Engine, attempting to create a sealed block using the local signing credentials.
func (*Clique) VerifyHeader ¶
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 ¶
VerifySeal implements consensus.Engine, checking whether the signature contained in the header satisfies the consensus protocol requirements.
type SignerFn ¶
SignerFn is a signer callback function to request a hash 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.