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



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    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.


      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.


        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 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

                  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(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) 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, stop <-chan struct{}) (*types.Block, error)

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

                                          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, []byte) ([]byte, error)

                                                    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.