Struct pallet_babe::Module

pub struct Module<T: Trait>(_);

The BABE Pallet

Implementations

impl<T: Trait + 'static> Module<T>

pub fn epoch_index() -> u64

Current epoch index.

pub fn authorities() -> Vec<(AuthorityId, BabeAuthorityWeight)>

Current epoch authorities.

pub fn genesis_slot() -> u64

The slot at which the first epoch actually started. This is 0 until the first block of the chain.

pub fn current_slot() -> u64

Current slot number.

pub fn randomness() -> Randomness

The epoch randomness for the current epoch.

Security

This MUST NOT be used for gambling, as it can be influenced by a malicious validator in the short term. It MAY be used in many cryptographic protocols, however, so long as one remembers that this (like everything else on-chain) it is public. For example, it can be used where a number is needed that cannot have been chosen by an adversary, for purposes such as public-coin zero-knowledge proofs.

pub fn initialized() -> Option<Option<Randomness>>

Temporary value (cleared at block finalization) which is Some if per-block initialization has already been called for current block.

pub fn lateness() -> T::BlockNumber

How late the current block is compared to its parent.

This entry is populated as part of block execution and is cleaned up on block finalization. Querying this storage entry outside of block execution context should always yield zero.

impl<T: Trait> Module<T>

pub fn slot_duration() -> T::Moment

Determine the BABE slot duration based on the Timestamp module configuration.

pub fn should_epoch_change(now: T::BlockNumber) -> bool

Determine whether an epoch change should take place at this block. Assumes that initialization has already taken place.

pub fn next_expected_epoch_change(now: T::BlockNumber) -> Option<T::BlockNumber>

Return the best guess block number, at which the next epoch change is predicted to happen.

Returns None if the prediction is in the past; This implies an error internally in the Babe and should not happen under normal circumstances.

In other word, this is only accurate if no slots are missed. Given missed slots, the slot number will grow while the block number will not. Hence, the result can be interpreted as an upper bound.

pub fn plan_config_change(config: NextConfigDescriptor)

Plan an epoch config change. The epoch config change is recorded and will be enacted on the next call to enact_epoch_change. The config will be activated one epoch after. Multiple calls to this method will replace any existing planned config change that had not been enacted yet.

pub fn enact_epoch_change(
    authorities: Vec<(AuthorityId, BabeAuthorityWeight)>,
    next_authorities: Vec<(AuthorityId, BabeAuthorityWeight)>
)

DANGEROUS: Enact an epoch change. Should be done on every block where should_epoch_change has returned true, and the caller is the only caller of this function.

Typically, this is not handled directly by the user, but by higher-level validator-set manager logic like pallet-session.

pub fn current_epoch_start() -> SlotNumber

Trait Implementations

impl<T: Trait> BoundToRuntimeAppPublic for Module<T>

type Public = AuthorityId

The RuntimeAppPublic this type is bound to.

impl<T: Trait> Callable<T> for Module<T>

type Call = Call<T>

impl<T: Clone + Trait> Clone for Module<T>

fn clone(&self) -> Module<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Copy + Trait> Copy for Module<T>

impl<T: Trait> Debug for Module<T> where
    T: Debug, 

fn fmt(&self, fmt: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<T: Eq + Trait> Eq for Module<T>

impl<T: Trait> EstimateNextSessionRotation<<T as Trait>::BlockNumber> for Module<T>

fn estimate_next_session_rotation(now: T::BlockNumber) -> Option<T::BlockNumber>

Return the block number at which the next session rotation is estimated to happen.

fn weight(_now: T::BlockNumber) -> Weight

Return the weight of calling estimate_next_session_rotation

impl<T: Trait> FindAuthor<u32> for Module<T>

fn find_author<'a, I>(digests: I) -> Option<u32> where
    I: 'a + IntoIterator<Item = (ConsensusEngineId, &'a [u8])>, 

Find the author of a block based on the pre-runtime digests.

impl<T: Trait> IntegrityTest for Module<T>

fn integrity_test()

Run integrity test.

impl<T: Trait> IsMember<Public> for Module<T>

fn is_member(authority_id: &AuthorityId) -> bool

Is the given MemberId a valid member?

impl<T: Trait> Lateness<<T as Trait>::BlockNumber> for Module<T>

fn lateness(&self) -> T::BlockNumber

Returns a generic measure of how late the current block is compared to its parent.

impl<T: Trait> ModuleErrorMetadata for Module<T>

fn metadata() -> &'static [ErrorMetadata]

impl<T: Trait> OffchainWorker<<T as Trait>::BlockNumber> for Module<T>

fn offchain_worker(_n: BlockNumber)

This function is being called after every block import (when fully synced).

impl<T: Trait> OnFinalize<<T as Trait>::BlockNumber> for Module<T>

fn on_finalize(_block_number_not_used: T::BlockNumber)

The block is being finalized. Implement to have something happen.

impl<T: Trait> OnInitialize<<T as Trait>::BlockNumber> for Module<T>

fn on_initialize(now: T::BlockNumber) -> Weight

The block is being initialized. Implement to have something happen.

impl<T: Trait> OnRuntimeUpgrade for Module<T>

fn on_runtime_upgrade() -> u64

Perform a module upgrade.

impl<T: Trait> OnTimestampSet<<T as Trait>::Moment> for Module<T>

fn on_timestamp_set(_moment: T::Moment)

impl<T: Trait> OneSessionHandler<<T as Trait>::AccountId> for Module<T>

type Key = AuthorityId

The key type expected.

fn on_genesis_session<'a, I: 'a>(validators: I) where
    I: Iterator<Item = (&'a T::AccountId, AuthorityId)>, 

fn on_new_session<'a, I: 'a>(
    _changed: bool,
    validators: I,
    queued_validators: I
) where
    I: Iterator<Item = (&'a T::AccountId, AuthorityId)>, 

Session set has changed; act appropriately. Note that this can be called before initialization of your module.

fn on_disabled(i: usize)

A validator got disabled. Act accordingly until a new session begins.

fn on_before_session_ending()

A notification for end of the session.

impl<T: PartialEq + Trait> PartialEq<Module<T>> for Module<T>

fn eq(&self, other: &Module<T>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Module<T>) -> bool

This method tests for !=.

impl<T: Trait> ProvideInherent for Module<T>

type Call = Call<T>

The call type of the module.

type Error = MakeFatalError<Error>

The error returned by check_inherent.

const INHERENT_IDENTIFIER: InherentIdentifier

The inherent identifier used by this inherent.

fn create_inherent(_: &InherentData) -> Option<Self::Call>

Create an inherent out of the given InherentData.

fn check_inherent(
    call: &Self::Call,
    data: &InherentData
) -> Result<(), Self::Error>

Check the given inherent if it is valid. Checking the inherent is optional and can be omitted.

fn is_inherent_required(
    &InherentData
) -> Result<Option<Self::Error>, Self::Error>

If Some, indicates that an inherent is required. Check will return the inner error if no inherent is found. If Err, indicates that the check failed and further operations should be aborted.

impl<T: Trait> Randomness<<T as Trait>::Hash> for Module<T>

fn random(subject: &[u8]) -> T::Hash

Some BABE blocks have VRF outputs where the block producer has exactly one bit of influence, either they make the block or they do not make the block and thus someone else makes the next block. Yet, this randomness is not fresh in all BABE blocks.

If that is an insufficient security guarantee then two things can be used to improve this randomness:

• Name, in advance, the block number whose random value will be used; ensure your module retains a buffer of previous random values for its subject and then index into these in order to obviate the ability of your user to look up the parent hash and choose when to transact based upon it.
• Require your user to first commit to an additional value by first posting its hash. Require them to reveal the value to determine the final result, hashing it with the output of this random function. This reduces the ability of a cabal of block producers from conspiring against individuals.

fn random_seed() -> Output

Get the basic random seed.

impl<T: Trait> ShouldEndSession<<T as Trait>::BlockNumber> for Module<T>

fn should_end_session(now: T::BlockNumber) -> bool

Return true if the session should be ended.

impl<T: Trait> StructuralEq for Module<T>

impl<T: Trait> StructuralPartialEq for Module<T>