Struct View 

pub struct View(/* private fields */);

A monotonically increasing counter within a single epoch.

Views represent individual consensus rounds within an epoch. Each view corresponds to one attempt to reach consensus on a proposal.

Implementations

impl View

pub const fn zero() -> Self

Returns view zero.

pub const fn new(value: u64) -> Self

Creates a new view from a u64 value.

pub const fn get(self) -> u64

Returns the underlying u64 value.

pub const fn is_zero(self) -> bool

Returns true if this is view zero.

pub const fn next(self) -> Self

Returns the next view.

Panics

Panics if the view would overflow u64::MAX. In practice, this is extremely unlikely to occur during normal operation.

pub fn previous(self) -> Option<Self>

Returns the previous view, or None if this is view zero.

Unlike View::next(), this returns an Option since reaching view zero is common, whereas overflowing u64::MAX is not expected in normal operation.

pub const fn saturating_add(self, delta: ViewDelta) -> Self

Adds a view delta, saturating at u64::MAX.

pub const fn saturating_sub(self, delta: ViewDelta) -> Self

Subtracts a view delta, saturating at zero.

pub const fn range(start: Self, end: Self) -> ViewRange

Returns an iterator over the range [start, end).

If start >= end, returns an empty range.

pub const fn term_start(self, term_length: TermLength) -> Self

Returns the first view of the term containing this view.

Terms group consecutive views so that the same leader serves for term_length views. View 0 (genesis) is its own term. For views >= 1, term boundaries are: [1, term_length], [term_length+1, 2*term_length], …

When term_length is 1, every view is its own term (no grouping).

pub const fn is_term_start(self, term_length: TermLength) -> bool

Returns whether this view is the first view of its term.

pub const fn same_term(self, other: Self, term_length: TermLength) -> bool

Returns whether this view shares a term with other.

pub const fn term_end(self, term_length: TermLength) -> Self

Returns the last view of the term containing this view.

See term_start for term boundary semantics.

When term_length is 1, returns self.

pub const fn next_term_start(self, term_length: TermLength) -> Self

Returns the first view of the term that follows this view’s term.

When term_length is 1, returns self.next().

pub const fn term_index(self, term_length: TermLength) -> u64

Returns the index of the term containing this view.

View 0 (genesis) is its own term with index 0; terms of later views are numbered from 1. When term_length is 1, the index equals the view.

pub const fn covers(self, view: Self, term_length: TermLength) -> bool

Returns whether a nullification at this view covers view.

A nullification covers the view it was created for and the rest of that view’s term.

pub const fn covering_range( self, term_length: TermLength, ) -> RangeInclusive<Self>

Returns the range of views whose nullifications cover this view.

The inverse of covers: a nullification covers the rest of its term, so this view is covered by a nullification at any view in [term_start, self].

pub const fn admits(self, pending: Self, term_length: TermLength) -> bool

Returns whether pending is an acceptable view relative to this view when future views are bounded.

Views at or below this view are always acceptable (callers enforce any lower bound separately). Beyond that, only the next view and the first view of the next term are acceptable: the only views this view can directly advance into (a nullification of the current view skips to the latter). When term_length is 1 the two views are the same.

This bound exists to limit memory committed to unverified messages (like votes) from future views. It should not be applied to self-certifying artifacts (like certificates), which may arrive from arbitrarily far ahead and let a lagging participant fast-forward.

Trait Implementations

impl Clone for View

fn clone(&self) -> View

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for View

impl Debug for View

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for View

fn default() -> View

Returns the “default value” for a type.

impl Display for View

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl EncodeSize for View

fn encode_size(&self) -> usize

Returns the encoded size of this value (in bytes).

fn encode_inline_size(&self) -> usize

Returns the encoded size excluding bytes passed to BufsMut::push during Write::write_bufs. Used to size the working buffer for inline writes. Override alongside Write::write_bufs for types where large Bytes fields go via push; failing to do so will over-allocate.

impl Eq for View

impl From<View> for U64

fn from(view: View) -> Self

Converts to this type from the input type.

impl Hash for View

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for View

fn cmp(&self, other: &View) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for View

fn eq(&self, other: &View) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for View

fn partial_cmp(&self, other: &View) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Read for View

type Cfg = ()

The Cfg type parameter allows passing configuration during the read process. This is crucial for safely decoding untrusted data, for example, by providing size limits for collections or strings.

fn read_cfg(buf: &mut impl Buf, _cfg: &Self::Cfg) -> Result<Self, Error>

Reads a value from the buffer using the provided configuration cfg.

impl StructuralPartialEq for View

impl TracedExt for View

Available on non-WebAssembly only.

fn traced(self) -> i64

Returns self as an i64 for use as a tracing field value.

impl Write for View

fn write(&self, buf: &mut impl BufMut)

Writes the binary representation of self to the provided buffer buf.

fn write_bufs(&self, buf: &mut impl BufsMut)

Writes to a BufsMut, allowing existing Bytes chunks to be appended via BufsMut::push instead of written inline. Must encode to the same format as Write::write. Defaults to Write::write.