Struct FencingToken 

pub struct FencingToken { /* private fields */ }

The quorum-minted proof that one member holds a role.

The transaction coordinator mints the pair when a member calls InitProducerId for the transactional.id of the role. The quorum picks the values, the broker enforces them, and a write from an older pair fails with a fenced error. A holder passes the token to every guarded write.

The field order is load-bearing. The derived Ord compares producer_id first and producer_epoch second, so it is lexicographic. A producer epoch is an i16 and it wraps. Kafka then allocates a new producer id and resets the epoch to zero. A comparison on the epoch alone would rank that fresh token below the stale one, and the old leader would keep the role. Never reorder these two fields, and never compare the epoch on its own.

Implementations

impl FencingToken

pub fn new(producer_id: i64, producer_epoch: i16) -> Result<Self, RecordError>

Builds a fencing token from a minted producer id and producer epoch.

Errors

Returns RecordError::NegativeFencingToken when either value is negative. Kafka writes -1 for “no producer”, and that pair never proves leadership.

pub const fn producer_id(self) -> i64

The producer id the transaction coordinator minted.

pub const fn producer_epoch(self) -> i16

The producer epoch the transaction coordinator minted.

Trait Implementations

impl Clone for FencingToken

fn clone(&self) -> FencingToken

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FencingToken

impl Debug for FencingToken

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

Formats the value using the given formatter.

impl Display for FencingToken

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

Formats the value using the given formatter.

impl Eq for FencingToken

impl FromStr for FencingToken

type Err = RecordError

The associated error which can be returned from parsing.

fn from_str(serialized: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for FencingToken

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 FencingToken

fn cmp(&self, other: &FencingToken) -> 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.

impl PartialEq for FencingToken

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for FencingToken

fn partial_cmp(&self, other: &FencingToken) -> 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 StructuralPartialEq for FencingToken