Enum StartOffset 

#[non_exhaustive]
pub enum StartOffset {
    Committed,
    Earliest,
    Latest,
}

Where a consumer group starts reading when it has no valid committed offset.

Kafka resumes from the group’s committed position when a valid one exists; this choice (it maps to librdkafka’s auto.offset.reset) applies when there is none - the group has never committed the partition, or the committed offset was deleted by retention / is out of range. The second case is why it matters for long-idle groups: with the librdkafka default (latest) an expired group skips to the end instead of reprocessing.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Committed

Leave the choice to librdkafka (its default resets to the latest offset).

Earliest

Start from the earliest retained offset.

Latest

Start from the latest offset: only messages published after the subscription opened.

Trait Implementations

impl Clone for StartOffset

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for StartOffset

impl Debug for StartOffset

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

Formats the value using the given formatter.

impl Default for StartOffset

fn default() -> Self

Returns the “default value” for a type.

impl Eq for StartOffset

impl PartialEq for StartOffset

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for StartOffset