Struct AggregatorBuilder 

pub struct AggregatorBuilder { /* private fields */ }

Builder for creating and committing events.

Use create() or aggregator() to create an instance, then chain method calls to add events and metadata before committing.

Optimistic Concurrency

If original_version is 0 (default for new aggregates), the builder queries the current version before writing. Otherwise, it uses the provided version for optimistic concurrency control.

Example

// New aggregate
let id = create()
    .event(&MyEvent { ... })
    .commit(&executor)
    .await?;

// Existing aggregate with version check
aggregator(&id)
    .original_version(5)
    .event(&AnotherEvent { ... })
    .commit(&executor)
    .await?;

Implementations

impl AggregatorBuilder

pub fn new(aggregator_id: impl Into<String>) -> AggregatorBuilder

Creates a new builder for the given aggregate ID.

pub fn ids(ids: Vec<impl Into<String>>) -> AggregatorBuilder

Creates a new builder for the given aggregate IDs.

pub fn original_version(&mut self, v: u16) -> &mut Self

Sets the expected version for optimistic concurrency control.

If the aggregate’s current version doesn’t match, the commit will fail with WriteError::InvalidOriginalVersion.

pub fn routing_key(&mut self, v: impl Into<String>) -> &mut Self

Sets the routing key for event distribution.

The routing key is used for partitioning events across consumers. Once set, subsequent calls are ignored (locked behavior).

pub fn routing_key_opt(&mut self, v: Option<String>) -> &mut Self

Sets an optional routing key for event distribution.

Pass None to explicitly clear the routing key. Once set, subsequent calls are ignored (locked behavior).

pub fn metadata<M>(&mut self, key: impl Into<String>, value: &M) -> &mut Self

where M: Encode,

Sets the metadata to attach to all events.

Metadata is serialized using bitcode and stored alongside each event.

pub fn requested_by(&mut self, value: impl Into<String>) -> &mut Self

pub fn requested_as(&mut self, value: impl Into<String>) -> &mut Self

pub fn metadata_from(&mut self, value: impl Into<Metadata>) -> &mut Self

Sets the metadata to attach to all events.

Metadata is serialized using bitcode and stored alongside each event.

pub fn event<D>(&mut self, v: &D) -> &mut Self

where D: AggregatorEvent + Encode,

Adds an event to be committed.

Multiple events can be added and will be committed atomically. The event data is serialized using bitcode.

pub async fn commit<E: Executor>( &self, executor: &E, ) -> Result<String, WriteError>

Commits all added events to the executor.

Returns the aggregate ID on success.

Errors

• WriteError::MissingData - No events were added
• WriteError::InvalidOriginalVersion - Version conflict occurred
• WriteError::Unknown - Executor error

Trait Implementations

impl Clone for AggregatorBuilder

fn clone(&self) -> AggregatorBuilder

Returns a duplicate of the value.

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

Performs copy-assignment from source.