Struct SimpleDispatcher

pub struct SimpleDispatcher {
    output: SmallVec<[BoxedOutput; 2]>,
    output_indices: Vec<usize>,
    dispatcher_id: DispatcherId,
    dispatcher_id_str: String,
}

SimpleDispatcher dispatches message to a single output.

Fields

output: SmallVec<[BoxedOutput; 2]>

In most cases, there is exactly one output. However, in some cases of configuration change, the field needs to be temporarily set to 0 or 2 outputs.

• When dropping a materialized view, the output will be removed and this field becomes empty. The DispatchExecutor will immediately clean-up this empty dispatcher before finishing processing the current mutation.
• When migrating a singleton fragment, the new output will be temporarily added in pre stage and this field becomes multiple, which is for broadcasting this configuration change barrier to both old and new downstream actors. In post stage, the old output will be removed and this field becomes single again.

Therefore, when dispatching data, we assert that there’s exactly one output by Self::output.

output_indices: Vec<usize>

dispatcher_id: DispatcherId

dispatcher_id_str: String

Implementations

impl SimpleDispatcher

pub fn new( output: BoxedOutput, output_indices: Vec<usize>, dispatcher_id: DispatcherId, ) -> Self

Trait Implementations

impl Debug for SimpleDispatcher

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

Formats the value using the given formatter.

impl Dispatcher for SimpleDispatcher

fn add_outputs(&mut self, outputs: impl IntoIterator<Item = BoxedOutput>)

Add new outputs to the dispatcher.

async fn dispatch_barrier( &mut self, barrier: DispatcherBarrier, ) -> StreamResult<()>

Dispatch a barrier to downstream actors, generally by broadcasting it.

async fn dispatch_data(&mut self, chunk: StreamChunk) -> StreamResult<()>

Dispatch a data chunk to downstream actors.

async fn dispatch_watermark(&mut self, watermark: Watermark) -> StreamResult<()>

Dispatch a watermark to downstream actors, generally by broadcasting it.

fn remove_outputs(&mut self, actor_ids: &HashSet<ActorId>)

Remove outputs to actor_ids from the dispatcher.

fn dispatcher_id(&self) -> DispatcherId

The ID of the dispatcher. A DispatchExecutor may have multiple dispatchers with different IDs.

fn dispatcher_id_str(&self) -> &str

Dispatcher id in string. See Dispatcher::dispatcher_id.

fn is_empty(&self) -> bool

Whether the dispatcher has no outputs. If so, it’ll be cleaned up from the DispatchExecutor.