Trait sea_streamer_types::Consumer

pub trait Consumer: Sized + Send + Sync {
    type Error: Error;
    type Message<'a>: Message
       where Self: 'a;
    type NextFuture<'a>: Future<Output = StreamResult<Self::Message<'a>, Self::Error>>
       where Self: 'a;
    type Stream<'a>: Stream<Item = StreamResult<Self::Message<'a>, Self::Error>>
       where Self: 'a;

    // Required methods
    fn seek(
        &mut self,
        to: Timestamp
    ) -> impl Future<Output = StreamResult<(), Self::Error>> + Send;
    fn rewind(
        &mut self,
        offset: SeqPos
    ) -> impl Future<Output = StreamResult<(), Self::Error>> + Send;
    fn assign(
        &mut self,
        ss: (StreamKey, ShardId)
    ) -> StreamResult<(), Self::Error>;
    fn unassign(
        &mut self,
        ss: (StreamKey, ShardId)
    ) -> StreamResult<(), Self::Error>;
    fn next(&self) -> Self::NextFuture<'_>;
    fn stream<'a, 'b: 'a>(&'b mut self) -> Self::Stream<'a>;
}

Common interface of consumers, to be implemented by all backends.

Required Associated Types

type Error: Error

type Message<'a>: Message where Self: 'a

type NextFuture<'a>: Future<Output = StreamResult<Self::Message<'a>, Self::Error>> where Self: 'a

type Stream<'a>: Stream<Item = StreamResult<Self::Message<'a>, Self::Error>> where Self: 'a

Required Methods

fn seek( &mut self, to: Timestamp ) -> impl Future<Output = StreamResult<(), Self::Error>> + Send

Seek all streams to an arbitrary point in time. It will start consuming from the earliest message with a timestamp later than to.

If the consumer is not already assigned, shard ZERO will be used.

fn rewind( &mut self, offset: SeqPos ) -> impl Future<Output = StreamResult<(), Self::Error>> + Send

Rewind all streams to a particular sequence number.

If the consumer is not already assigned, shard ZERO will be used.

fn assign(&mut self, ss: (StreamKey, ShardId)) -> StreamResult<(), Self::Error>

Assign this consumer to a particular shard. Can be called multiple times to assign to multiple shards. Returns error StreamKeyNotFound if the stream is not currently subscribed.

It will only take effect on the next Consumer::seek or Consumer::rewind.

fn unassign( &mut self, ss: (StreamKey, ShardId) ) -> StreamResult<(), Self::Error>

Unassign a shard. Returns error StreamKeyNotFound if the stream is not currently subscribed. Returns error StreamKeyEmpty if all streams have been unassigned.

fn next(&self) -> Self::NextFuture<'_>

Poll and receive one message: it awaits until there are new messages. This method can be called from multiple threads.

fn stream<'a, 'b: 'a>(&'b mut self) -> Self::Stream<'a>

Returns an async stream. You cannot create multiple streams from the same consumer, nor perform any operation while streaming.

Object Safety

This trait is not object safe.

Implementors