Trait StreamSealer 

pub trait StreamSealer: Send + 'static {
    // Required methods
    fn seal_item<'life0, 'async_trait>(
        &'life0 mut self,
        item: Bytes,
    ) -> Pin<Box<dyn Future<Output = Result<SealedItem, CratestackError>> + Send + 'async_trait>>
       where 'life0: 'async_trait,
             Self: 'async_trait;
    fn checkpoint_now<'life0, 'async_trait>(
        &'life0 mut self,
    ) -> Pin<Box<dyn Future<Output = Result<Option<Bytes>, CratestackError>> + Send + 'async_trait>>
       where 'life0: 'async_trait,
             Self: 'async_trait;
    fn finish<'async_trait>(
        self: Box<Self>,
        end: StreamEnd,
    ) -> Pin<Box<dyn Future<Output = Result<Bytes, CratestackError>> + Send + 'async_trait>>
       where Self: 'async_trait;
}

Seals one outgoing stream (§6). Created per stream by CratestackEnvelope::stream_sealer, which seeds the running hash with h₀ = SHA-256(external_aad).

Provisional; the shape is finalised in P1 (cratestack#1008).

Required Methods

fn seal_item<'life0, 'async_trait>( &'life0 mut self, item: Bytes, ) -> Pin<Box<dyn Future<Output = Result<SealedItem, CratestackError>> + Send + 'async_trait>>

where 'life0: 'async_trait, Self: 'async_trait,

Feed one item’s encoded bytes and return what to write.

fn checkpoint_now<'life0, 'async_trait>( &'life0 mut self, ) -> Pin<Box<dyn Future<Output = Result<Option<Bytes>, CratestackError>> + Send + 'async_trait>>

where 'life0: 'async_trait, Self: 'async_trait,

Emit a checkpoint now if any item is not yet covered by one. This is the hook for the time-based cadence (every 2 s; ADR 0006 Q3), which can fall due between items. None when there is nothing to cover.

fn finish<'async_trait>( self: Box<Self>, end: StreamEnd, ) -> Pin<Box<dyn Future<Output = Result<Bytes, CratestackError>> + Send + 'async_trait>>

where Self: 'async_trait,

The mandatory terminal checkpoint. It consumes the sealer, so a stream cannot be ended twice.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors