Skip to main content

EmbeddedChannel

hydro_lang::compile::embedded_runtime

Trait EmbeddedChannel 

Source 
pub trait EmbeddedChannel {
    type Ordering: Ordering;
    type Retries: Retries;
}
Expand description

A channel crossing the boundary of an embedded dataflow: a network channel end, a stream input, a membership stream, or an output, with its guarantees as marker types (Ordering and Retries).

  • For a stream input or membership stream, the guarantees are what the dataflow relies on, which the host’s Promises must meet.
  • For the sending end of a network channel, they are what the dataflow sends, which the host’s Acknowledgements must cover, as for an output.
  • For the receiving end of a network channel, they are what the dataflow relies on: the sent stream, weakened by the channel’s configuration. The host’s Promises must meet them, as for a stream input.
  • For an output, they are what the dataflow provides. The host’s Acknowledgements must cover every way the output may be weaker than ordered and exactly-once.

Each location’s generated module has a marker type implementing this for each channel crossing it, named after its field: under incoming / outgoing for network channel ends, inputs for stream inputs, membership for membership streams, and outputs for outputs. Each field of the generated structs is an EmbeddedInputChannel (a stream input or membership stream), a EmbeddedNetworkInputChannel (a receiving end), a EmbeddedNetworkOutputChannel (a sending end), or an EmbeddedOutputChannel (an output) over its marker. The marker is inferred from the field. The markers of network channel ends also implement EmbeddedNetworkChannel.

Required Associated Types§

Source

type Ordering: Ordering

The ordering the host must keep (for an output or the sending end of a network channel, the ordering the dataflow provides): TotalOrder or NoOrder. For a network channel, TotalOrder means each sender’s messages in the order it sent them; for an input, that the stream’s order is the order to process; for a membership stream, each member’s events in the order they happened.

Source

type Retries: Retries

The retry guarantee the host must keep (for an output or the sending end of a network channel, the one the dataflow provides): ExactlyOnce (nothing delivered twice) or AtLeastOnce.

Dyn Compatibility§

This trait is dyn compatible.

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

Implementors§