Responses

After sending a request using the read/write handle, the value returned is not the response, yet an asynchronous channel that will eventually return the response:

// Send a request.
//                                   tower::Service::call()
//                                          V
let response_channel: Channel = read_handle.call(BlockchainReadRequest::ChainHeight)?;

// Await the response.
let response: BlockchainReadRequest = response_channel.await?;

After awaiting the returned channel, a Response will eventually be returned when the Service threadpool has fetched the value from the database and sent it off.

Both read/write requests variants match in name with Response variants, i.e.

• BlockchainReadRequest::ChainHeight leads to BlockchainResponse::ChainHeight
• BlockchainWriteRequest::WriteBlock leads to BlockchainResponse::WriteBlockOk