Orders an event reception acknowledgement. If the sequencer node is honest, this normally results in a block.RawLedgerBlock.RawBlockEvent.Acknowledgment. In exceptional cases (crashes, high load, ...), a sequencer may drop acknowledgements.

The height of the first block to be returned by subscribe.

Determines if block timestamps emitted by subscribe are strictly monotonically increasing.

Orders a submission. If the sequencer node is honest, this normally results in a block.RawLedgerBlock.RawBlockEvent.Send. In exceptional cases (crashes, high load, ...), a sequencer may drop submissions. There's a double com.digitalasset.canton.sequencing.protocol.SignedContent wrapping because the outer signature is the sequencer's, and the inner signature is the sender's. The sequencer signature may be used by the implementation to ensure that the submission originates from the expected sequencer node. This may be necessary if the implementation is split across multiple processes.

Provides information for the SequencerSnapshot.additional field, which can be used for onboarding.

Delivers a stream of blocks.

Honest and correct implementations must ensure the following:

• If firstBlockHeight refers to a block whose sequencing number the sequencer node has not yet observed, returns a source that will eventually serve that block when it gets created.
• This method can be called only once per instance, so implementations do not have to try to create separate sources on every call to this method: it is acceptable for the implementation to have one internal source and just return it.
• The call must succeed if an earlier (across instances and restarts) call to subscribe delivered a block with height firstBlockHeight unless the block has been pruned in between, in which case it fails.
• Block heights must be consecutive and start at firstBlockHeight.
• For a given block height, all sequencer nodes of a synchronizer must emit the same block for that height.
• Every submission that has been sent to an honest node through send will be included in the output stream on a best effort basis. That means, the output stream normally contains every submission, but submissions may sometimes be dropped due to high load, crashes, etc...
• A submission may occur more than once in the output stream, as malicious sequencer nodes may replay requests.
• An event in the output can not necessarily be parsed to com.digitalasset.canton.synchronizer.block.LedgerBlockEvent. If they can be parsed, the embedded signatures are not necessarily valid.