Module cumulus_client_consensus_common::import_queue

(unstable) Composable utilities for constructing import queues for parachains.

Unlike standalone chains, parachains have the requirement that all consensus logic must be checked within the runtime. This property means that work which is normally done in the import queue per-block, such as checking signatures, quorums, and whether inherent extrinsics were constructed faithfully do not need to be done, per se.

It may seem that it would be beneficial for the client to do these checks regardless, but in practice this means that clients would just reject blocks which are valid according to their Parachain Validation Function, which is the ultimate source of consensus truth.

However, parachain runtimes expose two different access points for executing blocks in full nodes versus executing those blocks in the parachain validation environment. At the time of writing, the inherent and consensus checks in most Cumulus runtimes are only performed during parachain validation, not full node block execution.

See https://github.com/paritytech/cumulus/issues/2436 for details.

Structs

• VerifyNothing
  A Verifier for blocks which verifies absolutely nothing.

Functions

• verify_nothing_import_queue
  An import queue which does no verification.