Adrian Catangiu
fe8d2bc7f4
* beefy: add dummy latest_finalized() RPC * beefy: rpc latest_best_beefy() using shared mem * beefy: rpc populate latest_best_beefy() * beefy: rpc handle readiness * beefy: best block over channel - wip Not working because channel can't be simply opened and receiver passed to `rpc_extensions_builder` because `rpc_extensions_builder` has to be `Fn` and not `FnOnce`... and and Receiver side of mpsc can't be cloned yay!.. * beefy: make notification channels payload-agnostic * beefy: use notification mechanism instead of custom channel * beefy: add tracing key to notif channels * sc-utils: add notification channel - wip * beefy: use sc-utils generic notification channel * grandpa: use sc-utils generic notification channel * fix grumbles * beefy-rpc: get best block header instead of number * beefy-rpc: rename to `beefy_getFinalizedHead` * fix nitpicks * client-rpc-notifications: move generic Error from struct to fn * beefy: use header from notification instead of getting from database * beefy-rpc: get best block hash instead of header * beefy-rpc: fix and improve latestHead test * beefy-rpc: bubble up errors from rpc-handler instantiation * update lockfile * Apply suggestions from code review Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com> * fix errors and warnings * fix nit Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>
Integration of the GRANDPA finality gadget into substrate.
This crate is unstable and the API and usage may change.
This crate provides a long-running future that produces finality notifications.
Usage
First, create a block-import wrapper with the block_import function. The
GRANDPA worker needs to be linked together with this block import object, so
a LinkHalf is returned as well. All blocks imported (from network or
consensus or otherwise) must pass through this wrapper, otherwise consensus
is likely to break in unexpected ways.
Next, use the LinkHalf and a local configuration to run_grandpa_voter.
This requires a Network implementation. The returned future should be
driven to completion and will finalize blocks in the background.
Changing authority sets
The rough idea behind changing authority sets in GRANDPA is that at some point, we obtain agreement for some maximum block height that the current set can finalize, and once a block with that height is finalized the next set will pick up finalization from there.
Technically speaking, this would be implemented as a voting rule which says, "if there is a signal for a change in N blocks in block B, only vote on chains with length NUM(B) + N if they contain B". This conditional-inclusion logic is complex to compute because it requires looking arbitrarily far back in the chain.
Instead, we keep track of a list of all signals we've seen so far (across all forks), sorted ascending by the block number they would be applied at. We never vote on chains with number higher than the earliest handoff block number (this is num(signal) + N). When finalizing a block, we either apply or prune any signaled changes based on whether the signaling block is included in the newly-finalized chain.
License: GPL-3.0-or-later WITH Classpath-exception-2.0