Paul Hauner 02e2fd2fb8 Add early attester cache (#2872) ... ## Issue Addressed NA ## Proposed Changes Introduces a cache to attestation to produce atop blocks which will become the head, but are not fully imported (e.g., not inserted into the database). Whilst attesting to a block before it's imported is rather easy, if we're going to produce that attestation then we also need to be able to: 1. Verify that attestation. 1. Respond to RPC requests for the `beacon_block_root`. Attestation verification (1) is *partially* covered. Since we prime the shuffling cache before we insert the block into the early attester cache, we should be fine for all typical use-cases. However, it is possible that the cache is washed out before we've managed to insert the state into the database and then attestation verification will fail with a "missing beacon state"-type error. Providing the block via RPC (2) is also partially covered, since we'll check the database *and* the early attester cache when responding a blocks-by-root request. However, we'll still omit the block from blocks-by-range requests (until the block lands in the DB). I *think* this is fine, since there's no guarantee that we return all blocks for those responses. Another important consideration is whether or not the *parent* of the early attester block is available in the databse. If it were not, we might fail to respond to blocks-by-root request that are iterating backwards to collect a chain of blocks. I argue that *we will always have the parent of the early attester block in the database.* This is because we are holding the fork-choice write-lock when inserting the block into the early attester cache and we do not drop that until the block is in the database.		2022-01-11 01:35:55 +00:00
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src	Add early attester cache (#2872)	2022-01-11 01:35:55 +00:00
tests	Add early attester cache (#2872)	2022-01-11 01:35:55 +00:00
Cargo.toml	Update to superstruct v0.4.1 (#2886)	2022-01-06 03:14:58 +00:00