On `ELECTRA_FORK_EPOCH`, PeerDAS is not yet activated, hence the current
mechanism based on `BlobSidecar` is still in use. With EIP-7688, the
generalized indices of `BeaconBlockBody` get reindexed, changing the
length of the inclusion proof within the `BlobSidecar`. Because network
Req/Resp operations allow responses across fork boundaries, this creates
the need for a `ForkedBlobSidecar` in that layer, same as already done
for `ForkedSignedBeaconBock` for similar reasons.
Note: This PR is only needed if PeerDAS is adopted _after_ EIP-7688.
If PeerDAS is adopted _before_ EIP-7688, a similar PR may be needed for
forked columns. Coincidental `Forked` jank can only be fully avoided if
both features activate at the same epoch, actual changes to blobs aside.
Delaying EIP-7688 for sole purpose of epoch alignemnt is not worth it.
To avoid "forked" types creeping into `BlobSidecar`, move the reduction
to `BlobSidecarInfoObject` to the sole caller. The info object is fork
agnostic, so does not need "forked" if `BlobSidecar` ever updates.
Use the same eviction policy for blocks as already the case for blobs.
FIFO makes more sense, because it favors keeping ancestors of blocks
which need to be applied to the DAG before their children get eligible.
Blobs are cached from gossip and other sources for all orphans, not just
those specifically tagged as `blobless`. `blobless` only means that they
are actively fetched from the network. The `MaxBlobs` should be aligned
to match `MaxOrphans`. Note that blobs are tiny compared to blocks, so
this isn't a huge memory hog.
`v1.4.0-beta.4` made the Gossip rules more strict and now requires to
ignore blobs from other branches if there are equivocating blocks.
Those blobs are only requestable via Req/Resp.
Etan Kissling
tersec
Jacek Sieka
henridf