The Equihash check caused block index loading to take around 38x longer.
However, we don't need to check it directly, as the only paths to writing a
block header to disk already go through a proof-of-work check (e.g. receiving a
block over the network). By forcing the block header inside the CBlockIndex to
be re-serialized, we retain the benefits of the consistency check without the
overhead at startup.
Co-authored-by: Brad Miller <brad@z.cash>
Check Equihash solution when loading block index
An additional consistency check, which also ensures that the in-memory representation
matches the stored index.
read hashReserved from disk
This fixes a bug where the hashReserved field of the block header is not properly read back into CBlockIndex when loaded from disk. This happens to cause no issues currently because hashReserved has always been its default value (== 0), but if a block were ever mined where this was not the case, headers read back from disk would appear to have an invalid solution
We do not need to be able to calculate multiple SignatureHash versions for a
single transaction format; instead, we use the transaction format to determine
the SigVersion.
The consensus branch ID *does* need to be passed in from the outside, as only
the caller knows the context in which the SignatureHash is being calculated
(ie. mempool acceptance vs. block validation).
JoinSplit signature verification has been moved into ContextualCheckTransaction,
where the consensus branch ID can be obtained.
The argument to the sign command for zcash-tx has been modified to take a height
in addition to the optional sigtype flags.
Mempool improvements, branch ID awareness
Whenever the local chain tip is updated, transactions in the mempool which commit to an
unmineable branch ID (for example, just before a network upgrade activates, where the
next block will have a different branch ID) will be removed.
Includes commits cherry-picked from the following upstream PRs:
- bitcoin/bitcoin#6654
- Only the mempool index change.
- bitcoin/bitcoin#6776
- bitcoin/bitcoin#7020
- bitcoin/bitcoin#6915
Part of #2074.
Jack Grigg