This commit changes the state system and database format to track the
provenance of UTXOs, in addition to the outputs themselves.
Specifically, it tracks the following additional metadata:
- the height at which the UTXO was created;
- whether or not the UTXO was created from a coinbase transaction or
not.
This metadata will allow us to:
- check the coinbase maturity consensus rule;
- check the coinbase inputs => no transparent outputs rule;
- implement lookup of transactions by utxo (using the height to find the
block and then scanning the block) for a future RPC mechanism.
Closes#1342
This change introduces two new types:
- `PreparedBlock`, representing a block which has undergone semantic
validation and has been prepared for contextual validation;
- `FinalizedBlock`, representing a block which is ready to be finalized
immediately;
and changes the `Request::CommitBlock`,`Request::CommitFinalizedBlock`
variants to use these types instead of their previous fields.
This change solves the problem of passing data between semantic
validation and contextual validation, and cleans up the state code by
allowing it to pass around a bundle of data. Previously, the state code
just passed around an `Arc<Block>`, which forced it to needlessly
recompute block hashes and other data, and was incompatible with the
already-known but not-yet-implemented data transfer requirements, namely
passing in the Sprout and Sapling anchors computed during contextual
validation.
This commit propagates the `PreparedBlock` and `FinalizedBlock` types
through the state code but only uses their data opportunistically, e.g.,
changing .hash() computations to use the precomputed hash. In the
future, these structures can be extended to pass data through the
verification pipeline for reuse as appropriate. For instance, these
changes allow the sprout and sapling anchors to be propagated through
the state.
The UTXO query system assumes that a transaction will only request
information about UTXOs created in prior blocks. But transactions are
allowed to spend UTXOs created by prior transactions in the same block.
This doesn't fit with the existing query model, so instead of trying to
change it, allow the script verifier to take an additional set of known
UTXOs, and propagate this set from the block.
This consensus rule is supposed to apply to transactions whose
transparent inputs are the *outputs* of previous coinbase
transactions, not to transactions with coinbase inputs. Because that
logic is different enough from this logic, and requires different data
flow, it's cleaner to just remove this check for now.
Making this check's match statement exhaustive revealed a bug similar to
the previous commit. The logic in the spec is written in terms of
numbers, but our data is internally represented in terms of enums
(ADTs). This kind of cross-representation rule translation is a bug
surface, which we can avoid by converting to counts and summing up. (We
should use one style at a time).
This function caused spurious "WrongVersion" errors, because the match
pattern in the first arm was non-exhaustive, but the fallthrough match
arm was present and assumed it would only be reached if the version was
incorrect.
This commit cleans up the implemenation, splits out the error variants,
and renames the check to be more precise.
To avoid this kind of bug in the future, two guidelines are useful:
1. Avoid fallthrough cases that circumvent non-exhaustive match checks;
2. Avoid nested conditionals, preferring a "straight-line" sequence of
match arm => result pairs rather than nested matches or matches with
conditionals inside.
The BlockVerifier constructed a tracing span and manually entered it
inside of an async block. Manually entering spans inside async blocks
can cause problems where the span might not be entered and exited
correctly as the resulting future is polled. Instead, using the
.instrument creates a wrapper future that handles the bookkeeping.
I changed the span name and contents to be consistent with the spans in
the checkpoint verifier.
This change is mostly mechanical, with the exception of the changes to the
`tower-batch` middleware. This middleware was adapted from `tower::buffer`,
and the `tower::buffer` code was changed to implement its own bounded queue,
because Tokio 0.3 removed the `mpsc::Sender::poll_send` method. See
ddc64e8d4d
for more context on the Tower changes. To match Tower as closely as possible
in order to be able to upstream `tower-batch`, those changes are copied from
`tower::Buffer` to `tower-batch`.
This change explicitly documents cancellation contracts for our Tower services,
and tries to correct a bug in the implementation of the CheckpointVerifier,
which duplicates information from the state service but did not ensure that it
would be kept in sync.
* Implement Expanded to Compact Difficulty
* Implement Arbitrary for CompactDifficulty
Remove the derive, and generate values from random block
hashes.
* Implement Arbitrary for ExpandedDifficulty and Work
* Use Arbitrary for CompactDifficulty in Arbitrary for Block
* Test difficulty on all block test vectors
And cleanup some duplicate test code
* Round-trip tests for compact test cases
* Round-trip tests for compact difficulty in block test vectors
* Make Add for Work return PartialCumulativeWork
Remove AddAssign for Work
Rewrite a proptest using Sub for PartialCumulativeWork
Use Arbitrary for Work
* Add roundtrip work sum tests
* Add roundtrip comparison difficulty tests
* Add failing proptest cases due to test bugs
* Use Some(_) rather than _.into()
* Reduce visibility of difficulty type inner values
* Split work and other difficulty proptests
This change makes sure that rejected work values don't disable property
tests on other types.
There's no reason to return a pre-Buffer'd service (there's no need for
internal access to the state service, as in zebra-network), but wrapping
it internally removes control of the buffer size from the caller.
The previous debug output printed a message that the chain verifier had
recieved a block. But this provides no additional information compared
to printing no message in chain::Verifier and a message in whichever
verifier the block was sent to, since the resulting spans indicate where
the block was dispatched.
This commit also removes the "unexpected high block" detection; this was
an artefact of the original sync algorithm failing to handle block
advertisements, but we don't have that problem any more, so we can
simplify the code by eliminating that logic.
Henry de Valence
teor
Henry de Valence
Deirdre Connolly
dependabot[bot]
Alfredo Garcia