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 provides useful and not too noisy output at INFO level. We do an
info-level message on every block commit instead of trying to do one
message every N blocks, because this is useful both for initial block
sync as well as continuous state updates on new blocks.
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 behavior of a request for a UTXO from a previous block depends on
whether that block has already been submitted to the state, or not:
* if it has, the state should be able to find it and answer immediately.
* if it has not, the state should see it in a later request.
However, the previous code only checked committed blocks, not queued
blocks, so if the block containing the UTXO had already arrived but had
not been committed, it would never be scanned.
This patch fixes the problem but is a bad solution, duplicating
computation between the block verifier and the state. A better fix
follows in the next commit.
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.
Make tracing messages more concise by omitting information already
contained in a parent span and by shortening messages. This makes them
easier to read.
Previously, this function was instrumented with a span containing the
parent hash that was the entry to the function. But it doesn't make
sense to consider the work done by the function as happening in the
context of the supplied parent hash (as distinct from the context of the
hash of the newly arrived block, which is already contained in an outer
span), so this adds noise without conveying extra context.
Instead, use events that occur within the context of the existing spans.
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 derived Debug impl just shows u8s as numbers, which isn't what we
want. There are basically two reasonable options here:
1. Hex-encoded bytes
2. Escaped ASCII
I picked (2) because a lot of coinbase data has ascii text in it.
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.
Here the span is added to the body of the `Service::call`
implementation, not to the futures it returns, because the state service
does all of the work synchronously in `call` rather than in the futures
it returns.
The service is skipped as a span field. We could either include or
exclude the request itself. It would be useful, but the request body
can be very large. Instead, we make two spans, one at info level and
one at trace level, and filter that way.
The metrics code becomes much simpler because the current version of the
metrics crate builds its own single-threaded runtime on a dedicated worker
thread, so no dependency on the main Zebra Tokio runtime is required.
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`.
Some systems have a very small /dev/shm, for example, see:
https://github.com/docker-library/postgres/issues/416
So we should just use the temporary directory on all operating systems.
Also:
* use TempDir to generate the temporary path
* delete the code that we copied from sled
* prefix the temporary path with the state version and network
Per https://zips.z.cash/zip-0251, nodes compatible with Canopy
activation on mainnet MUST advertise protocol version 170013 or later.
Once Canopy activates on testnet or mainnet, Canopy nodes SHOULD reject
new connections from pre-Canopy nodes, so this also increases the
minimum version.