This commit adds an additional closure function to the mempool’s config
which computes the median time past from the point of view of the best
node in the chain. The mempool test harness has also been updated to allow
setting a mock median time past for testing purposes.
In addition to increasing the testability of the mempool, this commit
should also speed up transaction and block validation for BIP 113 as
the MTP no longer needs to be re-calculated each time from scratch.
This changes the transaction input standardness checks as follows:
- Allow any script in a pay-to-script-hash transaction to be relayed and
mined so long as it has no more than 15 signature operations
- Remove the obsolete checks which naively calculated the number of
expected inputs in favor of the more accurate ScriptVerifyCleanStack
and ScriptVerifySigPushOnly functionality of the script engine that was
added after these checks.
This adds a basic test harness infrastructure for the mempool package
which aims to make writing tests for it much easier.
The harness provides functionality for creating and signing transactions
as well as a fake chain that provides utxos for use in generating valid
transactions and allows an arbitrary chain height to be set. In order
to simplify transaction creation, a single signing key and payment
address is used throughout and a convenience type for spendable outputs
is provided.
The harness is initialized with a spendable coinbase output by default
and the fake chain height set to the maturity height needed to ensure
the provided output is in fact spendable as well as a policy that is
suitable for testing.
Since tests are in the same package and each harness provides a unique
pool and fake chain instance, the tests can safely reach into the pool
policy, or any other state, and change it for a given harness without
affecting the others.
In order to be able to make use of the existing blockchain.Viewpoint
type, a Clone method has been to the UtxoEntry type which allows the
fake chain instance to keep a single view with the actual available
unspent utxos while the mempool ends up fetching a subset of the view
with the specifically requested entries cloned.
To demo the harness, this also contains a couple of tests which make use
of it:
- TestSimpleOrphanChain -- Ensures an entire chain of orphans is
properly accepted and connects up when the missing parent transaction
is added
- TestOrphanRejects -- Ensure orphans are actually rejected when the
flag on ProcessTransactions is set to reject them
This modifies the config for the new mempool package such that it takes
a callback function to obtain the best chain height instead of requiring
a fully initialized blockchain.BlockChain instance.
This will make it much easier to test the mempool since the tests will
be able to provide their own height function to test various
functionality without having create and manipulate full blocks and chain
instances.
This does the minimum work necessary to refactor the mempool code into
its own package. The idea is that separating this code into its own
package will greatly improve its testability, allow independent
benchmarking and profiling, and open up some interesting opportunities
for future development related to the memory pool.
There are likely some areas related to policy that could be further
refactored, however it is better to do that in future commits in order
to keep the changeset as small as possible during this refactor.
Overview of the major changes:
- Create the new package
- Move several files into the new package:
- mempool.go -> mempool/mempool.go
- mempoolerror.go -> mempool/error.go
- policy.go -> mempool/policy.go
- policy_test.go -> mempool/policy_test.go
- Update mempool logging to use the new mempool package logger
- Rename mempoolPolicy to Policy (so it's now mempool.Policy)
- Rename mempoolConfig to Config (so it's now mempool.Config)
- Rename mempoolTxDesc to TxDesc (so it's now mempool.TxDesc)
- Rename txMemPool to TxPool (so it's now mempool.TxPool)
- Move defaultBlockPrioritySize to the new package and export it
- Export DefaultMinRelayTxFee from the mempool package
- Export the CalcPriority function from the mempool package
- Introduce a new RawMempoolVerbose function on the TxPool and update
the RPC server to use it
- Update all references to the mempool to use the package.
- Add a skeleton README.md
