During new transaction verification if there's an on-chain conflicting
transaction, we should check the signers of this conflicting transaction.
If the signers intersect with signers of the incoming transaction, then
the conflict is treated as valid and verification for new incoming
transaction should fail. Otherwise, the conflict is treated as the
malicious attack attempt and will not be taken into account;
verification for the new incoming transaction should continue.
This commint implements the scheme described at
https://github.com/neo-project/neo/pull/2818#issuecomment-1632972055,
thanks to @shargon for digging.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Move them to the core/network packages, close#2950. The name of
mempool's unsorted transactions metrics has been changed along the
way to match the core's metrics naming convention.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Everywhere including examples, external interop APIs, bindings generators
code and in other valuable places. A couple of `interface{}` usages are
intentionally left in the CHANGELOG.md, documentation and tests.
It's very effective in avoiding allocations for big.Int, we don't have a
microbenchmark for memppol, but this improves TPS metrics by ~1-2%, so it's
noticeable.
Transaction is added to verifiedMap before OOM check, so we may have a
case when OOM occurs during tx1 pooling, but mp.containsKey(tx1)
returns `true` after this. Fixed.
Prices are defined in as a coefficients to `BaseExecFee` which
is defined by Policy contract (TBD later).
Native method prices are defined without need to multiply.
There might be a case when identical nonces are generated for tx6, tx7 or
tx8 (they are not in mempool, so each of them pass mempool-presence
check). In this case test fails due to the lack of hashes into mp.conflicts
map (two of tx6, tx7 or tx8 have identical hashes) with the following
error:
```
=== RUN TestMempoolAddRemoveConflicts
--- FAIL: TestMempoolAddRemoveConflicts (0.00s)
mem_pool_test.go:376:
Error Trace: mem_pool_test.go:376
Error: Not equal:
expected: 4
actual : 3
Test: TestMempoolAddRemoveConflicts
```
Fixed by maling the nonce non-random.
It's not needed, we're either creating a new one and assigning it 6 lines
above or we're changing already existing big.Int via a pointer, so no update
is needed.
There is nothing requiring us to do so. It also is bad because it allows for
new transaction to replace some already existing one with the same fee
parameters just because it has "better" hash.
But the other thing is that for transactions with equal fees it's always
better for us to append them to the end of the list, instead of inserting them
in the middle, so this change allows to reduce slice item movements and gain
some 6-7% increase for single-node TPS.
Time is not really relevant for us here and we don't use this timestamp in any
way. Yet it occupies 24 bytes and we do two clock_gettime calls to get it.
Replace it with blockStamp which is going to be used in the future for
transaction retransmissions.
It allows to improve single-node TPS by another 3%.
Now we have VerifyTx() and PoolTx() APIs that either verify transaction in
isolation or verify it against the mempool (either the primary one or the one
given) and then add it there. There is no possibility to check against the
mempool, but not add a transaction to it, but I doubt we really need it.
It allows to remove some duplication between old PoolTx and verifyTx where
they both tried to check transaction against mempool (verifying first and then
adding it). It also saves us utility token balance check because it's done by
the mempool anyway and we no longer need to do that explicitly in verifyTx.
It makes AddBlock() and verifyBlock() transaction's checks more correct,
because previously they could miss that even though sender S has enough
balance to pay for A, B or C, he can't pay for all of them.
Caveats:
* consensus is running concurrently to other processes, so things could
change while verifyBlock() is iterating over transactions, this will be
mitigated in subsequent commits
Improves TPS value for single node by at least 11%.
Fixes#667, fixes#668.
