fa899fb7aa fuzz: Speed up utxo_snapshot fuzz target (MarcoFalke)
fa386642b4 fuzz: Speed up utxo_snapshot by lazy re-init (MarcoFalke)
fa645c7a86 fuzz: Remove unused DataStream object (MarcoFalke)
fae8c73d9e test: Disallow fee_estimator construction in ChainTestingSetup (MarcoFalke)
Pull request description:
Two commits to speed up unit and fuzz tests.
Can be tested by running the fuzz target and looking at the time it took, or by looking at the flamegraph. For example:
```
FUZZ=utxo_snapshot perf record -g --call-graph dwarf ./src/test/fuzz/fuzz -runs=100
hotspot ./perf.data
ACKs for top commit:
TheCharlatan:
Re-ACK fa899fb7aa
marcofleon:
Re ACK fa899fb7aa
brunoerg:
ACK fa899fb7aa
Tree-SHA512: d3a771bb12d7ef491eee61ca47325dd1cea5c20b6ad42554babf13ec98d03bef8e7786159d077e59cc7ab8112495037b0f6e55edae65b871c7cf1708687cf717
The flags SECP256K1_CONTEXT_{SIGN,VERIFY} have been deprecated since
libsecp256k1 version 0.2 (released in December 2022), with the
recommendation to use SECP256K1_CONTEXT_NONE instead.
This currently has no effect due to fPowNoRetargeting,
except for the getnetworkhashps when called with -1.
It will when the next commit enforces the timewarp attack mitigation on regtest.
16e95bda86 Move maximum timewarp attack threshold back to 600s from 7200s (Matt Corallo)
Pull request description:
In 6bfa26048d the testnet4 timewarp attack fix block time variation was increased from the Great Consensus Cleanup value of 600s to 7200s on the thesis that this allows miners to always create blocks with the current time. Sadly, doing so does allow for some nonzero inflation, even if not a huge amount.
While it could be that some hardware ignores the timestamp provided to it over Stratum and forces the block header timestamp to the current time, I'm not aware of any such hardware, and it would also likely suffer from random invalid blocks due to relying on NTP anyway, making its existence highly unlikely.
This leaves the only concern being pools, but most of those rely on work generated by Bitcoin Core (in one way or another, though when spy mining possibly not), and it seems likely that they will also not suffer any lost work. While its possible that a pool does generate invalid work due to spy mining or otherwise custom logic, it seems unlikely that a substantial portion of hashrate would do so, making the difference somewhat academic (any pool that screws this up will only do so once and the network would come out just fine).
Further, while we may end up deciding these assumptions were invalid and we should instead use 7200s, it seems prudent to try with the value we "want" on testnet4, giving us the ability to learn if the compatibility concerns are an issue before we go to mainnet.
ACKs for top commit:
fjahr:
tACK 16e95bda86
achow101:
ACK 16e95bda86
murchandamus:
crACK 16e95bda86
Tree-SHA512: ae46d03b728b6e23cb6ace64c9813bc01c01e38dd7f159cf0fab53b331ef84b3b811edab225453ccdfedb53b242f55b0efd69829782657490fe393d24dacbeb2
