Files
thehub/testing/common/TestMemPoolEntryHelper.cpp
T
TomZ 2aa462f8bb Replace SigOps with SigChecks
This is part of the protocol upgrade for 2020-05-15, and in general it
seems to go the direction of "we did this before, lets do this again".

The spec is clear enough, but there is still a lack of questioning and
testing. The problem this attempts to fix has been neutered for years[1].

The spec states:
> The essential idea of SigChecks is to perform counting solely in the
> spending transaction, and count actual executed signature check
> operations.

This, however nobel and logical, ignores that the
check-for-being-too-costly just pulled in a UTXO lookup and the loading
of the output script from the historical chain.
The goal that we protect against CPU over-use may be reached, but the
price is a total system slowdown. You can have multiple CPUs, but the
bus to permanent storage has one, max 2 parallel pipes.

To ensure theHub stays the number one scalable node, I didn't blindly
follow the spec, while making sure that the Hub is correctly going to
follow/reject consensus violations of newly mined blocks.

As a result the implementation in Flowee the Hub:

* does not check sigcheck-counts on historical blocks (more than 1000
  blocks in the past).

  This may increase the risk of chain-splits ever so slightly, but the cost
  of disk-IO would be too high.

* No longer stores the value in the mempool, nor uses it for the
  CPU-miner.

* Ties the sigcheck-limits to the user-set block-size-accept-limit.

  This is contrary to the spec which mistakenly thinks that BCH has a
  max block-size in the consensus rules. The effect is the same, though.

* The per-intput standardness suggestion is not implemented because
  standardness checks don't currently fetch the previous outputs and
  that would be too expensive to add.

* Standardness rules for the whole transaction are moved to the
  mempool-acceptance logic instead. The cost would be too great
  otherwise, similar to the previous point.
  Again, the effect is the same as likely intented.

---
1) since the intro of the CachingTransactionSignatureChecker
2020-04-13 15:57:42 +02:00

32 lines
1.3 KiB
C++

/*
* This file is part of the Flowee project
* Copyright (C) 2011-2015 The Bitcoin Core developers
* Copyright (C) 2017 Tom Zander <tomz@freedommail.ch>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "TestMemPoolEntryHelper.h"
CTxMemPoolEntry TestMemPoolEntryHelper::FromTx(CMutableTransaction &tx, CTxMemPool *pool)
{
CTransaction txn(tx);
bool hasNoDependencies = pool ? pool->HasNoInputsOf(tx) : hadNoDependencies;
// Hack to assume either its completely dependent on other mempool txs or not at all
CAmount inChainValue = hasNoDependencies ? txn.GetValueOut() : 0;
return CTxMemPoolEntry(txn, nFee, nTime, dPriority, nHeight,
hasNoDependencies, inChainValue, spendsCoinbase, lp);
}