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| author | W. J. van der Laan <laanwj@protonmail.com> | 2021-11-25 19:08:40 +0100 |
|---|---|---|
| committer | W. J. van der Laan <laanwj@protonmail.com> | 2021-11-25 19:41:53 +0100 |
| commit | cf2415259698e1b9d81d08e7b4ace10befdca2a9 (patch) | |
| tree | f51a7828b9bb4aa716b3b10cc2abc32ca924a815 /src/util | |
| parent | 681b25e3cd7d084f642693152322ed9a40f33ba0 (diff) | |
| parent | d8ee8f3cd32bbfefec931724f5798cbb088ceb6f (diff) | |
Merge bitcoin/bitcoin#21206: refactor: Make CWalletTx sync state type-safe
d8ee8f3cd32bbfefec931724f5798cbb088ceb6f refactor: Make CWalletTx sync state type-safe (Russell Yanofsky)
Pull request description:
Current `CWalletTx` state representation makes it possible to set inconsistent states that won't be handled correctly by wallet sync code or serialized & deserialized back into the same form.
For example, it is possible to call `setConflicted` without setting a conflicting block hash, or `setConfirmed` with no transaction index. And it's possible update individual `m_confirm` and `fInMempool` data fields without setting an overall consistent state that can be serialized and handled correctly.
Fix this without changing behavior by using `std::variant`, instead of an enum and collection of fields, to represent sync state, so state tracking code is safer and more legible.
This is a first step to fixing state tracking bugs https://github.com/bitcoin-core/bitcoin-devwiki/wiki/Wallet-Transaction-Conflict-Tracking, by adding an extra margin of safety that can prevent new bugs from being introduced as existing bugs are fixed.
ACKs for top commit:
laanwj:
re-ACK d8ee8f3cd32bbfefec931724f5798cbb088ceb6f
jonatack:
Code review ACK d8ee8f3cd32bbfefec931724f5798cbb088ceb6f
Tree-SHA512: b9f15e9d99dbdbdd3ef7a76764e11f66949f50e6227e284126f209e4cb106af6d55e9a9e8c7d4aa216ddc92c6d5acc6f4aa4746f209bbd77f03831b51a2841c3
Diffstat (limited to 'src/util')
| -rw-r--r-- | src/util/overloaded.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/util/overloaded.h b/src/util/overloaded.h new file mode 100644 index 0000000000..6be7453f81 --- /dev/null +++ b/src/util/overloaded.h @@ -0,0 +1,22 @@ +// Copyright (c) 2021 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_UTIL_OVERLOADED_H +#define BITCOIN_UTIL_OVERLOADED_H + +namespace util { +//! Overloaded helper for std::visit. This helper and std::visit in general are +//! useful to write code that switches on a variant type. Unlike if/else-if and +//! switch/case statements, std::visit will trigger compile errors if there are +//! unhandled cases. +//! +//! Implementation comes from and example usage can be found at +//! https://en.cppreference.com/w/cpp/utility/variant/visit#Example +template<class... Ts> struct Overloaded : Ts... { using Ts::operator()...; }; + +//! Explicit deduction guide (not needed as of C++20) +template<class... Ts> Overloaded(Ts...) -> Overloaded<Ts...>; +} // namespace util + +#endif // BITCOIN_UTIL_OVERLOADED_H |