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.
Follow-up to:
* commit 700c42b85d, which replaced pIndex
with block_hash in AddToWalletIfInvolvingMe.
* commit 9700fcb47f, which replaced
posInBlock with confirm.nIndex.
9d0379cea6 consensus: use <cstdint> over <stdint.h> in amount.h (fanquake)
863e52fe63 consensus: make COIN & MAX_MONEY constexpr (fanquake)
d09071da5b [MOVEONLY] consensus: move amount.h into consensus (fanquake)
Pull request description:
A first step (of a few) towards some source code reorganization, as well as making libbitcoinconsensus slightly more self contained.
Related to #15732.
ACKs for top commit:
MarcoFalke:
concept ACK 9d0379cea6 🏝
Tree-SHA512: 97fc79262dcb8c00996852a288fee69ddf8398ae2c95700bba5b326f1f38ffcfaf8fa66e29d0cb446d9b3f4e608a96525fae0c2ad9cd531ad98ad2a4a687cd6a
Since accounts were removed in commit c9c32e6b84,
this function is only called at one place and thus can be as well inlined. Also,
avoid a duplicate lookup by using the find() method and dereference, instead of
calling count() and operator[].
Followup to commit "MOVEONLY: CWallet transaction code out of
wallet.cpp/.h" that detaches and renames some CWalletTx methods, making
into them into standalone functions or CWallet methods instead.
There are no changes in behavior and no code changes that aren't purely
mechanical. It just gives spend and receive functions more consistent
names and removes the circular dependencies added by the earlier
MOVEONLY commit.
There are also no comment or documentation changes. Removed comments
from transaction.h are just migrated to spend.h, receive.h, and
wallet.h.
This commit just moves functions without making any changes. It can be
reviewed with `git log -p -n1 --color-moved=dimmed_zebra`
Motivation for this change is to make wallet.cpp/h less monolithic and
start to make wallet transaction state tracking comprehensible so bugs
in
https://github.com/bitcoin-core/bitcoin-devwiki/wiki/Wallet-Transaction-Conflict-Tracking
can be fixed safely without introducing new problems.
This commit moves wallet classes and methods that deal with transactions
out of wallet.cpp/.h into better organized files:
- transaction.cpp/.h - CWalletTx and CMerkleTx class definitions
- receive.cpp/.h - functions checking received transactions and computing balances
- spend.cpp/.h - functions creating transactions and finding spendable coins
After #20773, when loading is separated from syncing it will also be
possible to move more wallet.cpp/.h functions to:
- sync.cpp/.h - functions handling chain notifications and rescanning
This commit arranges receive.cpp and spend.cpp functions in dependency
order so it's possible to skim receive.cpp and get an idea of how
computing balances works, and skim spend.cpp and get an idea of how
transactions are created, without having to jump all over wallet.cpp
where functions are not in order and there is a lot of unrelated code.
Followup commit "refactor: Detach wallet transaction methods" in
https://github.com/bitcoin/bitcoin/pull/21206 follows up this PR and
tweaks function names and arguments to reflect new locations. The two
commits are split into separate PRs because this commit is more work to
maintain and less work to review, while the other commit is less work to
maintain and more work to review, so hopefully this commit can be merged
earlier.
