This is currently unused, but will by used by wallet to cache when
transactions are in the mempool, obviating the need for calls to
mempool from CWalletTx::InMempool()
CFeeRate and CTxMemPoolEntry have explicitly defined copy ctors which has the same functionality as the implicit default copy ctors which would have been generated otherwise.
Besides being redundant, it violates the rule of three (see https://en.wikipedia.org/wiki/Rule_of_three_(C%2B%2B_programming) ).
(Of course, the rule of three doesn't -really- cause a resource management issue here, but the reason for that is exactly that there is no need for an explicit copy ctor in the first place since no resources are being managed).
CFeeRate has an explicitly defined copy ctor which has the same functionality as the implicit default copy ctor which would h
ave been generated otherwise.
This removes the possibility for GetCoin/HaveCoin/HaveCoinInCache to return
true while the respective coin is spent. By doing it across all calls, some
extra checks can be eliminated.
coins_tests is modified to call HaveCoin sometimes before and sometimes
after AccessCoin. A further change is needed because the semantics for
GetCoin slightly changed, causing a pruned entry in the parent cache to not
be pulled into the child in FetchCoin.
This patch makes several related changes:
* Changes the CCoinsView virtual methods (GetCoins, HaveCoins, ...)
to be COutPoint/Coin-based rather than txid/CCoins-based.
* Changes the chainstate db to a new incompatible format that is also
COutPoint/Coin based.
* Implements reconstruction code for hash_serialized_2.
* Adapts the coins_tests unit tests (thanks to Russell Yanofsky).
A side effect of the new CCoinsView model is that we can no longer
use the (unreliable) test for transaction outputs in the UTXO set
to determine whether we already have a particular transaction.
Rather than re-add disconnected block transactions back to the mempool
immediately, store them in a separate disconnectpool for later processing,
because we expect most such transactions to reappear in the chain that is
still to be connected (and thus we can avoid the work of reprocessing those
transactions through the mempool altogether).
This a breaking API change to the prioritisetransaction RPC call which previously required exactly three arguments and now requires exactly two (hash and feeDelta). The function prioritiseTransaction is also updated.
Remove -limitfreerelay and always enforce minRelayTxFee in the mempool (except from disconnected blocks)
Remove -relaypriority, the option was only used for the ability to allow free transactions to be relayed regardless of their priority. Both notions no longer apply.
Add notification signals to make it possible to subscribe to mempool
changes:
- NotifyEntryAdded(CTransactionRef)>
- NotifyEntryRemoved(CTransactionRef, MemPoolRemovalReason)>
Also add a mempool removal reason enumeration, which is passed to the
removed notification based on why the transaction was removed from
the mempool.
All decisions about whether the transactions are valid data points are made at the time the transaction arrives. Updating on blocks all the time will now cause stale fee estimates to decay quickly when we restart a node.
Fee estimation can just check its own mapMemPoolTxs to determine the same information. Note that now fee estimation for block processing must happen before those transactions are removed, but this shoudl be a speedup.
Matt Corallo