Some specifics on consensus changes:
* Transactions must be anchored to a real anchor in the chain.
* Anchors are pushed and popped during ConnectBlock/DisconnectBlock as appropriate.
* DisconnectTip triggers evictions, under some circumstances, of transactions in the
mempool which are anchored to roots that are no longer valid.
* Commitments append to the tree at the current best root during ConnectBlock.
This class groups transactions that have been confirmed in blocks into buckets, based on either their fee or their priority. Then for each bucket, the class calculates what percentage of the transactions were confirmed within various numbers of blocks. It does this by keeping an exponentially decaying moving history for each bucket and confirm block count of the percentage of transactions in that bucket that were confirmed within that number of blocks.
-Eliminate txs which didn't have all inputs available at entry from fee/pri calcs
-Add dynamic breakpoints and tracking of confirmation delays in mempool transactions
-Remove old CMinerPolicyEstimator and CBlockAverage code
-New smartfees.py
-Pass a flag to the estimation code, using IsInitialBlockDownload as a proxy for when we are still catching up and we shouldn't be counting how many blocks it takes for transactions to be included.
-Add a policyestimator unit test
This fixes a subtle bug involving block re-orgs and non-standard transactions.
Start with a block containing a non-standard transaction, and
one or more transactions spending it in the memory pool.
Then re-org away from that block to another chain that does
not contain the non-standard transaction.
Result before this fix: the dependent transactions get stuck
in the mempool without their parent, putting the mempool
in an inconsistent state.
Tested with a new unit test.
'Sane' was already defined by this code as:
fee.GetFeePerK() > minRelayFee.GetFeePerK() * 10000
But sanity was only enforced for data loaded from disk.
Note that this is a pretty expansive definition of 'sane': A 10 BTC
fee is still passes the test if its on a 100kb transaction.
This prevents a single insane fee on the network from making us reject
our stored fee data at start. We still may reject valid saved fee
state if minRelayFee is changed between executions.
This also reduces the risk and limits the damage from a cascading
failure where one party pays a bunch of insane fees which cases
others to pay insane fees.
Jorge Timón