```
$ git blame src/policy/fees.cpp | grep becuase
3810e976 (2017-03-07 11:33:44 -0500 789) * checks for 2*target becuase we are taking the max over all time
$ git blame src/policy/fees.h | grep successfullly
2d2e1705 (2017-04-12 12:29:03 -0400 54) * representing that a tx was successfullly confirmed in less than or equal to
$ git blame src/wallet/feebumper.cpp | grep "hasen't"
a3878374 (2017-05-11 09:34:39 +0200 258) // make sure the transaction still has no descendants and hasen't been mined in the meantime
```
For the per confirmation number tracking of data, introduce a scale factor so that in the longer horizones confirmations are bucketed together at a resolution of the scale. (instead of 1008 individual data points for each fee bucket, have 42 data points each covering 24 different confirmation values.. (1-24), (25-48), etc.. )
Store in fee estimate file the block span for which we were tracking estimates, so we know what targets we can successfully evaluate with the data in the file. When restarting use either this historical block span to set valid range of targets until our current span of tracking estimates is just as long.
Track the first time we seen txs in a block that we have been tracking in our mempool. Used to evaluate validity of fee estimates for different targets.
Change the logic of estimateSmartFee to check a 60% threshold at half the target, a 85% threshold at the target and a 95% threshold at double the target. Always check the shortest time horizon possible and ensure that estimates are monotonically decreasing. Add a conservative mode, which makes sure that the 95% threshold is also met at longer time horizons as well.
Track information the ranges of fee rates that were used to calculate the fee estimates (the last range of fee rates in which the data points met the threshold and the first to fail) and provide an RPC call to return this information.
Instead of stopping if it encounters a "sufficient" number of transactions which don't meet the threshold for being confirmed within the target, it keeps looking to add more transactions to see if there is a temporary blip in the data. This allows a smaller number of required data points.
Move buckets and bucketMap to be stored as part of overall serialization of estimator.
Add some placeholder data so file format is only changed once.
Maintain 3 different TxConfirmStats with potential for different decays and scales.
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.
Once priority estimation was removed, not all transactions in the mempool are tracked in the fee estimation mempool tracking. So there is no error if a transaction is not found for removal.
Three categories of modifications:
1)
1 instance of 'The Bitcoin Core developers \n',
1 instance of 'the Bitcoin Core developers\n',
3 instances of 'Bitcoin Core Developers\n', and
12 instances of 'The Bitcoin developers\n'
are made uniform with the 443 instances of 'The Bitcoin Core developers\n'
2)
3 instances of 'BitPay, Inc\.\n' are made uniform with the other 6
instances of 'BitPay Inc\.\n'
3)
4 instances where there was no '(c)' between the 'Copyright' and the year
where it deviates from the style of the local directory.
There are only a few uses of `insecure_random` outside the tests.
This PR replaces uses of insecure_random (and its accompanying global
state) in the core code with an FastRandomContext that is automatically
seeded on creation.
This is meant to be used for inner loops. The FastRandomContext
can be in the outer scope, or the class itself, then rand32() is used
inside the loop. Useful e.g. for pushing addresses in CNode or the fee
rounding, or randomization for coin selection.
As a context is created per purpose, thus it gets rid of
cross-thread unprotected shared usage of a single set of globals, this
should also get rid of the potential race conditions.
- I'd say TxMempool::check is not called enough to warrant using a special
fast random context, this is switched to GetRand() (open for
discussion...)
- The use of `insecure_rand` in ConnectThroughProxy has been replaced by
an atomic integer counter. The only goal here is to have a different
credentials pair for each connection to go on a different Tor circuit,
it does not need to be random nor unpredictable.
- To avoid having a FastRandomContext on every CNode, the context is
passed into PushAddress as appropriate.
There remains an insecure_random for test usage in `test_random.h`.
The "feefilter" p2p message is used to inform other nodes of your mempool min fee which is the feerate that any new transaction must meet to be accepted to your mempool. This will allow them to filter invs to you according to this feerate.
This provides more conservative estimates and reacts more quickly to a backlog.
Unfortunately the unit test for fee estimation depends on the success threshold (and the decay) chosen; also modify the unit test for the new default success thresholds.
These are more useful fee and priority estimation functions. If there is no fee/pri high enough for the target you are aiming for, it will give you the estimate for the lowest target that you can reliably obtain. This is better than defaulting to the minimum. It will also pass back the target for which it returned an answer.
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
Alex Morcos