diff options
Diffstat (limited to 'src/policy/fees.h')
| -rw-r--r-- | src/policy/fees.h | 115 |
1 files changed, 44 insertions, 71 deletions
diff --git a/src/policy/fees.h b/src/policy/fees.h index 2c1ac3b934..b5881afadf 100644 --- a/src/policy/fees.h +++ b/src/policy/fees.h @@ -19,60 +19,50 @@ class CTxMemPoolEntry; class CTxMemPool; /** \class CBlockPolicyEstimator - * The BlockPolicyEstimator is used for estimating the fee or priority needed + * The BlockPolicyEstimator is used for estimating the feerate needed * for a transaction to be included in a block within a certain number of * blocks. * * At a high level the algorithm works by grouping transactions into buckets - * based on having similar priorities or fees and then tracking how long it + * based on having similar feerates and then tracking how long it * takes transactions in the various buckets to be mined. It operates under - * the assumption that in general transactions of higher fee/priority will be - * included in blocks before transactions of lower fee/priority. So for - * example if you wanted to know what fee you should put on a transaction to + * the assumption that in general transactions of higher feerate will be + * included in blocks before transactions of lower feerate. So for + * example if you wanted to know what feerate you should put on a transaction to * be included in a block within the next 5 blocks, you would start by looking - * at the bucket with the highest fee transactions and verifying that a + * at the bucket with the highest feerate transactions and verifying that a * sufficiently high percentage of them were confirmed within 5 blocks and - * then you would look at the next highest fee bucket, and so on, stopping at - * the last bucket to pass the test. The average fee of transactions in this - * bucket will give you an indication of the lowest fee you can put on a + * then you would look at the next highest feerate bucket, and so on, stopping at + * the last bucket to pass the test. The average feerate of transactions in this + * bucket will give you an indication of the lowest feerate you can put on a * transaction and still have a sufficiently high chance of being confirmed * within your desired 5 blocks. * - * When a transaction enters the mempool or is included within a block we - * decide whether it can be used as a data point for fee estimation, priority - * estimation or neither. If the value of exactly one of those properties was - * below the required minimum it can be used to estimate the other. In - * addition, if a priori our estimation code would indicate that the - * transaction would be much more quickly included in a block because of one - * of the properties compared to the other, we can also decide to use it as - * an estimate for that property. - * - * Here is a brief description of the implementation for fee estimation. - * When a transaction that counts for fee estimation enters the mempool, we + * Here is a brief description of the implementation: + * When a transaction enters the mempool, we * track the height of the block chain at entry. Whenever a block comes in, - * we count the number of transactions in each bucket and the total amount of fee + * we count the number of transactions in each bucket and the total amount of feerate * paid in each bucket. Then we calculate how many blocks Y it took each * transaction to be mined and we track an array of counters in each bucket * for how long it to took transactions to get confirmed from 1 to a max of 25 * and we increment all the counters from Y up to 25. This is because for any * number Z>=Y the transaction was successfully mined within Z blocks. We * want to save a history of this information, so at any time we have a - * counter of the total number of transactions that happened in a given fee + * counter of the total number of transactions that happened in a given feerate * bucket and the total number that were confirmed in each number 1-25 blocks * or less for any bucket. We save this history by keeping an exponentially * decaying moving average of each one of these stats. Furthermore we also * keep track of the number unmined (in mempool) transactions in each bucket * and for how many blocks they have been outstanding and use that to increase - * the number of transactions we've seen in that fee bucket when calculating + * the number of transactions we've seen in that feerate bucket when calculating * an estimate for any number of confirmations below the number of blocks * they've been outstanding. */ /** - * We will instantiate two instances of this class, one to track transactions - * that were included in a block due to fee, and one for tx's included due to - * priority. We will lump transactions into a bucket according to their approximate - * fee or priority and then track how long it took for those txs to be included in a block + * We will instantiate an instance of this class to track transactions that were + * included in a block. We will lump transactions into a bucket according to their + * approximate feerate and then track how long it took for those txs to be included in a block * * The tracking of unconfirmed (mempool) transactions is completely independent of the * historical tracking of transactions that have been confirmed in a block. @@ -80,7 +70,7 @@ class CTxMemPool; class TxConfirmStats { private: - //Define the buckets we will group transactions into (both fee buckets and priority buckets) + //Define the buckets we will group transactions into std::vector<double> buckets; // The upper-bound of the range for the bucket (inclusive) std::map<double, unsigned int> bucketMap; // Map of bucket upper-bound to index into all vectors by bucket @@ -97,16 +87,15 @@ private: // and calculate the totals for the current block to update the moving averages std::vector<std::vector<int> > curBlockConf; // curBlockConf[Y][X] - // Sum the total priority/fee of all tx's in each bucket + // Sum the total feerate of all tx's in each bucket // Track the historical moving average of this total over blocks std::vector<double> avg; // and calculate the total for the current block to update the moving average std::vector<double> curBlockVal; // Combine the conf counts with tx counts to calculate the confirmation % for each Y,X - // Combine the total value with the tx counts to calculate the avg fee/priority per bucket + // Combine the total value with the tx counts to calculate the avg feerate per bucket - std::string dataTypeString; double decay; // Mempool counts of outstanding transactions @@ -123,9 +112,8 @@ public: * @param defaultBuckets contains the upper limits for the bucket boundaries * @param maxConfirms max number of confirms to track * @param decay how much to decay the historical moving average per block - * @param dataTypeString for logging purposes */ - void Initialize(std::vector<double>& defaultBuckets, unsigned int maxConfirms, double decay, std::string dataTypeString); + void Initialize(std::vector<double>& defaultBuckets, unsigned int maxConfirms, double decay); /** Clear the state of the curBlock variables to start counting for the new block */ void ClearCurrent(unsigned int nBlockHeight); @@ -133,7 +121,7 @@ public: /** * Record a new transaction data point in the current block stats * @param blocksToConfirm the number of blocks it took this transaction to confirm - * @param val either the fee or the priority when entered of the transaction + * @param val the feerate of the transaction * @warning blocksToConfirm is 1-based and has to be >= 1 */ void Record(int blocksToConfirm, double val); @@ -150,14 +138,14 @@ public: void UpdateMovingAverages(); /** - * Calculate a fee or priority estimate. Find the lowest value bucket (or range of buckets + * Calculate a feerate estimate. Find the lowest value bucket (or range of buckets * to make sure we have enough data points) whose transactions still have sufficient likelihood * of being confirmed within the target number of confirmations * @param confTarget target number of confirmations * @param sufficientTxVal required average number of transactions per block in a bucket range * @param minSuccess the success probability we require - * @param requireGreater return the lowest fee/pri such that all higher values pass minSuccess OR - * return the highest fee/pri such that all lower values fail minSuccess + * @param requireGreater return the lowest feerate such that all higher values pass minSuccess OR + * return the highest feerate such that all lower values fail minSuccess * @param nBlockHeight the current block height */ double EstimateMedianVal(int confTarget, double sufficientTxVal, @@ -184,35 +172,27 @@ static const unsigned int MAX_BLOCK_CONFIRMS = 25; /** Decay of .998 is a half-life of 346 blocks or about 2.4 days */ static const double DEFAULT_DECAY = .998; -/** Require greater than 95% of X fee transactions to be confirmed within Y blocks for X to be big enough */ +/** Require greater than 95% of X feerate transactions to be confirmed within Y blocks for X to be big enough */ static const double MIN_SUCCESS_PCT = .95; static const double UNLIKELY_PCT = .5; -/** Require an avg of 1 tx in the combined fee bucket per block to have stat significance */ +/** Require an avg of 1 tx in the combined feerate bucket per block to have stat significance */ static const double SUFFICIENT_FEETXS = 1; -/** Require only an avg of 1 tx every 5 blocks in the combined pri bucket (way less pri txs) */ -static const double SUFFICIENT_PRITXS = .2; - -// Minimum and Maximum values for tracking fees and priorities +// Minimum and Maximum values for tracking feerates static const double MIN_FEERATE = 10; static const double MAX_FEERATE = 1e7; static const double INF_FEERATE = MAX_MONEY; -static const double MIN_PRIORITY = 10; -static const double MAX_PRIORITY = 1e16; static const double INF_PRIORITY = 1e9 * MAX_MONEY; -// We have to lump transactions into buckets based on fee or priority, but we want to be able -// to give accurate estimates over a large range of potential fees and priorities +// We have to lump transactions into buckets based on feerate, but we want to be able +// to give accurate estimates over a large range of potential feerates // Therefore it makes sense to exponentially space the buckets /** Spacing of FeeRate buckets */ static const double FEE_SPACING = 1.1; -/** Spacing of Priority buckets */ -static const double PRI_SPACING = 2; - /** - * We want to be able to estimate fees or priorities that are needed on tx's to be included in + * We want to be able to estimate feerates that are needed on tx's to be included in * a certain number of blocks. Every time a block is added to the best chain, this class records * stats on the transactions included in that block */ @@ -235,27 +215,26 @@ public: /** Remove a transaction from the mempool tracking stats*/ void removeTx(uint256 hash); - /** Is this transaction likely included in a block because of its fee?*/ - bool isFeeDataPoint(const CFeeRate &fee, double pri); - - /** Is this transaction likely included in a block because of its priority?*/ - bool isPriDataPoint(const CFeeRate &fee, double pri); - - /** Return a fee estimate */ + /** Return a feerate estimate */ CFeeRate estimateFee(int confTarget); - /** Estimate fee rate needed to get be included in a block within + /** Estimate feerate needed to get be included in a block within * confTarget blocks. If no answer can be given at confTarget, return an * estimate at the lowest target where one can be given. */ CFeeRate estimateSmartFee(int confTarget, int *answerFoundAtTarget, const CTxMemPool& pool); - /** Return a priority estimate */ + /** Return a priority estimate. + * DEPRECATED + * Returns -1 + */ double estimatePriority(int confTarget); /** Estimate priority needed to get be included in a block within - * confTarget blocks. If no answer can be given at confTarget, return an - * estimate at the lowest target where one can be given. + * confTarget blocks. + * DEPRECATED + * Returns -1 unless mempool is currently limited then returns INF_PRIORITY + * answerFoundAtTarget is set to confTarget */ double estimateSmartPriority(int confTarget, int *answerFoundAtTarget, const CTxMemPool& pool); @@ -263,29 +242,23 @@ public: void Write(CAutoFile& fileout); /** Read estimation data from a file */ - void Read(CAutoFile& filein); + void Read(CAutoFile& filein, int nFileVersion); private: CFeeRate minTrackedFee; //!< Passed to constructor to avoid dependency on main - double minTrackedPriority; //!< Set to AllowFreeThreshold unsigned int nBestSeenHeight; struct TxStatsInfo { - TxConfirmStats *stats; unsigned int blockHeight; unsigned int bucketIndex; - TxStatsInfo() : stats(NULL), blockHeight(0), bucketIndex(0) {} + TxStatsInfo() : blockHeight(0), bucketIndex(0) {} }; // map of txids to information about that transaction std::map<uint256, TxStatsInfo> mapMemPoolTxs; /** Classes to track historical data on transaction confirmations */ - TxConfirmStats feeStats, priStats; - - /** Breakpoints to help determine whether a transaction was confirmed by priority or Fee */ - CFeeRate feeLikely, feeUnlikely; - double priLikely, priUnlikely; + TxConfirmStats feeStats; }; class FeeFilterRounder |