Implement the new monetary policy (#1892)

* Remove unused functions, constants, and variables.

* Rename maxSubsidy to baseSubsidy.

* Remove unused parameters from CalcBlockSubsidy.

* Remove link to old monetary policy.

* If a block's DAA score is smaller than half a year, it should have a base subsidy.

* Fix merge errors.

* Fix more merge errors.

* Add DeflationaryPhaseBaseSubsidy to the params.

* Implement TestCalcDeflationaryPeriodBlockSubsidy.

* Implement calcDeflationaryPeriodBlockSubsidy naively.

* Implement calcDeflationaryPeriodBlockSubsidy not naively.

* Adjust the subsidy based on target block rate.

* Fix deflationaryPhaseDaaScore in TestCalcDeflationaryPeriodBlockSubsidy.

* Explain how secondsPerMonth is calculated.

* Don't adjust the subsidy based on the target block rate.

* Update defaultDeflationaryPhaseDaaScore and add an explanation.

* Use a pre-calculated table for subsidy per month

* Make the generation function fail if base subsidy is changed

* go fmt

* Use test logger for printing + simplify print loop

Co-authored-by: msutton <mikisiton2@gmail.com>
Co-authored-by: Ori Newman <orinewman1@gmail.com>

domain/consensus/factory.go

@@ -203,14 +203,11 @@ func (f *factory) NewConsensus(config *Config, db infrastructuredatabase.Databas
 	coinbaseManager := coinbasemanager.New(
 		dbManager,
 		config.SubsidyGenesisReward,
-		config.MinSubsidy,
+		config.PreDeflationaryPhaseBaseSubsidy,
-		config.MaxSubsidy,
-		config.SubsidyPastRewardMultiplier,
-		config.SubsidyMergeSetRewardMultiplier,
 		config.CoinbasePayloadScriptPublicKeyMaxLength,
 		config.GenesisHash,
-		config.FixedSubsidySwitchPruningPointInterval,
+		config.DeflationaryPhaseDaaScore,
-		config.FixedSubsidySwitchHashRateThreshold,
+		config.DeflationaryPhaseBaseSubsidy,
 		dagTraversalManager,
 		ghostdagDataStore,
 		acceptanceDataStore,

domain/consensus/model/interface_processes_coinbasemanager.go

@@ -7,6 +7,6 @@ import "github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
 type CoinbaseManager interface {
 	ExpectedCoinbaseTransaction(stagingArea *StagingArea, blockHash *externalapi.DomainHash,
 		coinbaseData *externalapi.DomainCoinbaseData) (*externalapi.DomainTransaction, error)
-	CalcBlockSubsidy(blockHash *externalapi.DomainHash) (uint64, error)
+	CalcBlockSubsidy(stagingArea *StagingArea, blockHash *externalapi.DomainHash) (uint64, error)
 	ExtractCoinbaseDataBlueScoreAndSubsidy(coinbaseTx *externalapi.DomainTransaction) (blueScore uint64, coinbaseData *externalapi.DomainCoinbaseData, subsidy uint64, err error)
 }

domain/consensus/processes/blockvalidator/block_body_in_context.go

@@ -178,7 +178,7 @@ func (v *blockValidator) checkCoinbaseSubsidy(
 		return err
 	}
 
-	expectedSubsidy, err := v.coinbaseManager.CalcBlockSubsidy(blockHash)
+	expectedSubsidy, err := v.coinbaseManager.CalcBlockSubsidy(stagingArea, blockHash)
 	if err != nil {
 		return err
 	}

domain/consensus/processes/coinbasemanager/block_reward_switch.go

@@ -1,86 +0,0 @@
-package coinbasemanager
-
-import (
-	"github.com/kaspanet/kaspad/domain/consensus/model"
-	"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
-	"math/big"
-)
-
-func (c *coinbaseManager) isBlockRewardFixed(stagingArea *model.StagingArea, blockPruningPoint *externalapi.DomainHash) (bool, error) {
-	blockPruningPointIndex, found, err := c.findPruningPointIndex(stagingArea, blockPruningPoint)
-	if err != nil {
-		return false, err
-	}
-
-	// The given `pruningPointBlock` may only not be found under one circumstance:
-	// we're currently in the process of building the next pruning point. As such,
-	// we must manually set highIndex to currentIndex + 1 because the next pruning
-	// point is not yet stored in the database
-	highPruningPointIndex := blockPruningPointIndex
-	highPruningPointHash := blockPruningPoint
-	if !found {
-		currentPruningPointIndex, err := c.pruningStore.CurrentPruningPointIndex(c.databaseContext, stagingArea)
-		if err != nil {
-			return false, err
-		}
-		highPruningPointIndex = currentPruningPointIndex + 1
-	}
-
-	for {
-		if highPruningPointIndex <= c.fixedSubsidySwitchPruningPointInterval {
-			break
-		}
-
-		lowPruningPointIndex := highPruningPointIndex - c.fixedSubsidySwitchPruningPointInterval
-		lowPruningPointHash, err := c.pruningStore.PruningPointByIndex(c.databaseContext, stagingArea, lowPruningPointIndex)
-		if err != nil {
-			return false, err
-		}
-
-		highPruningPointHeader, err := c.blockHeaderStore.BlockHeader(c.databaseContext, stagingArea, highPruningPointHash)
-		if err != nil {
-			return false, err
-		}
-		lowPruningPointHeader, err := c.blockHeaderStore.BlockHeader(c.databaseContext, stagingArea, lowPruningPointHash)
-		if err != nil {
-			return false, err
-		}
-
-		blueWorkDifference := new(big.Int).Sub(highPruningPointHeader.BlueWork(), lowPruningPointHeader.BlueWork())
-		blueScoreDifference := new(big.Int).SetUint64(highPruningPointHeader.BlueScore() - lowPruningPointHeader.BlueScore())
-		estimatedAverageHashRate := new(big.Int).Div(blueWorkDifference, blueScoreDifference)
-		if estimatedAverageHashRate.Cmp(c.fixedSubsidySwitchHashRateThreshold) >= 0 {
-			return true, nil
-		}
-
-		highPruningPointIndex--
-		highPruningPointHash, err = c.pruningStore.PruningPointByIndex(c.databaseContext, stagingArea, highPruningPointIndex)
-		if err != nil {
-			return false, err
-		}
-	}
-
-	return false, nil
-}
-
-func (c *coinbaseManager) findPruningPointIndex(stagingArea *model.StagingArea, pruningPointHash *externalapi.DomainHash) (uint64, bool, error) {
-	currentPruningPointHash, err := c.pruningStore.PruningPoint(c.databaseContext, stagingArea)
-	if err != nil {
-		return 0, false, err
-	}
-	currentPruningPointIndex, err := c.pruningStore.CurrentPruningPointIndex(c.databaseContext, stagingArea)
-	if err != nil {
-		return 0, false, err
-	}
-	for !currentPruningPointHash.Equal(pruningPointHash) && currentPruningPointIndex > 0 {
-		currentPruningPointIndex--
-		currentPruningPointHash, err = c.pruningStore.PruningPointByIndex(c.databaseContext, stagingArea, currentPruningPointIndex)
-		if err != nil {
-			return 0, false, err
-		}
-	}
-	if currentPruningPointIndex == 0 && !currentPruningPointHash.Equal(pruningPointHash) {
-		return 0, false, nil
-	}
-	return currentPruningPointIndex, true, nil
-}

domain/consensus/processes/coinbasemanager/block_reward_switch_test.go

@@ -1,90 +0,0 @@
-package coinbasemanager_test
-
-import (
-	"github.com/kaspanet/kaspad/domain/consensus"
-	"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
-	"github.com/kaspanet/kaspad/domain/consensus/utils/consensushashing"
-	"github.com/kaspanet/kaspad/domain/consensus/utils/constants"
-	"github.com/kaspanet/kaspad/domain/consensus/utils/testutils"
-	"github.com/kaspanet/kaspad/domain/consensus/utils/transactionhelper"
-	"github.com/kaspanet/kaspad/util/difficulty"
-	"testing"
-	"time"
-)
-
-func TestBlockRewardSwitch(t *testing.T) {
-	testutils.ForAllNets(t, true, func(t *testing.T, consensusConfig *consensus.Config) {
-		// Set the pruning depth to 10
-		consensusConfig.MergeSetSizeLimit = 1
-		consensusConfig.K = 1
-		consensusConfig.FinalityDuration = 1 * time.Second
-		consensusConfig.TargetTimePerBlock = 1 * time.Second
-
-		// Disable difficulty adjustment so that we could reason about blue work
-		consensusConfig.DisableDifficultyAdjustment = true
-
-		// Disable pruning so that we could have access to all the blocks
-		consensusConfig.IsArchival = true
-
-		// Set the interval to 10
-		consensusConfig.FixedSubsidySwitchPruningPointInterval = 10
-
-		// Set the hash rate difference such that the switch would trigger exactly
-		// on the `FixedSubsidySwitchPruningPointInterval + 1`th pruning point
-		workToAcceptGenesis := difficulty.CalcWork(consensusConfig.GenesisBlock.Header.Bits())
-		consensusConfig.FixedSubsidySwitchHashRateThreshold = workToAcceptGenesis
-
-		// Set the min, max, and post-switch subsidies to values that would make it
-		// easy to tell whether the switch happened
-		consensusConfig.MinSubsidy = 2 * constants.SompiPerKaspa
-		consensusConfig.MaxSubsidy = 2 * constants.SompiPerKaspa
-		consensusConfig.SubsidyGenesisReward = 1 * constants.SompiPerKaspa
-
-		factory := consensus.NewFactory()
-		tc, teardown, err := factory.NewTestConsensus(consensusConfig, "TestBlockRewardSwitch")
-		if err != nil {
-			t.Fatalf("Error setting up consensus: %+v", err)
-		}
-		defer teardown(false)
-
-		// Make the pruning point move FixedSubsidySwitchPruningPointInterval times
-		tipHash := consensusConfig.GenesisHash
-		for i := uint64(0); i < consensusConfig.PruningDepth()+consensusConfig.FixedSubsidySwitchPruningPointInterval; i++ {
-			addedBlockHash, _, err := tc.AddBlock([]*externalapi.DomainHash{tipHash}, nil, nil)
-			if err != nil {
-				t.Fatalf("AddBlock: %+v", err)
-			}
-			tipHash = addedBlockHash
-		}
-
-		// We expect to see `FixedSubsidySwitchPruningPointInterval` pruning points + the genesis
-		pruningPointHeaders, err := tc.PruningPointHeaders()
-		if err != nil {
-			t.Fatalf("PruningPointHeaders: %+v", pruningPointHeaders)
-		}
-		expectedPruningPointHeaderAmount := consensusConfig.FixedSubsidySwitchPruningPointInterval + 1
-		if uint64(len(pruningPointHeaders)) != expectedPruningPointHeaderAmount {
-			t.Fatalf("Unexpected amount of pruning point headers. "+
-				"Want: %d, got: %d", expectedPruningPointHeaderAmount, len(pruningPointHeaders))
-		}
-
-		// Make sure that all the headers thus far had a non-fixed subsidies
-		// Note that we skip the genesis, since that always has the post-switch
-		// value
-		for _, pruningPointHeader := range pruningPointHeaders[1:] {
-			pruningPointHash := consensushashing.HeaderHash(pruningPointHeader)
-			pruningPoint, err := tc.GetBlock(pruningPointHash)
-			if err != nil {
-				t.Fatalf("GetBlock: %+v", err)
-			}
-			pruningPointCoinbase := pruningPoint.Transactions[transactionhelper.CoinbaseTransactionIndex]
-			_, _, subsidy, err := tc.CoinbaseManager().ExtractCoinbaseDataBlueScoreAndSubsidy(pruningPointCoinbase)
-			if err != nil {
-				t.Fatalf("ExtractCoinbaseDataBlueScoreAndSubsidy: %+v", err)
-			}
-			if subsidy != consensusConfig.MinSubsidy {
-				t.Fatalf("Subsidy has unexpected value. Want: %d, got: %d", consensusConfig.MinSubsidy, subsidy)
-			}
-		}
-	})
-}

domain/consensus/processes/coinbasemanager/coinbasemanager.go

@@ -1,9 +1,6 @@
 package coinbasemanager
 
 import (
-	"encoding/binary"
-	"math/big"
-
 	"github.com/kaspanet/kaspad/domain/consensus/model"
 	"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
 	"github.com/kaspanet/kaspad/domain/consensus/utils/constants"
@@ -12,18 +9,16 @@ import (
 	"github.com/kaspanet/kaspad/domain/consensus/utils/transactionhelper"
 	"github.com/kaspanet/kaspad/infrastructure/db/database"
 	"github.com/pkg/errors"
+	"math"
 )
 
 type coinbaseManager struct {
 	subsidyGenesisReward                    uint64
-	minSubsidy                              uint64
+	preDeflationaryPhaseBaseSubsidy         uint64
-	maxSubsidy                              uint64
-	subsidyPastRewardMultiplier             *big.Rat
-	subsidyMergeSetRewardMultiplier         *big.Rat
 	coinbasePayloadScriptPublicKeyMaxLength uint8
 	genesisHash                             *externalapi.DomainHash
-	fixedSubsidySwitchPruningPointInterval  uint64
+	deflationaryPhaseDaaScore               uint64
-	fixedSubsidySwitchHashRateThreshold     *big.Int
+	deflationaryPhaseBaseSubsidy            uint64
 
 	databaseContext     model.DBReader
 	dagTraversalManager model.DAGTraversalManager
@@ -84,7 +79,7 @@ func (c *coinbaseManager) ExpectedCoinbaseTransaction(stagingArea *model.Staging
 		txOuts = append(txOuts, txOut)
 	}
 
-	subsidy, err := c.CalcBlockSubsidy(blockHash)
+	subsidy, err := c.CalcBlockSubsidy(stagingArea, blockHash)
 	if err != nil {
 		return nil, err
 	}
@@ -182,97 +177,68 @@ func acceptanceDataFromArrayToMap(acceptanceData externalapi.AcceptanceData) map
 // should have. This is mainly used for determining how much the coinbase for
 // newly generated blocks awards as well as validating the coinbase for blocks
 // has the expected value.
-//
+func (c *coinbaseManager) CalcBlockSubsidy(stagingArea *model.StagingArea, blockHash *externalapi.DomainHash) (uint64, error) {
-// Further details: https://hashdag.medium.com/kaspa-launch-plan-9a63f4d754a6
-func (c *coinbaseManager) CalcBlockSubsidy(blockHash *externalapi.DomainHash) (uint64, error) {
 	if blockHash.Equal(c.genesisHash) {
 		return c.subsidyGenesisReward, nil
 	}
-
+	blockDaaScore, err := c.daaBlocksStore.DAAScore(c.databaseContext, stagingArea, blockHash)
-	return c.maxSubsidy, nil
-}
-
-func (c *coinbaseManager) calculateAveragePastSubsidy(stagingArea *model.StagingArea, blockHash *externalapi.DomainHash) (*big.Rat, error) {
-	const subsidyPastWindowSize = 100
-	blockWindow, err := c.dagTraversalManager.BlockWindow(stagingArea, blockHash, subsidyPastWindowSize)
-	if err != nil {
-		return nil, err
-	}
-	if len(blockWindow) == 0 {
-		return new(big.Rat).SetFrac64(int64(c.subsidyGenesisReward), 1), nil
-	}
-
-	pastBlocks, err := c.blockStore.Blocks(c.databaseContext, stagingArea, blockWindow)
-	if err != nil {
-		return nil, err
-	}
-
-	pastBlockSubsidySum := int64(0)
-	for _, pastBlock := range pastBlocks {
-		coinbaseTransaction := pastBlock.Transactions[transactionhelper.CoinbaseTransactionIndex]
-		_, _, pastBlockSubsidy, err := c.ExtractCoinbaseDataBlueScoreAndSubsidy(coinbaseTransaction)
-		if err != nil {
-			return nil, err
-		}
-		pastBlockSubsidySum += int64(pastBlockSubsidy)
-	}
-	return big.NewRat(pastBlockSubsidySum, int64(len(blockWindow))), nil
-}
-
-func (c *coinbaseManager) calculateMergeSetSubsidySum(stagingArea *model.StagingArea, blockHash *externalapi.DomainHash) (*big.Rat, error) {
-	ghostdagData, err := c.ghostdagDataStore.Get(c.databaseContext, stagingArea, blockHash, true)
-	if !database.IsNotFoundError(err) && err != nil {
-		return nil, err
-	}
-
-	// If there's ghostdag data with trusted data we prefer it because we need the original merge set non-pruned merge set.
-	if database.IsNotFoundError(err) {
-		ghostdagData, err = c.ghostdagDataStore.Get(c.databaseContext, stagingArea, blockHash, false)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	mergeSet := append(ghostdagData.MergeSetBlues(), ghostdagData.MergeSetReds()...)
-	mergeSetBlocks, err := c.blockStore.Blocks(c.databaseContext, stagingArea, mergeSet)
-	if err != nil {
-		return nil, err
-	}
-
-	mergeSetSubsidySum := int64(0)
-	for _, mergeSetBlock := range mergeSetBlocks {
-		coinbaseTransaction := mergeSetBlock.Transactions[transactionhelper.CoinbaseTransactionIndex]
-		_, _, mergeSetBlockSubsidy, err := c.ExtractCoinbaseDataBlueScoreAndSubsidy(coinbaseTransaction)
-		if err != nil {
-			return nil, err
-		}
-		mergeSetSubsidySum += int64(mergeSetBlockSubsidy)
-	}
-	return big.NewRat(mergeSetSubsidySum, 1), nil
-}
-
-func (c *coinbaseManager) calculateSubsidyRandomVariable(stagingArea *model.StagingArea, blockHash *externalapi.DomainHash) (int64, error) {
-	ghostdagData, err := c.ghostdagDataStore.Get(c.databaseContext, stagingArea, blockHash, false)
 	if err != nil {
 		return 0, err
 	}
-	selectedParentHash := ghostdagData.SelectedParent()
+	if blockDaaScore < c.deflationaryPhaseDaaScore {
-	if selectedParentHash == nil {
+		return c.preDeflationaryPhaseBaseSubsidy, nil
-		return 0, nil
 	}
 
-	const binomialSteps = 10
+	blockSubsidy := c.calcDeflationaryPeriodBlockSubsidy(blockDaaScore)
-	binomialSum := int64(0)
+	return blockSubsidy, nil
+}
 
-	// The first two bytes of a hash are a good deterministic source
+func (c *coinbaseManager) calcDeflationaryPeriodBlockSubsidy(blockDaaScore uint64) uint64 {
-	// of randomness, so we use that instead of any rand implementation
+	// We define a year as 365.25 days and a month as 365.25 / 12 = 30.4375
-	firstTwoBytes := binary.LittleEndian.Uint16(selectedParentHash.ByteSlice()[:2])
+	// secondsPerMonth = 30.4375 * 24 * 60 * 60
-	for i := 0; i < binomialSteps; i++ {
+	const secondsPerMonth = 2629800
-		step := firstTwoBytes & 1
+	// Note that this calculation implicitly assumes that block per second = 1 (by assuming daa score diff is in second units).
-		firstTwoBytes >>= 1
+	monthsSinceDeflationaryPhaseStarted := (blockDaaScore - c.deflationaryPhaseDaaScore) / secondsPerMonth
-		binomialSum += int64(step)
+	// Return the pre-calculated value from subsidy-per-month table
+	return c.getDeflationaryPeriodBlockSubsidyFromTable(monthsSinceDeflationaryPhaseStarted)
+}
+
+/*
+	This table was pre-calculated by calling `calcDeflationaryPeriodBlockSubsidyFloatCalc` for all months until reaching 0 subsidy.
+	To regenerate this table, run `TestBuildSubsidyTable` in coinbasemanager_test.go (note the `deflationaryPhaseBaseSubsidy` therein)
+*/
+var subsidyByDeflationaryMonthTable = []uint64{
+	44000000000, 41530469757, 39199543598, 36999442271, 34922823143, 32962755691, 31112698372, 29366476791, 27718263097, 26162556530, 24694165062, 23308188075, 22000000000, 20765234878, 19599771799, 18499721135, 17461411571, 16481377845, 15556349186, 14683238395, 13859131548, 13081278265, 12347082531, 11654094037, 11000000000,
+	10382617439, 9799885899, 9249860567, 8730705785, 8240688922, 7778174593, 7341619197, 6929565774, 6540639132, 6173541265, 5827047018, 5500000000, 5191308719, 4899942949, 4624930283, 4365352892, 4120344461, 3889087296, 3670809598, 3464782887, 3270319566, 3086770632, 2913523509, 2750000000, 2595654359,
+	2449971474, 2312465141, 2182676446, 2060172230, 1944543648, 1835404799, 1732391443, 1635159783, 1543385316, 1456761754, 1375000000, 1297827179, 1224985737, 1156232570, 1091338223, 1030086115, 972271824, 917702399, 866195721, 817579891, 771692658, 728380877, 687500000, 648913589, 612492868,
+	578116285, 545669111, 515043057, 486135912, 458851199, 433097860, 408789945, 385846329, 364190438, 343750000, 324456794, 306246434, 289058142, 272834555, 257521528, 243067956, 229425599, 216548930, 204394972, 192923164, 182095219, 171875000, 162228397, 153123217, 144529071,
+	136417277, 128760764, 121533978, 114712799, 108274465, 102197486, 96461582, 91047609, 85937500, 81114198, 76561608, 72264535, 68208638, 64380382, 60766989, 57356399, 54137232, 51098743, 48230791, 45523804, 42968750, 40557099, 38280804, 36132267, 34104319,
+	32190191, 30383494, 28678199, 27068616, 25549371, 24115395, 22761902, 21484375, 20278549, 19140402, 18066133, 17052159, 16095095, 15191747, 14339099, 13534308, 12774685, 12057697, 11380951, 10742187, 10139274, 9570201, 9033066, 8526079, 8047547,
+	7595873, 7169549, 6767154, 6387342, 6028848, 5690475, 5371093, 5069637, 4785100, 4516533, 4263039, 4023773, 3797936, 3584774, 3383577, 3193671, 3014424, 2845237, 2685546, 2534818, 2392550, 2258266, 2131519, 2011886, 1898968,
+	1792387, 1691788, 1596835, 1507212, 1422618, 1342773, 1267409, 1196275, 1129133, 1065759, 1005943, 949484, 896193, 845894, 798417, 753606, 711309, 671386, 633704, 598137, 564566, 532879, 502971, 474742, 448096,
+	422947, 399208, 376803, 355654, 335693, 316852, 299068, 282283, 266439, 251485, 237371, 224048, 211473, 199604, 188401, 177827, 167846, 158426, 149534, 141141, 133219, 125742, 118685, 112024, 105736,
+	99802, 94200, 88913, 83923, 79213, 74767, 70570, 66609, 62871, 59342, 56012, 52868, 49901, 47100, 44456, 41961, 39606, 37383, 35285, 33304, 31435, 29671, 28006, 26434, 24950,
+	23550, 22228, 20980, 19803, 18691, 17642, 16652, 15717, 14835, 14003, 13217, 12475, 11775, 11114, 10490, 9901, 9345, 8821, 8326, 7858, 7417, 7001, 6608, 6237, 5887,
+	5557, 5245, 4950, 4672, 4410, 4163, 3929, 3708, 3500, 3304, 3118, 2943, 2778, 2622, 2475, 2336, 2205, 2081, 1964, 1854, 1750, 1652, 1559, 1471, 1389,
+	1311, 1237, 1168, 1102, 1040, 982, 927, 875, 826, 779, 735, 694, 655, 618, 584, 551, 520, 491, 463, 437, 413, 389, 367, 347, 327,
+	309, 292, 275, 260, 245, 231, 218, 206, 194, 183, 173, 163, 154, 146, 137, 130, 122, 115, 109, 103, 97, 91, 86, 81, 77,
+	73, 68, 65, 61, 57, 54, 51, 48, 45, 43, 40, 38, 36, 34, 32, 30, 28, 27, 25, 24, 22, 21, 20, 19, 18,
+	17, 16, 15, 14, 13, 12, 12, 11, 10, 10, 9, 9, 8, 8, 7, 7, 6, 6, 6, 5, 5, 5, 4, 4, 4,
+	4, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	0,
+}
+
+func (c *coinbaseManager) getDeflationaryPeriodBlockSubsidyFromTable(month uint64) uint64 {
+	if month >= uint64(len(subsidyByDeflationaryMonthTable)) {
+		month = uint64(len(subsidyByDeflationaryMonthTable) - 1)
 	}
-	return binomialSum - (binomialSteps / 2), nil
+	return subsidyByDeflationaryMonthTable[month]
+}
+
+func (c *coinbaseManager) calcDeflationaryPeriodBlockSubsidyFloatCalc(month uint64) uint64 {
+	baseSubsidy := c.deflationaryPhaseBaseSubsidy
+	subsidy := float64(baseSubsidy) / math.Pow(2, float64(month)/12)
+	return uint64(subsidy)
 }
 
 func (c *coinbaseManager) calcMergedBlockReward(stagingArea *model.StagingArea, blockHash *externalapi.DomainHash,
@@ -312,14 +278,11 @@ func New(
 	databaseContext model.DBReader,
 
 	subsidyGenesisReward uint64,
-	minSubsidy uint64,
+	preDeflationaryPhaseBaseSubsidy uint64,
-	maxSubsidy uint64,
-	subsidyPastRewardMultiplier *big.Rat,
-	subsidyMergeSetRewardMultiplier *big.Rat,
 	coinbasePayloadScriptPublicKeyMaxLength uint8,
 	genesisHash *externalapi.DomainHash,
-	fixedSubsidySwitchPruningPointInterval uint64,
+	deflationaryPhaseDaaScore uint64,
-	fixedSubsidySwitchHashRateThreshold *big.Int,
+	deflationaryPhaseBaseSubsidy uint64,
 
 	dagTraversalManager model.DAGTraversalManager,
 	ghostdagDataStore model.GHOSTDAGDataStore,
@@ -333,14 +296,11 @@ func New(
 		databaseContext: databaseContext,
 
 		subsidyGenesisReward:                    subsidyGenesisReward,
-		minSubsidy:                              minSubsidy,
+		preDeflationaryPhaseBaseSubsidy:         preDeflationaryPhaseBaseSubsidy,
-		maxSubsidy:                              maxSubsidy,
-		subsidyPastRewardMultiplier:             subsidyPastRewardMultiplier,
-		subsidyMergeSetRewardMultiplier:         subsidyMergeSetRewardMultiplier,
 		coinbasePayloadScriptPublicKeyMaxLength: coinbasePayloadScriptPublicKeyMaxLength,
 		genesisHash:                             genesisHash,
-		fixedSubsidySwitchPruningPointInterval:  fixedSubsidySwitchPruningPointInterval,
+		deflationaryPhaseDaaScore:               deflationaryPhaseDaaScore,
-		fixedSubsidySwitchHashRateThreshold:     fixedSubsidySwitchHashRateThreshold,
+		deflationaryPhaseBaseSubsidy:            deflationaryPhaseBaseSubsidy,
 
 		dagTraversalManager: dagTraversalManager,
 		ghostdagDataStore:   ghostdagDataStore,

domain/consensus/processes/coinbasemanager/coinbasemanager_test.go

@@ -0,0 +1,126 @@
+package coinbasemanager
+
+import (
+	"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
+	"github.com/kaspanet/kaspad/domain/consensus/utils/constants"
+	"github.com/kaspanet/kaspad/domain/dagconfig"
+	"strconv"
+	"testing"
+)
+
+func TestCalcDeflationaryPeriodBlockSubsidy(t *testing.T) {
+	const secondsPerMonth = 2629800
+	const secondsPerHalving = secondsPerMonth * 12
+	const deflationaryPhaseDaaScore = secondsPerMonth * 6
+	const deflationaryPhaseBaseSubsidy = 440 * constants.SompiPerKaspa
+	coinbaseManagerInterface := New(
+		nil,
+		0,
+		0,
+		0,
+		&externalapi.DomainHash{},
+		deflationaryPhaseDaaScore,
+		deflationaryPhaseBaseSubsidy,
+		nil,
+		nil,
+		nil,
+		nil,
+		nil,
+		nil,
+		nil)
+	coinbaseManagerInstance := coinbaseManagerInterface.(*coinbaseManager)
+
+	tests := []struct {
+		name                 string
+		blockDaaScore        uint64
+		expectedBlockSubsidy uint64
+	}{
+		{
+			name:                 "start of deflationary phase",
+			blockDaaScore:        deflationaryPhaseDaaScore,
+			expectedBlockSubsidy: deflationaryPhaseBaseSubsidy,
+		},
+		{
+			name:                 "after one halving",
+			blockDaaScore:        deflationaryPhaseDaaScore + secondsPerHalving,
+			expectedBlockSubsidy: deflationaryPhaseBaseSubsidy / 2,
+		},
+		{
+			name:                 "after two halvings",
+			blockDaaScore:        deflationaryPhaseDaaScore + secondsPerHalving*2,
+			expectedBlockSubsidy: deflationaryPhaseBaseSubsidy / 4,
+		},
+		{
+			name:                 "after five halvings",
+			blockDaaScore:        deflationaryPhaseDaaScore + secondsPerHalving*5,
+			expectedBlockSubsidy: deflationaryPhaseBaseSubsidy / 32,
+		},
+		{
+			name:                 "after 32 halvings",
+			blockDaaScore:        deflationaryPhaseDaaScore + secondsPerHalving*32,
+			expectedBlockSubsidy: deflationaryPhaseBaseSubsidy / 4294967296,
+		},
+		{
+			name:                 "just before subsidy depleted",
+			blockDaaScore:        deflationaryPhaseDaaScore + secondsPerHalving*35,
+			expectedBlockSubsidy: 1,
+		},
+		{
+			name:                 "after subsidy depleted",
+			blockDaaScore:        deflationaryPhaseDaaScore + secondsPerHalving*36,
+			expectedBlockSubsidy: 0,
+		},
+	}
+
+	for _, test := range tests {
+		blockSubsidy := coinbaseManagerInstance.calcDeflationaryPeriodBlockSubsidy(test.blockDaaScore)
+		if blockSubsidy != test.expectedBlockSubsidy {
+			t.Errorf("TestCalcDeflationaryPeriodBlockSubsidy: test '%s' failed. Want: %d, got: %d",
+				test.name, test.expectedBlockSubsidy, blockSubsidy)
+		}
+	}
+}
+
+func TestBuildSubsidyTable(t *testing.T) {
+	deflationaryPhaseBaseSubsidy := dagconfig.MainnetParams.DeflationaryPhaseBaseSubsidy
+	if deflationaryPhaseBaseSubsidy != 440*constants.SompiPerKaspa {
+		t.Errorf("TestBuildSubsidyTable: table generation function was not updated to reflect "+
+			"the new base subsidy %d. Please fix the constant above and replace subsidyByDeflationaryMonthTable "+
+			"in coinbasemanager.go with the printed table", deflationaryPhaseBaseSubsidy)
+	}
+	coinbaseManagerInterface := New(
+		nil,
+		0,
+		0,
+		0,
+		&externalapi.DomainHash{},
+		0,
+		deflationaryPhaseBaseSubsidy,
+		nil,
+		nil,
+		nil,
+		nil,
+		nil,
+		nil,
+		nil)
+	coinbaseManagerInstance := coinbaseManagerInterface.(*coinbaseManager)
+
+	var subsidyTable []uint64
+	for M := uint64(0); ; M++ {
+		subsidy := coinbaseManagerInstance.calcDeflationaryPeriodBlockSubsidyFloatCalc(M)
+		subsidyTable = append(subsidyTable, subsidy)
+		if subsidy == 0 {
+			break
+		}
+	}
+
+	tableStr := "\n{\t"
+	for i := 0; i < len(subsidyTable); i++ {
+		tableStr += strconv.FormatUint(subsidyTable[i], 10) + ", "
+		if (i+1)%25 == 0 {
+			tableStr += "\n\t"
+		}
+	}
+	tableStr += "\n}"
+	t.Logf(tableStr)
+}

domain/dagconfig/consensus_defaults.go

@@ -46,13 +46,11 @@ const (
 	// Should be at least an order of magnitude smaller than defaultFinalityDuration/defaultTargetTimePerBlock.
 	// (Higher values make pruning attacks easier by a constant, lower values make merging after a split or a spike
 	// in block take longer)
-	defaultMergeSetSizeLimit                              = defaultGHOSTDAGK * 10
+	defaultMergeSetSizeLimit                       = defaultGHOSTDAGK * 10
-	defaultSubsidyGenesisReward                           = 1 * constants.SompiPerKaspa
+	defaultSubsidyGenesisReward                    = 1 * constants.SompiPerKaspa
-	defaultMinSubsidy                                     = 1 * constants.SompiPerKaspa
+	defaultPreDeflationaryPhaseBaseSubsidy         = 500 * constants.SompiPerKaspa
-	defaultMaxSubsidy                                     = 500 * constants.SompiPerKaspa
+	defaultDeflationaryPhaseBaseSubsidy            = 440 * constants.SompiPerKaspa
-	defaultBaseSubsidy                                    = 50 * constants.SompiPerKaspa
+	defaultCoinbasePayloadScriptPublicKeyMaxLength = 150
-	defaultFixedSubsidySwitchPruningPointInterval  uint64 = 7
-	defaultCoinbasePayloadScriptPublicKeyMaxLength        = 150
 	// defaultDifficultyAdjustmentWindowSize is the number of blocks in a block's past used to calculate its difficulty
 	// target.
 	// The DAA should take the median of 2640 blocks, so in order to do that we need 2641 window size.
@@ -76,4 +74,12 @@ const (
 	defaultTargetTimePerBlock = 1 * time.Second
 
 	defaultPruningProofM = 1000
+
+	// defaultDeflationaryPhaseDaaScore is the DAA score after which the pre-deflationary period
+	// switches to the deflationary period. This number is calculated as follows:
+	// We define a year as 365.25 days
+	// Half a year in seconds = 365.25 / 2 * 24 * 60 * 60 = 15778800
+	// The network was down for three days shortly after launch
+	// Three days in seconds = 3 * 24 * 60 * 60 = 259200
+	defaultDeflationaryPhaseDaaScore = 15778800 - 259200
 )

domain/dagconfig/params.go

@@ -92,10 +92,8 @@ type Params struct {
 	// SubsidyPastRewardMultiplier are part of the block subsidy equation.
 	// Further details: https://hashdag.medium.com/kaspa-launch-plan-9a63f4d754a6
 	SubsidyGenesisReward            uint64
-	MinSubsidy                      uint64
+	PreDeflationaryPhaseBaseSubsidy uint64
-	MaxSubsidy                      uint64
+	DeflationaryPhaseBaseSubsidy    uint64
-	SubsidyPastRewardMultiplier     *big.Rat
-	SubsidyMergeSetRewardMultiplier *big.Rat
 
 	// TargetTimePerBlock is the desired amount of time to generate each
 	// block.
@@ -180,12 +178,9 @@ type Params struct {
 	// PruningProofM is the 'm' constant in the pruning proof. For more details see: https://github.com/kaspanet/research/issues/3
 	PruningProofM uint64
 
-	// BaseSubsidy is the starting subsidy amount for mined blocks.
+	// DeflationaryPhaseDaaScore is the DAA score after which the monetary policy switches
-	BaseSubsidy uint64
+	// to its deflationary phase
-
+	DeflationaryPhaseDaaScore uint64
-	FixedSubsidySwitchPruningPointInterval uint64
-
-	FixedSubsidySwitchHashRateThreshold *big.Int
 
 	DisallowDirectBlocksOnTopOfGenesis bool
 
@@ -243,10 +238,8 @@ var MainnetParams = Params{
 	PowMax:                          mainPowMax,
 	BlockCoinbaseMaturity:           100,
 	SubsidyGenesisReward:            defaultSubsidyGenesisReward,
-	MinSubsidy:                      defaultMinSubsidy,
+	PreDeflationaryPhaseBaseSubsidy: defaultPreDeflationaryPhaseBaseSubsidy,
-	MaxSubsidy:                      defaultMaxSubsidy,
+	DeflationaryPhaseBaseSubsidy:    defaultDeflationaryPhaseBaseSubsidy,
-	SubsidyPastRewardMultiplier:     big.NewRat(9, 10),
-	SubsidyMergeSetRewardMultiplier: big.NewRat(1, 10),
 	TargetTimePerBlock:              defaultTargetTimePerBlock,
 	FinalityDuration:                defaultFinalityDuration,
 	DifficultyAdjustmentWindowSize:  defaultDifficultyAdjustmentWindowSize,
@@ -286,8 +279,7 @@ var MainnetParams = Params{
 	MergeSetSizeLimit:                       defaultMergeSetSizeLimit,
 	CoinbasePayloadScriptPublicKeyMaxLength: defaultCoinbasePayloadScriptPublicKeyMaxLength,
 	PruningProofM:                           defaultPruningProofM,
-	FixedSubsidySwitchPruningPointInterval:  defaultFixedSubsidySwitchPruningPointInterval,
+	DeflationaryPhaseDaaScore:               defaultDeflationaryPhaseDaaScore,
-	FixedSubsidySwitchHashRateThreshold:     big.NewInt(150_000_000_000),
 	DisallowDirectBlocksOnTopOfGenesis:      true,
 }
 
@@ -306,10 +298,8 @@ var TestnetParams = Params{
 	PowMax:                          testnetPowMax,
 	BlockCoinbaseMaturity:           100,
 	SubsidyGenesisReward:            defaultSubsidyGenesisReward,
-	MinSubsidy:                      defaultMinSubsidy,
+	PreDeflationaryPhaseBaseSubsidy: defaultPreDeflationaryPhaseBaseSubsidy,
-	MaxSubsidy:                      defaultMaxSubsidy,
+	DeflationaryPhaseBaseSubsidy:    defaultDeflationaryPhaseBaseSubsidy,
-	SubsidyPastRewardMultiplier:     big.NewRat(9, 10),
-	SubsidyMergeSetRewardMultiplier: big.NewRat(1, 10),
 	TargetTimePerBlock:              defaultTargetTimePerBlock,
 	FinalityDuration:                defaultFinalityDuration,
 	DifficultyAdjustmentWindowSize:  defaultDifficultyAdjustmentWindowSize,
@@ -349,8 +339,7 @@ var TestnetParams = Params{
 	MergeSetSizeLimit:                       defaultMergeSetSizeLimit,
 	CoinbasePayloadScriptPublicKeyMaxLength: defaultCoinbasePayloadScriptPublicKeyMaxLength,
 	PruningProofM:                           defaultPruningProofM,
-	FixedSubsidySwitchPruningPointInterval:  defaultFixedSubsidySwitchPruningPointInterval,
+	DeflationaryPhaseDaaScore:               defaultDeflationaryPhaseDaaScore,
-	FixedSubsidySwitchHashRateThreshold:     big.NewInt(150_000_000_000),
 	IgnoreHeaderMass:                        true,
 }
 
@@ -375,10 +364,8 @@ var SimnetParams = Params{
 	PowMax:                          simnetPowMax,
 	BlockCoinbaseMaturity:           100,
 	SubsidyGenesisReward:            defaultSubsidyGenesisReward,
-	MinSubsidy:                      defaultMinSubsidy,
+	PreDeflationaryPhaseBaseSubsidy: defaultPreDeflationaryPhaseBaseSubsidy,
-	MaxSubsidy:                      defaultMaxSubsidy,
+	DeflationaryPhaseBaseSubsidy:    defaultDeflationaryPhaseBaseSubsidy,
-	SubsidyPastRewardMultiplier:     big.NewRat(9, 10),
-	SubsidyMergeSetRewardMultiplier: big.NewRat(1, 10),
 	TargetTimePerBlock:              time.Millisecond,
 	FinalityDuration:                time.Minute,
 	DifficultyAdjustmentWindowSize:  defaultDifficultyAdjustmentWindowSize,
@@ -416,8 +403,7 @@ var SimnetParams = Params{
 	MergeSetSizeLimit:                       defaultMergeSetSizeLimit,
 	CoinbasePayloadScriptPublicKeyMaxLength: defaultCoinbasePayloadScriptPublicKeyMaxLength,
 	PruningProofM:                           defaultPruningProofM,
-	FixedSubsidySwitchPruningPointInterval:  defaultFixedSubsidySwitchPruningPointInterval,
+	DeflationaryPhaseDaaScore:               defaultDeflationaryPhaseDaaScore,
-	FixedSubsidySwitchHashRateThreshold:     big.NewInt(150_000_000_000),
 }
 
 // DevnetParams defines the network parameters for the development Kaspa network.
@@ -435,10 +421,8 @@ var DevnetParams = Params{
 	PowMax:                          devnetPowMax,
 	BlockCoinbaseMaturity:           100,
 	SubsidyGenesisReward:            defaultSubsidyGenesisReward,
-	MinSubsidy:                      defaultMinSubsidy,
+	PreDeflationaryPhaseBaseSubsidy: defaultPreDeflationaryPhaseBaseSubsidy,
-	MaxSubsidy:                      defaultMaxSubsidy,
+	DeflationaryPhaseBaseSubsidy:    defaultDeflationaryPhaseBaseSubsidy,
-	SubsidyPastRewardMultiplier:     big.NewRat(9, 10),
-	SubsidyMergeSetRewardMultiplier: big.NewRat(1, 10),
 	TargetTimePerBlock:              defaultTargetTimePerBlock,
 	FinalityDuration:                defaultFinalityDuration,
 	DifficultyAdjustmentWindowSize:  defaultDifficultyAdjustmentWindowSize,
@@ -478,8 +462,7 @@ var DevnetParams = Params{
 	MergeSetSizeLimit:                       defaultMergeSetSizeLimit,
 	CoinbasePayloadScriptPublicKeyMaxLength: defaultCoinbasePayloadScriptPublicKeyMaxLength,
 	PruningProofM:                           defaultPruningProofM,
-	FixedSubsidySwitchPruningPointInterval:  defaultFixedSubsidySwitchPruningPointInterval,
+	DeflationaryPhaseDaaScore:               defaultDeflationaryPhaseDaaScore,
-	FixedSubsidySwitchHashRateThreshold:     big.NewInt(150_000_000_000),
 	IgnoreHeaderMass:                        true,
 }