Add fixedSize option to ABLA config and modify net params (gcash#553)

* Add fixedSize option to ABLA config

* Modify testnet params

* Fix linter issue

* Modify TestNet4Params

Author: OPReturnCode

blockchain/abla_ewma_elastic_buffer.go

@@ -94,18 +94,26 @@ type ABLAConfig struct {
 	epsilonMax uint64
 	// Maximum elastic buffer size value
 	betaMax uint64
+	// If true, it means we have a flat block size limit so epsilonMax and betaMax must equal epsilon0 and beta0
+	fixedSize bool
 }
 
 // Set epsilonMax and betaMax such that algo's internal arithmetic ops can't overflow UINT64_MAX
 func (config *ABLAConfig) SetMax() {
-	maxSafeBlocksizeLimit := UINT64_MAX / config.zetaXB7 * B7
+	if !config.fixedSize {
+		maxSafeBlocksizeLimit := UINT64_MAX / config.zetaXB7 * B7
 
-	// elastic_buffer_ratio_max = (delta * gamma / theta * (zeta - 1)) / (gamma / theta * (zeta - 1) + 1)
-	maxElasticBufferRatioNumerator := config.delta * ((config.zetaXB7 - B7) * config.thetaReciprocal / config.gammaReciprocal)
-	maxElasticBufferRatioDenominator := (config.zetaXB7-B7)*config.thetaReciprocal/config.gammaReciprocal + B7
+		// elastic_buffer_ratio_max = (delta * gamma / theta * (zeta - 1)) / (gamma / theta * (zeta - 1) + 1)
+		maxElasticBufferRatioNumerator := config.delta * ((config.zetaXB7 - B7) * config.thetaReciprocal / config.gammaReciprocal)
+		maxElasticBufferRatioDenominator := (config.zetaXB7-B7)*config.thetaReciprocal/config.gammaReciprocal + B7
 
-	config.epsilonMax = maxSafeBlocksizeLimit / (maxElasticBufferRatioNumerator + maxElasticBufferRatioDenominator) * maxElasticBufferRatioDenominator
-	config.betaMax = maxSafeBlocksizeLimit - config.epsilonMax
+		config.epsilonMax = maxSafeBlocksizeLimit / (maxElasticBufferRatioNumerator + maxElasticBufferRatioDenominator) * maxElasticBufferRatioDenominator
+		config.betaMax = maxSafeBlocksizeLimit - config.epsilonMax
+	} else {
+		// we have a flat limit
+		config.epsilonMax = config.epsilon0
+		config.betaMax = config.beta0
+	}
 
 	fmt.Fprintf(os.Stderr, "[INFO] Auto-configured epsilonMax: %d, betaMax: %d\n", config.epsilonMax, config.betaMax)
 }

blockchain/abla_ewma_elastic_buffer_test.go

@@ -113,6 +113,7 @@ func TestABLA(t *testing.T) {
 			zetaXB7:         testData.ABLAConfig.Zeta,
 			thetaReciprocal: testData.ABLAConfig.ThetaReciprocal,
 			delta:           testData.ABLAConfig.Delta,
+			fixedSize:       false,
 		}
 		ablaConfig.SetMax()
 

blockchain/chain.go

@@ -2296,6 +2296,7 @@ func New(config *Config) (*BlockChain, error) {
 		zetaXB7:         params.ABLAConfig.ZetaXB7,
 		thetaReciprocal: params.ABLAConfig.ThetaReciprocal,
 		delta:           params.ABLAConfig.Delta,
+		fixedSize:       params.ABLAConfig.FixedSize,
 	}
 	if uint64(config.ExcessiveBlockSize) > ablaConfig.beta0 && ablaConfig.beta0 > 0 {
 		ablaConfig.epsilon0 = uint64(config.ExcessiveBlockSize) - ablaConfig.beta0

chaincfg/params.go

@@ -109,6 +109,7 @@ type ABLAConstants struct {
 	ZetaXB7         uint64
 	ThetaReciprocal uint64
 	Delta           uint64
+	FixedSize       bool
 }
 
 // Params defines a Bitcoin network by its parameters.  These parameters may be
@@ -315,6 +316,7 @@ var MainNetParams = Params{
 		ZetaXB7:         192,
 		ThetaReciprocal: 37938,
 		Delta:           10,
+		FixedSize:       false,
 	},
 
 	CoinbaseMaturity:                     100,
@@ -495,6 +497,7 @@ var RegressionNetParams = Params{
 		ZetaXB7:         192,
 		ThetaReciprocal: 37938,
 		Delta:           10,
+		FixedSize:       true,
 	},
 
 	SubsidyReductionInterval:             150,
@@ -589,6 +592,20 @@ var TestNet3Params = Params{
 
 	CosmicInflationActivationTime: 1652616000,
 
+	Upgrade9ForkHeight: 1552787,
+	ABLAForkHeight:     1605520,
+
+	ABLAConfig: ABLAConstants{
+		Epsilon0:        16000000,
+		Beta0:           16000000,
+		N0:              845890,
+		GammaReciprocal: 37938,
+		ZetaXB7:         192,
+		ThetaReciprocal: 37938,
+		Delta:           10,
+		FixedSize:       true,
+	},
+
 	CoinbaseMaturity:                     100,
 	SubsidyReductionInterval:             210000,
 	TargetTimespan:                       time.Hour * 24 * 14, // 14 days
@@ -702,6 +719,7 @@ var ChipNetParams = Params{
 		ZetaXB7:         192,
 		ThetaReciprocal: 37938,
 		Delta:           10,
+		FixedSize:       false,
 	},
 
 	CosmicInflationActivationTime: 1637694000,
@@ -797,6 +815,20 @@ var TestNet4Params = Params{
 
 	CosmicInflationActivationTime: 1637694000,
 
+	Upgrade9ForkHeight: 148043,
+	ABLAForkHeight:     200740,
+
+	ABLAConfig: ABLAConstants{
+		Epsilon0:        1000000,
+		Beta0:           1000000,
+		N0:              845890,
+		GammaReciprocal: 37938,
+		ZetaXB7:         192,
+		ThetaReciprocal: 37938,
+		Delta:           10,
+		FixedSize:       true,
+	},
+
 	CoinbaseMaturity:                     100,
 	SubsidyReductionInterval:             210000,
 	TargetTimespan:                       time.Hour * 24 * 14, // 14 days
@@ -906,6 +938,7 @@ var SimNetParams = Params{
 		ZetaXB7:         192,
 		ThetaReciprocal: 37938,
 		Delta:           10,
+		FixedSize:       true,
 	},
 
 	// Checkpoints ordered from oldest to newest.