Remove duplicated one minus spread factor calculations (#8040)

(cherry picked from commit 670efe0)

x/concentrated-liquidity/swapstrategy/export_test.go

@@ -3,9 +3,12 @@ package swapstrategy
 import "github.com/osmosis-labs/osmosis/osmomath"
 
 func ComputeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget bool, amountIn, amountSpecifiedRemaining, spreadFactor osmomath.Dec) osmomath.Dec {
-	return computeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget, amountIn, amountSpecifiedRemaining, spreadFactor)
+	oneMinusSpreadFactorGetter := func() osmomath.Dec {
+		return osmomath.OneDec().Sub(spreadFactor)
+	}
+	return computeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget, amountIn, amountSpecifiedRemaining, spreadFactor, oneMinusSpreadFactorGetter)
 }
 
 func ComputeSpreadRewardChargeFromAmountIn(amountIn, spreadFactor osmomath.Dec) osmomath.Dec {
-	return computeSpreadRewardChargeFromAmountIn(amountIn, spreadFactor)
+	return computeSpreadRewardChargeFromAmountIn(amountIn, spreadFactor, oneDec.Sub(spreadFactor))
 }

x/concentrated-liquidity/swapstrategy/one_for_zero.go

@@ -24,6 +24,9 @@ type oneForZeroStrategy struct {
 	sqrtPriceLimit osmomath.BigDec
 	storeKey       storetypes.StoreKey
 	spreadFactor   osmomath.Dec
+
+	// oneMinusSpreadFactor is 1 - spreadFactor
+	oneMinusSpreadFactor osmomath.Dec
 }
 
 var _ SwapStrategy = (*oneForZeroStrategy)(nil)
@@ -64,7 +67,7 @@ func (s oneForZeroStrategy) ComputeSwapWithinBucketOutGivenIn(sqrtPriceCurrent,
 	amountOneIn := math.CalcAmount1Delta(liquidity, sqrtPriceTarget, sqrtPriceCurrent, true)
 
 	// Calculate sqrtPriceNext on the amount of token remaining after spread reward.
-	oneMinusTakerFee := oneDec.Sub(s.spreadFactor)
+	oneMinusTakerFee := s.getOneMinusSpreadFactor()
 	amountOneInRemainingLessSpreadReward := osmomath.NewBigDecFromDecMulDec(amountOneInRemaining, oneMinusTakerFee)
 
 	var sqrtPriceNext osmomath.BigDec
@@ -94,7 +97,7 @@ func (s oneForZeroStrategy) ComputeSwapWithinBucketOutGivenIn(sqrtPriceCurrent,
 
 	// Handle spread rewards.
 	// Note that spread reward is always charged on the amount in.
-	spreadRewardChargeTotal := computeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget, amountInDecFinal, amountOneInRemaining, s.spreadFactor)
+	spreadRewardChargeTotal := computeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget, amountInDecFinal, amountOneInRemaining, s.spreadFactor, s.getOneMinusSpreadFactor)
 
 	// Round down amount out to give user less in pool's favor.
 	return sqrtPriceNext, amountInDecFinal, amountZeroOut.Dec(), spreadRewardChargeTotal
@@ -159,7 +162,7 @@ func (s oneForZeroStrategy) ComputeSwapWithinBucketInGivenOut(sqrtPriceCurrent,
 
 	// Handle spread rewards.
 	// Note that spread reward is always charged on the amount in.
-	spreadRewardChargeTotal := computeSpreadRewardChargeFromAmountIn(amountOneInFinal, s.spreadFactor)
+	spreadRewardChargeTotal := computeSpreadRewardChargeFromAmountIn(amountOneInFinal, s.spreadFactor, s.getOneMinusSpreadFactor())
 
 	// Cap the output amount to not exceed the remaining output amount.
 	// The reason why we must do this for in given out and NOT out given in is the following:
@@ -180,6 +183,13 @@ func (s oneForZeroStrategy) ComputeSwapWithinBucketInGivenOut(sqrtPriceCurrent,
 	return sqrtPriceNext, amountZeroOut.Dec(), amountOneInFinal, spreadRewardChargeTotal
 }
 
+func (s oneForZeroStrategy) getOneMinusSpreadFactor() osmomath.Dec {
+	if s.oneMinusSpreadFactor.IsNil() {
+		s.oneMinusSpreadFactor = oneDec.Sub(s.spreadFactor)
+	}
+	return s.oneMinusSpreadFactor
+}
+
 // InitializeNextTickIterator returns iterator that seeks to the next tick from the given tickIndex.
 // In one for zero direction, the search is EXCLUSIVE of the current tick index.
 // If next tick relative to currentTickIndex is not initialized (does not exist in the store),

x/concentrated-liquidity/swapstrategy/spread_rewards.go

@@ -6,6 +6,8 @@ import (
 	"github.com/osmosis-labs/osmosis/osmomath"
 )
 
+type oneMinusSpreadFactorGetter func() osmomath.Dec
+
 // computeSpreadRewardChargePerSwapStepOutGivenIn returns the total spread factor charge per swap step given the parameters.
 // Assumes swapping for token out given token in.
 //
@@ -22,7 +24,7 @@ import (
 //
 // If spread factor is negative, it panics.
 // If spread factor is 0, returns 0. Otherwise, computes and returns the spread factor charge per step.
-func computeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget bool, amountIn, amountSpecifiedRemaining, spreadFactor osmomath.Dec) osmomath.Dec {
+func computeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget bool, amountIn, amountSpecifiedRemaining, spreadFactor osmomath.Dec, oneMinSf oneMinusSpreadFactorGetter) osmomath.Dec {
 	if spreadFactor.IsZero() {
 		return osmomath.ZeroDec()
 	} else if spreadFactor.IsNegative() {
@@ -37,7 +39,7 @@ func computeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget bool, amoun
 		// 2) or sqrtPriceLimit is reached
 		// In both cases, we charge the spread factor on the amount in actually consumed before
 		// hitting the target.
-		spreadRewardChargeTotal = computeSpreadRewardChargeFromAmountIn(amountIn, spreadFactor)
+		spreadRewardChargeTotal = computeSpreadRewardChargeFromAmountIn(amountIn, spreadFactor, oneMinSf())
 	} else {
 		// Otherwise, the current tick had enough liquidity to fulfill the swap
 		// and we ran out of amount remaining before reaching either the next tick or the limit.
@@ -59,6 +61,6 @@ func computeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget bool, amoun
 // at precision end. This is necessary to ensure that the spread factor charge is always
 // rounded in favor of the pool.
 // TODO: Change this fn to take in 1 - spreadFactor as it should already have been computed.
-func computeSpreadRewardChargeFromAmountIn(amountIn osmomath.Dec, spreadFactor osmomath.Dec) osmomath.Dec {
-	return amountIn.MulRoundUp(spreadFactor).QuoRoundupMut(osmomath.OneDec().SubMut(spreadFactor))
+func computeSpreadRewardChargeFromAmountIn(amountIn osmomath.Dec, spreadFactor, oneMinusSpreadFactor osmomath.Dec) osmomath.Dec {
+	return amountIn.MulRoundUp(spreadFactor).QuoRoundupMut(oneMinusSpreadFactor)
 }

x/concentrated-liquidity/swapstrategy/zero_for_one.go

@@ -24,6 +24,9 @@ type zeroForOneStrategy struct {
 	sqrtPriceLimit osmomath.BigDec
 	storeKey       storetypes.StoreKey
 	spreadFactor   osmomath.Dec
+
+	// oneMinusSpreadFactor is 1 - spreadFactor
+	oneMinusSpreadFactor osmomath.Dec
 }
 
 var _ SwapStrategy = (*zeroForOneStrategy)(nil)
@@ -66,7 +69,7 @@ func (s zeroForOneStrategy) ComputeSwapWithinBucketOutGivenIn(sqrtPriceCurrent,
 	amountZeroIn := math.CalcAmount0Delta(liquidity, sqrtPriceTarget, sqrtPriceCurrent, true) // N.B.: if this is false, causes infinite loop
 
 	// Calculate sqrtPriceNext on the amount of token remaining after spread reward.
-	oneMinusTakerFee := oneDec.Sub(s.spreadFactor)
+	oneMinusTakerFee := s.getOneMinusSpreadFactor()
 	amountZeroInRemainingLessSpreadReward := osmomath.NewBigDecFromDecMulDec(amountZeroInRemaining, oneMinusTakerFee)
 
 	var sqrtPriceNext osmomath.BigDec
@@ -96,7 +99,7 @@ func (s zeroForOneStrategy) ComputeSwapWithinBucketOutGivenIn(sqrtPriceCurrent,
 
 	// Handle spread rewards.
 	// Note that spread reward is always charged on the amount in.
-	spreadRewardChargeTotal := computeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget, amountZeroInFinal, amountZeroInRemaining, s.spreadFactor)
+	spreadRewardChargeTotal := computeSpreadRewardChargePerSwapStepOutGivenIn(hasReachedTarget, amountZeroInFinal, amountZeroInRemaining, s.spreadFactor, s.getOneMinusSpreadFactor)
 
 	// Round down amount out to give user less in pool's favor.
 	return sqrtPriceNext, amountZeroInFinal, amountOneOut.Dec(), spreadRewardChargeTotal
@@ -158,7 +161,7 @@ func (s zeroForOneStrategy) ComputeSwapWithinBucketInGivenOut(sqrtPriceCurrent,
 
 	// Handle spread rewards.
 	// Note that spread reward is always charged on the amount in.
-	spreadRewardChargeTotal := computeSpreadRewardChargeFromAmountIn(amountZeroInFinal, s.spreadFactor)
+	spreadRewardChargeTotal := computeSpreadRewardChargeFromAmountIn(amountZeroInFinal, s.spreadFactor, s.getOneMinusSpreadFactor())
 
 	// Cap the output amount to not exceed the remaining output amount.
 	// The reason why we must do this for in given out and NOT out given in is the following:
@@ -179,6 +182,13 @@ func (s zeroForOneStrategy) ComputeSwapWithinBucketInGivenOut(sqrtPriceCurrent,
 	return sqrtPriceNext, amountOneOut.Dec(), amountZeroInFinal, spreadRewardChargeTotal
 }
 
+func (s zeroForOneStrategy) getOneMinusSpreadFactor() osmomath.Dec {
+	if s.oneMinusSpreadFactor.IsNil() {
+		s.oneMinusSpreadFactor = oneDec.Sub(s.spreadFactor)
+	}
+	return s.oneMinusSpreadFactor
+}
+
 // InitializeNextTickIterator returns iterator that searches for the next tick given currentTickIndex.
 // In zero for one direction, the search is INCLUSIVE of the current tick index.
 // If next tick relative to currentTickIndex is not initialized (does not exist in the store),