Add Easing mode for hodler yield calc

Author: youngkidwarrior

apps/distributor/src/distributorv2.test.ts

@@ -372,34 +372,62 @@ describe('Distributor V2 Worker', () => {
 
     //Expected values are a little different than back of the napkin because of rounding
     //Keep an eye on this, may need to investigate if we see distro problems
-    const expectedShares = [
-      {
-        address: bobAddr,
-        distribution_id: 4,
-        user_id,
-        bonus_pool_amount: '0', // Always 0 in V2
-        amount: '5578', // 75% of original (example slash)
-        fixed_pool_amount: '28', // 75% of 984
-        hodler_pool_amount: '5550', // 75% of 5872
-      },
-      {
-        address: aliceAddr,
-        distribution_id: 4,
-        user_id: user_id2,
-        bonus_pool_amount: '0', // Always 0 in V2
-        amount: '1111', // 50% of original (example slash)
-        fixed_pool_amount: '1', // 50% of 208
-        hodler_pool_amount: '1110', // 50% of 2936
-      },
-    ]
+    const expectedShares = {
+      linear: [
+        {
+          address: bobAddr,
+          distribution_id: 4,
+          user_id,
+          bonus_pool_amount: '0', // Always 0 in V2
+          amount: '5578', // 75% of original (example slash)
+          fixed_pool_amount: '28', // 75% of 984
+          hodler_pool_amount: '5550', // 75% of 5872
+        },
+        {
+          address: aliceAddr,
+          distribution_id: 4,
+          user_id: user_id2,
+          bonus_pool_amount: '0', // Always 0 in V2
+          amount: '1111', // 50% of original (example slash)
+          fixed_pool_amount: '1', // 50% of 208
+          hodler_pool_amount: '1110', // 50% of 2936
+        },
+      ],
+      easeInAndOut: [
+        {
+          address: bobAddr,
+          distribution_id: 4,
+          user_id,
+          bonus_pool_amount: '0', // Always 0 in V2
+          amount: '5825', // 75% of original (example slash) with cubic bezier
+          fixed_pool_amount: '28', // 75% of 984
+          hodler_pool_amount: '5797', // 5872 with cubic bezier
+        },
+        {
+          address: aliceAddr,
+          distribution_id: 4,
+          user_id: user_id2,
+          bonus_pool_amount: '0', // Always 0 in V2
+          amount: '864', // 50% of original (example slash) with cubic bezier
+          fixed_pool_amount: '1', // 50% of 208
+          hodler_pool_amount: '863', // 50% of 2936 with cubic bezier
+        },
+      ],
+    }
     expect(createDistributionShares).toHaveBeenCalled()
 
-    // @ts-expect-error supabase-js does not support bigint
-    expect(createDistributionShares.mock.calls[0]).toEqual([distribution.id, expectedShares])
+    expect(createDistributionShares.mock.calls[0]).toEqual([
+      distribution.id,
+      // @ts-expect-error supabase-js does not support bigint
+      expectedShares.easeInAndOut,
+    ])
 
     // expected share amounts cannot exceed the total distribution amount
     const totalDistributionAmount = BigInt(distribution.amount)
-    const totalShareAmounts = expectedShares.reduce((acc, share) => acc + BigInt(share.amount), 0n)
+    const totalShareAmounts = expectedShares.easeInAndOut.reduce(
+      (acc, share) => acc + BigInt(share.amount),
+      0n
+    )
     expect(totalShareAmounts).toBeLessThanOrEqual(totalDistributionAmount)
   })
 })

apps/distributor/src/distributorv2.ts

@@ -12,7 +12,7 @@ import {
   updateReferralVerifications,
 } from './supabase'
 import { fetchAllBalances, isMerkleDropActive } from './wagmi'
-import { calculateWeights, PERC_DENOM } from './weights'
+import { calculateWeights, Mode, PERC_DENOM } from './weights'
 import { assert } from 'app/utils/assert'
 
 type Multiplier = {
@@ -510,7 +510,7 @@ export class DistributorV2Worker {
 
       // Calculate weighted shares for current slashed state
 
-      const weightedShares = calculateWeights(slashedBalances, timeAdjustedAmount)
+      const weightedShares = calculateWeights(slashedBalances, timeAdjustedAmount, Mode.EaseInOut)
 
       hodlerShares = slashedBalances.map((balance) => ({
         address: balance.address,

apps/distributor/src/weights.test.ts

@@ -127,6 +127,33 @@ const testCases = [
       },
     },
   },
+  {
+    name: 'ease_in_out',
+    mode: 'ease_in_out',
+    expected: {
+      totalWeight: 26666n, // Approximate total based on the curve
+      weightPerSend: 2666n,
+      poolWeights: {
+        '0x1': 7466n, // ~28% weight for lowest balance
+        '0x2': 9600n, // ~36% weight for middle balance
+        '0x3': 9600n, // ~36% weight for highest balance
+      },
+      weightedShares: {
+        '0x1': {
+          address: '0x1',
+          amount: 28000n, // ~35% of 80000
+        },
+        '0x2': {
+          address: '0x2',
+          amount: 26000n, // ~32.5% of 80000
+        },
+        '0x3': {
+          address: '0x3',
+          amount: 26000n, // ~32.5% of 80000
+        },
+      },
+    },
+  },
 ] as const
 
 describe('calculateWeights', () => {

apps/distributor/src/weights.ts

@@ -5,6 +5,7 @@ export enum Mode {
   Logarithmic = 'logarithmic',
   SquareRoot = 'square_root',
   Exponential = 'exponential',
+  EaseInOut = 'ease_in_out',
 }
 
 export const PERC_DENOM = 10000000n
@@ -92,6 +93,8 @@ function calculateWeightByMode(
       return calculateSquareRootWeight(balance, totalBalance)
     case Mode.Exponential:
       return calculateExponentialWeight(balance, totalBalance, numBalances)
+    case Mode.EaseInOut:
+      return calculateCubicBezierWeight(balance, totalBalance)
     default:
       throw new Error(`Unknown weight mode: ${mode}`)
   }
@@ -119,3 +122,20 @@ function calculateExponentialWeight(
     Math.floor(Number(PERC_DENOM) * Math.exp((-k * Number(balance)) / Number(totalBalance)))
   )
 }
+
+function calculateCubicBezierWeight(balance: bigint, totalBalance: bigint): bigint {
+  // Normalize the balance to [0,1]
+  const t = Number(balance) / Number(totalBalance)
+
+  // Control points for flat behavior at extremes
+  const p0 = 0
+  const p1 = 0.2 // Close to start for flat beginning
+  const p2 = 0.8 // Close to end for flat ending
+  const p3 = 1
+
+  // Cubic Bezier formula
+  const bezier =
+    (1 - t) ** 3 * p0 + 3 * (1 - t) ** 2 * t * p1 + 3 * (1 - t) * t ** 2 * p2 + t ** 3 * p3
+
+  return BigInt(Math.floor(Number(PERC_DENOM) * bezier))
+}