Scale quadratic matching pool size (#136)

public-awesome · Aug 17, 2020 · 7b9ee3b · 7b9ee3b
1 parent b82fb72
commit 7b9ee3b
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Showing 6 changed files with 172 additions and 82 deletions.
diff --git a/x/curating/abci.go b/x/curating/abci.go
@@ -30,7 +30,7 @@ func EndBlocker(ctx sdk.Context, k Keeper) {
 			panic(err)
 		}
 
-		qv := NewQVFData()
+		qv := NewQVFData(ctx, k)
 
 		// iterate upvoters, returning deposits, and tallying upvotes
 		k.IterateUpvotes(ctx, post.VendorID, post.PostIDHash,

diff --git a/x/curating/abci_test.go b/x/curating/abci_test.go
@@ -10,25 +10,16 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// initial state
-// creator  = 10 FUEL
-// curator1 = 10 FUEL, upvote 1 FUEL
-// curator2 = 10 FUEL, upvote 9 FUEL
-//
-// qvf
-// voting_pool  = 10 FUEL
-// root_sum     = 4
-// match_pool   = 4^2 - 10 = 6
-// voter_reward = 5 FUEL
-// match_reward = match_pool / 2 = 3
-func TestEndBlockerExpiringPost(t *testing.T) {
+var addrs = []sdk.AccAddress{}
+
+func setup(t *testing.T) (*testdata.SimApp, sdk.Context) {
 	_, app, ctx := testdata.CreateTestInput()
 
 	postID := "500"
 	vendorID := uint32(1)
 
 	deposit := sdk.NewInt64Coin("ufuel", 1_000_000)
-	addrs := testdata.AddTestAddrsIncremental(app, ctx, 3, sdk.NewInt(10_000_000))
+	addrs = testdata.AddTestAddrsIncremental(app, ctx, 3, sdk.NewInt(10_000_000))
 
 	err := app.CuratingKeeper.CreatePost(
 		ctx, vendorID, postID, "body string", deposit, addrs[0], addrs[0])
@@ -69,23 +60,64 @@ func TestEndBlockerExpiringPost(t *testing.T) {
 		app.CuratingKeeper.GetParams(ctx).CurationWindow)
 	ctx = ctx.WithBlockHeader(h)
 
+	return app, ctx
+}
+
+// initial state
+// creator  = 10 FUEL
+// curator1 = 10 FUEL, upvote 1 FUEL
+// curator2 = 10 FUEL, upvote 9 FUEL
+//
+// qvf
+// voting_pool  = 10 FUEL
+// root_sum     = 4
+// match_pool   = 4^2 - 10 = 6
+// voter_reward = 5 FUEL
+// match_reward = match_pool / 2 = 3
+func TestEndBlockerExpiringPost(t *testing.T) {
+	app, ctx := setup(t)
+
 	// add funds to reward pool
-	funds := sdk.NewInt64Coin("ufuel", 10_000_000)
-	err = app.BankKeeper.MintCoins(ctx, curating.RewardPoolName, sdk.NewCoins(funds))
+	funds := sdk.NewInt64Coin("ufuel", 10_000_000_000)
+	err := app.BankKeeper.MintCoins(ctx, curating.RewardPoolName, sdk.NewCoins(funds))
 	require.NoError(t, err)
 
 	curating.EndBlocker(ctx, app.CuratingKeeper)
 
 	// creator match reward = 0.5 * match_reward = 3 FUEL
-	creatorBal = app.BankKeeper.GetBalance(ctx, addrs[0], "ufuel")
+	creatorBal := app.BankKeeper.GetBalance(ctx, addrs[0], "ufuel")
 	require.Equal(t, "13000000", creatorBal.Amount.String(),
 		"10 (initial) + 3 (creator match reward)")
 
-	curator1Bal = app.BankKeeper.GetBalance(ctx, addrs[1], "ufuel")
+	curator1Bal := app.BankKeeper.GetBalance(ctx, addrs[1], "ufuel")
 	require.Equal(t, "15500000", curator1Bal.Amount.String(),
 		"8 (bal) + 1 (deposit) + 5 (voting reward) + 1.5 (match reward)")
 
-	curator2Bal = app.BankKeeper.GetBalance(ctx, addrs[2], "ufuel")
+	curator2Bal := app.BankKeeper.GetBalance(ctx, addrs[2], "ufuel")
 	require.Equal(t, "7500000", curator2Bal.Amount.String(),
 		"0 (bal) + 1 (deposit) + 5 (voter reward) + 1.5 (match reward)")
 }
+
+func TestEndBlockerExpiringPostWithSmolRewardPool(t *testing.T) {
+	app, ctx := setup(t)
+
+	// add funds to reward pool
+	funds := sdk.NewInt64Coin("ufuel", 1_000_000)
+	err := app.BankKeeper.MintCoins(ctx, curating.RewardPoolName, sdk.NewCoins(funds))
+	require.NoError(t, err)
+
+	curating.EndBlocker(ctx, app.CuratingKeeper)
+
+	// creator match reward = 0.5 * match_reward = 3 FUEL
+	creatorBal := app.BankKeeper.GetBalance(ctx, addrs[0], "ufuel")
+	require.Equal(t, "10000500", creatorBal.Amount.String(),
+		"10 (initial) + 3 (creator match reward)")
+
+	curator1Bal := app.BankKeeper.GetBalance(ctx, addrs[1], "ufuel")
+	require.Equal(t, "14000249", curator1Bal.Amount.String(),
+		"8 (bal) + 1 (deposit) + 5 (voting reward) + 1.5 (match reward)")
+
+	curator2Bal := app.BankKeeper.GetBalance(ctx, addrs[2], "ufuel")
+	require.Equal(t, "6000249", curator2Bal.Amount.String(),
+		"0 (bal) + 1 (deposit) + 5 (voter reward) + 1.5 (match reward)")
+}
diff --git a/x/curating/keeper/reward_pool.go b/x/curating/keeper/reward_pool.go
@@ -12,6 +12,11 @@ func (k Keeper) GetRewardPool(ctx sdk.Context) (rewardPool authexported.ModuleAc
 	return k.accountKeeper.GetModuleAccount(ctx, types.RewardPoolName)
 }
 
+// GetRewardPoolBalance returns the reward pool balance
+func (k Keeper) GetRewardPoolBalance(ctx sdk.Context) sdk.Coin {
+	return k.bankKeeper.GetBalance(ctx, k.GetRewardPool(ctx).GetAddress(), types.DefaultStakeDenom)
+}
+
 // InflateRewardPool process the designated inflation to the reward pool
 func (k Keeper) InflateRewardPool(ctx sdk.Context) error {
 	blockInflationAddr := k.accountKeeper.GetModuleAccount(ctx, auth.FeeCollectorName).GetAddress()

diff --git a/x/curating/quadratic.go b/x/curating/quadratic.go
@@ -6,49 +6,63 @@ import (
 
 // QVFData holds vars for quadratic voting+funding calculations
 type QVFData struct {
-	VoterCount int64
-	VotingPool sdk.Int
-	RootSum    sdk.Dec
+	ctx        sdk.Context
+	keeper     Keeper
+	voterCount int64
+	votingPool sdk.Int
+	rootSum    sdk.Dec
 }
 
-func NewQVFData() QVFData {
+func NewQVFData(ctx sdk.Context, k Keeper) QVFData {
 	return QVFData{
-		VotingPool: sdk.ZeroInt(),
-		RootSum:    sdk.ZeroDec(),
+		ctx:        ctx,
+		keeper:     k,
+		votingPool: sdk.ZeroInt(),
+		rootSum:    sdk.ZeroDec(),
 	}
 }
 
 // TallyVote tallies a vote
 func (q QVFData) TallyVote(amount sdk.Int) (QVFData, error) {
-	q.VoterCount++
-	q.VotingPool = q.VotingPool.Add(amount)
+	q.voterCount++
+	q.votingPool = q.votingPool.Add(amount)
 
 	sqrt, err := amount.ToDec().ApproxSqrt()
 	if err != nil {
 		return q, err
 	}
-	q.RootSum = q.RootSum.Add(sqrt)
+	q.rootSum = q.rootSum.Add(sqrt)
 
 	return q, nil
 }
 
 // MatchPool calculates and returns the quadratic match pool
 func (q QVFData) MatchPool() sdk.Dec {
-	return q.RootSum.Power(2).Sub(q.VotingPool.ToDec())
+	idealPoolSize := q.rootSum.Power(2).Sub(q.votingPool.ToDec())
+
+	rewardPool := q.keeper.GetRewardPoolBalance(q.ctx).Amount.ToDec()
+	maxPoolPercent := q.keeper.GetParams(q.ctx).RewardPoolCurationMaxAlloc
+	maxPoolSize := rewardPool.MulTruncate(maxPoolPercent)
+
+	if idealPoolSize.GT(maxPoolSize) {
+		return maxPoolSize
+	}
+
+	return idealPoolSize
 }
 
 // VoterReward returns the distribution for a voter
 func (q QVFData) VoterReward() sdk.Int {
-	if q.VoterCount == 0 {
+	if q.voterCount == 0 {
 		return sdk.ZeroInt()
 	}
-	return q.VotingPool.QuoRaw(q.VoterCount)
+	return q.votingPool.QuoRaw(q.voterCount)
 }
 
 // MatchReward returns the funding match for a voter
 func (q QVFData) MatchReward() sdk.Dec {
-	if q.VoterCount == 0 {
+	if q.voterCount == 0 {
 		return sdk.ZeroDec()
 	}
-	return q.MatchPool().QuoInt64(q.VoterCount)
+	return q.MatchPool().QuoInt64(q.voterCount)
 }
diff --git a/x/curating/quadratic_test.go b/x/curating/quadratic_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/public-awesome/stakebird/testdata"
 	"github.com/public-awesome/stakebird/x/curating"
 	"github.com/stretchr/testify/require"
 )
@@ -14,26 +15,42 @@ import (
 // 4 votes = 16 vote credits
 // 5 votes = 25 vote credits
 func TestQVF(t *testing.T) {
-	q := curating.NewQVFData()
-	q, err := q.TallyVote(sdk.NewInt(1))
+	_, app, ctx := testdata.CreateTestInput()
+
+	// add funds to reward pool
+	funds := sdk.NewInt64Coin("ufuel", 10_000_000)
+	err := app.BankKeeper.MintCoins(ctx, curating.RewardPoolName, sdk.NewCoins(funds))
+	require.NoError(t, err)
+
+	q := curating.NewQVFData(ctx, app.CuratingKeeper)
+	q, err = q.TallyVote(sdk.NewInt(1))
 	require.NoError(t, err)
 	q, err = q.TallyVote(sdk.NewInt(9))
 	require.NoError(t, err)
 
-	require.Equal(t, int64(2), q.VoterCount)
-	require.Equal(t, "10", q.VotingPool.String())
-	require.Equal(t, "4.000000000000000000", q.RootSum.String())
+	// for reference...
+	// require.Equal(t, int64(2), q.VoterCount)
+	// require.Equal(t, "10", q.VotingPool.String())
+	// require.Equal(t, "4.000000000000000000", q.RootSum.String())
 	require.Equal(t, "6.000000000000000000", q.MatchPool().String())
 	require.Equal(t, "5", q.VoterReward().String())
 	require.Equal(t, "3.000000000000000000", q.MatchReward().String())
 }
 
 func TestQVFZeroVotes(t *testing.T) {
-	q := curating.NewQVFData()
+	_, app, ctx := testdata.CreateTestInput()
+
+	// add funds to reward pool
+	funds := sdk.NewInt64Coin("ufuel", 10_000_000)
+	err := app.BankKeeper.MintCoins(ctx, curating.RewardPoolName, sdk.NewCoins(funds))
+	require.NoError(t, err)
+
+	q := curating.NewQVFData(ctx, app.CuratingKeeper)
 
-	require.Equal(t, int64(0), q.VoterCount)
-	require.Equal(t, "0", q.VotingPool.String())
-	require.Equal(t, "0.000000000000000000", q.RootSum.String())
+	// for reference...
+	// require.Equal(t, int64(0), q.VoterCount)
+	// require.Equal(t, "0", q.VotingPool.String())
+	// require.Equal(t, "0.000000000000000000", q.RootSum.String())
 	require.Equal(t, "0.000000000000000000", q.MatchPool().String())
 	require.Equal(t, "0", q.VoterReward().String())
 	require.Equal(t, "0.000000000000000000", q.MatchReward().String())