chore: add burnt coins metrics (#2246)

* add burnt coins metrics * add changelog entry * add test case * small fix * small refactor
evmos · Jan 10, 2024 · ea75cb9 · ea75cb9
1 parent 7994ffb
commit ea75cb9
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Showing 3 changed files with 40 additions and 3 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -153,6 +153,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 - (outposts) [#2223](https://github.com/evmos/evmos/pull/2223) Update Outposts struct documentation and `ValidateBasic`.
 - (p256-precompile) [#2228](https://github.com/evmos/evmos/pull/2228) Adjust p256 precompile address from `0x0b` to `0x100`.
 - (staking-precompile) [#2234](https://github.com/evmos/evmos/pull/2234) Fix wrong error messages in `NewMsgCreateValidator`.
+- (metrics) [#2246](https://github.com/evmos/evmos/pull/2246) Add burnt cosmos transactions fees metric.
 
 ### Bug Fixes
 

diff --git a/app/post/burn.go b/app/post/burn.go
@@ -7,6 +7,8 @@ import (
 	errorsmod "cosmossdk.io/errors"
 	sdkmath "cosmossdk.io/math"
 
+	"github.com/armon/go-metrics"
+	"github.com/cosmos/cosmos-sdk/telemetry"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	errortypes "github.com/cosmos/cosmos-sdk/types/errors"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
@@ -54,7 +56,7 @@ func (bd BurnDecorator) PostHandle(ctx sdk.Context, tx sdk.Tx, simulate, success
 	}
 
 	// burn min(balance, fee)
-	var burnedCoins sdk.Coins
+	var burntCoins sdk.Coins
 	for _, fee := range fees {
 		balance := bd.bankKeeper.GetBalance(ctx, authtypes.NewModuleAddress(bd.feeCollectorName), fee.Denom)
 		if !balance.IsPositive() {
@@ -63,14 +65,30 @@ func (bd BurnDecorator) PostHandle(ctx sdk.Context, tx sdk.Tx, simulate, success
 
 		amount := sdkmath.MinInt(fee.Amount, balance.Amount)
 
-		burnedCoins = append(burnedCoins, sdk.Coin{Denom: fee.Denom, Amount: amount})
+		burntCoins = append(burntCoins, sdk.Coin{Denom: fee.Denom, Amount: amount})
 	}
 
 	// NOTE: since all Cosmos tx fees are pooled by the fee collector module account,
 	// we burn them directly from it
-	if err := bd.bankKeeper.BurnCoins(ctx, bd.feeCollectorName, burnedCoins); err != nil {
+	if err := bd.bankKeeper.BurnCoins(ctx, bd.feeCollectorName, burntCoins); err != nil {
 		return ctx, err
 	}
 
+	defer func() {
+		for _, c := range burntCoins {
+			// if fee amount is higher than uint64, skip the counter
+			if !c.Amount.IsUint64() {
+				continue
+			}
+			telemetry.IncrCounterWithLabels(
+				[]string{"burnt", "tx", "fee", "amount"},
+				float32(c.Amount.Uint64()),
+				[]metrics.Label{
+					telemetry.NewLabel("denom", c.Denom),
+				},
+			)
+		}
+	}()
+
 	return next(ctx, tx, simulate, success)
 }
diff --git a/app/post/burn_test.go b/app/post/burn_test.go
@@ -130,6 +130,24 @@ func (s *PostTestSuite) TestPostHandle() {
 				s.Require().Equal(expected, balance)
 			},
 		},
+		{
+			name: "pass - fees exceeds MaxUint64 (~18 EVMOS). Should not panic",
+			tx: func() sdk.Tx {
+				amt, ok := sdkmath.NewIntFromString("10000000000000000000000000000000000")
+				s.Require().True(ok)
+				feeAmount := sdk.Coins{sdk.Coin{Amount: amt, Denom: "evmos"}}
+				amount := sdk.Coins{sdk.Coin{Amount: amt, Denom: "evmos"}}
+				s.MintCoinsForFeeCollector(amount)
+
+				return s.BuildCosmosTxWithNSendMsg(1, feeAmount)
+			},
+			expPass: true,
+			postChecks: func() {
+				expected := sdk.Coins{}
+				balance := s.GetFeeCollectorBalance()
+				s.Require().Equal(expected, balance)
+			},
+		},
 	}
 
 	for _, tc := range testCases {