From 81c398f2ed6b44ad4736e788bb227290e169de2f Mon Sep 17 00:00:00 2001
From: yihuang <huang@crypto.com>
Date: Tue, 12 Sep 2023 12:34:01 +0800
Subject: [PATCH] Problem: no api to convert native events to logs (#343)

* Problem: no api to convert native events to logs

Solution:
- add event converters

* convert after commit

* Update CHANGELOG.md

Signed-off-by: mmsqe <mavis@crypto.com>

---------

Signed-off-by: mmsqe <mavis@crypto.com>
Co-authored-by: mmsqe <mavis@crypto.com>
---
 CHANGELOG.md                     |  1 +
 app/app.go                       |  1 +
 x/evm/keeper/keeper.go           |  7 +++++++
 x/evm/keeper/state_transition.go | 22 ++++++++++++++++++++++
 4 files changed, 31 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4e6195704f..c22c1fdfaf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -68,6 +68,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 - (cli) [#242](https://github.com/crypto-org-chain/ethermint/pull/242) Integrate tendermint bootstrap cmd.
 - (cli) [#246](https://github.com/crypto-org-chain/ethermint/pull/246) Call app.Close to cleanup resource on graceful shutdown.
 * (cli) [#288](https://github.com/crypto-org-chain/ethermint/pull/288) make abci handshake shutdown gracefully.
+- (evm) [#343](https://github.com/crypto-org-chain/ethermint/pull/343) Add native event converter APIs.
 
 
 ## [v0.21.0] - 2023-01-26
diff --git a/app/app.go b/app/app.go
index 32fe518b13..f5bfd907f5 100644
--- a/app/app.go
+++ b/app/app.go
@@ -472,6 +472,7 @@ func NewEthermintApp(
 		tracer,
 		evmSs, nil,
 		allKeys,
+		nil,
 	)
 
 	// Create IBC Keeper
diff --git a/x/evm/keeper/keeper.go b/x/evm/keeper/keeper.go
index abe4b55600..ffba366d6b 100644
--- a/x/evm/keeper/keeper.go
+++ b/x/evm/keeper/keeper.go
@@ -19,6 +19,7 @@ import (
 	"math/big"
 
 	errorsmod "cosmossdk.io/errors"
+	abci "github.com/cometbft/cometbft/abci/types"
 	"github.com/cometbft/cometbft/libs/log"
 	"github.com/cosmos/cosmos-sdk/codec"
 	"github.com/cosmos/cosmos-sdk/store/prefix"
@@ -37,6 +38,8 @@ import (
 	"github.com/evmos/ethermint/x/evm/types"
 )
 
+type EventConverter = func([]abci.EventAttribute) []*ethtypes.Log
+
 // Keeper grants access to the EVM module state and implements the go-ethereum StateDB interface.
 type Keeper struct {
 	// Protobuf codec
@@ -77,6 +80,8 @@ type Keeper struct {
 	// a set of store keys that should cover all the precompile use cases,
 	// or ideally just pass the application's all stores.
 	keys map[string]storetypes.StoreKey
+
+	eventConverters map[string]EventConverter
 }
 
 // NewKeeper generates new evm module keeper
@@ -92,6 +97,7 @@ func NewKeeper(
 	ss paramstypes.Subspace,
 	customContracts []precompiles.StatefulPrecompiledContract,
 	keys map[string]storetypes.StoreKey,
+	eventConverters map[string]EventConverter,
 ) *Keeper {
 	// ensure evm module account is set
 	if addr := ak.GetModuleAddress(types.ModuleName); addr == nil {
@@ -117,6 +123,7 @@ func NewKeeper(
 		ss:              ss,
 		customContracts: customContracts,
 		keys:            keys,
+		eventConverters: eventConverters,
 	}
 }
 
diff --git a/x/evm/keeper/state_transition.go b/x/evm/keeper/state_transition.go
index 59d2992dee..3cf291cbfb 100644
--- a/x/evm/keeper/state_transition.go
+++ b/x/evm/keeper/state_transition.go
@@ -422,6 +422,9 @@ func (k *Keeper) ApplyMessageWithConfig(ctx sdk.Context,
 		}
 	}
 
+	// convert native events to ethereum logs
+	convertNativeEvents(stateDB, k.eventConverters)
+
 	// calculate a minimum amount of gas to be charged to sender if GasLimit
 	// is considerably higher than GasUsed to stay more aligned with Tendermint gas mechanics
 	// for more info https://github.com/evmos/ethermint/issues/1085
@@ -445,3 +448,22 @@ func (k *Keeper) ApplyMessageWithConfig(ctx sdk.Context,
 		Hash:    txConfig.TxHash.Hex(),
 	}, nil
 }
+
+func convertNativeEvents(stateDB *statedb.StateDB, converters map[string]EventConverter) {
+	if len(converters) == 0 {
+		return
+	}
+
+	events := stateDB.NativeEvents()
+	if len(events) == 0 {
+		return
+	}
+
+	for _, event := range events {
+		if converter, ok := converters[event.Type]; ok {
+			for _, log := range converter(event.Attributes) {
+				stateDB.AddLog(log)
+			}
+		}
+	}
+}