rpc, feemarket: store base fee in event (#673)

* store base fee in event

* update changelog

x/feemarket/keeper/abci.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	abci "github.com/tendermint/tendermint/abci/types"
+	"github.com/tharsis/ethermint/x/feemarket/types"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
@@ -13,13 +14,22 @@ import (
 // an empty slice.
 func (k *Keeper) EndBlock(ctx sdk.Context, req abci.RequestEndBlock) {
 	baseFee := k.CalculateBaseFee(ctx)
+
+	// return immediately if base fee is nil
 	if baseFee == nil {
 		return
 	}
 
-	// only set base fee if the NoBaseFee param is false
 	k.SetBaseFee(ctx, baseFee)
 
+	// Store current base fee in event
+	ctx.EventManager().EmitEvents(sdk.Events{
+		sdk.NewEvent(
+			types.EventTypeFeeMarket,
+			sdk.NewAttribute(types.AttributeKeyBaseFee, baseFee.String()),
+		),
+	})
+
 	if ctx.BlockGasMeter() == nil {
 		k.Logger(ctx).Error("block gas meter is nil when setting block gas used")
 		return

x/feemarket/keeper/eip1559.go

@@ -10,20 +10,21 @@ import (
 )
 
 // CalculateBaseFee calculates the base fee for the current block. This is only calculated once per
-// block during EndBlock. If the NoBaseFee parameter is enabled, this function returns nil.
+// block during EndBlock. If the NoBaseFee parameter is enabled or below activation height, this function returns nil.
 // NOTE: This code is inspired from the go-ethereum EIP1559 implementation and adapted to Cosmos SDK-based
 // chains. For the canonical code refer to: https://github.com/ethereum/go-ethereum/blob/master/consensus/misc/eip1559.go
 func (k Keeper) CalculateBaseFee(ctx sdk.Context) *big.Int {
 	params := k.GetParams(ctx)
 
-	if params.NoBaseFee {
+	// Ignore the calculation if not enable
+	if !params.IsBaseFeeEnabled(ctx.BlockHeight()) {
 		return nil
 	}
 
 	consParams := ctx.ConsensusParams()
 
 	// If the current block is the first EIP-1559 block, return the InitialBaseFee.
-	if ctx.BlockHeight() <= params.EnableHeight {
+	if ctx.BlockHeight() == params.EnableHeight {
 		return new(big.Int).SetInt64(params.InitialBaseFee)
 	}
 

x/feemarket/keeper/keeper.go

@@ -71,7 +71,7 @@ func (k Keeper) SetBlockGasUsed(ctx sdk.Context, gas uint64) {
 // Required by EIP1559 base fee calculation.
 // ----------------------------------------------------------------------------
 
-// GetBlockGasUsed returns the last block gas used value from the store.
+// GetLastBaseFee returns the last base fee value from the store.
 func (k Keeper) GetBaseFee(ctx sdk.Context) *big.Int {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.KeyPrefixBaseFee)
@@ -82,7 +82,7 @@ func (k Keeper) GetBaseFee(ctx sdk.Context) *big.Int {
 	return new(big.Int).SetBytes(bz)
 }
 
-// SetBlockGasUsed gets the current block gas consumed to the store.
+// SetBaseFee set the last base fee value to the store.
 // CONTRACT: this should be only called during EndBlock.
 func (k Keeper) SetBaseFee(ctx sdk.Context, baseFee *big.Int) {
 	store := ctx.KVStore(k.storeKey)