Merge branch 'master' into aleem/8758-gov-deposits

CHANGELOG.md

@@ -128,8 +128,9 @@ if input key is empty, or input data contains empty key.
 
 ### Improvements
 
+* (store) [\#9403](https://github.com/cosmos/cosmos-sdk/pull/9403) Add `RefundGas` function to `GasMeter` interface
+* (baseapp, types) [\#9390](https://github.com/cosmos/cosmos-sdk/pull/9390) Add current block header hash to `Context`
 * (x/staking) [\#9423](https://github.com/cosmos/cosmos-sdk/pull/9423) Staking delegations now returns empty list instead of rpc error when no records found.
-* (baseapp, types) [#\9390](https://github.com/cosmos/cosmos-sdk/pull/9390) Add current block header hash to `Context`
 * (x/bank) [\#8614](https://github.com/cosmos/cosmos-sdk/issues/8614) Add `Name` and `Symbol` fields to denom metadata
 * (x/auth) [\#8522](https://github.com/cosmos/cosmos-sdk/pull/8522) Allow to query all stored accounts
 * (crypto/types) [\#8600](https://github.com/cosmos/cosmos-sdk/pull/8600) `CompactBitArray`: optimize the `NumTrueBitsBefore` method and add an `Equal` method.

client/flags/flags.go

@@ -97,7 +97,7 @@ func AddTxFlagsToCmd(cmd *cobra.Command) {
 	cmd.Flags().String(FlagFrom, "", "Name or address of private key with which to sign")
 	cmd.Flags().Uint64P(FlagAccountNumber, "a", 0, "The account number of the signing account (offline mode only)")
 	cmd.Flags().Uint64P(FlagSequence, "s", 0, "The sequence number of the signing account (offline mode only)")
-	cmd.Flags().String(FlagNote, "", "Note to add a description to the transaction (previously `--memo`)")
+	cmd.Flags().String(FlagNote, "", "Note to add a description to the transaction (previously --memo)")
 	cmd.Flags().String(FlagFees, "", "Fees to pay along with transaction; eg: 10uatom")
 	cmd.Flags().String(FlagGasPrices, "", "Gas prices in decimal format to determine the transaction fee (e.g. 0.1uatom)")
 	cmd.Flags().String(FlagNode, "tcp://localhost:26657", "<host>:<port> to tendermint rpc interface for this chain")

store/types/gas.go

@@ -20,6 +20,12 @@ const (
 // Gas measured by the SDK
 type Gas = uint64
 
+// ErrorNegativeGasConsumed defines an error thrown when the amount of gas refunded results in a
+// negative gas consumed amount.
+type ErrorNegativeGasConsumed struct {
+	Descriptor string
+}
+
 // ErrorOutOfGas defines an error thrown when an action results in out of gas.
 type ErrorOutOfGas struct {
 	Descriptor string
@@ -37,6 +43,7 @@ type GasMeter interface {
 	GasConsumedToLimit() Gas
 	Limit() Gas
 	ConsumeGas(amount Gas, descriptor string)
+	RefundGas(amount Gas, descriptor string)
 	IsPastLimit() bool
 	IsOutOfGas() bool
 	String() string
@@ -91,7 +98,20 @@ func (g *basicGasMeter) ConsumeGas(amount Gas, descriptor string) {
 	if g.consumed > g.limit {
 		panic(ErrorOutOfGas{descriptor})
 	}
+}
+
+// RefundGas will deduct the given amount from the gas consumed. If the amount is greater than the
+// gas consumed, the function will panic.
+//
+// Use case: This functionality enables refunding gas to the transaction or block gas pools so that
+// EVM-compatible chains can fully support the go-ethereum StateDb interface.
+// See https://github.com/cosmos/cosmos-sdk/pull/9403 for reference.
+func (g *basicGasMeter) RefundGas(amount Gas, descriptor string) {
+	if g.consumed < amount {
+		panic(ErrorNegativeGasConsumed{Descriptor: descriptor})
+	}
 
+	g.consumed -= amount
 }
 
 func (g *basicGasMeter) IsPastLimit() bool {
@@ -138,6 +158,20 @@ func (g *infiniteGasMeter) ConsumeGas(amount Gas, descriptor string) {
 	}
 }
 
+// RefundGas will deduct the given amount from the gas consumed. If the amount is greater than the
+// gas consumed, the function will panic.
+//
+// Use case: This functionality enables refunding gas to the trasaction or block gas pools so that
+// EVM-compatible chains can fully support the go-ethereum StateDb interface.
+// See https://github.com/cosmos/cosmos-sdk/pull/9403 for reference.
+func (g *infiniteGasMeter) RefundGas(amount Gas, descriptor string) {
+	if g.consumed < amount {
+		panic(ErrorNegativeGasConsumed{Descriptor: descriptor})
+	}
+
+	g.consumed -= amount
+}
+
 func (g *infiniteGasMeter) IsPastLimit() bool {
 	return false
 }

store/types/gas_test.go

@@ -16,10 +16,13 @@ func TestInfiniteGasMeter(t *testing.T) {
 	meter.ConsumeGas(10, "consume 10")
 	require.Equal(t, uint64(10), meter.GasConsumed())
 	require.Equal(t, uint64(10), meter.GasConsumedToLimit())
+	meter.RefundGas(1, "refund 1")
+	require.Equal(t, uint64(9), meter.GasConsumed())
 	require.False(t, meter.IsPastLimit())
 	require.False(t, meter.IsOutOfGas())
 	meter.ConsumeGas(Gas(math.MaxUint64/2), "consume half max uint64")
 	require.Panics(t, func() { meter.ConsumeGas(Gas(math.MaxUint64/2)+2, "panic") })
+	require.Panics(t, func() { meter.RefundGas(meter.GasConsumed()+1, "refund greater than consumed") })
 }
 
 func TestGasMeter(t *testing.T) {
@@ -57,6 +60,11 @@ func TestGasMeter(t *testing.T) {
 		require.Panics(t, func() { meter.ConsumeGas(1, "") }, "Exceeded but not panicked. tc #%d", tcnum)
 		require.Equal(t, meter.GasConsumedToLimit(), meter.Limit(), "Gas consumption (to limit) not match limit")
 		require.Equal(t, meter.GasConsumed(), meter.Limit()+1, "Gas consumption not match limit+1")
+
+		require.NotPanics(t, func() { meter.RefundGas(1, "refund 1") })
+		require.Equal(t, meter.GasConsumed(), meter.Limit(), "Gas consumption not match limit+1")
+		require.Panics(t, func() { meter.RefundGas(meter.GasConsumed()+1, "refund greater than consumed") })
+
 		meter2 := NewGasMeter(math.MaxUint64)
 		meter2.ConsumeGas(Gas(math.MaxUint64/2), "consume half max uint64")
 		require.Panics(t, func() { meter2.ConsumeGas(Gas(math.MaxUint64/2)+2, "panic") })