Add base cost for getVerifiedWarpMessage

ava-labs · Jul 25, 2023 · 1ad4ea6 · 1ad4ea6
1 parent 9507e18
commit 1ad4ea6
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Showing 2 changed files with 15 additions and 13 deletions.
diff --git a/x/warp/contract.go b/x/warp/contract.go
@@ -22,8 +22,9 @@ import (
 )
 
 const (
-	GetBlockchainIDGasCost uint64 = 2      // Based on GasQuickStep used in existing EVM instructions
-	AddWarpMessageGasCost  uint64 = 20_000 // Cost of producing and serving a BLS Signature
+	GetVerifiedWarpMessageBaseCost uint64 = 2      // Base cost of entering getVerifiedWarpMessage
+	GetBlockchainIDGasCost         uint64 = 2      // Based on GasQuickStep used in existing EVM instructions
+	AddWarpMessageGasCost          uint64 = 20_000 // Cost of producing and serving a BLS Signature
 	// Sum of base log gas cost, cost of producing 4 topics, and producing + serving a BLS Signature (sign + trie write)
 	// Note: using trie write for the gas cost results in a conservative overestimate since the message is stored in a
 	// flat database that can be cleaned up after a period of time instead of the EVM trie.
@@ -117,9 +118,10 @@ func PackGetVerifiedWarpMessageOutput(outputStruct GetVerifiedWarpMessageOutput)
 // getVerifiedWarpMessage retrieves the pre-verified warp message from the predicate storage slots and returns
 // the expected ABI encoding of the message to the caller.
 func getVerifiedWarpMessage(accessibleState contract.AccessibleState, caller common.Address, addr common.Address, _ []byte, suppliedGas uint64, readOnly bool) (ret []byte, remainingGas uint64, err error) {
-	remainingGas = suppliedGas
-	// XXX Note: there is no base cost for retrieving a verified warp message. Instead, we charge for each piece of gas,
-	// prior to each execution step.
+	remainingGas, err = contract.DeductGas(suppliedGas, GetVerifiedWarpMessageBaseCost)
+	if err != nil {
+		return nil, remainingGas, err
+	}
 	// Ignore input since there are no arguments
 	predicateBytes, exists := accessibleState.GetStateDB().GetPredicateStorageSlots(ContractAddress)
 	// If there is no such value, return false to the caller.

diff --git a/x/warp/contract_test.go b/x/warp/contract_test.go
@@ -180,7 +180,7 @@ func TestGetVerifiedWarpMessage(t *testing.T) {
 			BeforeHook: func(t testing.TB, state contract.StateDB) {
 				state.SetPredicateStorageSlots(ContractAddress, warpMessagePredicateBytes)
 			},
-			SuppliedGas: GasCostPerWarpMessageBytes * uint64(len(warpMessagePredicateBytes)),
+			SuppliedGas: GetVerifiedWarpMessageBaseCost + GasCostPerWarpMessageBytes*uint64(len(warpMessagePredicateBytes)),
 			ReadOnly:    false,
 			ExpectedRes: func() []byte {
 				res, err := PackGetVerifiedWarpMessageOutput(GetVerifiedWarpMessageOutput{
@@ -202,7 +202,7 @@ func TestGetVerifiedWarpMessage(t *testing.T) {
 		"get non-existent message": {
 			Caller:      callerAddr,
 			InputFn:     func(t testing.TB) []byte { return getVerifiedWarpMsg },
-			SuppliedGas: 0,
+			SuppliedGas: GetVerifiedWarpMessageBaseCost,
 			ReadOnly:    false,
 			ExpectedRes: func() []byte {
 				res, err := PackGetVerifiedWarpMessageOutput(GetVerifiedWarpMessageOutput{Exists: false})
@@ -218,7 +218,7 @@ func TestGetVerifiedWarpMessage(t *testing.T) {
 			BeforeHook: func(t testing.TB, state contract.StateDB) {
 				state.SetPredicateStorageSlots(ContractAddress, warpMessagePredicateBytes)
 			},
-			SuppliedGas: GasCostPerWarpMessageBytes * uint64(len(warpMessagePredicateBytes)),
+			SuppliedGas: GetVerifiedWarpMessageBaseCost + GasCostPerWarpMessageBytes*uint64(len(warpMessagePredicateBytes)),
 			ReadOnly:    true,
 			ExpectedRes: func() []byte {
 				res, err := PackGetVerifiedWarpMessageOutput(GetVerifiedWarpMessageOutput{
@@ -240,7 +240,7 @@ func TestGetVerifiedWarpMessage(t *testing.T) {
 		"get non-existent message readOnly": {
 			Caller:      callerAddr,
 			InputFn:     func(t testing.TB) []byte { return getVerifiedWarpMsg },
-			SuppliedGas: 0,
+			SuppliedGas: GetVerifiedWarpMessageBaseCost,
 			ReadOnly:    true,
 			ExpectedRes: func() []byte {
 				res, err := PackGetVerifiedWarpMessageOutput(GetVerifiedWarpMessageOutput{Exists: false})
@@ -256,7 +256,7 @@ func TestGetVerifiedWarpMessage(t *testing.T) {
 			BeforeHook: func(t testing.TB, state contract.StateDB) {
 				state.SetPredicateStorageSlots(ContractAddress, warpMessagePredicateBytes)
 			},
-			SuppliedGas: GasCostPerWarpMessageBytes*uint64(len(warpMessagePredicateBytes)) - 1,
+			SuppliedGas: GetVerifiedWarpMessageBaseCost + GasCostPerWarpMessageBytes*uint64(len(warpMessagePredicateBytes)) - 1,
 			ReadOnly:    false,
 			ExpectedErr: vmerrs.ErrOutOfGas.Error(),
 		},
@@ -266,7 +266,7 @@ func TestGetVerifiedWarpMessage(t *testing.T) {
 			BeforeHook: func(t testing.TB, state contract.StateDB) {
 				state.SetPredicateStorageSlots(ContractAddress, warpMessage.Bytes())
 			},
-			SuppliedGas: GasCostPerWarpMessageBytes * uint64(len(warpMessage.Bytes())),
+			SuppliedGas: GetVerifiedWarpMessageBaseCost + GasCostPerWarpMessageBytes*uint64(len(warpMessage.Bytes())),
 			ReadOnly:    false,
 			ExpectedErr: errInvalidPredicateBytes.Error(),
 		},
@@ -276,7 +276,7 @@ func TestGetVerifiedWarpMessage(t *testing.T) {
 			BeforeHook: func(t testing.TB, state contract.StateDB) {
 				state.SetPredicateStorageSlots(ContractAddress, predicateutils.PackPredicate([]byte{1, 2, 3}))
 			},
-			SuppliedGas: GasCostPerWarpMessageBytes * uint64(32),
+			SuppliedGas: GetVerifiedWarpMessageBaseCost + GasCostPerWarpMessageBytes*uint64(32),
 			ReadOnly:    false,
 			ExpectedErr: errInvalidWarpMsg.Error(),
 		},
@@ -291,7 +291,7 @@ func TestGetVerifiedWarpMessage(t *testing.T) {
 
 				state.SetPredicateStorageSlots(ContractAddress, predicateutils.PackPredicate(warpMessage.Bytes()))
 			},
-			SuppliedGas: GasCostPerWarpMessageBytes * uint64(192),
+			SuppliedGas: GetVerifiedWarpMessageBaseCost + GasCostPerWarpMessageBytes*uint64(192),
 			ReadOnly:    false,
 			ExpectedErr: errInvalidAddressedPayload.Error(),
 		},