core: move GetPrice from core to interop

We have additional logic for getting BaseExecFee policy value. This
logic should be moved to interop context instead of being in Policer,
because Policer is just an interface over Policy contract.

After moving this logic to interop context, we need to use it to define
BaseExecFee instead of (Policer).BaseExecFee. Thus, moving
(*Blockchain).GetPrice to (*Context).GetPrice is necessary.

pkg/core/blockchain.go

@@ -641,7 +641,7 @@ func (bc *Blockchain) storeBlock(block *block.Block, txpool *mempool.Pool) error
 		systemInterop := bc.newInteropContext(trigger.Application, cache, block, tx)
 		v := systemInterop.SpawnVM()
 		v.LoadScriptWithFlags(tx.Script, callflag.All)
-		v.SetPriceGetter(bc.getPrice)
+		v.SetPriceGetter(systemInterop.GetPrice)
 		v.LoadToken = contract.LoadToken(systemInterop)
 		v.GasLimit = tx.SystemFee
 
@@ -849,7 +849,7 @@ func (bc *Blockchain) runPersist(script []byte, block *block.Block, cache *dao.C
 	systemInterop := bc.newInteropContext(trig, cache, block, nil)
 	v := systemInterop.SpawnVM()
 	v.LoadScriptWithFlags(script, callflag.WriteStates|callflag.AllowCall)
-	v.SetPriceGetter(bc.getPrice)
+	v.SetPriceGetter(systemInterop.GetPrice)
 	if err := v.Run(); err != nil {
 		return nil, fmt.Errorf("VM has failed: %w", err)
 	} else if _, err := systemInterop.DAO.Persist(); err != nil {
@@ -1718,7 +1718,7 @@ func (bc *Blockchain) GetTestVM(t trigger.Type, tx *transaction.Transaction, b *
 	d.MPT = nil
 	systemInterop := bc.newInteropContext(t, d, b, tx)
 	vm := systemInterop.SpawnVM()
-	vm.SetPriceGetter(bc.getPrice)
+	vm.SetPriceGetter(systemInterop.GetPrice)
 	vm.LoadToken = contract.LoadToken(systemInterop)
 	return vm
 }
@@ -1794,7 +1794,7 @@ func (bc *Blockchain) verifyHashAgainstScript(hash util.Uint160, witness *transa
 	}
 
 	vm := interopCtx.SpawnVM()
-	vm.SetPriceGetter(bc.getPrice)
+	vm.SetPriceGetter(interopCtx.GetPrice)
 	vm.LoadToken = contract.LoadToken(interopCtx)
 	vm.GasLimit = gas
 	if err := bc.initVerificationVM(interopCtx, hash, witness); err != nil {
@@ -1918,9 +1918,6 @@ func (bc *Blockchain) GetPolicer() blockchainer.Policer {
 
 // GetBaseExecFee return execution price for `NOP`.
 func (bc *Blockchain) GetBaseExecFee() int64 {
-	if bc.BlockHeight() == 0 {
-		return interop.DefaultBaseExecFee
-	}
 	return bc.contracts.Policy.GetExecFeeFactorInternal(bc.dao)
 }
 

pkg/core/fee/calculate.go

@@ -1,13 +1,15 @@
 package fee
 
 import (
-	"github.com/nspcc-dev/neo-go/pkg/core/interop/crypto"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
 	"github.com/nspcc-dev/neo-go/pkg/vm/emit"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
 )
 
+// ECDSAVerifyPrice is a gas price of a single verification.
+const ECDSAVerifyPrice = 1 << 15
+
 // Calculate returns network fee for transaction
 func Calculate(base int64, script []byte) (int64, int) {
 	var (
@@ -16,13 +18,13 @@ func Calculate(base int64, script []byte) (int64, int) {
 	)
 	if vm.IsSignatureContract(script) {
 		size += 67 + io.GetVarSize(script)
-		netFee += Opcode(base, opcode.PUSHDATA1, opcode.PUSHNULL, opcode.PUSHDATA1) + base*crypto.ECDSAVerifyPrice
+		netFee += Opcode(base, opcode.PUSHDATA1, opcode.PUSHNULL, opcode.PUSHDATA1) + base*ECDSAVerifyPrice
 	} else if m, pubs, ok := vm.ParseMultiSigContract(script); ok {
 		n := len(pubs)
 		sizeInv := 66 * m
 		size += io.GetVarSize(sizeInv) + sizeInv + io.GetVarSize(script)
 		netFee += calculateMultisig(base, m) + calculateMultisig(base, n)
-		netFee += Opcode(base, opcode.PUSHNULL) + base*crypto.ECDSAVerifyPrice*int64(n)
+		netFee += Opcode(base, opcode.PUSHNULL) + base*ECDSAVerifyPrice*int64(n)
 	} else {
 		// We can support more contract types in the future.
 	}

pkg/core/gas_price.go

@@ -1,12 +0,0 @@
-package core
-
-import (
-	"github.com/nspcc-dev/neo-go/pkg/core/fee"
-	"github.com/nspcc-dev/neo-go/pkg/vm"
-	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
-)
-
-// getPrice returns a price for executing op with the provided parameter.
-func (bc *Blockchain) getPrice(v *vm.VM, op opcode.Opcode, parameter []byte) int64 {
-	return fee.Opcode(bc.GetBaseExecFee(), op)
-}

pkg/core/interop/context.go

@@ -199,7 +199,7 @@ func (ic *Context) GetFunction(id uint32) *Function {
 
 // BaseExecFee represents factor to multiply syscall prices with.
 func (ic *Context) BaseExecFee() int64 {
-	if ic.Chain == nil {
+	if ic.Chain == nil || (ic.Block != nil && ic.Block.Index == 0) {
 		return DefaultBaseExecFee
 	}
 	return ic.Chain.GetPolicer().GetBaseExecFee()

pkg/core/interop/crypto/ecdsa.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 
 	"github.com/btcsuite/btcd/btcec"
+	"github.com/nspcc-dev/neo-go/pkg/core/fee"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/crypto"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
@@ -15,9 +16,6 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
 
-// ECDSAVerifyPrice is a gas price of a single verification.
-const ECDSAVerifyPrice = 1 << 15
-
 // ECDSASecp256r1Verify checks ECDSA signature using Secp256r1 elliptic curve.
 func ECDSASecp256r1Verify(ic *interop.Context) error {
 	return ecdsaVerify(ic, elliptic.P256())
@@ -69,7 +67,7 @@ func ecdsaCheckMultisig(ic *interop.Context, curve elliptic.Curve) error {
 	if err != nil {
 		return fmt.Errorf("wrong parameters: %w", err)
 	}
-	if !ic.VM.AddGas(ic.BaseExecFee() * ECDSAVerifyPrice * int64(len(pkeys))) {
+	if !ic.VM.AddGas(ic.BaseExecFee() * fee.ECDSAVerifyPrice * int64(len(pkeys))) {
 		return errors.New("gas limit exceeded")
 	}
 	sigs, err := ic.VM.Estack().PopSigElements()

pkg/core/interop/crypto/ecdsa_test.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
 	"github.com/nspcc-dev/neo-go/pkg/core/dao"
+	"github.com/nspcc-dev/neo-go/pkg/core/fee"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/core/storage"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
@@ -247,7 +248,7 @@ func testCurveCHECKMULTISIGBad(t *testing.T, isR1 bool) {
 	t.Run("1_2 too many signatures", func(t *testing.T) { testCHECKMULTISIGBad(t, isR1, true, 2, []int{0}, []int{0, 1}) })
 	t.Run("gas limit exceeded", func(t *testing.T) {
 		v := initCHECKMULTISIGVM(t, isR1, 1, []int{0}, []int{0})
-		v.GasLimit = ECDSAVerifyPrice - 1
+		v.GasLimit = fee.ECDSAVerifyPrice - 1
 		require.Error(t, v.Run())
 	})
 

pkg/core/interop/gas_price.go

@@ -0,0 +1,11 @@
+package interop
+
+import (
+	"github.com/nspcc-dev/neo-go/pkg/core/fee"
+	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
+)
+
+// GetPrice returns a price for executing op with the provided parameter.
+func (ic *Context) GetPrice(op opcode.Opcode, parameter []byte) int64 {
+	return fee.Opcode(ic.BaseExecFee(), op)
+}

pkg/core/interops.go

@@ -8,6 +8,7 @@ package core
 */
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/core/fee"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/binary"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/contract"
@@ -98,9 +99,9 @@ var systemInterops = []interop.Function{
 
 var neoInterops = []interop.Function{
 	{Name: interopnames.NeoCryptoVerifyWithECDsaSecp256r1, Func: crypto.ECDSASecp256r1Verify,
-		Price: crypto.ECDSAVerifyPrice, ParamCount: 3},
+		Price: fee.ECDSAVerifyPrice, ParamCount: 3},
 	{Name: interopnames.NeoCryptoVerifyWithECDsaSecp256k1, Func: crypto.ECDSASecp256k1Verify,
-		Price: crypto.ECDSAVerifyPrice, ParamCount: 3},
+		Price: fee.ECDSAVerifyPrice, ParamCount: 3},
 	{Name: interopnames.NeoCryptoCheckMultisigWithECDsaSecp256r1, Func: crypto.ECDSASecp256r1CheckMultisig, Price: 0, ParamCount: 3},
 	{Name: interopnames.NeoCryptoCheckMultisigWithECDsaSecp256k1, Func: crypto.ECDSASecp256k1CheckMultisig, Price: 0, ParamCount: 3},
 	{Name: interopnames.NeoCryptoSHA256, Func: crypto.Sha256, Price: 1 << 15, ParamCount: 1},

pkg/rpc/server/server_test.go

@@ -28,9 +28,9 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
 	"github.com/nspcc-dev/neo-go/pkg/io"
-	rpc2 "github.com/nspcc-dev/neo-go/pkg/services/oracle/broadcaster"
 	"github.com/nspcc-dev/neo-go/pkg/rpc/response"
 	"github.com/nspcc-dev/neo-go/pkg/rpc/response/result"
+	rpc2 "github.com/nspcc-dev/neo-go/pkg/services/oracle/broadcaster"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm"

pkg/vm/vm.go

@@ -65,7 +65,7 @@ type VM struct {
 	state State
 
 	// callback to get interop price
-	getPrice func(*VM, opcode.Opcode, []byte) int64
+	getPrice func(opcode.Opcode, []byte) int64
 
 	istack *Stack // invocation stack.
 	estack *Stack // execution stack.
@@ -119,7 +119,7 @@ func (v *VM) newItemStack(n string) *Stack {
 
 // SetPriceGetter registers the given PriceGetterFunc in v.
 // f accepts vm's Context, current instruction and instruction parameter.
-func (v *VM) SetPriceGetter(f func(*VM, opcode.Opcode, []byte) int64) {
+func (v *VM) SetPriceGetter(f func(opcode.Opcode, []byte) int64) {
 	v.getPrice = f
 }
 
@@ -528,7 +528,7 @@ func (v *VM) execute(ctx *Context, op opcode.Opcode, parameter []byte) (err erro
 	}()
 
 	if v.getPrice != nil && ctx.ip < len(ctx.prog) {
-		v.gasConsumed += v.getPrice(v, op, parameter)
+		v.gasConsumed += v.getPrice(op, parameter)
 		if v.GasLimit >= 0 && v.gasConsumed > v.GasLimit {
 			panic("gas limit is exceeded")
 		}

pkg/vm/vm_test.go

@@ -62,7 +62,7 @@ func TestVM_SetPriceGetter(t *testing.T) {
 		require.EqualValues(t, 0, v.GasConsumed())
 	})
 
-	v.SetPriceGetter(func(_ *VM, op opcode.Opcode, p []byte) int64 {
+	v.SetPriceGetter(func(op opcode.Opcode, p []byte) int64 {
 		if op == opcode.PUSH4 {
 			return 1
 		} else if op == opcode.PUSHDATA1 && bytes.Equal(p, []byte{0xCA, 0xFE}) {