core: move GetScriptContainer to runtime

It also brings ToStackItem to Block and Transaction, previously this was
avoided to separate block and transaction packages from VM. But turns out
`transaction` depends on `stackitem` already, so this makes little sense (but
can be shuffled in another way if needed).

Context.Container is still a hash.Hashable because we have a number of
occasions (header or MPT root verification) where there is no ToStackItem
implementation possible. Maybe they can go with `nil` Container, but I don't
want to have this risk for now.

pkg/core/block/block.go

@@ -4,11 +4,13 @@ import (
 	"encoding/json"
 	"errors"
 	"math"
+	"math/big"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
 
 const (
@@ -211,3 +213,18 @@ func (b *Block) GetExpectedBlockSizeWithoutTransactions(txCount int) int {
 	}
 	return size
 }
+
+// ToStackItem converts Block to stackitem.Item.
+func (b *Block) ToStackItem() stackitem.Item {
+	return stackitem.NewArray([]stackitem.Item{
+		stackitem.NewByteArray(b.Hash().BytesBE()),
+		stackitem.NewBigInteger(big.NewInt(int64(b.Version))),
+		stackitem.NewByteArray(b.PrevHash.BytesBE()),
+		stackitem.NewByteArray(b.MerkleRoot.BytesBE()),
+		stackitem.NewBigInteger(big.NewInt(int64(b.Timestamp))),
+		stackitem.NewBigInteger(new(big.Int).SetUint64(b.Nonce)),
+		stackitem.NewBigInteger(big.NewInt(int64(b.Index))),
+		stackitem.NewByteArray(b.NextConsensus.BytesBE()),
+		stackitem.NewBigInteger(big.NewInt(int64(len(b.Transactions)))),
+	})
+}

pkg/core/interop/runtime/engine.go

@@ -10,6 +10,10 @@ import (
 	"go.uber.org/zap"
 )
 
+type itemable interface {
+	ToStackItem() stackitem.Item
+}
+
 const (
 	// MaxEventNameLen is the maximum length of a name for event.
 	MaxEventNameLen = 32
@@ -37,6 +41,17 @@ func GetEntryScriptHash(ic *interop.Context) error {
 	return ic.VM.PushContextScriptHash(ic.VM.Istack().Len() - 1)
 }
 
+// GetScriptContainer returns transaction or block that contains the script
+// being run.
+func GetScriptContainer(ic *interop.Context) error {
+	c, ok := ic.Container.(itemable)
+	if !ok {
+		return errors.New("unknown script container")
+	}
+	ic.VM.Estack().PushItem(c.ToStackItem())
+	return nil
+}
+
 // Platform returns the name of the platform.
 func Platform(ic *interop.Context) error {
 	ic.VM.Estack().PushItem(stackitem.NewByteArray([]byte("NEO")))

pkg/core/interop_system.go

@@ -5,12 +5,9 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/nspcc-dev/neo-go/pkg/core/block"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	istorage "github.com/nspcc-dev/neo-go/pkg/core/interop/storage"
-	"github.com/nspcc-dev/neo-go/pkg/core/native"
 	"github.com/nspcc-dev/neo-go/pkg/core/storage"
-	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
 
@@ -26,22 +23,6 @@ type StorageContext struct {
 	ReadOnly bool
 }
 
-// engineGetScriptContainer returns transaction or block that contains the script
-// being run.
-func engineGetScriptContainer(ic *interop.Context) error {
-	var item stackitem.Item
-	switch t := ic.Container.(type) {
-	case *transaction.Transaction:
-		item = native.TransactionToStackItem(t)
-	case *block.Block:
-		item = native.BlockToStackItem(t)
-	default:
-		return errors.New("unknown script container")
-	}
-	ic.VM.Estack().PushItem(item)
-	return nil
-}
-
 // storageDelete deletes stored key-value pair.
 func storageDelete(ic *interop.Context) error {
 	stcInterface := ic.VM.Estack().Pop().Value()

pkg/core/interops.go

@@ -54,7 +54,7 @@ var systemInterops = []interop.Function{
 	{Name: interopnames.SystemRuntimeGetNetwork, Func: runtime.GetNetwork, Price: 1 << 3},
 	{Name: interopnames.SystemRuntimeGetNotifications, Func: runtime.GetNotifications, Price: 1 << 12, ParamCount: 1},
 	{Name: interopnames.SystemRuntimeGetRandom, Func: runtime.GetRandom, Price: 0},
-	{Name: interopnames.SystemRuntimeGetScriptContainer, Func: engineGetScriptContainer, Price: 1 << 3},
+	{Name: interopnames.SystemRuntimeGetScriptContainer, Func: runtime.GetScriptContainer, Price: 1 << 3},
 	{Name: interopnames.SystemRuntimeGetTime, Func: runtime.GetTime, Price: 1 << 3, RequiredFlags: callflag.ReadStates},
 	{Name: interopnames.SystemRuntimeGetTrigger, Func: runtime.GetTrigger, Price: 1 << 3},
 	{Name: interopnames.SystemRuntimeLog, Func: runtime.Log, Price: 1 << 15, RequiredFlags: callflag.AllowNotify,

pkg/core/native/ledger.go

@@ -5,7 +5,6 @@ import (
 	"math"
 	"math/big"
 
-	"github.com/nspcc-dev/neo-go/pkg/core/block"
 	"github.com/nspcc-dev/neo-go/pkg/core/dao"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/core/native/nativenames"
@@ -117,7 +116,7 @@ func (l *Ledger) getBlock(ic *interop.Context, params []stackitem.Item) stackite
 	if err != nil || !isTraceableBlock(ic, block.Index) {
 		return stackitem.Null{}
 	}
-	return BlockToStackItem(block)
+	return block.ToStackItem()
 }
 
 // getTransaction returns transaction to the SC.
@@ -126,7 +125,7 @@ func (l *Ledger) getTransaction(ic *interop.Context, params []stackitem.Item) st
 	if err != nil || !isTraceableBlock(ic, h) {
 		return stackitem.Null{}
 	}
-	return TransactionToStackItem(tx)
+	return tx.ToStackItem()
 }
 
 // getTransactionHeight returns transaction height to the SC.
@@ -150,7 +149,7 @@ func (l *Ledger) getTransactionFromBlock(ic *interop.Context, params []stackitem
 	if index >= uint32(len(block.Transactions)) {
 		panic("wrong transaction index")
 	}
-	return TransactionToStackItem(block.Transactions[index])
+	return block.Transactions[index].ToStackItem()
 }
 
 // getTransactionSigners returns transaction signers to the SC.
@@ -228,35 +227,6 @@ func getTransactionAndHeight(d *dao.Simple, item stackitem.Item) (*transaction.T
 	return d.GetTransaction(hash)
 }
 
-// BlockToStackItem converts block.Block to stackitem.Item.
-func BlockToStackItem(b *block.Block) stackitem.Item {
-	return stackitem.NewArray([]stackitem.Item{
-		stackitem.NewByteArray(b.Hash().BytesBE()),
-		stackitem.NewBigInteger(big.NewInt(int64(b.Version))),
-		stackitem.NewByteArray(b.PrevHash.BytesBE()),
-		stackitem.NewByteArray(b.MerkleRoot.BytesBE()),
-		stackitem.NewBigInteger(big.NewInt(int64(b.Timestamp))),
-		stackitem.NewBigInteger(new(big.Int).SetUint64(b.Nonce)),
-		stackitem.NewBigInteger(big.NewInt(int64(b.Index))),
-		stackitem.NewByteArray(b.NextConsensus.BytesBE()),
-		stackitem.NewBigInteger(big.NewInt(int64(len(b.Transactions)))),
-	})
-}
-
-// TransactionToStackItem converts transaction.Transaction to stackitem.Item.
-func TransactionToStackItem(t *transaction.Transaction) stackitem.Item {
-	return stackitem.NewArray([]stackitem.Item{
-		stackitem.NewByteArray(t.Hash().BytesBE()),
-		stackitem.NewBigInteger(big.NewInt(int64(t.Version))),
-		stackitem.NewBigInteger(big.NewInt(int64(t.Nonce))),
-		stackitem.NewByteArray(t.Sender().BytesBE()),
-		stackitem.NewBigInteger(big.NewInt(int64(t.SystemFee))),
-		stackitem.NewBigInteger(big.NewInt(int64(t.NetworkFee))),
-		stackitem.NewBigInteger(big.NewInt(int64(t.ValidUntilBlock))),
-		stackitem.NewByteArray(t.Script),
-	})
-}
-
 // SignersToStackItem converts transaction.Signers to stackitem.Item.
 func SignersToStackItem(signers []transaction.Signer) stackitem.Item {
 	res := make([]stackitem.Item, len(signers))

pkg/core/transaction/transaction.go

@@ -6,12 +6,14 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"math/big"
 	"math/rand"
 
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
 
 const (
@@ -451,3 +453,17 @@ func (t *Transaction) HasSigner(hash util.Uint160) bool {
 	}
 	return false
 }
+
+// ToStackItem converts Transaction to stackitem.Item.
+func (t *Transaction) ToStackItem() stackitem.Item {
+	return stackitem.NewArray([]stackitem.Item{
+		stackitem.NewByteArray(t.Hash().BytesBE()),
+		stackitem.NewBigInteger(big.NewInt(int64(t.Version))),
+		stackitem.NewBigInteger(big.NewInt(int64(t.Nonce))),
+		stackitem.NewByteArray(t.Sender().BytesBE()),
+		stackitem.NewBigInteger(big.NewInt(int64(t.SystemFee))),
+		stackitem.NewBigInteger(big.NewInt(int64(t.NetworkFee))),
+		stackitem.NewBigInteger(big.NewInt(int64(t.ValidUntilBlock))),
+		stackitem.NewByteArray(t.Script),
+	})
+}