1 files changed, 28 insertions, 24 deletions
diff --git a/vm/stack.go b/vm/stack.go
index 69ded6562..a9aafdb9d 100644
--- a/vm/stack.go
+++ b/vm/stack.go
@@ -2,7 +2,6 @@ package vm
 
 import (
 	"fmt"
-	"math"
 	"math/big"
 )
 
@@ -91,6 +90,12 @@ func (st *Stack) Get(amount *big.Int) []*big.Int {
 	return nil
 }
 
+func (st *Stack) require(n int) {
+	if st.Len() < n {
+		panic(fmt.Sprintf("stack underflow (%d <=> %d)", st.Len(), n))
+	}
+}
+
 func (st *Stack) Print() {
 	fmt.Println("### stack ###")
 	if len(st.data) > 0 {
@@ -107,20 +112,26 @@ type Memory struct {
 	store []byte
 }
 
-func (m *Memory) Set(offset, size int64, value []byte) {
-	totSize := offset + size
-	lenSize := int64(len(m.store) - 1)
-	if totSize > lenSize {
-		// Calculate the diff between the sizes
-		diff := totSize - lenSize
-		if diff > 0 {
-			// Create a new empty slice and append it
-			newSlice := make([]byte, diff-1)
-			// Resize slice
-			m.store = append(m.store, newSlice...)
+func NewMemory() *Memory {
+	return &Memory{nil}
+}
+
+func (m *Memory) Set(offset, size uint64, value []byte) {
+	if len(value) > 0 {
+		totSize := offset + size
+		lenSize := uint64(len(m.store) - 1)
+		if totSize > lenSize {
+			// Calculate the diff between the sizes
+			diff := totSize - lenSize
+			if diff > 0 {
+				// Create a new empty slice and append it
+				newSlice := make([]byte, diff-1)
+				// Resize slice
+				m.store = append(m.store, newSlice...)
+			}
 		}
+		copy(m.store[offset:offset+size], value)
 	}
-	copy(m.store[offset:offset+size], value)
 }
 
 func (m *Memory) Resize(size uint64) {
@@ -129,21 +140,14 @@ func (m *Memory) Resize(size uint64) {
 	}
 }
 
-func (m *Memory) Get(offset, size int64) []byte {
-	if len(m.store) > int(offset) {
-		end := int(math.Min(float64(len(m.store)), float64(offset+size)))
-
-		return m.store[offset:end]
+func (self *Memory) Get(offset, size int64) (cpy []byte) {
+	if size == 0 {
+		return nil
 	}
 
-	return nil
-}
-
-func (self *Memory) Geti(offset, size int64) (cpy []byte) {
 	if len(self.store) > int(offset) {
-		s := int64(math.Min(float64(len(self.store)), float64(offset+size)))
 		cpy = make([]byte, size)
-		copy(cpy, self.store[offset:offset+s])
+		copy(cpy, self.store[offset:offset+size])
 
 		return
 	}