1 files changed, 76 insertions, 0 deletions
diff --git a/core/vm/memory.go b/core/vm/memory.go
new file mode 100644
index 000000000..dd47fa1b5
--- /dev/null
+++ b/core/vm/memory.go
@@ -0,0 +1,76 @@
+package vm
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+type Memory struct {
+	store []byte
+}
+
+func NewMemory() *Memory {
+	return &Memory{nil}
+}
+
+func (m *Memory) Set(offset, size uint64, value []byte) {
+	value = common.RightPadBytes(value, int(size))
+
+	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)
+}
+
+func (m *Memory) Resize(size uint64) {
+	if uint64(m.Len()) < size {
+		m.store = append(m.store, make([]byte, size-uint64(m.Len()))...)
+	}
+}
+
+func (self *Memory) Get(offset, size int64) (cpy []byte) {
+	if size == 0 {
+		return nil
+	}
+
+	if len(self.store) > int(offset) {
+		cpy = make([]byte, size)
+		copy(cpy, self.store[offset:offset+size])
+
+		return
+	}
+
+	return
+}
+
+func (m *Memory) Len() int {
+	return len(m.store)
+}
+
+func (m *Memory) Data() []byte {
+	return m.store
+}
+
+func (m *Memory) Print() {
+	fmt.Printf("### mem %d bytes ###\n", len(m.store))
+	if len(m.store) > 0 {
+		addr := 0
+		for i := 0; i+32 <= len(m.store); i += 32 {
+			fmt.Printf("%03d: % x\n", addr, m.store[i:i+32])
+			addr++
+		}
+	} else {
+		fmt.Println("-- empty --")
+	}
+	fmt.Println("####################")
+}