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) { // length of store may never be less than offset + size. // The store should be resized PRIOR to setting the memory if size > uint64(len(m.store)) { panic("INVALID memory: store empty") } // It's possible the offset is greater than 0 and size equals 0. This is because // the calcMemSize (common.go) could potentially return 0 when size is zero (NO-OP) if size > 0 { copy(m.store[offset:offset+size], common.RightPadBytes(value, int(size))) } } 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 (self *Memory) GetPtr(offset, size int64) []byte { if size == 0 { return nil } if len(self.store) > int(offset) { return self.store[offset : offset+size] } return nil } 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("####################") }