package vm
import (
"fmt"
"math/big"
)
type OpType int
const (
tNorm = iota
tData
tExtro
tCrypto
)
type TxCallback func(opType OpType) bool
// Simple push/pop stack mechanism
type Stack struct {
data []*big.Int
}
func NewStack() *Stack {
return &Stack{}
}
func (st *Stack) Data() []*big.Int {
return st.data
}
func (st *Stack) Len() int {
return len(st.data)
}
func (st *Stack) Pop() *big.Int {
str := st.data[len(st.data)-1]
copy(st.data[:len(st.data)-1], st.data[:len(st.data)-1])
st.data = st.data[:len(st.data)-1]
return str
}
func (st *Stack) Popn() (*big.Int, *big.Int) {
ints := st.data[len(st.data)-2:]
copy(st.data[:len(st.data)-2], st.data[:len(st.data)-2])
st.data = st.data[:len(st.data)-2]
return ints[0], ints[1]
}
func (st *Stack) Peek() *big.Int {
str := st.data[len(st.data)-1]
return str
}
func (st *Stack) Peekn() (*big.Int, *big.Int) {
ints := st.data[len(st.data)-2:]
return ints[0], ints[1]
}
func (st *Stack) Swapn(n int) (*big.Int, *big.Int) {
st.data[len(st.data)-n], st.data[len(st.data)-1] = st.data[len(st.data)-1], st.data[len(st.data)-n]
return st.data[len(st.data)-n], st.data[len(st.data)-1]
}
func (st *Stack) Dupn(n int) *big.Int {
st.Push(st.data[len(st.data)-n])
return st.Peek()
}
func (st *Stack) Push(d *big.Int) {
st.data = append(st.data, new(big.Int).Set(d))
}
func (st *Stack) Get(amount *big.Int) []*big.Int {
// offset + size <= len(data)
length := big.NewInt(int64(len(st.data)))
if amount.Cmp(length) <= 0 {
start := new(big.Int).Sub(length, amount)
return st.data[start.Int64():length.Int64()]
}
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 {
for i, val := range st.data {
fmt.Printf("%-3d %v\n", i, val)
}
} else {
fmt.Println("-- empty --")
}
fmt.Println("#############")
}
type Memory struct {
store []byte
}
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)
}
}
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("####################")
}
