mirror of
https://gitlab.com/pulsechaincom/go-pulse.git
synced 2024-12-22 03:30:35 +00:00
83 lines
2.1 KiB
Go
83 lines
2.1 KiB
Go
// Copyright 2014 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package vm
|
|
|
|
import (
|
|
"sync"
|
|
|
|
"github.com/holiman/uint256"
|
|
)
|
|
|
|
var stackPool = sync.Pool{
|
|
New: func() interface{} {
|
|
return &Stack{data: make([]uint256.Int, 0, 16)}
|
|
},
|
|
}
|
|
|
|
// Stack is an object for basic stack operations. Items popped to the stack are
|
|
// expected to be changed and modified. stack does not take care of adding newly
|
|
// initialised objects.
|
|
type Stack struct {
|
|
data []uint256.Int
|
|
}
|
|
|
|
func newstack() *Stack {
|
|
return stackPool.Get().(*Stack)
|
|
}
|
|
|
|
func returnStack(s *Stack) {
|
|
s.data = s.data[:0]
|
|
stackPool.Put(s)
|
|
}
|
|
|
|
// Data returns the underlying uint256.Int array.
|
|
func (st *Stack) Data() []uint256.Int {
|
|
return st.data
|
|
}
|
|
|
|
func (st *Stack) push(d *uint256.Int) {
|
|
// NOTE push limit (1024) is checked in baseCheck
|
|
st.data = append(st.data, *d)
|
|
}
|
|
|
|
func (st *Stack) pop() (ret uint256.Int) {
|
|
ret = st.data[len(st.data)-1]
|
|
st.data = st.data[:len(st.data)-1]
|
|
return
|
|
}
|
|
|
|
func (st *Stack) len() int {
|
|
return len(st.data)
|
|
}
|
|
|
|
func (st *Stack) swap(n int) {
|
|
st.data[st.len()-n], st.data[st.len()-1] = st.data[st.len()-1], st.data[st.len()-n]
|
|
}
|
|
|
|
func (st *Stack) dup(n int) {
|
|
st.push(&st.data[st.len()-n])
|
|
}
|
|
|
|
func (st *Stack) peek() *uint256.Int {
|
|
return &st.data[st.len()-1]
|
|
}
|
|
|
|
// Back returns the n'th item in stack
|
|
func (st *Stack) Back(n int) *uint256.Int {
|
|
return &st.data[st.len()-n-1]
|
|
}
|