115 lines
2.3 KiB
Go
115 lines
2.3 KiB
Go
package vm
|
|
|
|
import (
|
|
"math"
|
|
"math/big"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
)
|
|
|
|
type ContextRef interface {
|
|
ReturnGas(*big.Int, *big.Int)
|
|
Address() common.Address
|
|
SetCode([]byte)
|
|
}
|
|
|
|
type Context struct {
|
|
caller ContextRef
|
|
self ContextRef
|
|
|
|
Code []byte
|
|
CodeAddr *common.Address
|
|
|
|
value, Gas, UsedGas, Price *big.Int
|
|
|
|
Args []byte
|
|
}
|
|
|
|
// Create a new context for the given data items
|
|
func NewContext(caller ContextRef, object ContextRef, value, gas, price *big.Int) *Context {
|
|
c := &Context{caller: caller, self: object, Args: nil}
|
|
|
|
// Gas should be a pointer so it can safely be reduced through the run
|
|
// This pointer will be off the state transition
|
|
c.Gas = gas //new(big.Int).Set(gas)
|
|
c.value = new(big.Int).Set(value)
|
|
// In most cases price and value are pointers to transaction objects
|
|
// and we don't want the transaction's values to change.
|
|
c.Price = new(big.Int).Set(price)
|
|
c.UsedGas = new(big.Int)
|
|
|
|
return c
|
|
}
|
|
|
|
func (c *Context) GetOp(n uint64) OpCode {
|
|
return OpCode(c.GetByte(n))
|
|
}
|
|
|
|
func (c *Context) GetByte(n uint64) byte {
|
|
if n < uint64(len(c.Code)) {
|
|
return c.Code[n]
|
|
}
|
|
|
|
return 0
|
|
}
|
|
|
|
func (c *Context) GetBytes(x, y int) []byte {
|
|
return c.GetRangeValue(uint64(x), uint64(y))
|
|
}
|
|
|
|
func (c *Context) GetRangeValue(x, size uint64) []byte {
|
|
x = uint64(math.Min(float64(x), float64(len(c.Code))))
|
|
y := uint64(math.Min(float64(x+size), float64(len(c.Code))))
|
|
|
|
return common.RightPadBytes(c.Code[x:y], int(size))
|
|
}
|
|
|
|
func (c *Context) GetCode(x, size uint64) []byte {
|
|
return getCode(c.Code, x, size)
|
|
}
|
|
|
|
func (c *Context) Return(ret []byte) []byte {
|
|
// Return the remaining gas to the caller
|
|
c.caller.ReturnGas(c.Gas, c.Price)
|
|
|
|
return ret
|
|
}
|
|
|
|
/*
|
|
* Gas functions
|
|
*/
|
|
func (c *Context) UseGas(gas *big.Int) bool {
|
|
if c.Gas.Cmp(gas) < 0 {
|
|
return false
|
|
}
|
|
|
|
// Sub the amount of gas from the remaining
|
|
c.Gas.Sub(c.Gas, gas)
|
|
c.UsedGas.Add(c.UsedGas, gas)
|
|
|
|
return true
|
|
}
|
|
|
|
// Implement the caller interface
|
|
func (c *Context) ReturnGas(gas, price *big.Int) {
|
|
// Return the gas to the context
|
|
c.Gas.Add(c.Gas, gas)
|
|
c.UsedGas.Sub(c.UsedGas, gas)
|
|
}
|
|
|
|
/*
|
|
* Set / Get
|
|
*/
|
|
func (c *Context) Address() common.Address {
|
|
return c.self.Address()
|
|
}
|
|
|
|
func (self *Context) SetCode(code []byte) {
|
|
self.Code = code
|
|
}
|
|
|
|
func (self *Context) SetCallCode(addr *common.Address, code []byte) {
|
|
self.Code = code
|
|
self.CodeAddr = addr
|
|
}
|