141 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			141 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| package ethvm
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| 
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| // TODO Re write VM to use values instead of big integers?
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| 
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| import (
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| 	"math/big"
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| 
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| 	"github.com/ethereum/eth-go/ethstate"
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| 	"github.com/ethereum/eth-go/ethutil"
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| )
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| 
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| type ClosureRef interface {
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| 	ReturnGas(*big.Int, *big.Int)
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| 	Address() []byte
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| 	Object() *ethstate.StateObject
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| 	GetStorage(*big.Int) *ethutil.Value
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| 	SetStorage(*big.Int, *ethutil.Value)
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| }
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| 
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| // Basic inline closure object which implement the 'closure' interface
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| type Closure struct {
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| 	caller  ClosureRef
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| 	object  *ethstate.StateObject
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| 	Code    []byte
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| 	message *ethstate.Message
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| 	exe     *Execution
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| 
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| 	Gas, UsedGas, Price *big.Int
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| 
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| 	Args []byte
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| }
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| 
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| // Create a new closure for the given data items
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| func NewClosure(msg *ethstate.Message, caller ClosureRef, object *ethstate.StateObject, code []byte, gas, price *big.Int) *Closure {
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| 	c := &Closure{message: msg, caller: caller, object: object, Code: code, Args: nil}
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| 
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| 	// Gas should be a pointer so it can safely be reduced through the run
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| 	// This pointer will be off the state transition
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| 	c.Gas = gas //new(big.Int).Set(gas)
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| 	// In most cases price and value are pointers to transaction objects
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| 	// and we don't want the transaction's values to change.
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| 	c.Price = new(big.Int).Set(price)
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| 	c.UsedGas = new(big.Int)
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| 
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| 	return c
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| }
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| 
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| // Retuns the x element in data slice
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| func (c *Closure) GetStorage(x *big.Int) *ethutil.Value {
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| 	m := c.object.GetStorage(x)
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| 	if m == nil {
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| 		return ethutil.EmptyValue()
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| 	}
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| 
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| 	return m
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| }
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| 
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| func (c *Closure) Get(x *big.Int) *ethutil.Value {
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| 	return c.Gets(x, big.NewInt(1))
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| }
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| 
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| func (c *Closure) GetOp(x int) OpCode {
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| 	return OpCode(c.GetByte(x))
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| }
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| 
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| func (c *Closure) GetByte(x int) byte {
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| 	if x < len(c.Code) {
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| 		return c.Code[x]
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| 	}
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| 
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| 	return 0
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| }
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| 
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| func (c *Closure) GetBytes(x, y int) []byte {
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| 	if x >= len(c.Code) || y >= len(c.Code) {
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| 		return nil
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| 	}
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| 
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| 	return c.Code[x : x+y]
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| }
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| 
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| func (c *Closure) Gets(x, y *big.Int) *ethutil.Value {
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| 	if x.Int64() >= int64(len(c.Code)) || y.Int64() >= int64(len(c.Code)) {
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| 		return ethutil.NewValue(0)
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| 	}
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| 
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| 	partial := c.Code[x.Int64() : x.Int64()+y.Int64()]
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| 
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| 	return ethutil.NewValue(partial)
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| }
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| 
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| func (c *Closure) SetStorage(x *big.Int, val *ethutil.Value) {
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| 	c.object.SetStorage(x, val)
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| }
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| 
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| func (c *Closure) Address() []byte {
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| 	return c.object.Address()
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| }
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| 
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| func (c *Closure) Call(vm VirtualMachine, args []byte) ([]byte, *big.Int, error) {
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| 	c.Args = args
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| 
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| 	ret, err := vm.RunClosure(c)
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| 
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| 	return ret, c.UsedGas, err
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| }
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| 
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| func (c *Closure) Return(ret []byte) []byte {
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| 	// Return the remaining gas to the caller
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| 	c.caller.ReturnGas(c.Gas, c.Price)
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| 
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| 	return ret
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| }
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| 
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| func (c *Closure) UseGas(gas *big.Int) bool {
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| 	if c.Gas.Cmp(gas) < 0 {
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| 		return false
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| 	}
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| 
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| 	// Sub the amount of gas from the remaining
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| 	c.Gas.Sub(c.Gas, gas)
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| 	c.UsedGas.Add(c.UsedGas, gas)
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| 
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| 	return true
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| }
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| 
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| // Implement the caller interface
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| func (c *Closure) ReturnGas(gas, price *big.Int) {
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| 	// Return the gas to the closure
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| 	c.Gas.Add(c.Gas, gas)
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| 	c.UsedGas.Sub(c.UsedGas, gas)
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| }
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| 
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| func (c *Closure) Object() *ethstate.StateObject {
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| 	return c.object
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| }
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| 
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| func (c *Closure) Caller() ClosureRef {
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| 	return c.caller
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| }
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