* JUMPDEST analysis is faster because less type conversions are performed. * The map of JUMPDEST locations is now created lazily at the first JUMP. * The result of the analysis is kept around for recursive invocations through CALL/CALLCODE. Fixes #1147
		
			
				
	
	
		
			104 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			104 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
package vm
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import (
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	"math/big"
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	"github.com/ethereum/go-ethereum/common"
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)
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type ContextRef interface {
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	ReturnGas(*big.Int, *big.Int)
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	Address() common.Address
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	SetCode([]byte)
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}
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type Context struct {
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	caller ContextRef
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	self   ContextRef
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	jumpdests destinations // result of JUMPDEST analysis.
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	Code     []byte
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	CodeAddr *common.Address
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	value, Gas, UsedGas, Price *big.Int
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	Args []byte
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}
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// Create a new context for the given data items.
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func NewContext(caller ContextRef, object ContextRef, value, gas, price *big.Int) *Context {
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	c := &Context{caller: caller, self: object, Args: nil}
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	if parent, ok := caller.(*Context); ok {
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		// Reuse JUMPDEST analysis from parent context if available.
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		c.jumpdests = parent.jumpdests
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	} else {
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		c.jumpdests = make(destinations)
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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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	c.value = new(big.Int).Set(value)
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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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	return c
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}
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func (c *Context) GetOp(n *big.Int) OpCode {
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	return OpCode(c.GetByte(n))
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}
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func (c *Context) GetByte(n *big.Int) byte {
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	if n.Cmp(big.NewInt(int64(len(c.Code)))) < 0 {
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		return c.Code[n.Int64()]
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	}
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	return 0
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}
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func (c *Context) 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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	return ret
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}
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/*
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 * Gas functions
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 */
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func (c *Context) UseGas(gas *big.Int) (ok bool) {
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	ok = UseGas(c.Gas, gas)
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	if ok {
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		c.UsedGas.Add(c.UsedGas, gas)
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	}
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	return
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}
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// Implement the caller interface
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func (c *Context) ReturnGas(gas, price *big.Int) {
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	// Return the gas to the context
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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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 * Set / Get
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 */
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func (c *Context) Address() common.Address {
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	return c.self.Address()
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}
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func (self *Context) SetCode(code []byte) {
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	self.Code = code
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}
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func (self *Context) SetCallCode(addr *common.Address, code []byte) {
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	self.Code = code
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	self.CodeAddr = addr
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}
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