diff options
Diffstat (limited to 'core/vm/context.go')
-rw-r--r-- | core/vm/context.go | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/core/vm/context.go b/core/vm/context.go new file mode 100644 index 000000000..29bb9f74e --- /dev/null +++ b/core/vm/context.go @@ -0,0 +1,94 @@ +package vm + +import ( + "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 *big.Int) OpCode { + return OpCode(c.GetByte(n)) +} + +func (c *Context) GetByte(n *big.Int) byte { + if n.Cmp(big.NewInt(int64(len(c.Code)))) < 0 { + return c.Code[n.Int64()] + } + + return 0 +} + +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) (ok bool) { + ok = UseGas(c.Gas, gas) + if ok { + c.UsedGas.Add(c.UsedGas, gas) + } + return +} + +// 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 +} |