core/vm/runtime: added simple execution runtime

The runtime environment can be used for simple basic execution of
contract code without the requirement of setting up a full stack and
operates fully in memory.

core/vm/runtime/env.go

@@ -0,0 +1,106 @@
+// 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 runtime
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/vm"
+)
+
+// Env is a basic runtime environment required for running the EVM.
+type Env struct {
+	depth int
+	state *state.StateDB
+
+	origin   common.Address
+	coinbase common.Address
+
+	number     *big.Int
+	time       *big.Int
+	difficulty *big.Int
+	gasLimit   *big.Int
+
+	logs []vm.StructLog
+
+	getHashFn func(uint64) common.Hash
+}
+
+// NewEnv returns a new vm.Environment
+func NewEnv(cfg *Config, state *state.StateDB) vm.Environment {
+	return &Env{
+		state:      state,
+		origin:     cfg.Origin,
+		coinbase:   cfg.Coinbase,
+		number:     cfg.BlockNumber,
+		time:       cfg.Time,
+		difficulty: cfg.Difficulty,
+		gasLimit:   cfg.GasLimit,
+	}
+}
+
+func (self *Env) StructLogs() []vm.StructLog {
+	return self.logs
+}
+
+func (self *Env) AddStructLog(log vm.StructLog) {
+	self.logs = append(self.logs, log)
+}
+
+func (self *Env) Origin() common.Address   { return self.origin }
+func (self *Env) BlockNumber() *big.Int    { return self.number }
+func (self *Env) Coinbase() common.Address { return self.coinbase }
+func (self *Env) Time() *big.Int           { return self.time }
+func (self *Env) Difficulty() *big.Int     { return self.difficulty }
+func (self *Env) Db() vm.Database          { return self.state }
+func (self *Env) GasLimit() *big.Int       { return self.gasLimit }
+func (self *Env) VmType() vm.Type          { return vm.StdVmTy }
+func (self *Env) GetHash(n uint64) common.Hash {
+	return self.getHashFn(n)
+}
+func (self *Env) AddLog(log *vm.Log) {
+	self.state.AddLog(log)
+}
+func (self *Env) Depth() int     { return self.depth }
+func (self *Env) SetDepth(i int) { self.depth = i }
+func (self *Env) CanTransfer(from common.Address, balance *big.Int) bool {
+	return self.state.GetBalance(from).Cmp(balance) >= 0
+}
+func (self *Env) MakeSnapshot() vm.Database {
+	return self.state.Copy()
+}
+func (self *Env) SetSnapshot(copy vm.Database) {
+	self.state.Set(copy.(*state.StateDB))
+}
+
+func (self *Env) Transfer(from, to vm.Account, amount *big.Int) {
+	core.Transfer(from, to, amount)
+}
+
+func (self *Env) Call(caller vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
+	return core.Call(self, caller, addr, data, gas, price, value)
+}
+func (self *Env) CallCode(caller vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
+	return core.CallCode(self, caller, addr, data, gas, price, value)
+}
+
+func (self *Env) Create(caller vm.ContractRef, data []byte, gas, price, value *big.Int) ([]byte, common.Address, error) {
+	return core.Create(self, caller, data, gas, price, value)
+}