1 files changed, 170 insertions, 0 deletions
diff --git a/core/vm/evm/runtime/runtime.go b/core/vm/evm/runtime/runtime.go
new file mode 100644
index 000000000..93e6322f4
--- /dev/null
+++ b/core/vm/evm/runtime/runtime.go
@@ -0,0 +1,170 @@
+// Copyright 2015 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"
+	"math/big"
+	"time"
+
+	"github.com/dexon-foundation/dexon/common"
+	"github.com/dexon-foundation/dexon/core/state"
+	vm "github.com/dexon-foundation/dexon/core/vm/evm"
+	"github.com/dexon-foundation/dexon/crypto"
+	"github.com/dexon-foundation/dexon/ethdb"
+	"github.com/dexon-foundation/dexon/params"
+)
+
+// Config is a basic type specifying certain configuration flags for running
+// the EVM.
+type Config struct {
+	ChainConfig *params.ChainConfig
+	Difficulty  *big.Int
+	Origin      common.Address
+	Coinbase    common.Address
+	BlockNumber *big.Int
+	Time        *big.Int
+	GasLimit    uint64
+	GasPrice    *big.Int
+	Value       *big.Int
+	Debug       bool
+	EVMConfig   vm.Config
+
+	State     *state.StateDB
+	GetHashFn func(n uint64) common.Hash
+}
+
+// sets defaults on the config
+func setDefaults(cfg *Config) {
+	if cfg.ChainConfig == nil {
+		cfg.ChainConfig = &params.ChainConfig{
+			ChainID:        big.NewInt(1),
+			HomesteadBlock: new(big.Int),
+			DAOForkBlock:   new(big.Int),
+			DAOForkSupport: false,
+			EIP150Block:    new(big.Int),
+			EIP155Block:    new(big.Int),
+			EIP158Block:    new(big.Int),
+		}
+	}
+
+	if cfg.Difficulty == nil {
+		cfg.Difficulty = new(big.Int)
+	}
+	if cfg.Time == nil {
+		cfg.Time = big.NewInt(time.Now().Unix())
+	}
+	if cfg.GasLimit == 0 {
+		cfg.GasLimit = math.MaxUint64
+	}
+	if cfg.GasPrice == nil {
+		cfg.GasPrice = new(big.Int)
+	}
+	if cfg.Value == nil {
+		cfg.Value = new(big.Int)
+	}
+	if cfg.BlockNumber == nil {
+		cfg.BlockNumber = new(big.Int)
+	}
+	if cfg.GetHashFn == nil {
+		cfg.GetHashFn = func(n uint64) common.Hash {
+			return common.BytesToHash(crypto.Keccak256([]byte(new(big.Int).SetUint64(n).String())))
+		}
+	}
+}
+
+// Execute executes the code using the input as call data during the execution.
+// It returns the EVM's return value, the new state and an error if it failed.
+//
+// Executes sets up a in memory, temporarily, environment for the execution of
+// the given code. It makes sure that it's restored to it's original state afterwards.
+func Execute(code, input []byte, cfg *Config) ([]byte, *state.StateDB, error) {
+	if cfg == nil {
+		cfg = new(Config)
+	}
+	setDefaults(cfg)
+
+	if cfg.State == nil {
+		cfg.State, _ = state.New(common.Hash{}, state.NewDatabase(ethdb.NewMemDatabase()))
+	}
+	var (
+		address = common.BytesToAddress([]byte("contract"))
+		vmenv   = NewEnv(cfg)
+		sender  = vm.AccountRef(cfg.Origin)
+	)
+	cfg.State.CreateAccount(address)
+	// set the receiver's (the executing contract) code for execution.
+	cfg.State.SetCode(address, code)
+	// Call the code with the given configuration.
+	ret, _, err := vmenv.Call(
+		sender,
+		common.BytesToAddress([]byte("contract")),
+		input,
+		cfg.GasLimit,
+		cfg.Value,
+	)
+
+	return ret, cfg.State, err
+}
+
+// Create executes the code using the EVM create method
+func Create(input []byte, cfg *Config) ([]byte, common.Address, uint64, error) {
+	if cfg == nil {
+		cfg = new(Config)
+	}
+	setDefaults(cfg)
+
+	if cfg.State == nil {
+		cfg.State, _ = state.New(common.Hash{}, state.NewDatabase(ethdb.NewMemDatabase()))
+	}
+	var (
+		vmenv  = NewEnv(cfg)
+		sender = vm.AccountRef(cfg.Origin)
+	)
+
+	// Call the code with the given configuration.
+	code, address, leftOverGas, err := vmenv.Create(
+		sender,
+		input,
+		cfg.GasLimit,
+		cfg.Value,
+	)
+	return code, address, leftOverGas, err
+}
+
+// Call executes the code given by the contract's address. It will return the
+// EVM's return value or an error if it failed.
+//
+// Call, unlike Execute, requires a config and also requires the State field to
+// be set.
+func Call(address common.Address, input []byte, cfg *Config) ([]byte, uint64, error) {
+	setDefaults(cfg)
+
+	vmenv := NewEnv(cfg)
+
+	sender := cfg.State.GetOrNewStateObject(cfg.Origin)
+	// Call the code with the given configuration.
+	ret, leftOverGas, err := vmenv.Call(
+		sender,
+		address,
+		input,
+		cfg.GasLimit,
+		cfg.Value,
+	)
+
+	return ret, leftOverGas, err
+}