github.com/murrekatt/go-ethereum@v1.5.8-0.20170123175102-fc52f2c007fb/core/vm/runtime/runtime.go (about)

     1  // Copyright 2015 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package runtime
    18  
    19  import (
    20  	"math/big"
    21  	"time"
    22  
    23  	"github.com/ethereum/go-ethereum/common"
    24  	"github.com/ethereum/go-ethereum/core/state"
    25  	"github.com/ethereum/go-ethereum/core/vm"
    26  	"github.com/ethereum/go-ethereum/crypto"
    27  	"github.com/ethereum/go-ethereum/ethdb"
    28  	"github.com/ethereum/go-ethereum/params"
    29  )
    30  
    31  // Config is a basic type specifying certain configuration flags for running
    32  // the EVM.
    33  type Config struct {
    34  	ChainConfig *params.ChainConfig
    35  	Difficulty  *big.Int
    36  	Origin      common.Address
    37  	Coinbase    common.Address
    38  	BlockNumber *big.Int
    39  	Time        *big.Int
    40  	GasLimit    *big.Int
    41  	GasPrice    *big.Int
    42  	Value       *big.Int
    43  	DisableJit  bool // "disable" so it's enabled by default
    44  	Debug       bool
    45  	EVMConfig   vm.Config
    46  
    47  	State     *state.StateDB
    48  	GetHashFn func(n uint64) common.Hash
    49  }
    50  
    51  // sets defaults on the config
    52  func setDefaults(cfg *Config) {
    53  	if cfg.ChainConfig == nil {
    54  		cfg.ChainConfig = &params.ChainConfig{
    55  			ChainId:        big.NewInt(1),
    56  			HomesteadBlock: new(big.Int),
    57  			DAOForkBlock:   new(big.Int),
    58  			DAOForkSupport: false,
    59  			EIP150Block:    new(big.Int),
    60  			EIP155Block:    new(big.Int),
    61  			EIP158Block:    new(big.Int),
    62  		}
    63  	}
    64  
    65  	if cfg.Difficulty == nil {
    66  		cfg.Difficulty = new(big.Int)
    67  	}
    68  	if cfg.Time == nil {
    69  		cfg.Time = big.NewInt(time.Now().Unix())
    70  	}
    71  	if cfg.GasLimit == nil {
    72  		cfg.GasLimit = new(big.Int).Set(common.MaxBig)
    73  	}
    74  	if cfg.GasPrice == nil {
    75  		cfg.GasPrice = new(big.Int)
    76  	}
    77  	if cfg.Value == nil {
    78  		cfg.Value = new(big.Int)
    79  	}
    80  	if cfg.BlockNumber == nil {
    81  		cfg.BlockNumber = new(big.Int)
    82  	}
    83  	if cfg.GetHashFn == nil {
    84  		cfg.GetHashFn = func(n uint64) common.Hash {
    85  			return common.BytesToHash(crypto.Keccak256([]byte(new(big.Int).SetUint64(n).String())))
    86  		}
    87  	}
    88  }
    89  
    90  // Execute executes the code using the input as call data during the execution.
    91  // It returns the EVM's return value, the new state and an error if it failed.
    92  //
    93  // Executes sets up a in memory, temporarily, environment for the execution of
    94  // the given code. It enabled the JIT by default and make sure that it's restored
    95  // to it's original state afterwards.
    96  func Execute(code, input []byte, cfg *Config) ([]byte, *state.StateDB, error) {
    97  	if cfg == nil {
    98  		cfg = new(Config)
    99  	}
   100  	setDefaults(cfg)
   101  
   102  	if cfg.State == nil {
   103  		db, _ := ethdb.NewMemDatabase()
   104  		cfg.State, _ = state.New(common.Hash{}, db)
   105  	}
   106  	var (
   107  		vmenv    = NewEnv(cfg, cfg.State)
   108  		sender   = cfg.State.CreateAccount(cfg.Origin)
   109  		receiver = cfg.State.CreateAccount(common.StringToAddress("contract"))
   110  	)
   111  	// set the receiver's (the executing contract) code for execution.
   112  	receiver.SetCode(crypto.Keccak256Hash(code), code)
   113  
   114  	// Call the code with the given configuration.
   115  	ret, err := vmenv.Call(
   116  		sender,
   117  		receiver.Address(),
   118  		input,
   119  		cfg.GasLimit,
   120  		cfg.Value,
   121  	)
   122  
   123  	return ret, cfg.State, err
   124  }
   125  
   126  // Create executes the code using the EVM create method
   127  func Create(input []byte, cfg *Config) ([]byte, common.Address, error) {
   128  	if cfg == nil {
   129  		cfg = new(Config)
   130  	}
   131  	setDefaults(cfg)
   132  
   133  	if cfg.State == nil {
   134  		db, _ := ethdb.NewMemDatabase()
   135  		cfg.State, _ = state.New(common.Hash{}, db)
   136  	}
   137  	var (
   138  		vmenv  = NewEnv(cfg, cfg.State)
   139  		sender = cfg.State.CreateAccount(cfg.Origin)
   140  	)
   141  
   142  	// Call the code with the given configuration.
   143  	return vmenv.Create(
   144  		sender,
   145  		input,
   146  		cfg.GasLimit,
   147  		cfg.Value,
   148  	)
   149  }
   150  
   151  // Call executes the code given by the contract's address. It will return the
   152  // EVM's return value or an error if it failed.
   153  //
   154  // Call, unlike Execute, requires a config and also requires the State field to
   155  // be set.
   156  func Call(address common.Address, input []byte, cfg *Config) ([]byte, error) {
   157  	setDefaults(cfg)
   158  
   159  	vmenv := NewEnv(cfg, cfg.State)
   160  
   161  	sender := cfg.State.GetOrNewStateObject(cfg.Origin)
   162  	// Call the code with the given configuration.
   163  	ret, err := vmenv.Call(
   164  		sender,
   165  		address,
   166  		input,
   167  		cfg.GasLimit,
   168  		cfg.Value,
   169  	)
   170  
   171  	return ret, err
   172  }