github.com/ylsgit/go-ethereum@v1.6.5/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"
    21  	"math/big"
    22  	"time"
    23  
    24  	"github.com/ethereum/go-ethereum/common"
    25  	"github.com/ethereum/go-ethereum/core/state"
    26  	"github.com/ethereum/go-ethereum/core/vm"
    27  	"github.com/ethereum/go-ethereum/crypto"
    28  	"github.com/ethereum/go-ethereum/ethdb"
    29  	"github.com/ethereum/go-ethereum/params"
    30  )
    31  
    32  // Config is a basic type specifying certain configuration flags for running
    33  // the EVM.
    34  type Config struct {
    35  	ChainConfig *params.ChainConfig
    36  	Difficulty  *big.Int
    37  	Origin      common.Address
    38  	Coinbase    common.Address
    39  	BlockNumber *big.Int
    40  	Time        *big.Int
    41  	GasLimit    uint64
    42  	GasPrice    *big.Int
    43  	Value       *big.Int
    44  	DisableJit  bool // "disable" so it's enabled by default
    45  	Debug       bool
    46  	EVMConfig   vm.Config
    47  
    48  	State     *state.StateDB
    49  	GetHashFn func(n uint64) common.Hash
    50  }
    51  
    52  // sets defaults on the config
    53  func setDefaults(cfg *Config) {
    54  	if cfg.ChainConfig == nil {
    55  		cfg.ChainConfig = &params.ChainConfig{
    56  			ChainId:        big.NewInt(1),
    57  			HomesteadBlock: new(big.Int),
    58  			DAOForkBlock:   new(big.Int),
    59  			DAOForkSupport: false,
    60  			EIP150Block:    new(big.Int),
    61  			EIP155Block:    new(big.Int),
    62  			EIP158Block:    new(big.Int),
    63  		}
    64  	}
    65  
    66  	if cfg.Difficulty == nil {
    67  		cfg.Difficulty = new(big.Int)
    68  	}
    69  	if cfg.Time == nil {
    70  		cfg.Time = big.NewInt(time.Now().Unix())
    71  	}
    72  	if cfg.GasLimit == 0 {
    73  		cfg.GasLimit = math.MaxUint64
    74  	}
    75  	if cfg.GasPrice == nil {
    76  		cfg.GasPrice = new(big.Int)
    77  	}
    78  	if cfg.Value == nil {
    79  		cfg.Value = new(big.Int)
    80  	}
    81  	if cfg.BlockNumber == nil {
    82  		cfg.BlockNumber = new(big.Int)
    83  	}
    84  	if cfg.GetHashFn == nil {
    85  		cfg.GetHashFn = func(n uint64) common.Hash {
    86  			return common.BytesToHash(crypto.Keccak256([]byte(new(big.Int).SetUint64(n).String())))
    87  		}
    88  	}
    89  }
    90  
    91  // Execute executes the code using the input as call data during the execution.
    92  // It returns the EVM's return value, the new state and an error if it failed.
    93  //
    94  // Executes sets up a in memory, temporarily, environment for the execution of
    95  // the given code. It enabled the JIT by default and make sure that it's restored
    96  // to it's original state afterwards.
    97  func Execute(code, input []byte, cfg *Config) ([]byte, *state.StateDB, error) {
    98  	if cfg == nil {
    99  		cfg = new(Config)
   100  	}
   101  	setDefaults(cfg)
   102  
   103  	if cfg.State == nil {
   104  		db, _ := ethdb.NewMemDatabase()
   105  		cfg.State, _ = state.New(common.Hash{}, db)
   106  	}
   107  	var (
   108  		address = common.StringToAddress("contract")
   109  		vmenv   = NewEnv(cfg, cfg.State)
   110  		sender  = vm.AccountRef(cfg.Origin)
   111  	)
   112  	cfg.State.CreateAccount(address)
   113  	// set the receiver's (the executing contract) code for execution.
   114  	cfg.State.SetCode(address, code)
   115  	// Call the code with the given configuration.
   116  	ret, _, err := vmenv.Call(
   117  		sender,
   118  		common.StringToAddress("contract"),
   119  		input,
   120  		cfg.GasLimit,
   121  		cfg.Value,
   122  	)
   123  
   124  	return ret, cfg.State, err
   125  }
   126  
   127  // Create executes the code using the EVM create method
   128  func Create(input []byte, cfg *Config) ([]byte, common.Address, error) {
   129  	if cfg == nil {
   130  		cfg = new(Config)
   131  	}
   132  	setDefaults(cfg)
   133  
   134  	if cfg.State == nil {
   135  		db, _ := ethdb.NewMemDatabase()
   136  		cfg.State, _ = state.New(common.Hash{}, db)
   137  	}
   138  	var (
   139  		vmenv  = NewEnv(cfg, cfg.State)
   140  		sender = vm.AccountRef(cfg.Origin)
   141  	)
   142  
   143  	// Call the code with the given configuration.
   144  	code, address, _, err := vmenv.Create(
   145  		sender,
   146  		input,
   147  		cfg.GasLimit,
   148  		cfg.Value,
   149  	)
   150  	return code, address, err
   151  }
   152  
   153  // Call executes the code given by the contract's address. It will return the
   154  // EVM's return value or an error if it failed.
   155  //
   156  // Call, unlike Execute, requires a config and also requires the State field to
   157  // be set.
   158  func Call(address common.Address, input []byte, cfg *Config) ([]byte, error) {
   159  	setDefaults(cfg)
   160  
   161  	vmenv := NewEnv(cfg, cfg.State)
   162  
   163  	sender := cfg.State.GetOrNewStateObject(cfg.Origin)
   164  	// Call the code with the given configuration.
   165  	ret, _, err := vmenv.Call(
   166  		sender,
   167  		address,
   168  		input,
   169  		cfg.GasLimit,
   170  		cfg.Value,
   171  	)
   172  
   173  	return ret, err
   174  }