github.com/baptiste-b-pegasys/quorum/v22@v22.4.2/core/evm.go (about) 1 // Copyright 2016 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 core 18 19 import ( 20 "math/big" 21 22 "github.com/ethereum/go-ethereum/common" 23 "github.com/ethereum/go-ethereum/consensus" 24 "github.com/ethereum/go-ethereum/core/mps" 25 "github.com/ethereum/go-ethereum/core/state" 26 "github.com/ethereum/go-ethereum/core/types" 27 "github.com/ethereum/go-ethereum/core/vm" 28 "github.com/ethereum/go-ethereum/params" 29 ) 30 31 // ChainContext supports retrieving headers and consensus parameters from the 32 // current blockchain to be used during transaction processing. 33 // TODO: Split this interface for the quorum functions ex: ChainContextWithQuorum 34 type ChainContext interface { 35 // Engine retrieves the chain's consensus engine. 36 Engine() consensus.Engine 37 38 // GetHeader returns the hash corresponding to their hash. 39 GetHeader(common.Hash, uint64) *types.Header 40 41 // Config retrieves the chain's fork configuration 42 Config() *params.ChainConfig 43 44 // Quorum 45 46 // QuorumConfig retrieves the Quorum chain's configuration 47 QuorumConfig() *QuorumChainConfig 48 49 // PrivateStateManager returns the private state manager 50 PrivateStateManager() mps.PrivateStateManager 51 52 // CheckAndSetPrivateState updates the private state as a part contract state extension 53 CheckAndSetPrivateState(txLogs []*types.Log, privateState *state.StateDB, psi types.PrivateStateIdentifier) 54 55 // End Quorum 56 } 57 58 // NewEVMBlockContext creates a new context for use in the EVM. 59 func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common.Address) vm.BlockContext { 60 // If we don't have an explicit author (i.e. not mining), extract from the header 61 var beneficiary common.Address 62 if author == nil { 63 beneficiary, _ = chain.Engine().Author(header) // Ignore error, we're past header validation 64 } else { 65 beneficiary = *author 66 } 67 return vm.BlockContext{ 68 CanTransfer: CanTransfer, 69 Transfer: Transfer, 70 GetHash: GetHashFn(header, chain), 71 Coinbase: beneficiary, 72 BlockNumber: new(big.Int).Set(header.Number), 73 Time: new(big.Int).SetUint64(header.Time), 74 Difficulty: new(big.Int).Set(header.Difficulty), 75 GasLimit: header.GasLimit, 76 } 77 } 78 79 // NewEVMTxContext creates a new transaction context for a single transaction. 80 func NewEVMTxContext(msg Message) vm.TxContext { 81 return vm.TxContext{ 82 Origin: msg.From(), 83 GasPrice: new(big.Int).Set(msg.GasPrice()), 84 } 85 } 86 87 // GetHashFn returns a GetHashFunc which retrieves header hashes by number 88 func GetHashFn(ref *types.Header, chain ChainContext) func(n uint64) common.Hash { 89 // Cache will initially contain [refHash.parent], 90 // Then fill up with [refHash.p, refHash.pp, refHash.ppp, ...] 91 var cache []common.Hash 92 93 return func(n uint64) common.Hash { 94 // If there's no hash cache yet, make one 95 if len(cache) == 0 { 96 cache = append(cache, ref.ParentHash) 97 } 98 if idx := ref.Number.Uint64() - n - 1; idx < uint64(len(cache)) { 99 return cache[idx] 100 } 101 // No luck in the cache, but we can start iterating from the last element we already know 102 lastKnownHash := cache[len(cache)-1] 103 lastKnownNumber := ref.Number.Uint64() - uint64(len(cache)) 104 105 for { 106 header := chain.GetHeader(lastKnownHash, lastKnownNumber) 107 if header == nil { 108 break 109 } 110 cache = append(cache, header.ParentHash) 111 lastKnownHash = header.ParentHash 112 lastKnownNumber = header.Number.Uint64() - 1 113 if n == lastKnownNumber { 114 return lastKnownHash 115 } 116 } 117 return common.Hash{} 118 } 119 } 120 121 // CanTransfer checks whether there are enough funds in the address' account to make a transfer. 122 // This does not take the necessary gas in to account to make the transfer valid. 123 func CanTransfer(db vm.StateDB, addr common.Address, amount *big.Int) bool { 124 return db.GetBalance(addr).Cmp(amount) >= 0 125 } 126 127 // Transfer subtracts amount from sender and adds amount to recipient using the given Db 128 func Transfer(db vm.StateDB, sender, recipient common.Address, amount *big.Int) { 129 db.SubBalance(sender, amount) 130 db.AddBalance(recipient, amount) 131 }