github.com/amazechain/amc@v0.1.3/internal/evm.go (about) 1 // Copyright 2023 The AmazeChain Authors 2 // This file is part of the AmazeChain library. 3 // 4 // The AmazeChain 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 AmazeChain 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 AmazeChain library. If not, see <http://www.gnu.org/licenses/>. 16 17 package internal 18 19 import ( 20 "fmt" 21 "github.com/amazechain/amc/common/block" 22 "github.com/amazechain/amc/common/types" 23 "github.com/amazechain/amc/internal/consensus" 24 "github.com/amazechain/amc/internal/vm/evmtypes" 25 "github.com/amazechain/amc/params" 26 "github.com/holiman/uint256" 27 ) 28 29 // NewEVMBlockContext creates a new context for use in the EVM. 30 func NewEVMBlockContext(header *block.Header, blockHashFunc func(n uint64) types.Hash, engine consensus.Engine, author *types.Address) evmtypes.BlockContext { 31 // If we don't have an explicit author (i.e. not mining), extract from the header 32 var beneficiary types.Address 33 if author == nil { 34 beneficiary, _ = engine.Author(header) // Ignore error, we're past header validation 35 } else { 36 beneficiary = *author 37 } 38 var baseFee uint256.Int 39 if header.BaseFee != nil { 40 overflow := baseFee.SetFromBig(header.BaseFee.ToBig()) 41 if overflow { 42 panic(fmt.Errorf("header.BaseFee higher than 2^256-1")) 43 } 44 } 45 46 var prevRandDao *types.Hash 47 if header.Difficulty.Cmp(uint256.NewInt(0)) == 0 { 48 // EIP-4399. We use SerenityDifficulty (i.e. 0) as a telltale of Proof-of-Stake blocks. 49 prevRandDao = &header.MixDigest 50 } 51 52 var transferFunc evmtypes.TransferFunc 53 if engine != nil && engine.Type() == params.BorConsensus { 54 transferFunc = BorTransfer 55 } else { 56 transferFunc = Transfer 57 } 58 59 return evmtypes.BlockContext{ 60 CanTransfer: CanTransfer, 61 Transfer: transferFunc, 62 GetHash: blockHashFunc, 63 Coinbase: beneficiary, 64 BlockNumber: header.Number.Uint64(), 65 Time: header.Time, 66 Difficulty: header.Difficulty.ToBig(), 67 BaseFee: &baseFee, 68 GasLimit: header.GasLimit, 69 PrevRanDao: prevRandDao, 70 } 71 } 72 73 // NewEVMTxContext creates a new transaction context for a single transaction. 74 func NewEVMTxContext(msg Message) evmtypes.TxContext { 75 return evmtypes.TxContext{ 76 Origin: msg.From(), 77 GasPrice: msg.GasPrice(), 78 } 79 } 80 81 // GetHashFn returns a GetHashFunc which retrieves header hashes by number 82 func GetHashFn(ref *block.Header, getHeader func(hash types.Hash, number uint64) *block.Header) func(n uint64) types.Hash { 83 // Cache will initially contain [refHash.parent], 84 // Then fill up with [refHash.p, refHash.pp, refHash.ppp, ...] 85 var cache []types.Hash 86 87 return func(n uint64) types.Hash { 88 // If there's no hash cache yet, make one 89 if len(cache) == 0 { 90 cache = append(cache, ref.ParentHash) 91 } 92 if idx := ref.Number.Uint64() - n - 1; idx < uint64(len(cache)) { 93 return cache[idx] 94 } 95 // No luck in the cache, but we can start iterating from the last element we already know 96 lastKnownHash := cache[len(cache)-1] 97 lastKnownNumber := ref.Number.Uint64() - uint64(len(cache)) 98 99 for { 100 header := getHeader(lastKnownHash, lastKnownNumber) 101 if header == nil { 102 break 103 } 104 cache = append(cache, header.ParentHash) 105 lastKnownHash = header.ParentHash 106 lastKnownNumber = header.Number.Uint64() - 1 107 if n == lastKnownNumber { 108 return lastKnownHash 109 } 110 } 111 return types.Hash{} 112 } 113 } 114 115 // CanTransfer checks whether there are enough funds in the address' account to make a transfer. 116 // This does not take the necessary gas in to account to make the transfer valid. 117 func CanTransfer(db evmtypes.IntraBlockState, addr types.Address, amount *uint256.Int) bool { 118 return !db.GetBalance(addr).Lt(amount) 119 } 120 121 // Transfer subtracts amount from sender and adds amount to recipient using the given Db 122 func Transfer(db evmtypes.IntraBlockState, sender, recipient types.Address, amount *uint256.Int, bailout bool) { 123 if !bailout { 124 db.SubBalance(sender, amount) 125 } 126 db.AddBalance(recipient, amount) 127 } 128 129 // BorTransfer transfer in Bor 130 func BorTransfer(db evmtypes.IntraBlockState, sender, recipient types.Address, amount *uint256.Int, bailout bool) { 131 // get inputs before 132 //input1 := db.GetBalance(sender).Clone() 133 //input2 := db.GetBalance(recipient).Clone() 134 135 if !bailout { 136 db.SubBalance(sender, amount) 137 } 138 db.AddBalance(recipient, amount) 139 140 //// get outputs after 141 //output1 := db.GetBalance(sender).Clone() 142 //output2 := db.GetBalance(recipient).Clone() 143 // 144 //// add transfer log 145 //AddTransferLog(db, sender, recipient, amount, input1, input2, output1, output2) 146 } 147 148 // ChainContext supports retrieving headers and consensus parameters from the 149 // current blockchain to be used during transaction processing. 150 type ChainContext interface { 151 // Engine retrieves the chain's consensus engine. 152 Engine() consensus.Engine 153 154 // GetHeader returns the header corresponding to the hash/number argument pair. 155 GetHeader(types.Hash, uint64) *block.Header 156 }