github.com/aidoskuneen/adk-node@v0.0.0-20220315131952-2e32567cb7f4/core/evm.go (about) 1 // Copyright 2021 The adkgo Authors 2 // This file is part of the adkgo library (adapted for adkgo from go--ethereum v1.10.8). 3 // 4 // the adkgo 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 adkgo 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 adkgo library. If not, see <http://www.gnu.org/licenses/>. 16 17 package core 18 19 import ( 20 "math/big" 21 "strconv" 22 "os" 23 "github.com/aidoskuneen/adk-node/common" 24 "github.com/aidoskuneen/adk-node/consensus" 25 "github.com/aidoskuneen/adk-node/core/types" 26 "github.com/aidoskuneen/adk-node/core/vm" 27 ) 28 29 // ChainContext supports retrieving headers and consensus parameters from the 30 // current blockchain to be used during transaction processing. 31 type ChainContext interface { 32 // Engine retrieves the chain's consensus engine. 33 Engine() consensus.Engine 34 35 // GetHeader returns the hash corresponding to their hash. 36 GetHeader(common.Hash, uint64) *types.Header 37 } 38 39 // NewEVMBlockContext creates a new context for use in the EVM. 40 func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common.Address) vm.BlockContext { 41 var ( 42 beneficiary common.Address 43 baseFee *big.Int 44 ) 45 46 // If we don't have an explicit author (i.e. not mining), extract from the header 47 if author == nil { 48 beneficiary, _ = chain.Engine().Author(header) // Ignore error, we're past header validation 49 } else { 50 beneficiary = *author 51 } 52 if header.BaseFee != nil { 53 baseFee = new(big.Int).Set(header.BaseFee) 54 } 55 return vm.BlockContext{ 56 CanTransfer: CanTransfer, 57 Transfer: Transfer, 58 GetHash: GetHashFn(header, chain), 59 Coinbase: beneficiary, 60 BlockNumber: new(big.Int).Set(header.Number), 61 Time: new(big.Int).SetUint64(header.Time), 62 Difficulty: new(big.Int).Set(header.Difficulty), 63 BaseFee: baseFee, 64 GasLimit: header.GasLimit, 65 } 66 } 67 68 // NewEVMTxContext creates a new transaction context for a single transaction. 69 func NewEVMTxContext(msg Message) vm.TxContext { 70 return vm.TxContext{ 71 Origin: msg.From(), 72 GasPrice: new(big.Int).Set(msg.GasPrice()), 73 } 74 } 75 76 // GetHashFn returns a GetHashFunc which retrieves header hashes by number 77 func GetHashFn(ref *types.Header, chain ChainContext) func(n uint64) common.Hash { 78 // Cache will initially contain [refHash.parent], 79 // Then fill up with [refHash.p, refHash.pp, refHash.ppp, ...] 80 var cache []common.Hash 81 82 return func(n uint64) common.Hash { 83 // If there's no hash cache yet, make one 84 if len(cache) == 0 { 85 cache = append(cache, ref.ParentHash) 86 } 87 if idx := ref.Number.Uint64() - n - 1; idx < uint64(len(cache)) { 88 return cache[idx] 89 } 90 // No luck in the cache, but we can start iterating from the last element we already know 91 lastKnownHash := cache[len(cache)-1] 92 lastKnownNumber := ref.Number.Uint64() - uint64(len(cache)) 93 94 for { 95 header := chain.GetHeader(lastKnownHash, lastKnownNumber) 96 if header == nil { 97 break 98 } 99 cache = append(cache, header.ParentHash) 100 lastKnownHash = header.ParentHash 101 lastKnownNumber = header.Number.Uint64() - 1 102 if n == lastKnownNumber { 103 return lastKnownHash 104 } 105 } 106 return common.Hash{} 107 } 108 } 109 110 // CanTransfer checks whether there are enough funds in the address' account to make a transfer. 111 // This does not take the necessary gas in to account to make the transfer valid. 112 func CanTransfer(db vm.StateDB, addr common.Address, amount *big.Int) bool { 113 return db.GetBalance(addr).Cmp(amount) >= 0 114 } 115 116 // Transfer subtracts amount from sender and adds amount to recipient using the given Db 117 func Transfer(db vm.StateDB, sender, recipient common.Address, amount *big.Int) { 118 db.SubBalance(sender, amount) 119 db.AddBalance(recipient, amount) 120 121 // log all transfers 122 logLine := db.GetHash().Hex() +","+strconv.Itoa(db.GetInternalCounter())+","+sender.Hex()+","+recipient.Hex()+","+amount.String() 123 124 f, err := os.OpenFile("adk_value_transfer.log", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644) 125 if err != nil { 126 return // ignore error 127 } 128 defer f.Close() 129 f.WriteString(logLine+"\n"); 130 131 }