// Copyright 2019 The go-ethereum Authors // This file is part of the go-ethereum library. // // The go-ethereum library is free software: you can redistribute it and/or modify // it under the terms of the GNU Lesser General Public License as published by // the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // The go-ethereum library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public License // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. package core import ( "sync/atomic" "github.com/ava-labs/coreth/consensus" "github.com/ava-labs/coreth/core/state" "github.com/ava-labs/coreth/core/types" "github.com/ava-labs/coreth/core/vm" "github.com/ava-labs/coreth/params" "github.com/ava-labs/go-ethereum/common" ) // statePrefetcher is a basic Prefetcher, which blindly executes a block on top // of an arbitrary state with the goal of prefetching potentially useful state // data from disk before the main block processor start executing. type statePrefetcher struct { config *params.ChainConfig // Chain configuration options bc *BlockChain // Canonical block chain engine consensus.Engine // Consensus engine used for block rewards } // newStatePrefetcher initialises a new statePrefetcher. func newStatePrefetcher(config *params.ChainConfig, bc *BlockChain, engine consensus.Engine) *statePrefetcher { return &statePrefetcher{ config: config, bc: bc, engine: engine, } } // Prefetch processes the state changes according to the Ethereum rules by running // the transaction messages using the statedb, but any changes are discarded. The // only goal is to pre-cache transaction signatures and state trie nodes. func (p *statePrefetcher) Prefetch(block *types.Block, statedb *state.StateDB, cfg vm.Config, interrupt *uint32) { var ( header = block.Header() gaspool = new(GasPool).AddGas(block.GasLimit()) ) // Iterate over and process the individual transactions for i, tx := range block.Transactions() { // If block precaching was interrupted, abort if interrupt != nil && atomic.LoadUint32(interrupt) == 1 { return } // Block precaching permitted to continue, execute the transaction statedb.Prepare(tx.Hash(), block.Hash(), i) if err := precacheTransaction(p.config, p.bc, nil, gaspool, statedb, header, tx, cfg); err != nil { return // Ugh, something went horribly wrong, bail out } } } // precacheTransaction attempts to apply a transaction to the given state database // and uses the input parameters for its environment. The goal is not to execute // the transaction successfully, rather to warm up touched data slots. func precacheTransaction(config *params.ChainConfig, bc ChainContext, author *common.Address, gaspool *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, cfg vm.Config) error { // Convert the transaction into an executable message and pre-cache its sender msg, err := tx.AsMessage(types.MakeSigner(config, header.Number)) if err != nil { return err } // Create the EVM and execute the transaction context := NewEVMContext(msg, header, bc, author) vm := vm.NewEVM(context, statedb, config, cfg) _, _, _, err = ApplyMessage(vm, msg, gaspool) return err }