go-pulse/core/state_prefetcher.go
2019-04-01 11:06:15 +03:00

86 lines
3.5 KiB
Go

// 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/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/consensus"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/params"
)
// 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
}