state_processor.go

// Copyright 2015 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 (
	"errors"
	"fmt"
	"math/big"
	"sync"
	"time"

	"github.com/dominant-strategies/go-quai/common"
	"github.com/dominant-strategies/go-quai/common/prque"
	"github.com/dominant-strategies/go-quai/consensus"
	"github.com/dominant-strategies/go-quai/core/rawdb"
	"github.com/dominant-strategies/go-quai/core/state"
	"github.com/dominant-strategies/go-quai/core/state/snapshot"
	"github.com/dominant-strategies/go-quai/core/types"
	"github.com/dominant-strategies/go-quai/core/vm"
	"github.com/dominant-strategies/go-quai/crypto"
	"github.com/dominant-strategies/go-quai/ethdb"
	"github.com/dominant-strategies/go-quai/event"
	"github.com/dominant-strategies/go-quai/log"
	"github.com/dominant-strategies/go-quai/metrics"
	"github.com/dominant-strategies/go-quai/params"
	"github.com/dominant-strategies/go-quai/trie"
	lru "github.com/hashicorp/golang-lru"
)

var (
	accountReadTimer   = metrics.NewRegisteredTimer("chain/account/reads", nil)
	accountHashTimer   = metrics.NewRegisteredTimer("chain/account/hashes", nil)
	accountUpdateTimer = metrics.NewRegisteredTimer("chain/account/updates", nil)
	accountCommitTimer = metrics.NewRegisteredTimer("chain/account/commits", nil)

	storageReadTimer   = metrics.NewRegisteredTimer("chain/storage/reads", nil)
	storageHashTimer   = metrics.NewRegisteredTimer("chain/storage/hashes", nil)
	storageUpdateTimer = metrics.NewRegisteredTimer("chain/storage/updates", nil)
	storageCommitTimer = metrics.NewRegisteredTimer("chain/storage/commits", nil)

	snapshotAccountReadTimer = metrics.NewRegisteredTimer("chain/snapshot/account/reads", nil)
	snapshotStorageReadTimer = metrics.NewRegisteredTimer("chain/snapshot/storage/reads", nil)
	snapshotCommitTimer      = metrics.NewRegisteredTimer("chain/snapshot/commits", nil)
)

const (
	receiptsCacheLimit = 32
	txLookupCacheLimit = 1024
	TriesInMemory      = 128

	// BlockChainVersion ensures that an incompatible database forces a resync from scratch.
	//
	// Changelog:
	//
	// - Version 4
	//   The following incompatible database changes were added:
	//   * the `BlockNumber`, `TxHash`, `TxIndex`, `BlockHash` and `Index` fields of log are deleted
	//   * the `Bloom` field of receipt is deleted
	//   * the `BlockIndex` and `TxIndex` fields of txlookup are deleted
	// - Version 5
	//  The following incompatible database changes were added:
	//    * the `TxHash`, `GasCost`, and `ContractAddress` fields are no longer stored for a receipt
	//    * the `TxHash`, `GasCost`, and `ContractAddress` fields are computed by looking up the
	//      receipts' corresponding block
	// - Version 6
	//  The following incompatible database changes were added:
	//    * Transaction lookup information stores the corresponding block number instead of block hash
	// - Version 7
	//  The following incompatible database changes were added:
	//    * Use freezer as the ancient database to maintain all ancient data
	// - Version 8
	//  The following incompatible database changes were added:
	//    * New scheme for contract code in order to separate the codes and trie nodes
	BlockChainVersion uint64 = 8
)

// CacheConfig contains the configuration values for the trie caching/pruning
// that's resident in a blockchain.
type CacheConfig struct {
	TrieCleanLimit      int           // Memory allowance (MB) to use for caching trie nodes in memory
	TrieCleanJournal    string        // Disk journal for saving clean cache entries.
	TrieCleanRejournal  time.Duration // Time interval to dump clean cache to disk periodically
	TrieCleanNoPrefetch bool          // Whether to disable heuristic state prefetching for followup blocks
	TrieDirtyLimit      int           // Memory limit (MB) at which to start flushing dirty trie nodes to disk
	TrieDirtyDisabled   bool          // Whether to disable trie write caching and GC altogether (archive node)
	TrieTimeLimit       time.Duration // Time limit after which to flush the current in-memory trie to disk
	SnapshotLimit       int           // Memory allowance (MB) to use for caching snapshot entries in memory
	Preimages           bool          // Whether to store preimage of trie key to the disk
}

// defaultCacheConfig are the default caching values if none are specified by the
// user (also used during testing).
var defaultCacheConfig = &CacheConfig{
	TrieCleanLimit: 256,
	TrieDirtyLimit: 256,
	TrieTimeLimit:  5 * time.Minute,
	SnapshotLimit:  256,
}

// StateProcessor is a basic Processor, which takes care of transitioning
// state from one point to another.
//
// StateProcessor implements Processor.
type StateProcessor struct {
	config        *params.ChainConfig // Chain configuration options
	hc            *HeaderChain        // Canonical block chain
	engine        consensus.Engine    // Consensus engine used for block rewards
	logsFeed      event.Feed
	rmLogsFeed    event.Feed
	cacheConfig   *CacheConfig   // CacheConfig for StateProcessor
	stateCache    state.Database // State database to reuse between imports (contains state cache)
	receiptsCache *lru.Cache     // Cache for the most recent receipts per block
	txLookupCache *lru.Cache
	validator     Validator // Block and state validator interface
	prefetcher    Prefetcher
	vmConfig      vm.Config

	scope         event.SubscriptionScope
	wg            sync.WaitGroup // chain processing wait group for shutting down
	quit          chan struct{}  // state processor quit channel
	txLookupLimit uint64

	snaps  *snapshot.Tree
	triegc *prque.Prque  // Priority queue mapping block numbers to tries to gc
	gcproc time.Duration // Accumulates canonical block processing for trie dumping
}

// NewStateProcessor initialises a new StateProcessor.
func NewStateProcessor(config *params.ChainConfig, hc *HeaderChain, engine consensus.Engine, vmConfig vm.Config, cacheConfig *CacheConfig, txLookupLimit *uint64) *StateProcessor {
	receiptsCache, _ := lru.New(receiptsCacheLimit)
	txLookupCache, _ := lru.New(txLookupCacheLimit)

	if cacheConfig == nil {
		cacheConfig = defaultCacheConfig
	}

	sp := &StateProcessor{
		config:        config,
		hc:            hc,
		receiptsCache: receiptsCache,
		txLookupCache: txLookupCache,
		vmConfig:      vmConfig,
		cacheConfig:   cacheConfig,
		stateCache: state.NewDatabaseWithConfig(hc.headerDb, &trie.Config{
			Cache:     cacheConfig.TrieCleanLimit,
			Journal:   cacheConfig.TrieCleanJournal,
			Preimages: cacheConfig.Preimages,
		}),
		engine: engine,
		triegc: prque.New(nil),
		quit:   make(chan struct{}),
	}
	sp.validator = NewBlockValidator(config, hc, engine)

	// Load any existing snapshot, regenerating it if loading failed
	if sp.cacheConfig.SnapshotLimit > 0 {
		// TODO: If the state is not available, enable snapshot recovery
		head := hc.CurrentHeader()
		sp.snaps, _ = snapshot.New(hc.headerDb, sp.stateCache.TrieDB(), sp.cacheConfig.SnapshotLimit, head.Root(), true, false)
	}
	if txLookupLimit != nil {
		sp.txLookupLimit = *txLookupLimit
	}
	// If periodic cache journal is required, spin it up.
	if sp.cacheConfig.TrieCleanRejournal > 0 {
		if sp.cacheConfig.TrieCleanRejournal < time.Minute {
			log.Warn("Sanitizing invalid trie cache journal time", "provided", sp.cacheConfig.TrieCleanRejournal, "updated", time.Minute)
			sp.cacheConfig.TrieCleanRejournal = time.Minute
		}
		triedb := sp.stateCache.TrieDB()
		sp.wg.Add(1)
		go func() {
			defer sp.wg.Done()
			triedb.SaveCachePeriodically(sp.cacheConfig.TrieCleanJournal, sp.cacheConfig.TrieCleanRejournal, sp.quit)
		}()
	}
	return sp
}

// Process processes the state changes according to the Quai rules by running
// the transaction messages using the statedb and applying any rewards to both
// the processor (coinbase) and any included uncles.
//
// Process returns the receipts and logs accumulated during the process and
// returns the amount of gas that was used in the process. If any of the
// transactions failed to execute due to insufficient gas it will return an error.
func (p *StateProcessor) Process(block *types.Block, etxSet types.EtxSet) (types.Receipts, []*types.Log, *state.StateDB, uint64, error) {
	var (
		receipts    types.Receipts
		usedGas     = new(uint64)
		header      = block.Header()
		blockHash   = block.Hash()
		blockNumber = block.Number()
		allLogs     []*types.Log
		gp          = new(GasPool).AddGas(block.GasLimit())
	)

	parent := p.hc.GetBlock(block.Header().ParentHash(), block.NumberU64()-1)
	if parent == nil {
		return types.Receipts{}, []*types.Log{}, nil, 0, errors.New("parent block is nil for the block given to process")
	}

	// Initialize a statedb
	statedb, err := state.New(parent.Header().Root(), p.stateCache, p.snaps)
	if err != nil {
		return types.Receipts{}, []*types.Log{}, nil, 0, err
	}

	blockContext := NewEVMBlockContext(header, p.hc, nil)
	vmenv := vm.NewEVM(blockContext, vm.TxContext{}, statedb, p.config, p.vmConfig)

	// Iterate over and process the individual transactions.
	etxRLimit := len(parent.Transactions()) / params.ETXRegionMaxFraction
	if etxRLimit < params.ETXRLimitMin {
		etxRLimit = params.ETXRLimitMin
	}
	etxPLimit := len(parent.Transactions()) / params.ETXPrimeMaxFraction
	if etxPLimit < params.ETXPLimitMin {
		etxPLimit = params.ETXPLimitMin
	}
	var emittedEtxs types.Transactions
	for i, tx := range block.Transactions() {
		msg, err := tx.AsMessage(types.MakeSigner(p.config, header.Number()), header.BaseFee())
		if err != nil {
			return nil, nil, nil, 0, fmt.Errorf("could not apply tx %d [%v]: %w", i, tx.Hash().Hex(), err)
		}
		statedb.Prepare(tx.Hash(), i)
		var receipt *types.Receipt
		if tx.Type() == types.ExternalTxType {
			if _, exists := etxSet[tx.Hash()]; !exists { // Verify that the ETX exists in the set
				return nil, nil, nil, 0, fmt.Errorf("invalid external transaction: etx %x not found in unspent etx set", tx.Hash())
			}
			prevZeroBal := prepareApplyETX(statedb, tx)
			receipt, err = applyTransaction(msg, p.config, p.hc, nil, gp, statedb, blockNumber, blockHash, tx, usedGas, vmenv, &etxRLimit, &etxPLimit)
			statedb.SetBalance(common.ZeroInternal, prevZeroBal) // Reset the balance to what it previously was. Residual balance will be lost

			if err != nil {
				return nil, nil, nil, 0, fmt.Errorf("could not apply tx %d [%v]: %w", i, tx.Hash().Hex(), err)
			}

			delete(etxSet, tx.Hash()) // This ETX has been spent so remove it from the unspent set

		} else if tx.Type() == types.InternalTxType || tx.Type() == types.InternalToExternalTxType {
			receipt, err = applyTransaction(msg, p.config, p.hc, nil, gp, statedb, blockNumber, blockHash, tx, usedGas, vmenv, &etxRLimit, &etxPLimit)
			if err != nil {
				return nil, nil, nil, 0, fmt.Errorf("could not apply tx %d [%v]: %w", i, tx.Hash().Hex(), err)
			}
			emittedEtxs = append(emittedEtxs, receipt.Etxs...)
		} else {
			return nil, nil, nil, 0, ErrTxTypeNotSupported
		}
		receipts = append(receipts, receipt)
		allLogs = append(allLogs, receipt.Logs...)
		i++
	}

	// Finalize the block, applying any consensus engine specific extras (e.g. block rewards)
	p.engine.Finalize(p.hc, header, statedb, block.Transactions(), block.Uncles())

	return receipts, allLogs, statedb, *usedGas, nil
}

func applyTransaction(msg types.Message, config *params.ChainConfig, bc ChainContext, author *common.Address, gp *GasPool, statedb *state.StateDB, blockNumber *big.Int, blockHash common.Hash, tx *types.Transaction, usedGas *uint64, evm *vm.EVM, etxRLimit, etxPLimit *int) (*types.Receipt, error) {
	// Create a new context to be used in the EVM environment.
	txContext := NewEVMTxContext(msg)
	evm.Reset(txContext, statedb)

	// Apply the transaction to the current state (included in the env).
	result, err := ApplyMessage(evm, msg, gp)
	if err != nil {
		return nil, err
	}
	var ETXRCount int
	var ETXPCount int
	for _, tx := range result.Etxs {
		// Count which ETXs are cross-region
		if tx.To().Location().CommonDom(common.NodeLocation).Context() == common.REGION_CTX {
			ETXRCount++
		}
		// Count which ETXs are cross-prime
		if tx.To().Location().CommonDom(common.NodeLocation).Context() == common.PRIME_CTX {
			ETXPCount++
		}
	}
	if ETXRCount > *etxRLimit {
		return nil, fmt.Errorf("tx %032x emits too many cross-region ETXs for block. emitted: %d, limit: %d", tx.Hash(), ETXRCount, etxRLimit)
	}
	if ETXPCount > *etxPLimit {
		return nil, fmt.Errorf("tx %032x emits too many cross-prime ETXs for block. emitted: %d, limit: %d", tx.Hash(), ETXPCount, etxPLimit)
	}
	*etxRLimit -= ETXRCount
	*etxPLimit -= ETXPCount

	// Update the state with pending changes.
	var root []byte
	statedb.Finalise(true)

	*usedGas += result.UsedGas

	// Create a new receipt for the transaction, storing the intermediate root and gas used
	// by the tx.
	receipt := &types.Receipt{Type: tx.Type(), PostState: root, CumulativeGasUsed: *usedGas, Etxs: result.Etxs}
	if result.Failed() {
		receipt.Status = types.ReceiptStatusFailed
		log.Debug(result.Err.Error())
	} else {
		receipt.Status = types.ReceiptStatusSuccessful
	}
	receipt.TxHash = tx.Hash()
	receipt.GasUsed = result.UsedGas

	// If the transaction created a contract, store the creation address in the receipt.
	if msg.To() == nil {
		receipt.ContractAddress = crypto.CreateAddress(evm.TxContext.Origin, tx.Nonce(), tx.Data())
	}

	// Set the receipt logs and create the bloom filter.
	receipt.Logs = statedb.GetLogs(tx.Hash(), blockHash)
	receipt.Bloom = types.CreateBloom(types.Receipts{receipt})
	receipt.BlockHash = blockHash
	receipt.BlockNumber = blockNumber
	receipt.TransactionIndex = uint(statedb.TxIndex())
	return receipt, err
}

var lastWrite uint64

// Apply State
func (p *StateProcessor) Apply(batch ethdb.Batch, block *types.Block, newInboundEtxs types.Transactions) ([]*types.Log, error) {
	// Update the set of inbound ETXs which may be mined. This adds new inbound
	// ETXs to the set and removes expired ETXs so they are no longer available
	start := time.Now()
	etxSet := rawdb.ReadEtxSet(p.hc.bc.db, block.ParentHash(), block.NumberU64()-1)
	time1 := common.PrettyDuration(time.Since(start))
	if etxSet == nil {
		return nil, errors.New("failed to load etx set")
	}
	etxSet.Update(newInboundEtxs, block.NumberU64())
	time2 := common.PrettyDuration(time.Since(start))
	// Process our block
	receipts, logs, statedb, usedGas, err := p.Process(block, etxSet)
	if err != nil {
		return nil, err
	}
	time3 := common.PrettyDuration(time.Since(start))
	err = p.validator.ValidateState(block, statedb, receipts, usedGas)
	if err != nil {
		return nil, err
	}
	time4 := common.PrettyDuration(time.Since(start))
	rawdb.WriteReceipts(batch, block.Hash(), block.NumberU64(), receipts)
	time4_5 := common.PrettyDuration(time.Since(start))
	// Create bloom filter and write it to cache/db
	bloom := types.CreateBloom(receipts)
	p.hc.AddBloom(bloom, block.Hash())
	time5 := common.PrettyDuration(time.Since(start))
	rawdb.WritePreimages(batch, statedb.Preimages())
	time6 := common.PrettyDuration(time.Since(start))
	// Commit all cached state changes into underlying memory database.
	root, err := statedb.Commit(true)
	if err != nil {
		return nil, err
	}
	triedb := p.stateCache.TrieDB()
	time7 := common.PrettyDuration(time.Since(start))
	var time8 common.PrettyDuration
	var time9 common.PrettyDuration
	var time10 common.PrettyDuration
	var time11 common.PrettyDuration
	// If we're running an archive node, always flush
	if p.cacheConfig.TrieDirtyDisabled {
		if err := triedb.Commit(root, false, nil); err != nil {
			return nil, err
		}
		time8 = common.PrettyDuration(time.Since(start))
	} else {
		// Full but not archive node, do proper garbage collection
		triedb.Reference(root, common.Hash{}) // metadata reference to keep trie alive
		p.triegc.Push(root, -int64(block.NumberU64()))
		time8 = common.PrettyDuration(time.Since(start))
		if current := block.NumberU64(); current > TriesInMemory {
			// If we exceeded our memory allowance, flush matured singleton nodes to disk
			var (
				nodes, imgs = triedb.Size()
				limit       = common.StorageSize(p.cacheConfig.TrieDirtyLimit) * 1024 * 1024
			)
			if nodes > limit || imgs > 4*1024*1024 {
				triedb.Cap(limit - ethdb.IdealBatchSize)
			}
			// Find the next state trie we need to commit
			chosen := current - TriesInMemory
			time9 = common.PrettyDuration(time.Since(start))
			// If we exceeded out time allowance, flush an entire trie to disk
			if p.gcproc > p.cacheConfig.TrieTimeLimit {
				// If the header is missing (canonical chain behind), we're reorging a low
				// diff sidechain. Suspend committing until this operation is completed.
				header := p.hc.GetHeaderByNumber(chosen)
				if header == nil {
					log.Warn("Reorg in progress, trie commit postponed", "number", chosen)
				} else {
					// If we're exceeding limits but haven't reached a large enough memory gap,
					// warn the user that the system is becoming unstable.
					if chosen < lastWrite+TriesInMemory && p.gcproc >= 2*p.cacheConfig.TrieTimeLimit {
						log.Info("State in memory for too long, committing", "time", p.gcproc, "allowance", p.cacheConfig.TrieTimeLimit, "optimum", float64(chosen-lastWrite)/TriesInMemory)
					}
					// Flush an entire trie and restart the counters
					triedb.Commit(header.Root(), true, nil)
					lastWrite = chosen
					p.gcproc = 0
				}
			}
			time10 = common.PrettyDuration(time.Since(start))
			// Garbage collect anything below our required write retention
			for !p.triegc.Empty() {
				root, number := p.triegc.Pop()
				if uint64(-number) > chosen {
					p.triegc.Push(root, number)
					break
				}
				triedb.Dereference(root.(common.Hash))
			}
			time11 = common.PrettyDuration(time.Since(start))
		}
	}
	rawdb.WriteEtxSet(p.hc.bc.db, block.Hash(), block.NumberU64(), etxSet)
	time12 := common.PrettyDuration(time.Since(start))

	log.Info("times during state processor apply:", "t1:", time1, "t2:", time2, "t3:", time3, "t4:", time4, "t4.5:", time4_5, "t5:", time5, "t6:", time6, "t7:", time7, "t8:", time8, "t9:", time9, "t10:", time10, "t11:", time11, "t12:", time12)
	return logs, nil
}

// ApplyTransaction attempts to apply a transaction to the given state database
// and uses the input parameters for its environment. It returns the receipt
// for the transaction, gas used and an error if the transaction failed,
// indicating the block was invalid.
func ApplyTransaction(config *params.ChainConfig, bc ChainContext, author *common.Address, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *uint64, cfg vm.Config, etxRLimit, etxPLimit *int) (*types.Receipt, error) {
	msg, err := tx.AsMessage(types.MakeSigner(config, header.Number()), header.BaseFee())
	if err != nil {
		return nil, err
	}
	// Create a new context to be used in the EVM environment
	blockContext := NewEVMBlockContext(header, bc, author)
	vmenv := vm.NewEVM(blockContext, vm.TxContext{}, statedb, config, cfg)
	if tx.Type() == types.ExternalTxType {
		prevZeroBal := prepareApplyETX(statedb, tx)
		receipt, err := applyTransaction(msg, config, bc, author, gp, statedb, header.Number(), header.Hash(), tx, usedGas, vmenv, etxRLimit, etxPLimit)
		statedb.SetBalance(common.ZeroInternal, prevZeroBal) // Reset the balance to what it previously was (currently a failed external transaction removes all the sent coins from the supply and any residual balance is gone as well)
		return receipt, err
	}
	return applyTransaction(msg, config, bc, author, gp, statedb, header.Number(), header.Hash(), tx, usedGas, vmenv, etxRLimit, etxPLimit)
}

// GetVMConfig returns the block chain VM config.
func (p *StateProcessor) GetVMConfig() *vm.Config {
	return &p.vmConfig
}

// State returns a new mutable state based on the current HEAD block.
func (p *StateProcessor) State() (*state.StateDB, error) {
	return p.StateAt(p.hc.GetBlockByHash(p.hc.CurrentHeader().Hash()).Root())
}

// StateAt returns a new mutable state based on a particular point in time.
func (p *StateProcessor) StateAt(root common.Hash) (*state.StateDB, error) {
	return state.New(root, p.stateCache, p.snaps)
}

// StateCache returns the caching database underpinning the blockchain instance.
func (p *StateProcessor) StateCache() state.Database {
	return p.stateCache
}

// HasState checks if state trie is fully present in the database or not.
func (p *StateProcessor) HasState(hash common.Hash) bool {
	_, err := p.stateCache.OpenTrie(hash)
	return err == nil
}

// HasBlockAndState checks if a block and associated state trie is fully present
// in the database or not, caching it if present.
func (p *StateProcessor) HasBlockAndState(hash common.Hash, number uint64) bool {
	// Check first that the block itself is known
	block := p.hc.GetBlock(hash, number)
	if block == nil {
		return false
	}
	return p.HasState(block.Root())
}

// GetReceiptsByHash retrieves the receipts for all transactions in a given block.
func (p *StateProcessor) GetReceiptsByHash(hash common.Hash) types.Receipts {
	if receipts, ok := p.receiptsCache.Get(hash); ok {
		return receipts.(types.Receipts)
	}
	number := rawdb.ReadHeaderNumber(p.hc.headerDb, hash)
	if number == nil {
		return nil
	}
	receipts := rawdb.ReadReceipts(p.hc.headerDb, hash, *number, p.hc.config)
	if receipts == nil {
		return nil
	}
	p.receiptsCache.Add(hash, receipts)
	return receipts
}

// GetTransactionLookup retrieves the lookup associate with the given transaction
// hash from the cache or database.
func (p *StateProcessor) GetTransactionLookup(hash common.Hash) *rawdb.LegacyTxLookupEntry {
	// Short circuit if the txlookup already in the cache, retrieve otherwise
	if lookup, exist := p.txLookupCache.Get(hash); exist {
		return lookup.(*rawdb.LegacyTxLookupEntry)
	}
	tx, blockHash, blockNumber, txIndex := rawdb.ReadTransaction(p.hc.headerDb, hash)
	if tx == nil {
		return nil
	}
	lookup := &rawdb.LegacyTxLookupEntry{BlockHash: blockHash, BlockIndex: blockNumber, Index: txIndex}
	p.txLookupCache.Add(hash, lookup)
	return lookup
}

// ContractCode retrieves a blob of data associated with a contract hash
// either from ephemeral in-memory cache, or from persistent storage.
func (p *StateProcessor) ContractCode(hash common.Hash) ([]byte, error) {
	return p.stateCache.ContractCode(common.Hash{}, hash)
}

// either from ephemeral in-memory cache, or from persistent storage.
func (p *StateProcessor) TrieNode(hash common.Hash) ([]byte, error) {
	return p.stateCache.TrieDB().Node(hash)
}

// ContractCodeWithPrefix retrieves a blob of data associated with a contract
// hash either from ephemeral in-memory cache, or from persistent storage.
//
// If the code doesn't exist in the in-memory cache, check the storage with
// new code scheme.
func (p *StateProcessor) ContractCodeWithPrefix(hash common.Hash) ([]byte, error) {
	type codeReader interface {
		ContractCodeWithPrefix(addrHash, codeHash common.Hash) ([]byte, error)
	}
	return p.stateCache.(codeReader).ContractCodeWithPrefix(common.Hash{}, hash)
}

// StateAtBlock retrieves the state database associated with a certain block.
// If no state is locally available for the given block, a number of blocks
// are attempted to be reexecuted to generate the desired state. The optional
// base layer statedb can be passed then it's regarded as the statedb of the
// parent block.
// Parameters:
//   - block: The block for which we want the state (== state at the stateRoot of the parent)
//   - reexec: The maximum number of blocks to reprocess trying to obtain the desired state
//   - base: If the caller is tracing multiple blocks, the caller can provide the parent state
//     continuously from the callsite.
//   - checklive: if true, then the live 'blockchain' state database is used. If the caller want to
//     perform Commit or other 'save-to-disk' changes, this should be set to false to avoid
//     storing trash persistently
func (p *StateProcessor) StateAtBlock(block *types.Block, reexec uint64, base *state.StateDB, checkLive bool) (statedb *state.StateDB, err error) {
	var (
		current  *types.Block
		etxSet   types.EtxSet
		database state.Database
		report   = true
		origin   = block.NumberU64()
	)
	// Check the live database first if we have the state fully available, use that.
	if checkLive {
		statedb, err = p.StateAt(block.Root())
		if err == nil {
			return statedb, nil
		}
	}
	etxSet = rawdb.ReadEtxSet(p.hc.bc.db, block.Hash(), block.NumberU64())
	if base != nil {
		// The optional base statedb is given, mark the start point as parent block
		statedb, database, report = base, base.Database(), false
		current = p.hc.GetBlock(block.ParentHash(), block.NumberU64()-1)
	} else {
		// Otherwise try to reexec blocks until we find a state or reach our limit
		current = block

		// Create an ephemeral trie.Database for isolating the live one. Otherwise
		// the internal junks created by tracing will be persisted into the disk.
		database = state.NewDatabaseWithConfig(p.hc.headerDb, &trie.Config{Cache: 16})

		// If we didn't check the dirty database, do check the clean one, otherwise
		// we would rewind past a persisted block (specific corner case is chain
		// tracing from the genesis).
		if !checkLive {
			statedb, err = state.New(current.Root(), database, nil)
			if err == nil {
				return statedb, nil
			}
		}
		// Database does not have the state for the given block, try to regenerate
		for i := uint64(0); i < reexec; i++ {
			if current.NumberU64() == 0 {
				return nil, errors.New("genesis state is missing")
			}
			parent := p.hc.GetBlock(current.ParentHash(), current.NumberU64()-1)
			if parent == nil {
				return nil, fmt.Errorf("missing block %v %d", current.ParentHash(), current.NumberU64()-1)
			}
			current = parent

			statedb, err = state.New(current.Root(), database, nil)
			if err == nil {
				break
			}
		}
		if err != nil {
			switch err.(type) {
			case *trie.MissingNodeError:
				return nil, fmt.Errorf("required historical state unavailable (reexec=%d)", reexec)
			default:
				return nil, err
			}
		}
	}
	// State was available at historical point, regenerate
	var (
		start  = time.Now()
		logged time.Time
		parent common.Hash
	)
	for current.NumberU64() < origin {
		// Print progress logs if long enough time elapsed
		if time.Since(logged) > 8*time.Second && report {
			log.Info("Regenerating historical state", "block", current.NumberU64()+1, "target", origin, "remaining", origin-current.NumberU64()-1, "elapsed", time.Since(start))
			logged = time.Now()
		}
		// Retrieve the next block to regenerate and process it
		next := current.NumberU64() + 1
		if current = p.hc.GetBlockByNumber(next); current == nil {
			return nil, fmt.Errorf("block #%d not found", next)
		}
		_, _, _, _, err := p.Process(current, etxSet)
		if err != nil {
			return nil, fmt.Errorf("processing block %d failed: %v", current.NumberU64(), err)
		}
		// Finalize the state so any modifications are written to the trie
		root, err := statedb.Commit(true)
		if err != nil {
			return nil, fmt.Errorf("stateAtBlock commit failed, number %d root %v: %w",
				current.NumberU64(), current.Root().Hex(), err)
		}
		statedb, err = state.New(root, database, nil)
		if err != nil {
			return nil, fmt.Errorf("state reset after block %d failed: %v", current.NumberU64(), err)
		}
		database.TrieDB().Reference(root, common.Hash{})
		if parent != (common.Hash{}) {
			database.TrieDB().Dereference(parent)
		}
		parent = root
	}
	if report {
		nodes, imgs := database.TrieDB().Size()
		log.Info("Historical state regenerated", "block", current.NumberU64(), "elapsed", time.Since(start), "nodes", nodes, "preimages", imgs)
	}
	return statedb, nil
}

// stateAtTransaction returns the execution environment of a certain transaction.
func (p *StateProcessor) StateAtTransaction(block *types.Block, txIndex int, reexec uint64) (Message, vm.BlockContext, *state.StateDB, error) {
	// Short circuit if it's genesis block.
	if block.NumberU64() == 0 {
		return nil, vm.BlockContext{}, nil, errors.New("no transaction in genesis")
	}
	// Create the parent state database
	parent := p.hc.GetBlock(block.ParentHash(), block.NumberU64()-1)
	if parent == nil {
		return nil, vm.BlockContext{}, nil, fmt.Errorf("parent %#x not found", block.ParentHash())
	}
	// Lookup the statedb of parent block from the live database,
	// otherwise regenerate it on the flight.
	statedb, err := p.StateAtBlock(parent, reexec, nil, true)
	if err != nil {
		return nil, vm.BlockContext{}, nil, err
	}
	if txIndex == 0 && len(block.Transactions()) == 0 {
		return nil, vm.BlockContext{}, statedb, nil
	}
	// Recompute transactions up to the target index.
	signer := types.MakeSigner(p.hc.Config(), block.Number())
	for idx, tx := range block.Transactions() {
		// Assemble the transaction call message and return if the requested offset
		msg, _ := tx.AsMessage(signer, block.BaseFee())
		txContext := NewEVMTxContext(msg)
		context := NewEVMBlockContext(block.Header(), p.hc, nil)
		if idx == txIndex {
			return msg, context, statedb, nil
		}
		// Not yet the searched for transaction, execute on top of the current state
		vmenv := vm.NewEVM(context, txContext, statedb, p.hc.Config(), vm.Config{})
		statedb.Prepare(tx.Hash(), idx)
		if _, err := ApplyMessage(vmenv, msg, new(GasPool).AddGas(tx.Gas())); err != nil {
			return nil, vm.BlockContext{}, nil, fmt.Errorf("transaction %#x failed: %v", tx.Hash(), err)
		}
		// Ensure any modifications are committed to the state
		statedb.Finalise(true)
	}
	return nil, vm.BlockContext{}, nil, fmt.Errorf("transaction index %d out of range for block %#x", txIndex, block.Hash())
}

func (p *StateProcessor) Stop() {
	// Ensure that the entirety of the state snapshot is journalled to disk.
	var snapBase common.Hash
	if p.snaps != nil {
		var err error
		if snapBase, err = p.snaps.Journal(p.hc.CurrentBlock().Root()); err != nil {
			log.Error("Failed to journal state snapshot", "err", err)
		}
	}
	// Ensure the state of a recent block is also stored to disk before exiting.
	// We're writing three different states to catch different restart scenarios:
	//  - HEAD:     So we don't need to reprocess any blocks in the general case
	//  - HEAD-1:   So we don't do large reorgs if our HEAD becomes an uncle
	//  - HEAD-127: So we have a hard limit on the number of blocks reexecuted
	if !p.cacheConfig.TrieDirtyDisabled {
		triedb := p.stateCache.TrieDB()

		for _, offset := range []uint64{0, 1, TriesInMemory - 1} {
			if number := p.hc.CurrentBlock().NumberU64(); number > offset {
				recent := p.hc.GetBlockByNumber(number - offset)

				log.Info("Writing cached state to disk", "block", recent.Number(), "hash", recent.Hash(), "root", recent.Root())
				if err := triedb.Commit(recent.Root(), true, nil); err != nil {
					log.Error("Failed to commit recent state trie", "err", err)
				}
			}
		}
		if snapBase != (common.Hash{}) {
			log.Info("Writing snapshot state to disk", "root", snapBase)
			if err := triedb.Commit(snapBase, true, nil); err != nil {
				log.Error("Failed to commit recent state trie", "err", err)
			}
		}
		for !p.triegc.Empty() {
			triedb.Dereference(p.triegc.PopItem().(common.Hash))
		}
		if size, _ := triedb.Size(); size != 0 {
			log.Error("Dangling trie nodes after full cleanup")
		}
	}
	// Ensure all live cached entries be saved into disk, so that we can skip
	// cache warmup when node restarts.
	if p.cacheConfig.TrieCleanJournal != "" {
		triedb := p.stateCache.TrieDB()
		triedb.SaveCache(p.cacheConfig.TrieCleanJournal)
	}
	close(p.quit)
	log.Info("State Processor stopped")
}

func prepareApplyETX(statedb *state.StateDB, tx *types.Transaction) *big.Int {
	prevZeroBal := statedb.GetBalance(common.ZeroInternal)   // Get current zero address balance
	fee := big.NewInt(0).Add(tx.GasFeeCap(), tx.GasTipCap()) // Add gas price cap to miner tip cap
	fee.Mul(fee, big.NewInt(int64(tx.Gas())))                // Multiply gas price by gas limit (may need to check for int64 overflow)
	total := big.NewInt(0).Add(fee, tx.Value())              // Add gas fee to value
	statedb.SetBalance(common.ZeroInternal, total)           // Use zero address at temp placeholder and set it to gas fee plus value
	return prevZeroBal
}