ipld-eth-statedb/statedb.go

503 lines
15 KiB
Go

package ipld_eth_statedb
import (
"fmt"
"math/big"
"sort"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/metrics"
)
/*
The portions of the EVM we want to leverage only use the following methods:
GetBalance
Snapshot
Exist
CreateAccount
SubBalance
AddBalance
GetCode
GetCodeHash
RevertToSnapshot
GetNonce
SetNonce
AddAddressToAccessList
SetCode
The rest can be left with panics for now
*/
var _ vm.StateDB = &StateDB{}
type revision struct {
id int
journalIndex int
}
// StateDB structs within the ethereum protocol are used to store anything
// within the merkle trie. StateDBs take care of caching and storing
// nested states. It's the general query interface to retrieve:
// * Contracts
// * Accounts
type StateDB struct {
db StateDatabase
hasher crypto.KeccakState
// originBlockHash is the blockhash for the state we are working on top of
originBlockHash common.Hash
// This map holds 'live' objects, which will get modified while processing a state transition.
stateObjects map[common.Address]*stateObject
stateObjectsPending map[common.Address]struct{} // State objects finalized but not yet written to the trie
stateObjectsDirty map[common.Address]struct{} // State objects modified in the current execution
// DB error.
// State objects are used by the consensus core and VM which are
// unable to deal with database-level errors. Any error that occurs
// during a database read is memoized here and will eventually be returned
// by StateDB.Commit.
dbErr error
// The refund counter, also used by state transitioning.
refund uint64
thash common.Hash
txIndex int
logs map[common.Hash][]*types.Log
logSize uint
preimages map[common.Hash][]byte
// Per-transaction access list
accessList *accessList
// Journal of state modifications. This is the backbone of
// Snapshot and RevertToSnapshot.
journal *journal
validRevisions []revision
nextRevisionId int
// Measurements gathered during execution for debugging purposes
AccountReads time.Duration
StorageReads time.Duration
}
// New creates a new StateDB on the state for the provided blockHash
func New(blockHash common.Hash, db StateDatabase) (*StateDB, error) {
sdb := &StateDB{
db: db,
originBlockHash: blockHash,
stateObjects: make(map[common.Address]*stateObject),
stateObjectsPending: make(map[common.Address]struct{}),
stateObjectsDirty: make(map[common.Address]struct{}),
logs: make(map[common.Hash][]*types.Log),
preimages: make(map[common.Hash][]byte),
journal: newJournal(),
accessList: newAccessList(),
hasher: crypto.NewKeccakState(),
}
return sdb, nil
}
// setError remembers the first non-nil error it is called with.
func (s *StateDB) setError(err error) {
if s.dbErr == nil {
s.dbErr = err
}
}
func (s *StateDB) AddLog(log *types.Log) {
s.journal.append(addLogChange{txhash: s.thash})
log.TxHash = s.thash
log.TxIndex = uint(s.txIndex)
log.Index = s.logSize
s.logs[s.thash] = append(s.logs[s.thash], log)
s.logSize++
}
// AddPreimage records a SHA3 preimage seen by the VM.
func (s *StateDB) AddPreimage(hash common.Hash, preimage []byte) {
if _, ok := s.preimages[hash]; !ok {
s.journal.append(addPreimageChange{hash: hash})
pi := make([]byte, len(preimage))
copy(pi, preimage)
s.preimages[hash] = pi
}
}
// AddRefund adds gas to the refund counter
func (s *StateDB) AddRefund(gas uint64) {
s.journal.append(refundChange{prev: s.refund})
s.refund += gas
}
// SubRefund removes gas from the refund counter.
// This method will panic if the refund counter goes below zero
func (s *StateDB) SubRefund(gas uint64) {
s.journal.append(refundChange{prev: s.refund})
if gas > s.refund {
panic(fmt.Sprintf("Refund counter below zero (gas: %d > refund: %d)", gas, s.refund))
}
s.refund -= gas
}
// Exist reports whether the given account address exists in the state.
// Notably this also returns true for suicided accounts.
func (s *StateDB) Exist(addr common.Address) bool {
return s.getStateObject(addr) != nil
}
// Empty returns whether the state object is either non-existent
// or empty according to the EIP161 specification (balance = nonce = code = 0)
func (s *StateDB) Empty(addr common.Address) bool {
so := s.getStateObject(addr)
return so == nil || so.empty()
}
// GetBalance retrieves the balance from the given address or 0 if object not found
func (s *StateDB) GetBalance(addr common.Address) *big.Int {
stateObject := s.getStateObject(addr)
if stateObject != nil {
return stateObject.Balance()
}
return common.Big0
}
func (s *StateDB) GetNonce(addr common.Address) uint64 {
stateObject := s.getStateObject(addr)
if stateObject != nil {
return stateObject.Nonce()
}
return 0
}
func (s *StateDB) GetCode(addr common.Address) []byte {
stateObject := s.getStateObject(addr)
if stateObject != nil {
return stateObject.Code(s.db)
}
return nil
}
func (s *StateDB) GetCodeSize(addr common.Address) int {
stateObject := s.getStateObject(addr)
if stateObject != nil {
return stateObject.CodeSize(s.db)
}
return 0
}
func (s *StateDB) GetCodeHash(addr common.Address) common.Hash {
stateObject := s.getStateObject(addr)
if stateObject == nil {
return common.Hash{}
}
return common.BytesToHash(stateObject.CodeHash())
}
// GetState retrieves a value from the given account's storage trie.
func (s *StateDB) GetState(addr common.Address, hash common.Hash) common.Hash {
stateObject := s.getStateObject(addr)
if stateObject != nil {
return stateObject.GetState(s.db, hash)
}
return common.Hash{}
}
// GetCommittedState retrieves a value from the given account's committed storage trie.
func (s *StateDB) GetCommittedState(addr common.Address, hash common.Hash) common.Hash {
stateObject := s.getStateObject(addr)
if stateObject != nil {
return stateObject.GetCommittedState(s.db, hash)
}
return common.Hash{}
}
func (s *StateDB) HasSuicided(addr common.Address) bool {
stateObject := s.getStateObject(addr)
if stateObject != nil {
return stateObject.suicided
}
return false
}
/*
* SETTERS
*/
// AddBalance adds amount to the account associated with addr.
func (s *StateDB) AddBalance(addr common.Address, amount *big.Int) {
stateObject := s.getOrNewStateObject(addr)
if stateObject != nil {
stateObject.AddBalance(amount)
}
}
// SubBalance subtracts amount from the account associated with addr.
func (s *StateDB) SubBalance(addr common.Address, amount *big.Int) {
stateObject := s.getOrNewStateObject(addr)
if stateObject != nil {
stateObject.SubBalance(amount)
}
}
func (s *StateDB) SetBalance(addr common.Address, amount *big.Int) {
stateObject := s.getOrNewStateObject(addr)
if stateObject != nil {
stateObject.SetBalance(amount)
}
}
func (s *StateDB) SetNonce(addr common.Address, nonce uint64) {
stateObject := s.getOrNewStateObject(addr)
if stateObject != nil {
stateObject.SetNonce(nonce)
}
}
func (s *StateDB) SetCode(addr common.Address, code []byte) {
stateObject := s.getOrNewStateObject(addr)
if stateObject != nil {
stateObject.SetCode(crypto.Keccak256Hash(code), code)
}
}
func (s *StateDB) SetState(addr common.Address, key, value common.Hash) {
stateObject := s.getOrNewStateObject(addr)
if stateObject != nil {
stateObject.SetState(s.db, key, value)
}
}
// SetStorage replaces the entire storage for the specified account with given
// storage. This function should only be used for debugging.
func (s *StateDB) SetStorage(addr common.Address, storage map[common.Hash]common.Hash) {
stateObject := s.getOrNewStateObject(addr)
if stateObject != nil {
stateObject.SetStorage(storage)
}
}
// Suicide marks the given account as suicided.
// This clears the account balance.
//
// The account's state object is still available until the state is committed,
// getStateObject will return a non-nil account after Suicide.
func (s *StateDB) Suicide(addr common.Address) bool {
stateObject := s.getStateObject(addr)
if stateObject == nil {
return false
}
s.journal.append(suicideChange{
account: &addr,
prev: stateObject.suicided,
prevbalance: new(big.Int).Set(stateObject.Balance()),
})
stateObject.markSuicided()
stateObject.data.Balance = new(big.Int)
return true
}
//
// Setting, updating & deleting state object methods.
//
// getStateObject retrieves a state object given by the address, returning nil if
// the object is not found or was deleted in this execution context. If you need
// to differentiate between non-existent/just-deleted, use getDeletedStateObject.
func (s *StateDB) getStateObject(addr common.Address) *stateObject {
if obj := s.getDeletedStateObject(addr); obj != nil && !obj.deleted {
return obj
}
return nil
}
// getDeletedStateObject is similar to getStateObject, but instead of returning
// nil for a deleted state object, it returns the actual object with the deleted
// flag set. This is needed by the state journal to revert to the correct s-
// destructed object instead of wiping all knowledge about the state object.
// TODO:
func (s *StateDB) getDeletedStateObject(addr common.Address) *stateObject {
// Prefer live objects if any is available
if obj := s.stateObjects[addr]; obj != nil {
return obj
}
// If no live objects are available, load from the database
// TODO: REPLACE TRIE ACCESS HERE
// can add a fallback option to use ipfsethdb to do the trie access if direct access fails
start := time.Now()
addrHash := crypto.Keccak256Hash(addr.Bytes())
data, err := s.db.StateAccount(addrHash, s.originBlockHash)
if metrics.EnabledExpensive {
s.AccountReads += time.Since(start)
}
if err != nil {
s.setError(fmt.Errorf("getDeletedStateObject (%x) error: %w", addr.Bytes(), err))
return nil
}
if data == nil {
return nil
}
// Insert into the live set
obj := newObject(s, addr, *data, s.originBlockHash)
s.setStateObject(obj)
return obj
}
func (s *StateDB) setStateObject(object *stateObject) {
s.stateObjects[object.Address()] = object
}
// getOrNewStateObject retrieves a state object or create a new state object if nil.
func (s *StateDB) getOrNewStateObject(addr common.Address) *stateObject {
stateObject := s.getStateObject(addr)
if stateObject == nil {
stateObject, _ = s.createObject(addr)
}
return stateObject
}
// createObject creates a new state object. If there is an existing account with
// the given address, it is overwritten and returned as the second return value.
func (s *StateDB) createObject(addr common.Address) (newobj, prev *stateObject) {
prev = s.getDeletedStateObject(addr) // Note, prev might have been deleted, we need that!
newobj = newObject(s, addr, types.StateAccount{}, s.originBlockHash)
if prev == nil {
s.journal.append(createObjectChange{account: &addr})
} else {
s.journal.append(resetObjectChange{prev: prev}) // NOTE: prevdestruct used to be set here from snapshot
}
s.setStateObject(newobj)
if prev != nil && !prev.deleted {
return newobj, prev
}
return newobj, nil
}
// CreateAccount explicitly creates a state object. If a state object with the address
// already exists the balance is carried over to the new account.
//
// CreateAccount is called during the EVM CREATE operation. The situation might arise that
// a contract does the following:
//
// 1. sends funds to sha(account ++ (nonce + 1))
// 2. tx_create(sha(account ++ nonce)) (note that this gets the address of 1)
//
// Carrying over the balance ensures that Ether doesn't disappear.
func (s *StateDB) CreateAccount(addr common.Address) {
newObj, prev := s.createObject(addr)
if prev != nil {
newObj.setBalance(prev.data.Balance)
}
}
// ForEachStorage satisfies vm.StateDB but is not implemented
func (db *StateDB) ForEachStorage(addr common.Address, cb func(key, value common.Hash) bool) error {
// NOTE: as far as I can tell this method is only ever used in tests
// in that case, we can leave it unimplemented
// or if it needs to be implemented we can use iplfs-ethdb to do normal trie access
panic("ForEachStorage is not implemented")
}
// Snapshot returns an identifier for the current revision of the state.
func (s *StateDB) Snapshot() int {
id := s.nextRevisionId
s.nextRevisionId++
s.validRevisions = append(s.validRevisions, revision{id, s.journal.length()})
return id
}
// RevertToSnapshot reverts all state changes made since the given revision.
func (s *StateDB) RevertToSnapshot(revid int) {
// Find the snapshot in the stack of valid snapshots.
idx := sort.Search(len(s.validRevisions), func(i int) bool {
return s.validRevisions[i].id >= revid
})
if idx == len(s.validRevisions) || s.validRevisions[idx].id != revid {
panic(fmt.Errorf("revision id %v cannot be reverted", revid))
}
snp := s.validRevisions[idx].journalIndex
// Replay the journal to undo changes and remove invalidated snapshots
s.journal.revert(s, snp)
s.validRevisions = s.validRevisions[:idx]
}
// GetRefund returns the current value of the refund counter.
func (s *StateDB) GetRefund() uint64 {
return s.refund
}
// PrepareAccessList handles the preparatory steps for executing a state transition with
// regards to both EIP-2929 and EIP-2930:
//
// - Add sender to access list (2929)
// - Add destination to access list (2929)
// - Add precompiles to access list (2929)
// - Add the contents of the optional tx access list (2930)
//
// This method should only be called if Berlin/2929+2930 is applicable at the current number.
func (s *StateDB) PrepareAccessList(sender common.Address, dst *common.Address, precompiles []common.Address, list types.AccessList) {
// Clear out any leftover from previous executions
s.accessList = newAccessList()
s.AddAddressToAccessList(sender)
if dst != nil {
s.AddAddressToAccessList(*dst)
// If it's a create-tx, the destination will be added inside evm.create
}
for _, addr := range precompiles {
s.AddAddressToAccessList(addr)
}
for _, el := range list {
s.AddAddressToAccessList(el.Address)
for _, key := range el.StorageKeys {
s.AddSlotToAccessList(el.Address, key)
}
}
}
// AddAddressToAccessList adds the given address to the access list
func (s *StateDB) AddAddressToAccessList(addr common.Address) {
if s.accessList.AddAddress(addr) {
s.journal.append(accessListAddAccountChange{&addr})
}
}
// AddSlotToAccessList adds the given (address, slot)-tuple to the access list
func (s *StateDB) AddSlotToAccessList(addr common.Address, slot common.Hash) {
addrMod, slotMod := s.accessList.AddSlot(addr, slot)
if addrMod {
// In practice, this should not happen, since there is no way to enter the
// scope of 'address' without having the 'address' become already added
// to the access list (via call-variant, create, etc).
// Better safe than sorry, though
s.journal.append(accessListAddAccountChange{&addr})
}
if slotMod {
s.journal.append(accessListAddSlotChange{
address: &addr,
slot: &slot,
})
}
}
// AddressInAccessList returns true if the given address is in the access list.
func (s *StateDB) AddressInAccessList(addr common.Address) bool {
return s.accessList.ContainsAddress(addr)
}
// SlotInAccessList returns true if the given (address, slot)-tuple is in the access list.
func (s *StateDB) SlotInAccessList(addr common.Address, slot common.Hash) (addressPresent bool, slotPresent bool) {
return s.accessList.Contains(addr, slot)
}