core/state: semantic journalling (part 1)

core/state/journal.go

@@ -17,12 +17,21 @@
 package state
 
 import (
+	"fmt"
 	"maps"
+	"slices"
+	"sort"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/holiman/uint256"
 )
 
+type revision struct {
+	id           int
+	journalIndex int
+}
+
 // journalEntry is a modification entry in the state change journal that can be
 // reverted on demand.
 type journalEntry interface {
@@ -42,6 +51,9 @@ type journalEntry interface {
 type journal struct {
 	entries []journalEntry         // Current changes tracked by the journal
 	dirties map[common.Address]int // Dirty accounts and the number of changes
+
+	validRevisions []revision
+	nextRevisionId int
 }
 
 // newJournal creates a new initialized journal.
@@ -51,6 +63,40 @@ func newJournal() *journal {
 	}
 }
 
+// Reset clears the journal, after this operation the journal can be used
+// anew. It is semantically similar to calling 'newJournal', but the underlying
+// slices can be reused
+func (j *journal) Reset() {
+	j.entries = j.entries[:0]
+	j.validRevisions = j.validRevisions[:0]
+	clear(j.dirties)
+	j.nextRevisionId = 0
+}
+
+// Snapshot returns an identifier for the current revision of the state.
+func (j *journal) Snapshot() int {
+	id := j.nextRevisionId
+	j.nextRevisionId++
+	j.validRevisions = append(j.validRevisions, revision{id, j.length()})
+	return id
+}
+
+// RevertToSnapshot reverts all state changes made since the given revision.
+func (j *journal) RevertToSnapshot(revid int, s *StateDB) {
+	// Find the snapshot in the stack of valid snapshots.
+	idx := sort.Search(len(j.validRevisions), func(i int) bool {
+		return j.validRevisions[i].id >= revid
+	})
+	if idx == len(j.validRevisions) || j.validRevisions[idx].id != revid {
+		panic(fmt.Errorf("revision id %v cannot be reverted", revid))
+	}
+	snapshot := j.validRevisions[idx].journalIndex
+
+	// Replay the journal to undo changes and remove invalidated snapshots
+	j.revert(s, snapshot)
+	j.validRevisions = j.validRevisions[:idx]
+}
+
 // append inserts a new modification entry to the end of the change journal.
 func (j *journal) append(entry journalEntry) {
 	j.entries = append(j.entries, entry)
@@ -95,8 +141,83 @@ func (j *journal) copy() *journal {
 		entries = append(entries, j.entries[i].copy())
 	}
 	return &journal{
-		entries: entries,
-		dirties: maps.Clone(j.dirties),
+		entries:        entries,
+		dirties:        maps.Clone(j.dirties),
+		validRevisions: slices.Clone(j.validRevisions),
+		nextRevisionId: j.nextRevisionId,
+	}
+}
+
+func (j *journal) AccessListAddAccount(addr common.Address) {
+	j.append(accessListAddAccountChange{&addr})
+}
+
+func (j *journal) AccessListAddSlot(addr common.Address, slot common.Hash) {
+	j.append(accessListAddSlotChange{
+		address: &addr,
+		slot:    &slot,
+	})
+}
+
+func (j *journal) Log(txHash common.Hash) {
+	j.append(addLogChange{txhash: txHash})
+}
+
+func (j *journal) Create(addr common.Address) {
+	j.append(createObjectChange{account: &addr})
+}
+
+func (j *journal) Destruct(addr common.Address) {
+	j.append(selfDestructChange{account: &addr})
+}
+
+func (j *journal) SetStorage(addr common.Address, key, prev, origin common.Hash) {
+	j.append(storageChange{
+		account:   &addr,
+		key:       key,
+		prevvalue: prev,
+		origvalue: origin,
+	})
+}
+
+func (j *journal) SetTransientState(addr common.Address, key, prev common.Hash) {
+	j.append(transientStorageChange{
+		account:  &addr,
+		key:      key,
+		prevalue: prev,
+	})
+}
+
+func (j *journal) RefundChange(previous uint64) {
+	j.append(refundChange{prev: previous})
+}
+
+func (j *journal) BalanceChange(addr common.Address, previous *uint256.Int) {
+	j.append(balanceChange{
+		account: &addr,
+		prev:    previous.Clone(),
+	})
+}
+
+func (j *journal) SetCode(address common.Address) {
+	j.append(codeChange{account: &address})
+}
+
+func (j *journal) NonceChange(address common.Address, prev uint64) {
+	j.append(nonceChange{
+		account: &address,
+		prev:    prev,
+	})
+}
+
+func (j *journal) Touch(address common.Address) {
+	j.append(touchChange{
+		account: &address,
+	})
+	if address == ripemd {
+		// Explicitly put it in the dirty-cache, which is otherwise generated from
+		// flattened journals.
+		j.dirty(address)
 	}
 }
 
@@ -114,9 +235,7 @@ type (
 	}
 
 	selfDestructChange struct {
-		account     *common.Address
-		prev        bool // whether account had already self-destructed
-		prevbalance *uint256.Int
+		account *common.Address
 	}
 
 	// Changes to individual accounts.
@@ -135,8 +254,7 @@ type (
 		origvalue common.Hash
 	}
 	codeChange struct {
-		account            *common.Address
-		prevcode, prevhash []byte
+		account *common.Address
 	}
 
 	// Changes to other state values.
@@ -146,9 +264,6 @@ type (
 	addLogChange struct {
 		txhash common.Hash
 	}
-	addPreimageChange struct {
-		hash common.Hash
-	}
 	touchChange struct {
 		account *common.Address
 	}
@@ -200,8 +315,7 @@ func (ch createContractChange) copy() journalEntry {
 func (ch selfDestructChange) revert(s *StateDB) {
 	obj := s.getStateObject(*ch.account)
 	if obj != nil {
-		obj.selfDestructed = ch.prev
-		obj.setBalance(ch.prevbalance)
+		obj.selfDestructed = false
 	}
 }
 
@@ -211,9 +325,7 @@ func (ch selfDestructChange) dirtied() *common.Address {
 
 func (ch selfDestructChange) copy() journalEntry {
 	return selfDestructChange{
-		account:     ch.account,
-		prev:        ch.prev,
-		prevbalance: new(uint256.Int).Set(ch.prevbalance),
+		account: ch.account,
 	}
 }
 
@@ -263,19 +375,15 @@ func (ch nonceChange) copy() journalEntry {
 }
 
 func (ch codeChange) revert(s *StateDB) {
-	s.getStateObject(*ch.account).setCode(common.BytesToHash(ch.prevhash), ch.prevcode)
+	s.getStateObject(*ch.account).setCode(types.EmptyCodeHash, nil)
 }
 
 func (ch codeChange) dirtied() *common.Address {
 	return ch.account
 }
 
 func (ch codeChange) copy() journalEntry {
-	return codeChange{
-		account:  ch.account,
-		prevhash: common.CopyBytes(ch.prevhash),
-		prevcode: common.CopyBytes(ch.prevcode),
-	}
+	return codeChange{account: ch.account}
 }
 
 func (ch storageChange) revert(s *StateDB) {
@@ -344,20 +452,6 @@ func (ch addLogChange) copy() journalEntry {
 	}
 }
 
-func (ch addPreimageChange) revert(s *StateDB) {
-	delete(s.preimages, ch.hash)
-}
-
-func (ch addPreimageChange) dirtied() *common.Address {
-	return nil
-}
-
-func (ch addPreimageChange) copy() journalEntry {
-	return addPreimageChange{
-		hash: ch.hash,
-	}
-}
-
 func (ch accessListAddAccountChange) revert(s *StateDB) {
 	/*
 		One important invariant here, is that whenever a (addr, slot) is added, if the

core/state/state_object.go

@@ -114,14 +114,7 @@ func (s *stateObject) markSelfdestructed() {
 }
 
 func (s *stateObject) touch() {
-	s.db.journal.append(touchChange{
-		account: &s.address,
-	})
-	if s.address == ripemd {
-		// Explicitly put it in the dirty-cache, which is otherwise generated from
-		// flattened journals.
-		s.db.journal.dirty(s.address)
-	}
+	s.db.journal.Touch(s.address)
 }
 
 // getTrie returns the associated storage trie. The trie will be opened if it's
@@ -251,16 +244,11 @@ func (s *stateObject) SetState(key, value common.Hash) {
 		return
 	}
 	// New value is different, update and journal the change
-	s.db.journal.append(storageChange{
-		account:   &s.address,
-		key:       key,
-		prevvalue: prev,
-		origvalue: origin,
-	})
+	s.db.journal.SetStorage(s.address, key, prev, origin)
+	s.setState(key, value, origin)
 	if s.db.logger != nil && s.db.logger.OnStorageChange != nil {
 		s.db.logger.OnStorageChange(s.address, key, prev, value)
 	}
-	s.setState(key, value, origin)
 }
 
 // setState updates a value in account dirty storage. The dirtiness will be
@@ -510,10 +498,7 @@ func (s *stateObject) SubBalance(amount *uint256.Int, reason tracing.BalanceChan
 }
 
 func (s *stateObject) SetBalance(amount *uint256.Int, reason tracing.BalanceChangeReason) {
-	s.db.journal.append(balanceChange{
-		account: &s.address,
-		prev:    new(uint256.Int).Set(s.data.Balance),
-	})
+	s.db.journal.BalanceChange(s.address, s.data.Balance)
 	if s.db.logger != nil && s.db.logger.OnBalanceChange != nil {
 		s.db.logger.OnBalanceChange(s.address, s.Balance().ToBig(), amount.ToBig(), reason)
 	}
@@ -589,14 +574,10 @@ func (s *stateObject) CodeSize() int {
 }
 
 func (s *stateObject) SetCode(codeHash common.Hash, code []byte) {
-	prevcode := s.Code()
-	s.db.journal.append(codeChange{
-		account:  &s.address,
-		prevhash: s.CodeHash(),
-		prevcode: prevcode,
-	})
+	s.db.journal.SetCode(s.address)
 	if s.db.logger != nil && s.db.logger.OnCodeChange != nil {
-		s.db.logger.OnCodeChange(s.address, common.BytesToHash(s.CodeHash()), prevcode, codeHash, code)
+		// TODO remove prevcode from this callback
+		s.db.logger.OnCodeChange(s.address, common.BytesToHash(s.CodeHash()), nil, codeHash, code)
 	}
 	s.setCode(codeHash, code)
 }
@@ -608,10 +589,7 @@ func (s *stateObject) setCode(codeHash common.Hash, code []byte) {
 }
 
 func (s *stateObject) SetNonce(nonce uint64) {
-	s.db.journal.append(nonceChange{
-		account: &s.address,
-		prev:    s.data.Nonce,
-	})
+	s.db.journal.NonceChange(s.address, s.data.Nonce)
 	if s.db.logger != nil && s.db.logger.OnNonceChange != nil {
 		s.db.logger.OnNonceChange(s.address, s.data.Nonce, nonce)
 	}