refactor(core): semantic journalling #28880

core/state/journal.go

@@ -17,13 +17,21 @@
 package state
 
 import (
+	"fmt"
 	"maps"
 	"math/big"
+	"slices"
+	"sort"
 
 	"github.com/XinFinOrg/XDPoSChain/common"
 	"github.com/XinFinOrg/XDPoSChain/crypto"
 )
 
+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 {
@@ -43,6 +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.
@@ -52,6 +63,41 @@ 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() {
+	clear(j.entries)
+	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)
@@ -96,22 +142,93 @@ 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) logChange(txHash common.Hash) {
+	j.append(addLogChange{txhash: txHash})
+}
+
+func (j *journal) createObject(addr common.Address) {
+	j.append(createObjectChange{account: addr})
+}
+
 func (j *journal) createContract(addr common.Address) {
 	j.append(createContractChange{account: addr})
 }
 
+func (j *journal) destruct(addr common.Address) {
+	j.append(selfDestructChange{account: addr})
+}
+
+func (j *journal) storageChange(addr common.Address, key, prev, origin common.Hash) {
+	j.append(storageChange{
+		account:   addr,
+		key:       key,
+		prevvalue: prev,
+		origvalue: origin,
+	})
+}
+
+func (j *journal) transientStateChange(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 *big.Int) {
+	j.append(balanceChange{
+		account: addr,
+		prev:    new(big.Int).Set(previous),
+	})
+}
+
 func (j *journal) setCode(address common.Address, prevCode []byte) {
 	j.append(codeChange{
 		account:  address,
 		prevCode: prevCode,
 	})
 }
 
+func (j *journal) nonceChange(address common.Address, prev uint64) {
+	j.append(nonceChange{
+		account: address,
+		prev:    prev,
+	})
+}
+
+func (j *journal) touchChange(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)
+	}
+}
+
+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,
+	})
+}
+
 type (
 	// Changes to the account trie.
 	createObjectChange struct {
@@ -124,9 +241,7 @@ type (
 		account common.Address
 	}
 	selfDestructChange struct {
-		account     common.Address
-		prev        bool // whether account had already self-destructed
-		prevbalance *big.Int
+		account common.Address
 	}
 
 	// Changes to individual accounts.
@@ -156,9 +271,6 @@ type (
 	addLogChange struct {
 		txhash common.Hash
 	}
-	addPreimageChange struct {
-		hash common.Hash
-	}
 	touchChange struct {
 		account common.Address
 	}
@@ -210,8 +322,7 @@ 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
 	}
 }
 
@@ -221,9 +332,7 @@ func (ch selfDestructChange) dirtied() *common.Address {
 
 func (ch selfDestructChange) copy() journalEntry {
 	return selfDestructChange{
-		account:     ch.account,
-		prev:        ch.prev,
-		prevbalance: new(big.Int).Set(ch.prevbalance),
+		account: ch.account,
 	}
 }
 
@@ -354,20 +463,6 @@ 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

@@ -107,14 +107,7 @@ 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.touchChange(s.address)
 }
 
 // getTrie returns the associated storage trie. The trie will be opened
@@ -194,12 +187,7 @@ func (s *stateObject) SetState(key, value common.Hash) common.Hash {
 		return prev
 	}
 	// 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.storageChange(s.address, key, prev, origin)
 	s.setState(key, value, origin)
 	return prev
 }
@@ -379,10 +367,7 @@ func (s *stateObject) AddBalance(amount *big.Int) *big.Int {
 // SetBalance sets the balance for the object, and returns the previous balance.
 func (s *stateObject) SetBalance(amount *big.Int) *big.Int {
 	prev := new(big.Int).Set(s.data.Balance)
-	s.db.journal.append(balanceChange{
-		account: s.address,
-		prev:    new(big.Int).Set(s.data.Balance),
-	})
+	s.db.journal.balanceChange(s.address, s.data.Balance)
 	s.setBalance(amount)
 	return prev
 }
@@ -468,10 +453,7 @@ 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)
 	s.setNonce(nonce)
 }