core/state: access trie through Database interface, track errors (#14589)

With this commit, core/state's access to the underlying key/value database is
mediated through an interface. Database errors are tracked in StateDB and
returned by CommitTo or the new Error method.

Motivation for this change: We can remove the light client's duplicated copy of
core/state. The light client now supports node iteration, so tracing and storage
enumeration can work with the light client (not implemented in this commit).

1 files changed, 34 insertions, 22 deletions

diff --git a/core/state/state_object.go b/core/state/state_object.go
index dcad9d068..b2378c69c 100644
--- a/core/state/state_object.go
+++ b/core/state/state_object.go
@@ -62,9 +62,10 @@ func (self Storage) Copy() Storage {
 // Account values can be accessed and modified through the object.
 // Finally, call CommitTrie to write the modified storage trie into a database.
 type stateObject struct {
-	address common.Address // Ethereum address of this account
-	data    Account
-	db      *StateDB
+	address  common.Address
+	addrHash common.Hash // hash of ethereum address of the account
+	data     Account
+	db       *StateDB
 
 	// DB error.
 	// State objects are used by the consensus core and VM which are
@@ -74,8 +75,8 @@ type stateObject struct {
 	dbErr error
 
 	// Write caches.
-	trie *trie.SecureTrie // storage trie, which becomes non-nil on first access
-	code Code             // contract bytecode, which gets set when code is loaded
+	trie Trie // storage trie, which becomes non-nil on first access
+	code Code // contract bytecode, which gets set when code is loaded
 
 	cachedStorage Storage // Storage entry cache to avoid duplicate reads
 	dirtyStorage  Storage // Storage entries that need to be flushed to disk
@@ -112,7 +113,15 @@ func newObject(db *StateDB, address common.Address, data Account, onDirty func(a
 	if data.CodeHash == nil {
 		data.CodeHash = emptyCodeHash
 	}
-	return &stateObject{db: db, address: address, data: data, cachedStorage: make(Storage), dirtyStorage: make(Storage), onDirty: onDirty}
+	return &stateObject{
+		db:            db,
+		address:       address,
+		addrHash:      crypto.Keccak256Hash(address[:]),
+		data:          data,
+		cachedStorage: make(Storage),
+		dirtyStorage:  make(Storage),
+		onDirty:       onDirty,
+	}
 }
 
 // EncodeRLP implements rlp.Encoder.
@@ -148,12 +157,12 @@ func (c *stateObject) touch() {
 	c.touched = true
 }
 
-func (c *stateObject) getTrie(db trie.Database) *trie.SecureTrie {
+func (c *stateObject) getTrie(db Database) Trie {
 	if c.trie == nil {
 		var err error
-		c.trie, err = trie.NewSecure(c.data.Root, db, 0)
+		c.trie, err = db.OpenStorageTrie(c.addrHash, c.data.Root)
 		if err != nil {
-			c.trie, _ = trie.NewSecure(common.Hash{}, db, 0)
+			c.trie, _ = db.OpenStorageTrie(c.addrHash, common.Hash{})
 			c.setError(fmt.Errorf("can't create storage trie: %v", err))
 		}
 	}
@@ -161,13 +170,18 @@ func (c *stateObject) getTrie(db trie.Database) *trie.SecureTrie {
 }
 
 // GetState returns a value in account storage.
-func (self *stateObject) GetState(db trie.Database, key common.Hash) common.Hash {
+func (self *stateObject) GetState(db Database, key common.Hash) common.Hash {
 	value, exists := self.cachedStorage[key]
 	if exists {
 		return value
 	}
 	// Load from DB in case it is missing.
-	if enc := self.getTrie(db).Get(key[:]); len(enc) > 0 {
+	enc, err := self.getTrie(db).TryGet(key[:])
+	if err != nil {
+		self.setError(err)
+		return common.Hash{}
+	}
+	if len(enc) > 0 {
 		_, content, _, err := rlp.Split(enc)
 		if err != nil {
 			self.setError(err)
@@ -181,7 +195,7 @@ func (self *stateObject) GetState(db trie.Database, key common.Hash) common.Hash
 }
 
 // SetState updates a value in account storage.
-func (self *stateObject) SetState(db trie.Database, key, value common.Hash) {
+func (self *stateObject) SetState(db Database, key, value common.Hash) {
 	self.db.journal = append(self.db.journal, storageChange{
 		account:  &self.address,
 		key:      key,
@@ -201,30 +215,30 @@ func (self *stateObject) setState(key, value common.Hash) {
 }
 
 // updateTrie writes cached storage modifications into the object's storage trie.
-func (self *stateObject) updateTrie(db trie.Database) *trie.SecureTrie {
+func (self *stateObject) updateTrie(db Database) Trie {
 	tr := self.getTrie(db)
 	for key, value := range self.dirtyStorage {
 		delete(self.dirtyStorage, key)
 		if (value == common.Hash{}) {
-			tr.Delete(key[:])
+			self.setError(tr.TryDelete(key[:]))
 			continue
 		}
 		// Encoding []byte cannot fail, ok to ignore the error.
 		v, _ := rlp.EncodeToBytes(bytes.TrimLeft(value[:], "\x00"))
-		tr.Update(key[:], v)
+		self.setError(tr.TryUpdate(key[:], v))
 	}
 	return tr
 }
 
 // UpdateRoot sets the trie root to the current root hash of
-func (self *stateObject) updateRoot(db trie.Database) {
+func (self *stateObject) updateRoot(db Database) {
 	self.updateTrie(db)
 	self.data.Root = self.trie.Hash()
 }
 
 // CommitTrie the storage trie of the object to dwb.
 // This updates the trie root.
-func (self *stateObject) CommitTrie(db trie.Database, dbw trie.DatabaseWriter) error {
+func (self *stateObject) CommitTrie(db Database, dbw trie.DatabaseWriter) error {
 	self.updateTrie(db)
 	if self.dbErr != nil {
 		return self.dbErr
@@ -282,9 +296,7 @@ func (c *stateObject) ReturnGas(gas *big.Int) {}
 func (self *stateObject) deepCopy(db *StateDB, onDirty func(addr common.Address)) *stateObject {
 	stateObject := newObject(db, self.address, self.data, onDirty)
 	if self.trie != nil {
-		// A shallow copy makes the two tries independent.
-		cpy := *self.trie
-		stateObject.trie = &cpy
+		stateObject.trie = db.db.CopyTrie(self.trie)
 	}
 	stateObject.code = self.code
 	stateObject.dirtyStorage = self.dirtyStorage.Copy()
@@ -305,14 +317,14 @@ func (c *stateObject) Address() common.Address {
 }
 
 // Code returns the contract code associated with this object, if any.
-func (self *stateObject) Code(db trie.Database) []byte {
+func (self *stateObject) Code(db Database) []byte {
 	if self.code != nil {
 		return self.code
 	}
 	if bytes.Equal(self.CodeHash(), emptyCodeHash) {
 		return nil
 	}
-	code, err := db.Get(self.CodeHash())
+	code, err := db.ContractCode(self.addrHash, common.BytesToHash(self.CodeHash()))
 	if err != nil {
 		self.setError(fmt.Errorf("can't load code hash %x: %v", self.CodeHash(), err))
 	}