trie, core/state: use cache unloading for account trie

core/blockchain.go

@@ -269,7 +269,7 @@ func (self *BlockChain) FastSyncCommitHead(hash common.Hash) error {
 	if block == nil {
 		return fmt.Errorf("non existent block [%x…]", hash[:4])
 	}
-	if _, err := trie.NewSecure(block.Root(), self.chainDb); err != nil {
+	if _, err := trie.NewSecure(block.Root(), self.chainDb, 0); err != nil {
 		return err
 	}
 	// If all checks out, manually set the head block

core/state/state_object.go

@@ -137,9 +137,9 @@ func (self *StateObject) markSuicided() {
 func (c *StateObject) getTrie(db trie.Database) *trie.SecureTrie {
 	if c.trie == nil {
 		var err error
-		c.trie, err = trie.NewSecure(c.data.Root, db)
+		c.trie, err = trie.NewSecure(c.data.Root, db, 0)
 		if err != nil {
-			c.trie, _ = trie.NewSecure(common.Hash{}, db)
+			c.trie, _ = trie.NewSecure(common.Hash{}, db, 0)
 			c.setError(fmt.Errorf("can't create storage trie: %v", err))
 		}
 	}

core/state/statedb.go

@@ -43,6 +43,9 @@ const (
 	// is max uncle depth + 1.
 	maxTrieCacheLength = 8
 
+	// Trie cache generation limit.
+	maxTrieCacheGen = 100
+
 	// Number of codehash->size associations to keep.
 	codeSizeCacheSize = 100000
 )
@@ -86,7 +89,7 @@ type StateDB struct {
 
 // Create a new state from a given trie
 func New(root common.Hash, db ethdb.Database) (*StateDB, error) {
-	tr, err := trie.NewSecure(root, db)
+	tr, err := trie.NewSecure(root, db, maxTrieCacheGen)
 	if err != nil {
 		return nil, err
 	}
@@ -155,7 +158,7 @@ func (self *StateDB) openTrie(root common.Hash) (*trie.SecureTrie, error) {
 			return &tr, nil
 		}
 	}
-	return trie.NewSecure(root, self.db)
+	return trie.NewSecure(root, self.db, maxTrieCacheGen)
 }
 
 func (self *StateDB) pushTrie(t *trie.SecureTrie) {

eth/downloader/downloader_test.go

@@ -286,7 +286,7 @@ func (dl *downloadTester) headFastBlock() *types.Block {
 func (dl *downloadTester) commitHeadBlock(hash common.Hash) error {
 	// For now only check that the state trie is correct
 	if block := dl.getBlock(hash); block != nil {
-		_, err := trie.NewSecure(block.Root(), dl.stateDb)
+		_, err := trie.NewSecure(block.Root(), dl.stateDb, 0)
 		return err
 	}
 	return fmt.Errorf("non existent block: %x", hash[:4])

light/trie.go

@@ -79,7 +79,7 @@ func (t *LightTrie) do(ctx context.Context, fallbackKey []byte, fn func() error)
 func (t *LightTrie) Get(ctx context.Context, key []byte) (res []byte, err error) {
 	err = t.do(ctx, key, func() (err error) {
 		if t.trie == nil {
-			t.trie, err = trie.NewSecure(t.originalRoot, t.db)
+			t.trie, err = trie.NewSecure(t.originalRoot, t.db, 0)
 		}
 		if err == nil {
 			res, err = t.trie.TryGet(key)
@@ -98,7 +98,7 @@ func (t *LightTrie) Get(ctx context.Context, key []byte) (res []byte, err error)
 func (t *LightTrie) Update(ctx context.Context, key, value []byte) (err error) {
 	err = t.do(ctx, key, func() (err error) {
 		if t.trie == nil {
-			t.trie, err = trie.NewSecure(t.originalRoot, t.db)
+			t.trie, err = trie.NewSecure(t.originalRoot, t.db, 0)
 		}
 		if err == nil {
 			err = t.trie.TryUpdate(key, value)
@@ -112,7 +112,7 @@ func (t *LightTrie) Update(ctx context.Context, key, value []byte) (err error) {
 func (t *LightTrie) Delete(ctx context.Context, key []byte) (err error) {
 	err = t.do(ctx, key, func() (err error) {
 		if t.trie == nil {
-			t.trie, err = trie.NewSecure(t.originalRoot, t.db)
+			t.trie, err = trie.NewSecure(t.originalRoot, t.db, 0)
 		}
 		if err == nil {
 			err = t.trie.TryDelete(key)

trie/secure_trie.go

@@ -49,8 +49,12 @@ type SecureTrie struct {
 // If root is the zero hash or the sha3 hash of an empty string, the
 // trie is initially empty. Otherwise, New will panic if db is nil
 // and returns MissingNodeError if the root node cannot be found.
+//
 // Accessing the trie loads nodes from db on demand.
-func NewSecure(root common.Hash, db Database) (*SecureTrie, error) {
+// Loaded nodes are kept around until their 'cache generation' expires.
+// A new cache generation is created by each call to Commit.
+// cachelimit sets the number of past cache generations to keep.
+func NewSecure(root common.Hash, db Database, cachelimit uint16) (*SecureTrie, error) {
 	if db == nil {
 		panic("NewSecure called with nil database")
 	}
@@ -58,9 +62,8 @@ func NewSecure(root common.Hash, db Database) (*SecureTrie, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &SecureTrie{
+	trie.SetCacheLimit(cachelimit)
-		trie: *trie,
+	return &SecureTrie{trie: *trie}, nil
-	}, nil
 }
 
 // Get returns the value for key stored in the trie.

trie/secure_trie_test.go

@@ -29,7 +29,7 @@ import (
 
 func newEmptySecure() *SecureTrie {
 	db, _ := ethdb.NewMemDatabase()
-	trie, _ := NewSecure(common.Hash{}, db)
+	trie, _ := NewSecure(common.Hash{}, db, 0)
 	return trie
 }
 
@@ -37,7 +37,7 @@ func newEmptySecure() *SecureTrie {
 func makeTestSecureTrie() (ethdb.Database, *SecureTrie, map[string][]byte) {
 	// Create an empty trie
 	db, _ := ethdb.NewMemDatabase()
-	trie, _ := NewSecure(common.Hash{}, db)
+	trie, _ := NewSecure(common.Hash{}, db, 0)
 
 	// Fill it with some arbitrary data
 	content := make(map[string][]byte)