rlp/encbuffer.go

@@ -36,27 +36,31 @@ func (buf *encBuffer) size() int {
 	return len(buf.str) + buf.lhsize
 }
 
-// toBytes creates the encoder output.
-func (w *encBuffer) toBytes() []byte {
+// makeBytes creates the encoder output.
+func (w *encBuffer) makeBytes() []byte {
 	out := make([]byte, w.size())
+	w.copyTo(out)
+	return out
+}
+
+func (w *encBuffer) copyTo(dst []byte) {
 	strpos := 0
 	pos := 0
 	for _, head := range w.lheads {
 		// write string data before header
-		n := copy(out[pos:], w.str[strpos:head.offset])
+		n := copy(dst[pos:], w.str[strpos:head.offset])
 		pos += n
 		strpos += n
 		// write the header
-		enc := head.encode(out[pos:])
+		enc := head.encode(dst[pos:])
 		pos += len(enc)
 	}
 	// copy string data after the last list header
-	copy(out[pos:], w.str[strpos:])
-	return out
+	copy(dst[pos:], w.str[strpos:])
 }
 
-// toWriter writes the encoder output to w.
-func (buf *encBuffer) toWriter(w io.Writer) (err error) {
+// writeTo writes the encoder output to w.
+func (buf *encBuffer) writeTo(w io.Writer) (err error) {
 	strpos := 0
 	for _, head := range buf.lheads {
 		// write string data before header
@@ -252,6 +256,19 @@ func (r *encReader) next() []byte {
 	}
 }
 
+func encBufferFromWriter(w io.Writer) *encBuffer {
+	switch w := w.(type) {
+	case EncoderBuffer:
+		return w.buf
+	case *EncoderBuffer:
+		return w.buf
+	case *encBuffer:
+		return w
+	default:
+		return nil
+	}
+}
+
 // EncoderBuffer is a buffer for incremental encoding.
 //
 // The zero value is NOT ready for use. To get a usable buffer,
@@ -279,14 +296,10 @@ func (w *EncoderBuffer) Reset(dst io.Writer) {
 	// If the destination writer has an *encBuffer, use it.
 	// Note that w.ownBuffer is left false here.
 	if dst != nil {
-		if outer, ok := dst.(*encBuffer); ok {
+		if outer := encBufferFromWriter(dst); outer != nil {
 			*w = EncoderBuffer{outer, nil, false}
 			return
 		}
-		if outer, ok := dst.(EncoderBuffer); ok {
-			*w = EncoderBuffer{outer.buf, nil, false}
-			return
-		}
 	}
 
 	// Get a fresh buffer.
@@ -303,7 +316,7 @@ func (w *EncoderBuffer) Reset(dst io.Writer) {
 func (w *EncoderBuffer) Flush() error {
 	var err error
 	if w.dst != nil {
-		err = w.buf.toWriter(w.dst)
+		err = w.buf.writeTo(w.dst)
 	}
 	// Release the internal buffer.
 	if w.ownBuffer {
@@ -315,7 +328,15 @@ func (w *EncoderBuffer) Flush() error {
 
 // ToBytes returns the encoded bytes.
 func (w *EncoderBuffer) ToBytes() []byte {
-	return w.buf.toBytes()
+	return w.buf.makeBytes()
+}
+
+// AppendToBytes appends the encoded bytes to dst.
+func (w *EncoderBuffer) AppendToBytes(dst []byte) []byte {
+	size := w.buf.size()
+	out := append(dst, make([]byte, size)...)
+	w.buf.copyTo(out[len(dst):])
+	return out
 }
 
 // Write appends b directly to the encoder output.

rlp/encode.go

@@ -56,20 +56,16 @@ type Encoder interface {
 // Please see package-level documentation of encoding rules.
 func Encode(w io.Writer, val interface{}) error {
 	// Optimization: reuse *encBuffer when called by EncodeRLP.
-	if buf, ok := w.(*encBuffer); ok {
+	if buf := encBufferFromWriter(w); buf != nil {
 		return buf.encode(val)
 	}
-	if ebuf, ok := w.(EncoderBuffer); ok {
-		return ebuf.buf.encode(val)
-	}
 
 	buf := getEncBuffer()
 	defer encBufferPool.Put(buf)
-
 	if err := buf.encode(val); err != nil {
 		return err
 	}
-	return buf.toWriter(w)
+	return buf.writeTo(w)
 }
 
 // EncodeToBytes returns the RLP encoding of val.
@@ -81,7 +77,7 @@ func EncodeToBytes(val interface{}) ([]byte, error) {
 	if err := buf.encode(val); err != nil {
 		return nil, err
 	}
-	return buf.toBytes(), nil
+	return buf.makeBytes(), nil
 }
 
 // EncodeToReader returns a reader from which the RLP encoding of val

rlp/encode_test.go

@@ -399,6 +399,21 @@ func TestEncodeToBytes(t *testing.T) {
 	runEncTests(t, EncodeToBytes)
 }
 
+func TestEncodeAppendToBytes(t *testing.T) {
+	buffer := make([]byte, 20)
+	runEncTests(t, func(val interface{}) ([]byte, error) {
+		w := NewEncoderBuffer(nil)
+		defer w.Flush()
+
+		err := Encode(w, val)
+		if err != nil {
+			return nil, err
+		}
+		output := w.AppendToBytes(buffer[:0])
+		return output, nil
+	})
+}
+
 func TestEncodeToReader(t *testing.T) {
 	runEncTests(t, func(val interface{}) ([]byte, error) {
 		_, r, err := EncodeToReader(val)

trie/committer.go

@@ -44,7 +44,6 @@ type leaf struct {
 // By 'some level' of parallelism, it's still the case that all leaves will be
 // processed sequentially - onleaf will never be called in parallel or out of order.
 type committer struct {
-	tmp sliceBuffer
 	sha crypto.KeccakState
 
 	onleaf LeafCallback
@@ -55,7 +54,6 @@ type committer struct {
 var committerPool = sync.Pool{
 	New: func() interface{} {
 		return &committer{
-			tmp: make(sliceBuffer, 0, 550), // cap is as large as a full fullNode.
 			sha: sha3.NewLegacyKeccak256().(crypto.KeccakState),
 		}
 	},

trie/database.go

@@ -113,16 +113,9 @@ func (n rawFullNode) cache() (hashNode, bool)   { panic("this should never end u
 func (n rawFullNode) fstring(ind string) string { panic("this should never end up in a live trie") }
 
 func (n rawFullNode) EncodeRLP(w io.Writer) error {
-	var nodes [17]node
-
-	for i, child := range n {
-		if child != nil {
-			nodes[i] = child
-		} else {
-			nodes[i] = nilValueNode
-		}
-	}
-	return rlp.Encode(w, nodes)
+	eb := rlp.NewEncoderBuffer(w)
+	n.encode(eb)
+	return eb.Flush()
 }
 
 // rawShortNode represents only the useful data content of a short node, with the
@@ -164,11 +157,7 @@ func (n *cachedNode) rlp() []byte {
 	if node, ok := n.node.(rawNode); ok {
 		return node
 	}
-	blob, err := rlp.EncodeToBytes(n.node)
-	if err != nil {
-		panic(err)
-	}
-	return blob
+	return nodeToBytes(n.node)
 }
 
 // obj returns the decoded and expanded trie node, either directly from the cache,

trie/hasher.go

@@ -24,22 +24,12 @@ import (
 	"golang.org/x/crypto/sha3"
 )
 
-type sliceBuffer []byte
-
-func (b *sliceBuffer) Write(data []byte) (n int, err error) {
-	*b = append(*b, data...)
-	return len(data), nil
-}
-
-func (b *sliceBuffer) Reset() {
-	*b = (*b)[:0]
-}
-
 // hasher is a type used for the trie Hash operation. A hasher has some
 // internal preallocated temp space
 type hasher struct {
 	sha      crypto.KeccakState
-	tmp      sliceBuffer
+	tmp      []byte
+	encbuf   rlp.EncoderBuffer
 	parallel bool // Whether to use paralallel threads when hashing
 }
 
@@ -47,8 +37,9 @@ type hasher struct {
 var hasherPool = sync.Pool{
 	New: func() interface{} {
 		return &hasher{
-			tmp: make(sliceBuffer, 0, 550), // cap is as large as a full fullNode.
-			sha: sha3.NewLegacyKeccak256().(crypto.KeccakState),
+			tmp:    make([]byte, 0, 550), // cap is as large as a full fullNode.
+			sha:    sha3.NewLegacyKeccak256().(crypto.KeccakState),
+			encbuf: rlp.NewEncoderBuffer(nil),
 		}
 	},
 }
@@ -153,30 +144,41 @@ func (h *hasher) hashFullNodeChildren(n *fullNode) (collapsed *fullNode, cached
 // into compact form for RLP encoding.
 // If the rlp data is smaller than 32 bytes, `nil` is returned.
 func (h *hasher) shortnodeToHash(n *shortNode, force bool) node {
-	h.tmp.Reset()
-	if err := rlp.Encode(&h.tmp, n); err != nil {
-		panic("encode error: " + err.Error())
-	}
+	n.encode(h.encbuf)
+	enc := h.encodedBytes()
 
-	if len(h.tmp) < 32 && !force {
+	if len(enc) < 32 && !force {
 		return n // Nodes smaller than 32 bytes are stored inside their parent
 	}
-	return h.hashData(h.tmp)
+	return h.hashData(enc)
 }
 
 // shortnodeToHash is used to creates a hashNode from a set of hashNodes, (which
 // may contain nil values)
 func (h *hasher) fullnodeToHash(n *fullNode, force bool) node {
-	h.tmp.Reset()
-	// Generate the RLP encoding of the node
-	if err := n.EncodeRLP(&h.tmp); err != nil {
-		panic("encode error: " + err.Error())
-	}
+	n.encode(h.encbuf)
+	enc := h.encodedBytes()
 
-	if len(h.tmp) < 32 && !force {
+	if len(enc) < 32 && !force {
 		return n // Nodes smaller than 32 bytes are stored inside their parent
 	}
-	return h.hashData(h.tmp)
+	return h.hashData(enc)
+}
+
+// encodedBytes returns the result of the last encoding operation on h.encbuf.
+// This also resets the encoder buffer.
+//
+// All node encoding must be done like this:
+//
+//     node.encode(h.encbuf)
+//     enc := h.encodedBytes()
+//
+// This convention exists because node.encode can only be inlined/escape-analyzed when
+// called on a concrete receiver type.
+func (h *hasher) encodedBytes() []byte {
+	h.tmp = h.encbuf.AppendToBytes(h.tmp[:0])
+	h.encbuf.Reset(nil)
+	return h.tmp
 }
 
 // hashData hashes the provided data

trie/iterator.go

@@ -23,7 +23,6 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethdb"
-	"github.com/ethereum/go-ethereum/rlp"
 )
 
 // Iterator is a key-value trie iterator that traverses a Trie.
@@ -214,8 +213,7 @@ func (it *nodeIterator) LeafProof() [][]byte {
 				// Gather nodes that end up as hash nodes (or the root)
 				node, hashed := hasher.proofHash(item.node)
 				if _, ok := hashed.(hashNode); ok || i == 0 {
-					enc, _ := rlp.EncodeToBytes(node)
-					proofs = append(proofs, enc)
+					proofs = append(proofs, nodeToBytes(node))
 				}
 			}
 			return proofs

trie/node.go

@@ -28,8 +28,9 @@ import (
 var indices = []string{"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f", "[17]"}
 
 type node interface {
-	fstring(string) string
 	cache() (hashNode, bool)
+	encode(w rlp.EncoderBuffer)
+	fstring(string) string
 }
 
 type (
@@ -52,16 +53,9 @@ var nilValueNode = valueNode(nil)
 
 // EncodeRLP encodes a full node into the consensus RLP format.
 func (n *fullNode) EncodeRLP(w io.Writer) error {
-	var nodes [17]node
-
-	for i, child := range &n.Children {
-		if child != nil {
-			nodes[i] = child
-		} else {
-			nodes[i] = nilValueNode
-		}
-	}
-	return rlp.Encode(w, nodes)
+	eb := rlp.NewEncoderBuffer(w)
+	n.encode(eb)
+	return eb.Flush()
 }
 
 func (n *fullNode) copy() *fullNode   { copy := *n; return &copy }

trie/node_enc.go

@@ -0,0 +1,87 @@
+// Copyright 2022 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package trie
+
+import (
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+func nodeToBytes(n node) []byte {
+	w := rlp.NewEncoderBuffer(nil)
+	n.encode(w)
+	result := w.ToBytes()
+	w.Flush()
+	return result
+}
+
+func (n *fullNode) encode(w rlp.EncoderBuffer) {
+	offset := w.List()
+	for _, c := range n.Children {
+		if c != nil {
+			c.encode(w)
+		} else {
+			w.Write(rlp.EmptyString)
+		}
+	}
+	w.ListEnd(offset)
+}
+
+func (n *shortNode) encode(w rlp.EncoderBuffer) {
+	offset := w.List()
+	w.WriteBytes(n.Key)
+	if n.Val != nil {
+		n.Val.encode(w)
+	} else {
+		w.Write(rlp.EmptyString)
+	}
+	w.ListEnd(offset)
+}
+
+func (n hashNode) encode(w rlp.EncoderBuffer) {
+	w.WriteBytes(n)
+}
+
+func (n valueNode) encode(w rlp.EncoderBuffer) {
+	w.WriteBytes(n)
+}
+
+func (n rawFullNode) encode(w rlp.EncoderBuffer) {
+	offset := w.List()
+	for _, c := range n {
+		if c != nil {
+			c.encode(w)
+		} else {
+			w.Write(rlp.EmptyString)
+		}
+	}
+	w.ListEnd(offset)
+}
+
+func (n *rawShortNode) encode(w rlp.EncoderBuffer) {
+	offset := w.List()
+	w.WriteBytes(n.Key)
+	if n.Val != nil {
+		n.Val.encode(w)
+	} else {
+		w.Write(rlp.EmptyString)
+	}
+	w.ListEnd(offset)
+}
+
+func (n rawNode) encode(w rlp.EncoderBuffer) {
+	w.Write(n)
+}

trie/proof.go

@@ -25,7 +25,6 @@ import (
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/ethdb/memorydb"
 	"github.com/ethereum/go-ethereum/log"
-	"github.com/ethereum/go-ethereum/rlp"
 )
 
 // Prove constructs a merkle proof for key. The result contains all encoded nodes
@@ -79,7 +78,7 @@ func (t *Trie) Prove(key []byte, fromLevel uint, proofDb ethdb.KeyValueWriter) e
 		if hash, ok := hn.(hashNode); ok || i == 0 {
 			// If the node's database encoding is a hash (or is the
 			// root node), it becomes a proof element.
-			enc, _ := rlp.EncodeToBytes(n)
+			enc := nodeToBytes(n)
 			if !ok {
 				hash = hasher.hashData(enc)
 			}

trie/stacktrie.go

@@ -28,7 +28,6 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/log"
-	"github.com/ethereum/go-ethereum/rlp"
 )
 
 var ErrCommitDisabled = errors.New("no database for committing")
@@ -224,6 +223,7 @@ func (st *StackTrie) insert(key, value []byte) {
 	switch st.nodeType {
 	case branchNode: /* Branch */
 		idx := int(key[0])
+
 		// Unresolve elder siblings
 		for i := idx - 1; i >= 0; i-- {
 			if st.children[i] != nil {
@@ -233,12 +233,14 @@ func (st *StackTrie) insert(key, value []byte) {
 				break
 			}
 		}
+
 		// Add new child
 		if st.children[idx] == nil {
 			st.children[idx] = newLeaf(key[1:], value, st.db)
 		} else {
 			st.children[idx].insert(key[1:], value)
 		}
+
 	case extNode: /* Ext */
 		// Compare both key chunks and see where they differ
 		diffidx := st.getDiffIndex(key)
@@ -326,10 +328,9 @@ func (st *StackTrie) insert(key, value []byte) {
 			p = st.children[0]
 		}
 
-		// Create the two child leaves: the one containing the
-		// original value and the one containing the new value
-		// The child leave will be hashed directly in order to
-		// free up some memory.
+		// Create the two child leaves: one containing the original
+		// value and another containing the new value. The child leaf
+		// is hashed directly in order to free up some memory.
 		origIdx := st.key[diffidx]
 		p.children[origIdx] = newLeaf(st.key[diffidx+1:], st.val, st.db)
 		p.children[origIdx].hash()
@@ -341,19 +342,22 @@ func (st *StackTrie) insert(key, value []byte) {
 		// over to the children.
 		st.key = st.key[:diffidx]
 		st.val = nil
+
 	case emptyNode: /* Empty */
 		st.nodeType = leafNode
 		st.key = key
 		st.val = value
+
 	case hashedNode:
 		panic("trying to insert into hash")
+
 	default:
 		panic("invalid type")
 	}
 }
 
-// hash() hashes the node 'st' and converts it into 'hashedNode', if possible.
-// Possible outcomes:
+// hash converts st into a 'hashedNode', if possible. Possible outcomes:
+//
 // 1. The rlp-encoded value was >= 32 bytes:
 //  - Then the 32-byte `hash` will be accessible in `st.val`.
 //  - And the 'st.type' will be 'hashedNode'
@@ -361,119 +365,116 @@ func (st *StackTrie) insert(key, value []byte) {
 //  - Then the <32 byte rlp-encoded value will be accessible in 'st.val'.
 //  - And the 'st.type' will be 'hashedNode' AGAIN
 //
-// This method will also:
-// set 'st.type' to hashedNode
-// clear 'st.key'
+// This method also sets 'st.type' to hashedNode, and clears 'st.key'.
 func (st *StackTrie) hash() {
-	/* Shortcut if node is already hashed */
-	if st.nodeType == hashedNode {
-		return
-	}
-	// The 'hasher' is taken from a pool, but we don't actually
-	// claim an instance until all children are done with their hashing,
-	// and we actually need one
-	var h *hasher
+	h := newHasher(false)
+	defer returnHasherToPool(h)
+
+	st.hashRec(h)
+}
+
+func (st *StackTrie) hashRec(hasher *hasher) {
+	// The switch below sets this to the RLP-encoding of this node.
+	var encodedNode []byte
 
 	switch st.nodeType {
-	case branchNode:
-		var nodes [17]node
-		for i, child := range st.children {
-			if child == nil {
-				nodes[i] = nilValueNode
-				continue
-			}
-			child.hash()
-			if len(child.val) < 32 {
-				nodes[i] = rawNode(child.val)
-			} else {
-				nodes[i] = hashNode(child.val)
-			}
-			st.children[i] = nil // Reclaim mem from subtree
-			returnToPool(child)
-		}
-		nodes[16] = nilValueNode
-		h = newHasher(false)
-		defer returnHasherToPool(h)
-		h.tmp.Reset()
-		if err := rlp.Encode(&h.tmp, nodes); err != nil {
-			panic(err)
-		}
-	case extNode:
-		st.children[0].hash()
-		h = newHasher(false)
-		defer returnHasherToPool(h)
-		h.tmp.Reset()
-		var valuenode node
-		if len(st.children[0].val) < 32 {
-			valuenode = rawNode(st.children[0].val)
-		} else {
-			valuenode = hashNode(st.children[0].val)
-		}
-		n := struct {
-			Key []byte
-			Val node
-		}{
-			Key: hexToCompact(st.key),
-			Val: valuenode,
-		}
-		if err := rlp.Encode(&h.tmp, n); err != nil {
-			panic(err)
-		}
-		returnToPool(st.children[0])
-		st.children[0] = nil // Reclaim mem from subtree
-	case leafNode:
-		h = newHasher(false)
-		defer returnHasherToPool(h)
-		h.tmp.Reset()
-		st.key = append(st.key, byte(16))
-		sz := hexToCompactInPlace(st.key)
-		n := [][]byte{st.key[:sz], st.val}
-		if err := rlp.Encode(&h.tmp, n); err != nil {
-			panic(err)
-		}
+	case hashedNode:
+		return
+
 	case emptyNode:
 		st.val = emptyRoot.Bytes()
 		st.key = st.key[:0]
 		st.nodeType = hashedNode
 		return
+
+	case branchNode:
+		var nodes rawFullNode
+		for i, child := range st.children {
+			if child == nil {
+				nodes[i] = nilValueNode
+				continue
+			}
+
+			child.hashRec(hasher)
+			if len(child.val) < 32 {
+				nodes[i] = rawNode(child.val)
+			} else {
+				nodes[i] = hashNode(child.val)
+			}
+
+			// Release child back to pool.
+			st.children[i] = nil
+			returnToPool(child)
+		}
+
+		nodes.encode(hasher.encbuf)
+		encodedNode = hasher.encodedBytes()
+
+	case extNode:
+		st.children[0].hashRec(hasher)
+
+		sz := hexToCompactInPlace(st.key)
+		n := rawShortNode{Key: st.key[:sz]}
+		if len(st.children[0].val) < 32 {
+			n.Val = rawNode(st.children[0].val)
+		} else {
+			n.Val = hashNode(st.children[0].val)
+		}
+
+		n.encode(hasher.encbuf)
+		encodedNode = hasher.encodedBytes()
+
+		// Release child back to pool.
+		returnToPool(st.children[0])
+		st.children[0] = nil
+
+	case leafNode:
+		st.key = append(st.key, byte(16))
+		sz := hexToCompactInPlace(st.key)
+		n := rawShortNode{Key: st.key[:sz], Val: valueNode(st.val)}
+
+		n.encode(hasher.encbuf)
+		encodedNode = hasher.encodedBytes()
+
 	default:
-		panic("Invalid node type")
+		panic("invalid node type")
 	}
-	st.key = st.key[:0]
+
 	st.nodeType = hashedNode
-	if len(h.tmp) < 32 {
-		st.val = common.CopyBytes(h.tmp)
+	st.key = st.key[:0]
+	if len(encodedNode) < 32 {
+		st.val = common.CopyBytes(encodedNode)
 		return
 	}
+
 	// Write the hash to the 'val'. We allocate a new val here to not mutate
 	// input values
-	st.val = make([]byte, 32)
-	h.sha.Reset()
-	h.sha.Write(h.tmp)
-	h.sha.Read(st.val)
+	st.val = hasher.hashData(encodedNode)
 	if st.db != nil {
 		// TODO! Is it safe to Put the slice here?
 		// Do all db implementations copy the value provided?
-		st.db.Put(st.val, h.tmp)
+		st.db.Put(st.val, encodedNode)
 	}
 }
 
-// Hash returns the hash of the current node
+// Hash returns the hash of the current node.
 func (st *StackTrie) Hash() (h common.Hash) {
-	st.hash()
-	if len(st.val) != 32 {
-		// If the node's RLP isn't 32 bytes long, the node will not
-		// be hashed, and instead contain the  rlp-encoding of the
-		// node. For the top level node, we need to force the hashing.
-		ret := make([]byte, 32)
-		h := newHasher(false)
-		defer returnHasherToPool(h)
-		h.sha.Reset()
-		h.sha.Write(st.val)
-		h.sha.Read(ret)
-		return common.BytesToHash(ret)
+	hasher := newHasher(false)
+	defer returnHasherToPool(hasher)
+
+	st.hashRec(hasher)
+	if len(st.val) == 32 {
+		copy(h[:], st.val)
+		return h
 	}
-	return common.BytesToHash(st.val)
+
+	// If the node's RLP isn't 32 bytes long, the node will not
+	// be hashed, and instead contain the  rlp-encoding of the
+	// node. For the top level node, we need to force the hashing.
+	hasher.sha.Reset()
+	hasher.sha.Write(st.val)
+	hasher.sha.Read(h[:])
+	return h
 }
 
 // Commit will firstly hash the entrie trie if it's still not hashed
@@ -483,23 +484,26 @@ func (st *StackTrie) Hash() (h common.Hash) {
 //
 // The associated database is expected, otherwise the whole commit
 // functionality should be disabled.
-func (st *StackTrie) Commit() (common.Hash, error) {
+func (st *StackTrie) Commit() (h common.Hash, err error) {
 	if st.db == nil {
 		return common.Hash{}, ErrCommitDisabled
 	}
-	st.hash()
-	if len(st.val) != 32 {
-		// If the node's RLP isn't 32 bytes long, the node will not
-		// be hashed (and committed), and instead contain the  rlp-encoding of the
-		// node. For the top level node, we need to force the hashing+commit.
-		ret := make([]byte, 32)
-		h := newHasher(false)
-		defer returnHasherToPool(h)
-		h.sha.Reset()
-		h.sha.Write(st.val)
-		h.sha.Read(ret)
-		st.db.Put(ret, st.val)
-		return common.BytesToHash(ret), nil
+
+	hasher := newHasher(false)
+	defer returnHasherToPool(hasher)
+
+	st.hashRec(hasher)
+	if len(st.val) == 32 {
+		copy(h[:], st.val)
+		return h, nil
 	}
-	return common.BytesToHash(st.val), nil
+
+	// If the node's RLP isn't 32 bytes long, the node will not
+	// be hashed (and committed), and instead contain the  rlp-encoding of the
+	// node. For the top level node, we need to force the hashing+commit.
+	hasher.sha.Reset()
+	hasher.sha.Write(st.val)
+	hasher.sha.Read(h[:])
+	st.db.Put(h[:], st.val)
+	return h, nil
 }

trie/trie_test.go

@@ -414,8 +414,9 @@ func runRandTest(rt randTest) bool {
 	values := make(map[string]string) // tracks content of the trie
 
 	for i, step := range rt {
-		fmt.Printf("{op: %d, key: common.Hex2Bytes(\"%x\"), value: common.Hex2Bytes(\"%x\")}, // step %d\n",
-			step.op, step.key, step.value, i)
+		// fmt.Printf("{op: %d, key: common.Hex2Bytes(\"%x\"), value: common.Hex2Bytes(\"%x\")}, // step %d\n",
+		// 	step.op, step.key, step.value, i)
+
 		switch step.op {
 		case opUpdate:
 			tr.Update(step.key, step.value)
@@ -885,7 +886,8 @@ func TestCommitSequenceSmallRoot(t *testing.T) {
 	if stRoot != root {
 		t.Fatalf("root wrong, got %x exp %x", stRoot, root)
 	}
-	fmt.Printf("root: %x\n", stRoot)
+
+	t.Logf("root: %x\n", stRoot)
 	if got, exp := stackTrieSponge.sponge.Sum(nil), s.sponge.Sum(nil); !bytes.Equal(got, exp) {
 		t.Fatalf("test, disk write sequence wrong:\ngot %x exp %x\n", got, exp)
 	}