Add encode method to Node interface

trie/database.go

@@ -106,6 +106,11 @@ type rawNode []byte
 func (n rawNode) Cache() (HashNode, bool)   { panic("this should never end up in a live trie") }
 func (n rawNode) fstring(ind string) string { panic("this should never end up in a live trie") }
 
+func (n rawNode) EncodeRLP(w io.Writer) error {
+	_, err := w.Write(n)
+	return err
+}
+
 // rawFullNode represents only the useful data content of a full Node, with the
 // caches and flags stripped out to minimize its data storage. This type honors
 // the same RLP encoding as the original parent.
@@ -184,7 +189,7 @@ func (n *cachedNode) obj(hash common.Hash) Node {
 
 // forChilds invokes the callback for  all the tracked children of this Node,
 // both the implicit ones  from inside the Node as well as the explicit ones
-//from outside the Node.
+// from outside the Node.
 func (n *cachedNode) forChilds(onChild func(hash common.Hash)) {
 	for child := range n.children {
 		onChild(child)

trie/hasher.go

@@ -1,4 +1,4 @@
-// Copyright 2019 The go-ethereum Authors
+// Copyright 2016 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
@@ -23,31 +23,22 @@ import (
 	"github.com/tomochain/tomochain/rlp"
 )
 
-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
-	parallel bool // Whether to use paralallel threads when hashing
+	tmp      []byte
+	encbuf   rlp.EncoderBuffer
+	parallel bool // Whether to use parallel threads when hashing
 }
 
 // hasherPool holds pureHashers
 var hasherPool = sync.Pool{
 	New: func() interface{} {
 		return &hasher{
-			tmp: make(sliceBuffer, 0, 550), // cap is as large as a full FullNode.
-			sha: crypto.NewKeccakState(),
+			tmp:    make([]byte, 0, 550), // cap is as large as a full fullNode.
+			sha:    crypto.NewKeccakState(),
+			encbuf: rlp.NewEncoderBuffer(nil),
 		}
 	},
 }
@@ -62,14 +53,14 @@ func returnHasherToPool(h *hasher) {
 	hasherPool.Put(h)
 }
 
-// hash collapses a Node down into a hash Node, also returning a copy of the
-// original Node initialized with the computed hash to replace the original one.
+// hash collapses a node down into a hash node, also returning a copy of the
+// original node initialized with the computed hash to replace the original one.
 func (h *hasher) hash(n Node, force bool) (hashed Node, cached Node) {
-	// We're not storing the Node, just hashing, use available cached data
+	// Return the cached hash if it's available
 	if hash, _ := n.Cache(); hash != nil {
 		return hash, n
 	}
-	// Trie not processed yet or needs storage, walk the children
+	// Trie not processed yet, walk the children
 	switch n := n.(type) {
 	case *ShortNode:
 		collapsed, cached := h.hashShortNodeChildren(n)
@@ -97,11 +88,11 @@ func (h *hasher) hash(n Node, force bool) (hashed Node, cached Node) {
 	}
 }
 
-// hashShortNodeChildren collapses the short Node. The returned collapsed Node
+// hashShortNodeChildren collapses the short node. The returned collapsed node
 // holds a live reference to the Key, and must not be modified.
 // The cached
 func (h *hasher) hashShortNodeChildren(n *ShortNode) (collapsed, cached *ShortNode) {
-	// Hash the short Node's child, caching the newly hashed subtree
+	// Hash the short node's child, caching the newly hashed subtree
 	collapsed, cached = n.copy(), n.copy()
 	// Previously, we did copy this one. We don't seem to need to actually
 	// do that, since we don't overwrite/reuse keys
@@ -116,7 +107,7 @@ func (h *hasher) hashShortNodeChildren(n *ShortNode) (collapsed, cached *ShortNo
 }
 
 func (h *hasher) hashFullNodeChildren(n *FullNode) (collapsed *FullNode, cached *FullNode) {
-	// Hash the full Node's children, caching the newly hashed subtrees
+	// Hash the full node's children, caching the newly hashed subtrees
 	cached = n.copy()
 	collapsed = n.copy()
 	if h.parallel {
@@ -147,35 +138,46 @@ func (h *hasher) hashFullNodeChildren(n *FullNode) (collapsed *FullNode, cached
 	return collapsed, cached
 }
 
-// shortnodeToHash creates a HashNode from a ShortNode. The supplied shortnode
+// shortnodeToHash creates a hashNode from a shortNode. The supplied shortnode
 // should have hex-type Key, which will be converted (without modification)
 // 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
+// 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
@@ -188,8 +190,8 @@ func (h *hasher) hashData(data []byte) HashNode {
 }
 
 // proofHash is used to construct trie proofs, and returns the 'collapsed'
-// Node (for later RLP encoding) aswell as the hashed Node -- unless the
-// Node is smaller than 32 bytes, in which case it will be returned as is.
+// node (for later RLP encoding) as well as the hashed node -- unless the
+// node is smaller than 32 bytes, in which case it will be returned as is.
 // This method does not do anything on value- or hash-nodes.
 func (h *hasher) proofHash(original Node) (collapsed, hashed Node) {
 	switch n := original.(type) {

trie/node.go

@@ -30,6 +30,7 @@ var indices = []string{"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b
 type Node interface {
 	fstring(string) string
 	Cache() (HashNode, bool)
+	encode(w rlp.EncoderBuffer)
 }
 
 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 +1,64 @@
+// 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/tomochain/tomochain/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 rawNode) encode(w rlp.EncoderBuffer) {
+	w.Write(n)
+}