diff options
Diffstat (limited to 'trie/trie.go')
-rw-r--r-- | trie/trie.go | 237 |
1 files changed, 150 insertions, 87 deletions
diff --git a/trie/trie.go b/trie/trie.go index cc5dcf2a6..a530e7b2a 100644 --- a/trie/trie.go +++ b/trie/trie.go @@ -129,7 +129,7 @@ func (t *Trie) TryGet(key []byte) ([]byte, error) { tn = n.Val pos += len(n.Key) case fullNode: - tn = n[key[pos]] + tn = n.Children[key[pos]] pos++ case nil: return nil, nil @@ -169,13 +169,13 @@ func (t *Trie) Update(key, value []byte) { func (t *Trie) TryUpdate(key, value []byte) error { k := compactHexDecode(key) if len(value) != 0 { - n, err := t.insert(t.root, nil, k, valueNode(value)) + _, n, err := t.insert(t.root, nil, k, valueNode(value)) if err != nil { return err } t.root = n } else { - n, err := t.delete(t.root, nil, k) + _, n, err := t.delete(t.root, nil, k) if err != nil { return err } @@ -184,9 +184,12 @@ func (t *Trie) TryUpdate(key, value []byte) error { return nil } -func (t *Trie) insert(n node, prefix, key []byte, value node) (node, error) { +func (t *Trie) insert(n node, prefix, key []byte, value node) (bool, node, error) { if len(key) == 0 { - return value, nil + if v, ok := n.(valueNode); ok { + return !bytes.Equal(v, value.(valueNode)), value, nil + } + return true, value, nil } switch n := n.(type) { case shortNode: @@ -194,53 +197,63 @@ func (t *Trie) insert(n node, prefix, key []byte, value node) (node, error) { // If the whole key matches, keep this short node as is // and only update the value. if matchlen == len(n.Key) { - nn, err := t.insert(n.Val, append(prefix, key[:matchlen]...), key[matchlen:], value) + dirty, nn, err := t.insert(n.Val, append(prefix, key[:matchlen]...), key[matchlen:], value) if err != nil { - return nil, err + return false, nil, err + } + if !dirty { + return false, n, nil } - return shortNode{n.Key, nn}, nil + return true, shortNode{n.Key, nn, nil, true}, nil } // Otherwise branch out at the index where they differ. - var branch fullNode + branch := fullNode{dirty: true} var err error - branch[n.Key[matchlen]], err = t.insert(nil, append(prefix, n.Key[:matchlen+1]...), n.Key[matchlen+1:], n.Val) + _, branch.Children[n.Key[matchlen]], err = t.insert(nil, append(prefix, n.Key[:matchlen+1]...), n.Key[matchlen+1:], n.Val) if err != nil { - return nil, err + return false, nil, err } - branch[key[matchlen]], err = t.insert(nil, append(prefix, key[:matchlen+1]...), key[matchlen+1:], value) + _, branch.Children[key[matchlen]], err = t.insert(nil, append(prefix, key[:matchlen+1]...), key[matchlen+1:], value) if err != nil { - return nil, err + return false, nil, err } // Replace this shortNode with the branch if it occurs at index 0. if matchlen == 0 { - return branch, nil + return true, branch, nil } // Otherwise, replace it with a short node leading up to the branch. - return shortNode{key[:matchlen], branch}, nil + return true, shortNode{key[:matchlen], branch, nil, true}, nil case fullNode: - nn, err := t.insert(n[key[0]], append(prefix, key[0]), key[1:], value) + dirty, nn, err := t.insert(n.Children[key[0]], append(prefix, key[0]), key[1:], value) if err != nil { - return nil, err + return false, nil, err } - n[key[0]] = nn - return n, nil + if !dirty { + return false, n, nil + } + n.Children[key[0]], n.hash, n.dirty = nn, nil, true + return true, n, nil case nil: - return shortNode{key, value}, nil + return true, shortNode{key, value, nil, true}, nil case hashNode: // We've hit a part of the trie that isn't loaded yet. Load // the node and insert into it. This leaves all child nodes on // the path to the value in the trie. - // - // TODO: track whether insertion changed the value and keep - // n as a hash node if it didn't. rn, err := t.resolveHash(n, prefix, key) if err != nil { - return nil, err + return false, nil, err + } + dirty, nn, err := t.insert(rn, prefix, key, value) + if err != nil { + return false, nil, err } - return t.insert(rn, prefix, key, value) + if !dirty { + return false, rn, nil + } + return true, nn, nil default: panic(fmt.Sprintf("%T: invalid node: %v", n, n)) @@ -258,7 +271,7 @@ func (t *Trie) Delete(key []byte) { // If a node was not found in the database, a MissingNodeError is returned. func (t *Trie) TryDelete(key []byte) error { k := compactHexDecode(key) - n, err := t.delete(t.root, nil, k) + _, n, err := t.delete(t.root, nil, k) if err != nil { return err } @@ -269,23 +282,26 @@ func (t *Trie) TryDelete(key []byte) error { // delete returns the new root of the trie with key deleted. // It reduces the trie to minimal form by simplifying // nodes on the way up after deleting recursively. -func (t *Trie) delete(n node, prefix, key []byte) (node, error) { +func (t *Trie) delete(n node, prefix, key []byte) (bool, node, error) { switch n := n.(type) { case shortNode: matchlen := prefixLen(key, n.Key) if matchlen < len(n.Key) { - return n, nil // don't replace n on mismatch + return false, n, nil // don't replace n on mismatch } if matchlen == len(key) { - return nil, nil // remove n entirely for whole matches + return true, nil, nil // remove n entirely for whole matches } // The key is longer than n.Key. Remove the remaining suffix // from the subtrie. Child can never be nil here since the // subtrie must contain at least two other values with keys // longer than n.Key. - child, err := t.delete(n.Val, append(prefix, key[:len(n.Key)]...), key[len(n.Key):]) + dirty, child, err := t.delete(n.Val, append(prefix, key[:len(n.Key)]...), key[len(n.Key):]) if err != nil { - return nil, err + return false, nil, err + } + if !dirty { + return false, n, nil } switch child := child.(type) { case shortNode: @@ -295,17 +311,21 @@ func (t *Trie) delete(n node, prefix, key []byte) (node, error) { // always creates a new slice) instead of append to // avoid modifying n.Key since it might be shared with // other nodes. - return shortNode{concat(n.Key, child.Key...), child.Val}, nil + return true, shortNode{concat(n.Key, child.Key...), child.Val, nil, true}, nil default: - return shortNode{n.Key, child}, nil + return true, shortNode{n.Key, child, nil, true}, nil } case fullNode: - nn, err := t.delete(n[key[0]], append(prefix, key[0]), key[1:]) + dirty, nn, err := t.delete(n.Children[key[0]], append(prefix, key[0]), key[1:]) if err != nil { - return nil, err + return false, nil, err } - n[key[0]] = nn + if !dirty { + return false, n, nil + } + n.Children[key[0]], n.hash, n.dirty = nn, nil, true + // Check how many non-nil entries are left after deleting and // reduce the full node to a short node if only one entry is // left. Since n must've contained at least two children @@ -316,7 +336,7 @@ func (t *Trie) delete(n node, prefix, key []byte) (node, error) { // value that is left in n or -2 if n contains at least two // values. pos := -1 - for i, cld := range n { + for i, cld := range n.Children { if cld != nil { if pos == -1 { pos = i @@ -334,37 +354,41 @@ func (t *Trie) delete(n node, prefix, key []byte) (node, error) { // shortNode{..., shortNode{...}}. Since the entry // might not be loaded yet, resolve it just for this // check. - cnode, err := t.resolve(n[pos], prefix, []byte{byte(pos)}) + cnode, err := t.resolve(n.Children[pos], prefix, []byte{byte(pos)}) if err != nil { - return nil, err + return false, nil, err } if cnode, ok := cnode.(shortNode); ok { k := append([]byte{byte(pos)}, cnode.Key...) - return shortNode{k, cnode.Val}, nil + return true, shortNode{k, cnode.Val, nil, true}, nil } } // Otherwise, n is replaced by a one-nibble short node // containing the child. - return shortNode{[]byte{byte(pos)}, n[pos]}, nil + return true, shortNode{[]byte{byte(pos)}, n.Children[pos], nil, true}, nil } // n still contains at least two values and cannot be reduced. - return n, nil + return true, n, nil case nil: - return nil, nil + return false, nil, nil case hashNode: // We've hit a part of the trie that isn't loaded yet. Load // the node and delete from it. This leaves all child nodes on // the path to the value in the trie. - // - // TODO: track whether deletion actually hit a key and keep - // n as a hash node if it didn't. rn, err := t.resolveHash(n, prefix, key) if err != nil { - return nil, err + return false, nil, err } - return t.delete(rn, prefix, key) + dirty, nn, err := t.delete(rn, prefix, key) + if err != nil { + return false, nil, err + } + if !dirty { + return false, rn, nil + } + return true, nn, nil default: panic(fmt.Sprintf("%T: invalid node: %v (%v)", n, n, key)) @@ -413,8 +437,9 @@ func (t *Trie) Root() []byte { return t.Hash().Bytes() } // Hash returns the root hash of the trie. It does not write to the // database and can be used even if the trie doesn't have one. func (t *Trie) Hash() common.Hash { - root, _ := t.hashRoot(nil) - return common.BytesToHash(root.(hashNode)) + hash, cached, _ := t.hashRoot(nil) + t.root = cached + return common.BytesToHash(hash.(hashNode)) } // Commit writes all nodes to the trie's database. @@ -437,17 +462,17 @@ func (t *Trie) Commit() (root common.Hash, err error) { // the changes made to db are written back to the trie's attached // database before using the trie. func (t *Trie) CommitTo(db DatabaseWriter) (root common.Hash, err error) { - n, err := t.hashRoot(db) + hash, cached, err := t.hashRoot(db) if err != nil { return (common.Hash{}), err } - t.root = n - return common.BytesToHash(n.(hashNode)), nil + t.root = cached + return common.BytesToHash(hash.(hashNode)), nil } -func (t *Trie) hashRoot(db DatabaseWriter) (node, error) { +func (t *Trie) hashRoot(db DatabaseWriter) (node, node, error) { if t.root == nil { - return hashNode(emptyRoot.Bytes()), nil + return hashNode(emptyRoot.Bytes()), nil, nil } if t.hasher == nil { t.hasher = newHasher() @@ -464,51 +489,87 @@ func newHasher() *hasher { return &hasher{tmp: new(bytes.Buffer), sha: sha3.NewKeccak256()} } -func (h *hasher) hash(n node, db DatabaseWriter, force bool) (node, error) { - hashed, err := h.replaceChildren(n, db) +// hash collapses a node down into a hash node, also returning a copy of the +// original node initialzied with the computed hash to replace the original one. +func (h *hasher) hash(n node, db DatabaseWriter, force bool) (node, node, error) { + // If we're not storing the node, just hashing, use avaialble cached data + if hash, dirty := n.cache(); hash != nil && (db == nil || !dirty) { + return hash, n, nil + } + // Trie not processed yet or needs storage, walk the children + collapsed, cached, err := h.hashChildren(n, db) if err != nil { - return hashNode{}, err + return hashNode{}, n, err } - if n, err = h.store(hashed, db, force); err != nil { - return hashNode{}, err + hashed, err := h.store(collapsed, db, force) + if err != nil { + return hashNode{}, n, err } - return n, nil + // Cache the hash and RLP blob of the ndoe for later reuse + if hash, ok := hashed.(hashNode); ok && !force { + switch cached := cached.(type) { + case shortNode: + cached.hash = hash + if db != nil { + cached.dirty = false + } + return hashed, cached, nil + case fullNode: + cached.hash = hash + if db != nil { + cached.dirty = false + } + return hashed, cached, nil + } + } + return hashed, cached, nil } -// hashChildren replaces child nodes of n with their hashes if the encoded -// size of the child is larger than a hash. -func (h *hasher) replaceChildren(n node, db DatabaseWriter) (node, error) { +// hashChildren replaces the children of a node with their hashes if the encoded +// size of the child is larger than a hash, returning the collapsed node as well +// as a replacement for the original node with the child hashes cached in. +func (h *hasher) hashChildren(original node, db DatabaseWriter) (node, node, error) { var err error - switch n := n.(type) { + + switch n := original.(type) { case shortNode: + // Hash the short node's child, caching the newly hashed subtree + cached := n + cached.Key = common.CopyBytes(cached.Key) + n.Key = compactEncode(n.Key) if _, ok := n.Val.(valueNode); !ok { - if n.Val, err = h.hash(n.Val, db, false); err != nil { - return n, err + if n.Val, cached.Val, err = h.hash(n.Val, db, false); err != nil { + return n, original, err } } if n.Val == nil { - // Ensure that nil children are encoded as empty strings. - n.Val = valueNode(nil) + n.Val = valueNode(nil) // Ensure that nil children are encoded as empty strings. } - return n, nil + return n, cached, nil + case fullNode: + // Hash the full node's children, caching the newly hashed subtrees + cached := fullNode{dirty: n.dirty} + for i := 0; i < 16; i++ { - if n[i] != nil { - if n[i], err = h.hash(n[i], db, false); err != nil { - return n, err + if n.Children[i] != nil { + if n.Children[i], cached.Children[i], err = h.hash(n.Children[i], db, false); err != nil { + return n, original, err } } else { - // Ensure that nil children are encoded as empty strings. - n[i] = valueNode(nil) + n.Children[i] = valueNode(nil) // Ensure that nil children are encoded as empty strings. } } - if n[16] == nil { - n[16] = valueNode(nil) + cached.Children[16] = n.Children[16] + if n.Children[16] == nil { + n.Children[16] = valueNode(nil) } - return n, nil + return n, cached, nil + default: - return n, nil + // Value and hash nodes don't have children so they're left as were + return n, original, nil } } @@ -517,21 +578,23 @@ func (h *hasher) store(n node, db DatabaseWriter, force bool) (node, error) { if _, isHash := n.(hashNode); n == nil || isHash { return n, nil } + // Generate the RLP encoding of the node h.tmp.Reset() if err := rlp.Encode(h.tmp, n); err != nil { panic("encode error: " + err.Error()) } if h.tmp.Len() < 32 && !force { - // Nodes smaller than 32 bytes are stored inside their parent. - return n, nil + return n, nil // Nodes smaller than 32 bytes are stored inside their parent } // Larger nodes are replaced by their hash and stored in the database. - h.sha.Reset() - h.sha.Write(h.tmp.Bytes()) - key := hashNode(h.sha.Sum(nil)) + hash, _ := n.cache() + if hash == nil { + h.sha.Reset() + h.sha.Write(h.tmp.Bytes()) + hash = hashNode(h.sha.Sum(nil)) + } if db != nil { - err := db.Put(key, h.tmp.Bytes()) - return key, err + return hash, db.Put(hash, h.tmp.Bytes()) } - return key, nil + return hash, nil } |