459 lines
13 KiB
Go
459 lines
13 KiB
Go
|
// Copyright 2014 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 (
|
||
|
|
"bytes"
|
||
|
|
"errors"
|
||
|
|
|
||
|
|
"github.com/ethereum/go-ethereum/common"
|
||
|
|
"github.com/ethereum/go-ethereum/ethdb"
|
||
|
|
"github.com/ethereum/go-ethereum/trie"
|
||
|
|
)
|
||
|
|
|
||
|
|
// NodeIterator is a re-export of the go-ethereum interface
|
||
|
|
type NodeIterator = trie.NodeIterator
|
||
|
|
|
||
|
|
// Iterator is a key-value trie iterator that traverses a Trie.
|
||
|
|
type Iterator struct {
|
||
|
|
nodeIt NodeIterator
|
||
|
|
|
||
|
|
Key []byte // Current data key on which the iterator is positioned on
|
||
|
|
Value []byte // Current data value on which the iterator is positioned on
|
||
|
|
Err error
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewIterator creates a new key-value iterator from a node iterator.
|
||
|
|
// Note that the value returned by the iterator is raw. If the content is encoded
|
||
|
|
// (e.g. storage value is RLP-encoded), it's caller's duty to decode it.
|
||
|
|
func NewIterator(it NodeIterator) *Iterator {
|
||
|
|
return &Iterator{
|
||
|
|
nodeIt: it,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Next moves the iterator forward one key-value entry.
|
||
|
|
func (it *Iterator) Next() bool {
|
||
|
|
for it.nodeIt.Next(true) {
|
||
|
|
if it.nodeIt.Leaf() {
|
||
|
|
it.Key = it.nodeIt.LeafKey()
|
||
|
|
it.Value = it.nodeIt.LeafBlob()
|
||
|
|
return true
|
||
|
|
}
|
||
|
|
}
|
||
|
|
it.Key = nil
|
||
|
|
it.Value = nil
|
||
|
|
it.Err = it.nodeIt.Error()
|
||
|
|
return false
|
||
|
|
}
|
||
|
|
|
||
|
|
// Prove generates the Merkle proof for the leaf node the iterator is currently
|
||
|
|
// positioned on.
|
||
|
|
func (it *Iterator) Prove() [][]byte {
|
||
|
|
return it.nodeIt.LeafProof()
|
||
|
|
}
|
||
|
|
|
||
|
|
// nodeIteratorState represents the iteration state at one particular node of the
|
||
|
|
// trie, which can be resumed at a later invocation.
|
||
|
|
type nodeIteratorState struct {
|
||
|
|
hash common.Hash // Hash of the node being iterated (nil if not standalone)
|
||
|
|
node node // Trie node being iterated
|
||
|
|
parent common.Hash // Hash of the first full ancestor node (nil if current is the root)
|
||
|
|
index int // Child to be processed next
|
||
|
|
pathlen int // Length of the path to this node
|
||
|
|
}
|
||
|
|
|
||
|
|
type nodeIterator struct {
|
||
|
|
trie *Trie // Trie being iterated
|
||
|
|
stack []*nodeIteratorState // Hierarchy of trie nodes persisting the iteration state
|
||
|
|
path []byte // Path to the current node
|
||
|
|
err error // Failure set in case of an internal error in the iterator
|
||
|
|
|
||
|
|
resolver ethdb.KeyValueReader // Optional intermediate resolver above the disk layer
|
||
|
|
}
|
||
|
|
|
||
|
|
// errIteratorEnd is stored in nodeIterator.err when iteration is done.
|
||
|
|
var errIteratorEnd = errors.New("end of iteration")
|
||
|
|
|
||
|
|
// seekError is stored in nodeIterator.err if the initial seek has failed.
|
||
|
|
type seekError struct {
|
||
|
|
key []byte
|
||
|
|
err error
|
||
|
|
}
|
||
|
|
|
||
|
|
func (e seekError) Error() string {
|
||
|
|
return "seek error: " + e.err.Error()
|
||
|
|
}
|
||
|
|
|
||
|
|
func newNodeIterator(trie *Trie, start []byte) NodeIterator {
|
||
|
|
if trie.Hash() == emptyRoot {
|
||
|
|
return &nodeIterator{
|
||
|
|
trie: trie,
|
||
|
|
err: errIteratorEnd,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
it := &nodeIterator{trie: trie}
|
||
|
|
it.err = it.seek(start)
|
||
|
|
return it
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) AddResolver(resolver ethdb.KeyValueReader) {
|
||
|
|
it.resolver = resolver
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) Hash() common.Hash {
|
||
|
|
if len(it.stack) == 0 {
|
||
|
|
return common.Hash{}
|
||
|
|
}
|
||
|
|
return it.stack[len(it.stack)-1].hash
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) Parent() common.Hash {
|
||
|
|
if len(it.stack) == 0 {
|
||
|
|
return common.Hash{}
|
||
|
|
}
|
||
|
|
return it.stack[len(it.stack)-1].parent
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) Leaf() bool {
|
||
|
|
return hasTerm(it.path)
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) LeafKey() []byte {
|
||
|
|
if len(it.stack) > 0 {
|
||
|
|
if _, ok := it.stack[len(it.stack)-1].node.(valueNode); ok {
|
||
|
|
return hexToKeyBytes(it.path)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
panic("not at leaf")
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) LeafBlob() []byte {
|
||
|
|
if len(it.stack) > 0 {
|
||
|
|
if node, ok := it.stack[len(it.stack)-1].node.(valueNode); ok {
|
||
|
|
return node
|
||
|
|
}
|
||
|
|
}
|
||
|
|
panic("not at leaf")
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) LeafProof() [][]byte {
|
||
|
|
if len(it.stack) > 0 {
|
||
|
|
if _, ok := it.stack[len(it.stack)-1].node.(valueNode); ok {
|
||
|
|
hasher := newHasher(false)
|
||
|
|
defer returnHasherToPool(hasher)
|
||
|
|
proofs := make([][]byte, 0, len(it.stack))
|
||
|
|
|
||
|
|
for i, item := range it.stack[:len(it.stack)-1] {
|
||
|
|
// Gather nodes that end up as hash nodes (or the root)
|
||
|
|
node, hashed := hasher.proofHash(item.node)
|
||
|
|
if _, ok := hashed.(hashNode); ok || i == 0 {
|
||
|
|
proofs = append(proofs, nodeToBytes(node))
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return proofs
|
||
|
|
}
|
||
|
|
}
|
||
|
|
panic("not at leaf")
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) Path() []byte {
|
||
|
|
return it.path
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) NodeBlob() []byte {
|
||
|
|
if it.Hash() == (common.Hash{}) {
|
||
|
|
return nil // skip the non-standalone node
|
||
|
|
}
|
||
|
|
blob, err := it.resolveBlob(it.Hash().Bytes(), it.Path())
|
||
|
|
if err != nil {
|
||
|
|
it.err = err
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
return blob
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) Error() error {
|
||
|
|
if it.err == errIteratorEnd {
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
if seek, ok := it.err.(seekError); ok {
|
||
|
|
return seek.err
|
||
|
|
}
|
||
|
|
return it.err
|
||
|
|
}
|
||
|
|
|
||
|
|
// Next moves the iterator to the next node, returning whether there are any
|
||
|
|
// further nodes. In case of an internal error this method returns false and
|
||
|
|
// sets the Error field to the encountered failure. If `descend` is false,
|
||
|
|
// skips iterating over any subnodes of the current node.
|
||
|
|
func (it *nodeIterator) Next(descend bool) bool {
|
||
|
|
if it.err == errIteratorEnd {
|
||
|
|
return false
|
||
|
|
}
|
||
|
|
if seek, ok := it.err.(seekError); ok {
|
||
|
|
if it.err = it.seek(seek.key); it.err != nil {
|
||
|
|
return false
|
||
|
|
}
|
||
|
|
}
|
||
|
|
// Otherwise step forward with the iterator and report any errors.
|
||
|
|
state, parentIndex, path, err := it.peek(descend)
|
||
|
|
it.err = err
|
||
|
|
if it.err != nil {
|
||
|
|
return false
|
||
|
|
}
|
||
|
|
it.push(state, parentIndex, path)
|
||
|
|
return true
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) seek(prefix []byte) error {
|
||
|
|
// The path we're looking for is the hex encoded key without terminator.
|
||
|
|
key := keybytesToHex(prefix)
|
||
|
|
key = key[:len(key)-1]
|
||
|
|
// Move forward until we're just before the closest match to key.
|
||
|
|
for {
|
||
|
|
state, parentIndex, path, err := it.peekSeek(key)
|
||
|
|
if err == errIteratorEnd {
|
||
|
|
return errIteratorEnd
|
||
|
|
} else if err != nil {
|
||
|
|
return seekError{prefix, err}
|
||
|
|
} else if bytes.Compare(path, key) >= 0 {
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
it.push(state, parentIndex, path)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// init initializes the iterator.
|
||
|
|
func (it *nodeIterator) init() (*nodeIteratorState, error) {
|
||
|
|
root := it.trie.Hash()
|
||
|
|
state := &nodeIteratorState{node: it.trie.root, index: -1}
|
||
|
|
if root != emptyRoot {
|
||
|
|
state.hash = root
|
||
|
|
}
|
||
|
|
return state, state.resolve(it, nil)
|
||
|
|
}
|
||
|
|
|
||
|
|
// peek creates the next state of the iterator.
|
||
|
|
func (it *nodeIterator) peek(descend bool) (*nodeIteratorState, *int, []byte, error) {
|
||
|
|
// Initialize the iterator if we've just started.
|
||
|
|
if len(it.stack) == 0 {
|
||
|
|
state, err := it.init()
|
||
|
|
return state, nil, nil, err
|
||
|
|
}
|
||
|
|
if !descend {
|
||
|
|
// If we're skipping children, pop the current node first
|
||
|
|
it.pop()
|
||
|
|
}
|
||
|
|
|
||
|
|
// Continue iteration to the next child
|
||
|
|
for len(it.stack) > 0 {
|
||
|
|
parent := it.stack[len(it.stack)-1]
|
||
|
|
ancestor := parent.hash
|
||
|
|
if (ancestor == common.Hash{}) {
|
||
|
|
ancestor = parent.parent
|
||
|
|
}
|
||
|
|
state, path, ok := it.nextChild(parent, ancestor)
|
||
|
|
if ok {
|
||
|
|
if err := state.resolve(it, path); err != nil {
|
||
|
|
return parent, &parent.index, path, err
|
||
|
|
}
|
||
|
|
return state, &parent.index, path, nil
|
||
|
|
}
|
||
|
|
// No more child nodes, move back up.
|
||
|
|
it.pop()
|
||
|
|
}
|
||
|
|
return nil, nil, nil, errIteratorEnd
|
||
|
|
}
|
||
|
|
|
||
|
|
// peekSeek is like peek, but it also tries to skip resolving hashes by skipping
|
||
|
|
// over the siblings that do not lead towards the desired seek position.
|
||
|
|
func (it *nodeIterator) peekSeek(seekKey []byte) (*nodeIteratorState, *int, []byte, error) {
|
||
|
|
// Initialize the iterator if we've just started.
|
||
|
|
if len(it.stack) == 0 {
|
||
|
|
state, err := it.init()
|
||
|
|
return state, nil, nil, err
|
||
|
|
}
|
||
|
|
if !bytes.HasPrefix(seekKey, it.path) {
|
||
|
|
// If we're skipping children, pop the current node first
|
||
|
|
it.pop()
|
||
|
|
}
|
||
|
|
|
||
|
|
// Continue iteration to the next child
|
||
|
|
for len(it.stack) > 0 {
|
||
|
|
parent := it.stack[len(it.stack)-1]
|
||
|
|
ancestor := parent.hash
|
||
|
|
if (ancestor == common.Hash{}) {
|
||
|
|
ancestor = parent.parent
|
||
|
|
}
|
||
|
|
state, path, ok := it.nextChildAt(parent, ancestor, seekKey)
|
||
|
|
if ok {
|
||
|
|
if err := state.resolve(it, path); err != nil {
|
||
|
|
return parent, &parent.index, path, err
|
||
|
|
}
|
||
|
|
return state, &parent.index, path, nil
|
||
|
|
}
|
||
|
|
// No more child nodes, move back up.
|
||
|
|
it.pop()
|
||
|
|
}
|
||
|
|
return nil, nil, nil, errIteratorEnd
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) resolveHash(hash hashNode, path []byte) (node, error) {
|
||
|
|
if it.resolver != nil {
|
||
|
|
if blob, err := it.resolver.Get(hash); err == nil && len(blob) > 0 {
|
||
|
|
if resolved, err := decodeNode(hash, blob); err == nil {
|
||
|
|
return resolved, nil
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return it.trie.resolveHash(hash, path)
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) resolveBlob(hash hashNode, path []byte) ([]byte, error) {
|
||
|
|
if it.resolver != nil {
|
||
|
|
if blob, err := it.resolver.Get(hash); err == nil && len(blob) > 0 {
|
||
|
|
return blob, nil
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return it.trie.resolveBlob(hash, path)
|
||
|
|
}
|
||
|
|
|
||
|
|
func (st *nodeIteratorState) resolve(it *nodeIterator, path []byte) error {
|
||
|
|
if hash, ok := st.node.(hashNode); ok {
|
||
|
|
resolved, err := it.resolveHash(hash, path)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
st.node = resolved
|
||
|
|
st.hash = common.BytesToHash(hash)
|
||
|
|
}
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func findChild(n *fullNode, index int, path []byte, ancestor common.Hash) (node, *nodeIteratorState, []byte, int) {
|
||
|
|
var (
|
||
|
|
child node
|
||
|
|
state *nodeIteratorState
|
||
|
|
childPath []byte
|
||
|
|
)
|
||
|
|
for ; index < len(n.Children); index++ {
|
||
|
|
if n.Children[index] != nil {
|
||
|
|
child = n.Children[index]
|
||
|
|
hash, _ := child.cache()
|
||
|
|
state = &nodeIteratorState{
|
||
|
|
hash: common.BytesToHash(hash),
|
||
|
|
node: child,
|
||
|
|
parent: ancestor,
|
||
|
|
index: -1,
|
||
|
|
pathlen: len(path),
|
||
|
|
}
|
||
|
|
childPath = append(childPath, path...)
|
||
|
|
childPath = append(childPath, byte(index))
|
||
|
|
return child, state, childPath, index
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return nil, nil, nil, 0
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) nextChild(parent *nodeIteratorState, ancestor common.Hash) (*nodeIteratorState, []byte, bool) {
|
||
|
|
switch node := parent.node.(type) {
|
||
|
|
case *fullNode:
|
||
|
|
// Full node, move to the first non-nil child.
|
||
|
|
if child, state, path, index := findChild(node, parent.index+1, it.path, ancestor); child != nil {
|
||
|
|
parent.index = index - 1
|
||
|
|
return state, path, true
|
||
|
|
}
|
||
|
|
case *shortNode:
|
||
|
|
// Short node, return the pointer singleton child
|
||
|
|
if parent.index < 0 {
|
||
|
|
hash, _ := node.Val.cache()
|
||
|
|
state := &nodeIteratorState{
|
||
|
|
hash: common.BytesToHash(hash),
|
||
|
|
node: node.Val,
|
||
|
|
parent: ancestor,
|
||
|
|
index: -1,
|
||
|
|
pathlen: len(it.path),
|
||
|
|
}
|
||
|
|
path := append(it.path, node.Key...)
|
||
|
|
return state, path, true
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return parent, it.path, false
|
||
|
|
}
|
||
|
|
|
||
|
|
// nextChildAt is similar to nextChild, except that it targets a child as close to the
|
||
|
|
// target key as possible, thus skipping siblings.
|
||
|
|
func (it *nodeIterator) nextChildAt(parent *nodeIteratorState, ancestor common.Hash, key []byte) (*nodeIteratorState, []byte, bool) {
|
||
|
|
switch n := parent.node.(type) {
|
||
|
|
case *fullNode:
|
||
|
|
// Full node, move to the first non-nil child before the desired key position
|
||
|
|
child, state, path, index := findChild(n, parent.index+1, it.path, ancestor)
|
||
|
|
if child == nil {
|
||
|
|
// No more children in this fullnode
|
||
|
|
return parent, it.path, false
|
||
|
|
}
|
||
|
|
// If the child we found is already past the seek position, just return it.
|
||
|
|
if bytes.Compare(path, key) >= 0 {
|
||
|
|
parent.index = index - 1
|
||
|
|
return state, path, true
|
||
|
|
}
|
||
|
|
// The child is before the seek position. Try advancing
|
||
|
|
for {
|
||
|
|
nextChild, nextState, nextPath, nextIndex := findChild(n, index+1, it.path, ancestor)
|
||
|
|
// If we run out of children, or skipped past the target, return the
|
||
|
|
// previous one
|
||
|
|
if nextChild == nil || bytes.Compare(nextPath, key) >= 0 {
|
||
|
|
parent.index = index - 1
|
||
|
|
return state, path, true
|
||
|
|
}
|
||
|
|
// We found a better child closer to the target
|
||
|
|
state, path, index = nextState, nextPath, nextIndex
|
||
|
|
}
|
||
|
|
case *shortNode:
|
||
|
|
// Short node, return the pointer singleton child
|
||
|
|
if parent.index < 0 {
|
||
|
|
hash, _ := n.Val.cache()
|
||
|
|
state := &nodeIteratorState{
|
||
|
|
hash: common.BytesToHash(hash),
|
||
|
|
node: n.Val,
|
||
|
|
parent: ancestor,
|
||
|
|
index: -1,
|
||
|
|
pathlen: len(it.path),
|
||
|
|
}
|
||
|
|
path := append(it.path, n.Key...)
|
||
|
|
return state, path, true
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return parent, it.path, false
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) push(state *nodeIteratorState, parentIndex *int, path []byte) {
|
||
|
|
it.path = path
|
||
|
|
it.stack = append(it.stack, state)
|
||
|
|
if parentIndex != nil {
|
||
|
|
*parentIndex++
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func (it *nodeIterator) pop() {
|
||
|
|
last := it.stack[len(it.stack)-1]
|
||
|
|
it.path = it.path[:last.pathlen]
|
||
|
|
it.stack[len(it.stack)-1] = nil
|
||
|
|
it.stack = it.stack[:len(it.stack)-1]
|
||
|
|
}
|