141 lines
2.9 KiB
Go
141 lines
2.9 KiB
Go
// Copyright 2014 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// go-ethereum is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package trie
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import (
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"bytes"
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)
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type Iterator struct {
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trie *Trie
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Key []byte
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Value []byte
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}
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func NewIterator(trie *Trie) *Iterator {
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return &Iterator{trie: trie, Key: nil}
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}
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func (self *Iterator) Next() bool {
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self.trie.mu.Lock()
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defer self.trie.mu.Unlock()
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isIterStart := false
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if self.Key == nil {
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isIterStart = true
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self.Key = make([]byte, 32)
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}
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key := RemTerm(CompactHexDecode(string(self.Key)))
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k := self.next(self.trie.root, key, isIterStart)
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self.Key = []byte(DecodeCompact(k))
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return len(k) > 0
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}
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func (self *Iterator) next(node Node, key []byte, isIterStart bool) []byte {
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if node == nil {
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return nil
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}
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switch node := node.(type) {
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case *FullNode:
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if len(key) > 0 {
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k := self.next(node.branch(key[0]), key[1:], isIterStart)
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if k != nil {
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return append([]byte{key[0]}, k...)
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}
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}
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var r byte
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if len(key) > 0 {
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r = key[0] + 1
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}
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for i := r; i < 16; i++ {
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k := self.key(node.branch(byte(i)))
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if k != nil {
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return append([]byte{i}, k...)
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}
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}
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case *ShortNode:
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k := RemTerm(node.Key())
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if vnode, ok := node.Value().(*ValueNode); ok {
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switch bytes.Compare([]byte(k), key) {
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case 0:
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if isIterStart {
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self.Value = vnode.Val()
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return k
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}
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case 1:
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self.Value = vnode.Val()
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return k
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}
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} else {
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cnode := node.Value()
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var ret []byte
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skey := key[len(k):]
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if BeginsWith(key, k) {
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ret = self.next(cnode, skey, isIterStart)
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} else if bytes.Compare(k, key[:len(k)]) > 0 {
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return self.key(node)
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}
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if ret != nil {
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return append(k, ret...)
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}
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}
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}
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return nil
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}
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func (self *Iterator) key(node Node) []byte {
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switch node := node.(type) {
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case *ShortNode:
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// Leaf node
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if vnode, ok := node.Value().(*ValueNode); ok {
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k := RemTerm(node.Key())
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self.Value = vnode.Val()
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return k
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} else {
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k := RemTerm(node.Key())
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return append(k, self.key(node.Value())...)
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}
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case *FullNode:
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if node.Value() != nil {
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self.Value = node.Value().(*ValueNode).Val()
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return []byte{16}
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}
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for i := 0; i < 16; i++ {
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k := self.key(node.branch(byte(i)))
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if k != nil {
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return append([]byte{byte(i)}, k...)
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}
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}
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}
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return nil
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}
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