plugeth/trie/iterator.go

141 lines
2.9 KiB
Go
Raw Normal View History

2015-07-07 00:54:22 +00:00
// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
2015-07-07 00:54:22 +00:00
//
// go-ethereum 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,
2015-07-07 00:54:22 +00:00
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
2015-07-07 00:54:22 +00:00
// 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/>.
2015-07-07 00:54:22 +00:00
2014-10-31 13:45:03 +00:00
package trie
2014-10-10 14:56:28 +00:00
import (
"bytes"
)
2014-10-10 14:56:28 +00:00
type Iterator struct {
trie *Trie
Key []byte
2015-01-08 10:47:04 +00:00
Value []byte
2014-10-10 14:56:28 +00:00
}
func NewIterator(trie *Trie) *Iterator {
return &Iterator{trie: trie, Key: nil}
2014-10-10 14:56:28 +00:00
}
2015-01-08 10:47:04 +00:00
func (self *Iterator) Next() bool {
self.trie.mu.Lock()
defer self.trie.mu.Unlock()
2014-10-10 14:56:28 +00:00
isIterStart := false
if self.Key == nil {
isIterStart = true
self.Key = make([]byte, 32)
}
2015-01-08 10:47:04 +00:00
key := RemTerm(CompactHexDecode(string(self.Key)))
k := self.next(self.trie.root, key, isIterStart)
2014-10-10 14:56:28 +00:00
2015-01-08 10:47:04 +00:00
self.Key = []byte(DecodeCompact(k))
2014-10-10 14:56:28 +00:00
2015-01-08 10:47:04 +00:00
return len(k) > 0
2014-10-10 14:56:28 +00:00
}
func (self *Iterator) next(node Node, key []byte, isIterStart bool) []byte {
2015-01-08 10:47:04 +00:00
if node == nil {
2014-10-10 14:56:28 +00:00
return nil
2015-01-08 10:47:04 +00:00
}
2014-10-10 14:56:28 +00:00
2015-01-08 10:47:04 +00:00
switch node := node.(type) {
case *FullNode:
if len(key) > 0 {
k := self.next(node.branch(key[0]), key[1:], isIterStart)
2015-01-08 10:47:04 +00:00
if k != nil {
return append([]byte{key[0]}, k...)
2014-10-10 14:56:28 +00:00
}
}
2015-01-08 10:47:04 +00:00
var r byte
2014-10-10 14:56:28 +00:00
if len(key) > 0 {
r = key[0] + 1
}
for i := r; i < 16; i++ {
2015-01-08 10:47:04 +00:00
k := self.key(node.branch(byte(i)))
if k != nil {
return append([]byte{i}, k...)
2014-10-10 14:56:28 +00:00
}
}
2015-01-08 10:47:04 +00:00
case *ShortNode:
k := RemTerm(node.Key())
if vnode, ok := node.Value().(*ValueNode); ok {
switch bytes.Compare([]byte(k), key) {
case 0:
if isIterStart {
self.Value = vnode.Val()
return k
}
case 1:
2015-01-08 10:47:04 +00:00
self.Value = vnode.Val()
2014-10-10 14:56:28 +00:00
return k
}
} else {
2015-01-08 10:47:04 +00:00
cnode := node.Value()
2014-10-10 14:56:28 +00:00
var ret []byte
2015-01-08 10:47:04 +00:00
skey := key[len(k):]
2014-10-10 14:56:28 +00:00
if BeginsWith(key, k) {
ret = self.next(cnode, skey, isIterStart)
2014-10-10 14:56:28 +00:00
} else if bytes.Compare(k, key[:len(k)]) > 0 {
2015-02-07 16:03:22 +00:00
return self.key(node)
2014-10-10 14:56:28 +00:00
}
if ret != nil {
return append(k, ret...)
}
}
}
return nil
}
2015-01-08 10:47:04 +00:00
func (self *Iterator) key(node Node) []byte {
switch node := node.(type) {
case *ShortNode:
// Leaf node
if vnode, ok := node.Value().(*ValueNode); ok {
k := RemTerm(node.Key())
self.Value = vnode.Val()
2014-10-10 14:56:28 +00:00
2015-01-08 10:47:04 +00:00
return k
} else {
k := RemTerm(node.Key())
return append(k, self.key(node.Value())...)
}
case *FullNode:
if node.Value() != nil {
self.Value = node.Value().(*ValueNode).Val()
2014-10-10 14:56:28 +00:00
2015-01-08 10:47:04 +00:00
return []byte{16}
}
2014-10-10 14:56:28 +00:00
2015-01-08 10:47:04 +00:00
for i := 0; i < 16; i++ {
k := self.key(node.branch(byte(i)))
if k != nil {
return append([]byte{byte(i)}, k...)
}
}
}
return nil
2014-10-10 14:56:28 +00:00
}