package ethtrie
import (
"bytes"
"fmt"
_ "reflect"
"sync"
"github.com/ethereum/go-ethereum/ethcrypto"
"github.com/ethereum/go-ethereum/ethutil"
)
func __ignore() { fmt.Println("") }
func ParanoiaCheck(t1 *Trie) (bool, *Trie) {
t2 := New(ethutil.Config.Db, "")
t1.NewIterator().Each(func(key string, v *ethutil.Value) {
t2.Update(key, v.Str())
})
a := ethutil.NewValue(t2.Root).Bytes()
b := ethutil.NewValue(t1.Root).Bytes()
return bytes.Compare(a, b) == 0, t2
}
func (s *Cache) Len() int {
return len(s.nodes)
}
// TODO
// A StateObject is an object that has a state root
// This is goig to be the object for the second level caching (the caching of object which have a state such as contracts)
type StateObject interface {
State() *Trie
Sync()
Undo()
}
type Node struct {
Key []byte
Value *ethutil.Value
Dirty bool
}
func NewNode(key []byte, val *ethutil.Value, dirty bool) *Node {
return &Node{Key: key, Value: val, Dirty: dirty}
}
func (n *Node) Copy() *Node {
return NewNode(n.Key, n.Value, n.Dirty)
}
type Cache struct {
nodes map[string]*Node
db ethutil.Database
IsDirty bool
}
func NewCache(db ethutil.Database) *Cache {
return &Cache{db: db, nodes: make(map[string]*Node)}
}
func (cache *Cache) PutValue(v interface{}, force bool) interface{} {
value := ethutil.NewValue(v)
enc := value.Encode()
if len(enc) >= 32 || force {
sha := ethcrypto.Sha3(enc)
cache.nodes[string(sha)] = NewNode(sha, value, true)
cache.IsDirty = true
return sha
}
return v
}
func (cache *Cache) Put(v interface{}) interface{} {
return cache.PutValue(v, false)
}
func (cache *Cache) Get(key []byte) *ethutil.Value {
// First check if the key is the cache
if cache.nodes[string(key)] != nil {
return cache.nodes[string(key)].Value
}
// Get the key of the database instead and cache it
data, _ := cache.db.Get(key)
// Create the cached value
value := ethutil.NewValueFromBytes(data)
defer func() {
if r := recover(); r != nil {
fmt.Println("RECOVER GET", cache, cache.nodes)
panic("bye")
}
}()
// Create caching node
cache.nodes[string(key)] = NewNode(key, value, false)
return value
}
func (cache *Cache) Delete(key []byte) {
delete(cache.nodes, string(key))
cache.db.Delete(key)
}
func (cache *Cache) Commit() {
// Don't try to commit if it isn't dirty
if !cache.IsDirty {
return
}
for key, node := range cache.nodes {
if node.Dirty {
cache.db.Put([]byte(key), node.Value.Encode())
node.Dirty = false
}
}
cache.IsDirty = false
// If the nodes grows beyond the 200 entries we simple empty it
// FIXME come up with something better
if len(cache.nodes) > 200 {
cache.nodes = make(map[string]*Node)
}
}
func (cache *Cache) Undo() {
for key, node := range cache.nodes {
if node.Dirty {
delete(cache.nodes, key)
}
}
cache.IsDirty = false
}
// A (modified) Radix Trie implementation. The Trie implements
// a caching mechanism and will used cached values if they are
// present. If a node is not present in the cache it will try to
// fetch it from the database and store the cached value.
// Please note that the data isn't persisted unless `Sync` is
// explicitly called.
type Trie struct {
mut sync.RWMutex
prevRoot interface{}
Root interface{}
//db Database
cache *Cache
}
func copyRoot(root interface{}) interface{} {
var prevRootCopy interface{}
if b, ok := root.([]byte); ok {
prevRootCopy = ethutil.CopyBytes(b)
} else {
prevRootCopy = root
}
return prevRootCopy
}
func New(db ethutil.Database, Root interface{}) *Trie {
// Make absolute sure the root is copied
r := copyRoot(Root)
p := copyRoot(Root)
return &Trie{cache: NewCache(db), Root: r, prevRoot: p}
}
/*
* Public (query) interface functions
*/
func (t *Trie) Update(key, value string) {
t.mut.Lock()
defer t.mut.Unlock()
k := CompactHexDecode(key)
root := t.UpdateState(t.Root, k, value)
switch root.(type) {
case string:
t.Root = root
case []byte:
t.Root = root
default:
t.Root = t.cache.PutValue(root, true)
}
}
func (t *Trie) Get(key string) string {
t.mut.Lock()
defer t.mut.Unlock()
k := CompactHexDecode(key)
c := ethutil.NewValue(t.getState(t.Root, k))
return c.Str()
}
func (t *Trie) Delete(key string) {
t.mut.Lock()
defer t.mut.Unlock()
k := CompactHexDecode(key)
root := t.deleteState(t.Root, k)
switch root.(type) {
case string:
t.Root = root
case []byte:
t.Root = root
default:
t.Root = t.cache.PutValue(root, true)
}
}
// Simple compare function which creates a rlp value out of the evaluated objects
func (t *Trie) Cmp(trie *Trie) bool {
return ethutil.NewValue(t.Root).Cmp(ethutil.NewValue(trie.Root))
}
// Returns a copy of this trie
func (t *Trie) Copy() *Trie {
trie := New(t.cache.db, t.Root)
for key, node := range t.cache.nodes {
trie.cache.nodes[key] = node.Copy()
}
return trie
}
// Save the cached value to the database.
func (t *Trie) Sync() {
t.cache.Commit()
t.prevRoot = copyRoot(t.Root)
}
func (t *Trie) Undo() {
t.cache.Undo()
t.Root = t.prevRoot
}
func (t *Trie) Cache() *Cache {
return t.cache
}
func (t *Trie) getState(node interface{}, key []byte) interface{} {
n := ethutil.NewValue(node)
// Return the node if key is empty (= found)
if len(key) == 0 || n.IsNil() || n.Len() == 0 {
return node
}
currentNode := t.getNode(node)
length := currentNode.Len()
if length == 0 {
return ""
} else if length == 2 {
// Decode the key
k := CompactDecode(currentNode.Get(0).Str())
v := currentNode.Get(1).Raw()
if len(key) >= len(k) && bytes.Equal(k, key[:len(k)]) { //CompareIntSlice(k, key[:len(k)]) {
return t.getState(v, key[len(k):])
} else {
return ""
}
} else if length == 17 {
return t.getState(currentNode.Get(int(key[0])).Raw(), key[1:])
}
// It shouldn't come this far
panic("unexpected return")
}
func (t *Trie) getNode(node interface{}) *ethutil.Value {
n := ethutil.NewValue(node)
if !n.Get(0).IsNil() {
return n
}
str := n.Str()
if len(str) == 0 {
return n
} else if len(str) < 32 {
return ethutil.NewValueFromBytes([]byte(str))
}
data := t.cache.Get(n.Bytes())
return data
}
func (t *Trie) UpdateState(node interface{}, key []byte, value string) interface{} {
return t.InsertState(node, key, value)
}
func (t *Trie) Put(node interface{}) interface{} {
return t.cache.Put(node)
}
func EmptyStringSlice(l int) []interface{} {
slice := make([]interface{}, l)
for i := 0; i < l; i++ {
slice[i] = ""
}
return slice
}
func (t *Trie) InsertState(node interface{}, key []byte, value interface{}) interface{} {
if len(key) == 0 {
return value
}
// New node
n := ethutil.NewValue(node)
if node == nil || n.Len() == 0 {
newNode := []interface{}{CompactEncode(key), value}
return t.Put(newNode)
}
currentNode := t.getNode(node)
// Check for "special" 2 slice type node
if currentNode.Len() == 2 {
// Decode the key
k := CompactDecode(currentNode.Get(0).Str())
v := currentNode.Get(1).Raw()
// Matching key pair (ie. there's already an object with this key)
if bytes.Equal(k, key) { //CompareIntSlice(k, key) {
newNode := []interface{}{CompactEncode(key), value}
return t.Put(newNode)
}
var newHash interface{}
matchingLength := MatchingNibbleLength(key, k)
if matchingLength == len(k) {
// Insert the hash, creating a new node
newHash = t.InsertState(v, key[matchingLength:], value)
} else {
// Expand the 2 length slice to a 17 length slice
oldNode := t.InsertState("", k[matchingLength+1:], v)
newNode := t.InsertState("", key[matchingLength+1:], value)
// Create an expanded slice
scaledSlice := EmptyStringSlice(17)
// Set the copied and new node
scaledSlice[k[matchingLength]] = oldNode
scaledSlice[key[matchingLength]] = newNode
newHash = t.Put(scaledSlice)
}
if matchingLength == 0 {
// End of the chain, return
return newHash
} else {
newNode := []interface{}{CompactEncode(key[:matchingLength]), newHash}
return t.Put(newNode)
}
} else {
// Copy the current node over to the new node and replace the first nibble in the key
newNode := EmptyStringSlice(17)
for i := 0; i < 17; i++ {
cpy := currentNode.Get(i).Raw()
if cpy != nil {
newNode[i] = cpy
}
}
newNode[key[0]] = t.InsertState(currentNode.Get(int(key[0])).Raw(), key[1:], value)
return t.Put(newNode)
}
panic("unexpected end")
}
func (t *Trie) deleteState(node interface{}, key []byte) interface{} {
if len(key) == 0 {
return ""
}
// New node
n := ethutil.NewValue(node)
//if node == nil || (n.Type() == reflect.String && (n.Str() == "" || n.Get(0).IsNil())) || n.Len() == 0 {
if node == nil || n.Len() == 0 {
//return nil
//fmt.Printf("<empty ret> %x %d\n", n, len(n.Bytes()))
return ""
}
currentNode := t.getNode(node)
// Check for "special" 2 slice type node
if currentNode.Len() == 2 {
// Decode the key
k := CompactDecode(currentNode.Get(0).Str())
v := currentNode.Get(1).Raw()
// Matching key pair (ie. there's already an object with this key)
if bytes.Equal(k, key) { //CompareIntSlice(k, key) {
//fmt.Printf("<delete ret> %x\n", v)
return ""
} else if bytes.Equal(key[:len(k)], k) { //CompareIntSlice(key[:len(k)], k) {
hash := t.deleteState(v, key[len(k):])
child := t.getNode(hash)
var newNode []interface{}
if child.Len() == 2 {
newKey := append(k, CompactDecode(child.Get(0).Str())...)
newNode = []interface{}{CompactEncode(newKey), child.Get(1).Raw()}
} else {
newNode = []interface{}{currentNode.Get(0).Str(), hash}
}
//fmt.Printf("%x\n", newNode)
return t.Put(newNode)
} else {
return node
}
} else {
// Copy the current node over to the new node and replace the first nibble in the key
n := EmptyStringSlice(17)
var newNode []interface{}
for i := 0; i < 17; i++ {
cpy := currentNode.Get(i).Raw()
if cpy != nil {
n[i] = cpy
}
}
n[key[0]] = t.deleteState(n[key[0]], key[1:])
amount := -1
for i := 0; i < 17; i++ {
if n[i] != "" {
if amount == -1 {
amount = i
} else {
amount = -2
}
}
}
if amount == 16 {
newNode = []interface{}{CompactEncode([]byte{16}), n[amount]}
} else if amount >= 0 {
child := t.getNode(n[amount])
if child.Len() == 17 {
newNode = []interface{}{CompactEncode([]byte{byte(amount)}), n[amount]}
} else if child.Len() == 2 {
key := append([]byte{byte(amount)}, CompactDecode(child.Get(0).Str())...)
newNode = []interface{}{CompactEncode(key), child.Get(1).Str()}
}
} else {
newNode = n
}
//fmt.Printf("%x\n", newNode)
return t.Put(newNode)
}
panic("unexpected return")
}
type TrieIterator struct {
trie *Trie
key string
value string
shas [][]byte
values []string
lastNode []byte
}
func (t *Trie) NewIterator() *TrieIterator {
return &TrieIterator{trie: t}
}
func (self *Trie) Iterator() *Iterator {
return NewIterator(self)
}
// Some time in the near future this will need refactoring :-)
// XXX Note to self, IsSlice == inline node. Str == sha3 to node
func (it *TrieIterator) workNode(currentNode *ethutil.Value) {
if currentNode.Len() == 2 {
k := CompactDecode(currentNode.Get(0).Str())
if currentNode.Get(1).Str() == "" {
it.workNode(currentNode.Get(1))
} else {
if k[len(k)-1] == 16 {
it.values = append(it.values, currentNode.Get(1).Str())
} else {
it.shas = append(it.shas, currentNode.Get(1).Bytes())
it.getNode(currentNode.Get(1).Bytes())
}
}
} else {
for i := 0; i < currentNode.Len(); i++ {
if i == 16 && currentNode.Get(i).Len() != 0 {
it.values = append(it.values, currentNode.Get(i).Str())
} else {
if currentNode.Get(i).Str() == "" {
it.workNode(currentNode.Get(i))
} else {
val := currentNode.Get(i).Str()
if val != "" {
it.shas = append(it.shas, currentNode.Get(1).Bytes())
it.getNode([]byte(val))
}
}
}
}
}
}
func (it *TrieIterator) getNode(node []byte) {
currentNode := it.trie.cache.Get(node)
it.workNode(currentNode)
}
func (it *TrieIterator) Collect() [][]byte {
if it.trie.Root == "" {
return nil
}
it.getNode(ethutil.NewValue(it.trie.Root).Bytes())
return it.shas
}
func (it *TrieIterator) Purge() int {
shas := it.Collect()
for _, sha := range shas {
it.trie.cache.Delete(sha)
}
return len(it.values)
}
func (it *TrieIterator) Key() string {
return ""
}
func (it *TrieIterator) Value() string {
return ""
}
type EachCallback func(key string, node *ethutil.Value)
func (it *TrieIterator) Each(cb EachCallback) {
it.fetchNode(nil, ethutil.NewValue(it.trie.Root).Bytes(), cb)
}
func (it *TrieIterator) fetchNode(key []byte, node []byte, cb EachCallback) {
it.iterateNode(key, it.trie.cache.Get(node), cb)
}
func (it *TrieIterator) iterateNode(key []byte, currentNode *ethutil.Value, cb EachCallback) {
if currentNode.Len() == 2 {
k := CompactDecode(currentNode.Get(0).Str())
pk := append(key, k...)
if currentNode.Get(1).Len() != 0 && currentNode.Get(1).Str() == "" {
it.iterateNode(pk, currentNode.Get(1), cb)
} else {
if k[len(k)-1] == 16 {
cb(DecodeCompact(pk), currentNode.Get(1))
} else {
it.fetchNode(pk, currentNode.Get(1).Bytes(), cb)
}
}
} else {
for i := 0; i < currentNode.Len(); i++ {
pk := append(key, byte(i))
if i == 16 && currentNode.Get(i).Len() != 0 {
cb(DecodeCompact(pk), currentNode.Get(i))
} else {
if currentNode.Get(i).Len() != 0 && currentNode.Get(i).Str() == "" {
it.iterateNode(pk, currentNode.Get(i), cb)
} else {
val := currentNode.Get(i).Str()
if val != "" {
it.fetchNode(pk, []byte(val), cb)
}
}
}
}
}
}
