package ptrie import ( "bytes" "sync" "github.com/ethereum/go-ethereum/crypto" "github.com/ethereum/go-ethereum/ethutil" "github.com/ethereum/go-ethereum/trie" ) type Backend interface { Get([]byte) []byte Set([]byte, []byte) } type Cache map[string][]byte func (self Cache) Get(key []byte) []byte { return self[string(key)] } func (self Cache) Set(key []byte, data []byte) { self[string(key)] = data } type Trie struct { mu sync.Mutex root Node roothash []byte backend Backend } func NewEmpty() *Trie { return &Trie{sync.Mutex{}, nil, nil, make(Cache)} } func New(root []byte, backend Backend) *Trie { trie := &Trie{} trie.roothash = root trie.backend = backend value := ethutil.NewValueFromBytes(trie.backend.Get(root)) trie.root = trie.mknode(value) return trie } // Legacy support func (self *Trie) Root() []byte { return self.Hash() } func (self *Trie) Hash() []byte { var hash []byte if self.root != nil { t := self.root.Hash() if byts, ok := t.([]byte); ok { hash = byts } else { hash = crypto.Sha3(ethutil.Encode(self.root.RlpData())) } } else { hash = crypto.Sha3(ethutil.Encode(self.root)) } self.roothash = hash return hash } func (self *Trie) UpdateString(key, value string) Node { return self.Update([]byte(key), []byte(value)) } func (self *Trie) Update(key, value []byte) Node { self.mu.Lock() defer self.mu.Unlock() k := trie.CompactHexDecode(string(key)) if len(value) != 0 { self.root = self.insert(self.root, k, &ValueNode{self, value}) } else { self.root = self.delete(self.root, k) } return self.root } func (self *Trie) GetString(key string) []byte { return self.Get([]byte(key)) } func (self *Trie) Get(key []byte) []byte { self.mu.Lock() defer self.mu.Unlock() k := trie.CompactHexDecode(string(key)) n := self.get(self.root, k) if n != nil { return n.(*ValueNode).Val() } return nil } func (self *Trie) DeleteString(key string) Node { return self.Delete([]byte(key)) } func (self *Trie) Delete(key []byte) Node { self.mu.Lock() defer self.mu.Unlock() k := trie.CompactHexDecode(string(key)) self.root = self.delete(self.root, k) return self.root } func (self *Trie) insert(node Node, key []byte, value Node) Node { if len(key) == 0 { return value } if node == nil { return NewShortNode(self, key, value) } switch node := node.(type) { case *ShortNode: k := node.Key() cnode := node.Value() if bytes.Equal(k, key) { return NewShortNode(self, key, value) } var n Node matchlength := trie.MatchingNibbleLength(key, k) if matchlength == len(k) { n = self.insert(cnode, key[matchlength:], value) } else { pnode := self.insert(nil, k[matchlength+1:], cnode) nnode := self.insert(nil, key[matchlength+1:], value) fulln := NewFullNode(self) fulln.set(k[matchlength], pnode) fulln.set(key[matchlength], nnode) n = fulln } if matchlength == 0 { return n } return NewShortNode(self, key[:matchlength], n) case *FullNode: cpy := node.Copy().(*FullNode) cpy.set(key[0], self.insert(node.get(key[0]), key[1:], value)) return cpy default: panic("Invalid node") } } func (self *Trie) get(node Node, key []byte) Node { if len(key) == 0 { return node } if node == nil { return nil } switch node := node.(type) { case *ShortNode: k := node.Key() cnode := node.Value() if len(key) >= len(k) && bytes.Equal(k, key[:len(k)]) { return self.get(cnode, key[len(k):]) } return nil case *FullNode: return self.get(node.get(key[0]), key[1:]) default: panic("Invalid node") } } func (self *Trie) delete(node Node, key []byte) Node { if len(key) == 0 { return nil } switch node := node.(type) { case *ShortNode: k := node.Key() cnode := node.Value() if bytes.Equal(key, k) { return nil } else if bytes.Equal(key[:len(k)], k) { child := self.delete(cnode, key[len(k):]) var n Node switch child := child.(type) { case *ShortNode: nkey := append(k, child.Key()...) n = NewShortNode(self, nkey, child.Value()) case *FullNode: n = NewShortNode(self, node.key, child) } return n } else { return node } case *FullNode: n := node.Copy().(*FullNode) n.set(key[0], self.delete(n.get(key[0]), key[1:])) pos := -1 for i := 0; i < 17; i++ { if n.get(byte(i)) != nil { if pos == -1 { pos = i } else { pos = -2 } } } var nnode Node if pos == 16 { nnode = NewShortNode(self, []byte{16}, n.get(byte(pos))) } else if pos >= 0 { cnode := n.get(byte(pos)) switch cnode := cnode.(type) { case *ShortNode: // Stitch keys k := append([]byte{byte(pos)}, cnode.Key()...) nnode = NewShortNode(self, k, cnode.Value()) case *FullNode: nnode = NewShortNode(self, []byte{byte(pos)}, n.get(byte(pos))) } } else { nnode = n } return nnode default: panic("Invalid node") } } // casting functions and cache storing func (self *Trie) mknode(value *ethutil.Value) Node { l := value.Len() switch l { case 2: return NewShortNode(self, trie.CompactDecode(string(value.Get(0).Bytes())), self.mknode(value.Get(1))) case 17: fnode := NewFullNode(self) for i := 0; i < l; i++ { fnode.set(byte(i), self.mknode(value.Get(i))) } return fnode case 32: return &HashNode{value.Bytes()} default: return &ValueNode{self, value.Bytes()} } } func (self *Trie) trans(node Node) Node { switch node := node.(type) { case *HashNode: value := ethutil.NewValueFromBytes(self.backend.Get(node.key)) return self.mknode(value) default: return node } } func (self *Trie) store(node Node) interface{} { data := ethutil.Encode(node) if len(data) >= 32 { key := crypto.Sha3(data) self.backend.Set(key, data) return key } return node.RlpData() }