diff --git a/core/state/dump.go b/core/state/dump.go index 6338ddf88d..ffa1a72832 100644 --- a/core/state/dump.go +++ b/core/state/dump.go @@ -45,7 +45,7 @@ func (self *StateDB) RawDump() Dump { Accounts: make(map[string]DumpAccount), } - it := trie.NewIterator(self.trie.NodeIterator()) + it := trie.NewIterator(self.trie.NodeIterator(nil)) for it.Next() { addr := self.trie.GetKey(it.Key) var data Account @@ -62,7 +62,7 @@ func (self *StateDB) RawDump() Dump { Code: common.Bytes2Hex(obj.Code(self.db)), Storage: make(map[string]string), } - storageIt := trie.NewIterator(obj.getTrie(self.db).NodeIterator()) + storageIt := trie.NewIterator(obj.getTrie(self.db).NodeIterator(nil)) for storageIt.Next() { account.Storage[common.Bytes2Hex(self.trie.GetKey(storageIt.Key))] = common.Bytes2Hex(storageIt.Value) } diff --git a/core/state/iterator.go b/core/state/iterator.go index d2dd5a74e6..a8a2722ae3 100644 --- a/core/state/iterator.go +++ b/core/state/iterator.go @@ -75,7 +75,7 @@ func (it *NodeIterator) step() error { } // Initialize the iterator if we've just started if it.stateIt == nil { - it.stateIt = it.state.trie.NodeIterator() + it.stateIt = it.state.trie.NodeIterator(nil) } // If we had data nodes previously, we surely have at least state nodes if it.dataIt != nil { @@ -118,7 +118,7 @@ func (it *NodeIterator) step() error { if err != nil { return err } - it.dataIt = dataTrie.NodeIterator() + it.dataIt = dataTrie.NodeIterator(nil) if !it.dataIt.Next(true) { it.dataIt = nil } diff --git a/core/state/statedb.go b/core/state/statedb.go index 24381ced5d..431f33e023 100644 --- a/core/state/statedb.go +++ b/core/state/statedb.go @@ -481,7 +481,7 @@ func (db *StateDB) ForEachStorage(addr common.Address, cb func(key, value common cb(h, value) } - it := trie.NewIterator(so.getTrie(db.db).NodeIterator()) + it := trie.NewIterator(so.getTrie(db.db).NodeIterator(nil)) for it.Next() { // ignore cached values key := common.BytesToHash(db.trie.GetKey(it.Key)) diff --git a/trie/iterator.go b/trie/iterator.go index fef5b2593f..26ae1d5ad7 100644 --- a/trie/iterator.go +++ b/trie/iterator.go @@ -19,10 +19,13 @@ package trie import ( "bytes" "container/heap" + "errors" "github.com/ethereum/go-ethereum/common" ) +var iteratorEnd = errors.New("end of iteration") + // Iterator is a key-value trie iterator that traverses a Trie. type Iterator struct { nodeIt NodeIterator @@ -79,25 +82,24 @@ 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) - child int // Child to be processed next + 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 - - err error // Failure set in case of an internal error in the iterator - - path []byte // Path to the current node + err error // Failure set in case of an internal error in the iterator + path []byte // Path to the current node } -// newNodeIterator creates an post-order trie iterator. -func newNodeIterator(trie *Trie) NodeIterator { +func newNodeIterator(trie *Trie, start []byte) NodeIterator { if trie.Hash() == emptyState { return new(nodeIterator) } - return &nodeIterator{trie: trie} + it := &nodeIterator{trie: trie} + it.seek(start) + return it } // Hash returns the hash of the current node @@ -147,6 +149,9 @@ func (it *nodeIterator) Path() []byte { // Error returns the error set in case of an internal error in the iterator func (it *nodeIterator) Error() error { + if it.err == iteratorEnd { + return nil + } return it.err } @@ -155,47 +160,54 @@ func (it *nodeIterator) Error() error { // 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 the iterator failed previously, don't do anything if it.err != nil { return false } // Otherwise step forward with the iterator and report any errors - if err := it.step(descend); err != nil { + state, parentIndex, path, err := it.peek(descend) + if err != nil { it.err = err return false } - return it.trie != nil + it.push(state, parentIndex, path) + return true } -// step moves the iterator to the next node of the trie. -func (it *nodeIterator) step(descend bool) error { - if it.trie == nil { - // Abort if we reached the end of the iteration - return nil +func (it *nodeIterator) seek(prefix []byte) { + // 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.peek(bytes.HasPrefix(key, it.path)) + if err != nil || bytes.Compare(path, key) >= 0 { + it.err = err + return + } + it.push(state, parentIndex, path) } +} + +// peek creates the next state of the iterator. +func (it *nodeIterator) peek(descend bool) (*nodeIteratorState, *int, []byte, error) { if len(it.stack) == 0 { // Initialize the iterator if we've just started. root := it.trie.Hash() - state := &nodeIteratorState{node: it.trie.root, child: -1} + state := &nodeIteratorState{node: it.trie.root, index: -1} if root != emptyRoot { state.hash = root } - it.stack = append(it.stack, state) - return nil + return state, nil, nil, nil } - if !descend { // If we're skipping children, pop the current node first - it.path = it.path[:it.stack[len(it.stack)-1].pathlen] - it.stack = it.stack[:len(it.stack)-1] + it.pop() } // Continue iteration to the next child -outer: for { if len(it.stack) == 0 { - it.trie = nil - return nil + return nil, nil, nil, iteratorEnd } parent := it.stack[len(it.stack)-1] ancestor := parent.hash @@ -203,63 +215,76 @@ outer: ancestor = parent.parent } if node, ok := parent.node.(*fullNode); ok { - // Full node, iterate over children - for parent.child++; parent.child < len(node.Children); parent.child++ { - child := node.Children[parent.child] + // Full node, move to the first non-nil child. + for i := parent.index + 1; i < len(node.Children); i++ { + child := node.Children[i] if child != nil { hash, _ := child.cache() - it.stack = append(it.stack, &nodeIteratorState{ + state := &nodeIteratorState{ hash: common.BytesToHash(hash), node: child, parent: ancestor, - child: -1, + index: -1, pathlen: len(it.path), - }) - it.path = append(it.path, byte(parent.child)) - break outer + } + path := append(it.path, byte(i)) + parent.index = i - 1 + return state, &parent.index, path, nil } } } else if node, ok := parent.node.(*shortNode); ok { // Short node, return the pointer singleton child - if parent.child < 0 { - parent.child++ + if parent.index < 0 { hash, _ := node.Val.cache() - it.stack = append(it.stack, &nodeIteratorState{ + state := &nodeIteratorState{ hash: common.BytesToHash(hash), node: node.Val, parent: ancestor, - child: -1, + index: -1, pathlen: len(it.path), - }) + } + var path []byte if hasTerm(node.Key) { - it.path = append(it.path, node.Key[:len(node.Key)-1]...) + path = append(it.path, node.Key[:len(node.Key)-1]...) } else { - it.path = append(it.path, node.Key...) + path = append(it.path, node.Key...) } - break + return state, &parent.index, path, nil } } else if hash, ok := parent.node.(hashNode); ok { // Hash node, resolve the hash child from the database - if parent.child < 0 { - parent.child++ + if parent.index < 0 { node, err := it.trie.resolveHash(hash, nil, nil) if err != nil { - return err + return it.stack[len(it.stack)-1], &parent.index, it.path, err } - it.stack = append(it.stack, &nodeIteratorState{ + state := &nodeIteratorState{ hash: common.BytesToHash(hash), node: node, parent: ancestor, - child: -1, + index: -1, pathlen: len(it.path), - }) - break + } + return state, &parent.index, it.path, nil } } - it.path = it.path[:parent.pathlen] - it.stack = it.stack[:len(it.stack)-1] + // No more child nodes, move back up. + it.pop() } - return nil +} + +func (it *nodeIterator) push(state *nodeIteratorState, parentIndex *int, path []byte) { + it.path = path + it.stack = append(it.stack, state) + if parentIndex != nil { + *parentIndex += 1 + } +} + +func (it *nodeIterator) pop() { + parent := it.stack[len(it.stack)-1] + it.path = it.path[:parent.pathlen] + it.stack = it.stack[:len(it.stack)-1] } func compareNodes(a, b NodeIterator) int { diff --git a/trie/iterator_test.go b/trie/iterator_test.go index 04d51aaf5f..f161fd99d8 100644 --- a/trie/iterator_test.go +++ b/trie/iterator_test.go @@ -17,6 +17,8 @@ package trie import ( + "bytes" + "fmt" "testing" "github.com/ethereum/go-ethereum/common" @@ -42,7 +44,7 @@ func TestIterator(t *testing.T) { trie.Commit() found := make(map[string]string) - it := NewIterator(trie.NodeIterator()) + it := NewIterator(trie.NodeIterator(nil)) for it.Next() { found[string(it.Key)] = string(it.Value) } @@ -72,7 +74,7 @@ func TestIteratorLargeData(t *testing.T) { vals[string(value2.k)] = value2 } - it := NewIterator(trie.NodeIterator()) + it := NewIterator(trie.NodeIterator(nil)) for it.Next() { vals[string(it.Key)].t = true } @@ -99,7 +101,7 @@ func TestNodeIteratorCoverage(t *testing.T) { // Gather all the node hashes found by the iterator hashes := make(map[common.Hash]struct{}) - for it := trie.NodeIterator(); it.Next(true); { + for it := trie.NodeIterator(nil); it.Next(true); { if it.Hash() != (common.Hash{}) { hashes[it.Hash()] = struct{}{} } @@ -117,18 +119,20 @@ func TestNodeIteratorCoverage(t *testing.T) { } } -var testdata1 = []struct{ k, v string }{ - {"bar", "b"}, +type kvs struct{ k, v string } + +var testdata1 = []kvs{ {"barb", "ba"}, - {"bars", "bb"}, {"bard", "bc"}, + {"bars", "bb"}, + {"bar", "b"}, {"fab", "z"}, - {"foo", "a"}, {"food", "ab"}, {"foos", "aa"}, + {"foo", "a"}, } -var testdata2 = []struct{ k, v string }{ +var testdata2 = []kvs{ {"aardvark", "c"}, {"bar", "b"}, {"barb", "bd"}, @@ -140,6 +144,47 @@ var testdata2 = []struct{ k, v string }{ {"jars", "d"}, } +func TestIteratorSeek(t *testing.T) { + trie := newEmpty() + for _, val := range testdata1 { + trie.Update([]byte(val.k), []byte(val.v)) + } + + // Seek to the middle. + it := NewIterator(trie.NodeIterator([]byte("fab"))) + if err := checkIteratorOrder(testdata1[4:], it); err != nil { + t.Fatal(err) + } + + // Seek to a non-existent key. + it = NewIterator(trie.NodeIterator([]byte("barc"))) + if err := checkIteratorOrder(testdata1[1:], it); err != nil { + t.Fatal(err) + } + + // Seek beyond the end. + it = NewIterator(trie.NodeIterator([]byte("z"))) + if err := checkIteratorOrder(nil, it); err != nil { + t.Fatal(err) + } +} + +func checkIteratorOrder(want []kvs, it *Iterator) error { + for it.Next() { + if len(want) == 0 { + return fmt.Errorf("didn't expect any more values, got key %q", it.Key) + } + if !bytes.Equal(it.Key, []byte(want[0].k)) { + return fmt.Errorf("wrong key: got %q, want %q", it.Key, want[0].k) + } + want = want[1:] + } + if len(want) > 0 { + return fmt.Errorf("iterator ended early, want key %q", want[0]) + } + return nil +} + func TestDifferenceIterator(t *testing.T) { triea := newEmpty() for _, val := range testdata1 { @@ -154,7 +199,7 @@ func TestDifferenceIterator(t *testing.T) { trieb.Commit() found := make(map[string]string) - di, _ := NewDifferenceIterator(triea.NodeIterator(), trieb.NodeIterator()) + di, _ := NewDifferenceIterator(triea.NodeIterator(nil), trieb.NodeIterator(nil)) it := NewIterator(di) for it.Next() { found[string(it.Key)] = string(it.Value) @@ -189,7 +234,7 @@ func TestUnionIterator(t *testing.T) { } trieb.Commit() - di, _ := NewUnionIterator([]NodeIterator{triea.NodeIterator(), trieb.NodeIterator()}) + di, _ := NewUnionIterator([]NodeIterator{triea.NodeIterator(nil), trieb.NodeIterator(nil)}) it := NewIterator(di) all := []struct{ k, v string }{ diff --git a/trie/secure_trie.go b/trie/secure_trie.go index 201716d189..37d1d4b092 100644 --- a/trie/secure_trie.go +++ b/trie/secure_trie.go @@ -156,8 +156,10 @@ func (t *SecureTrie) Root() []byte { return t.trie.Root() } -func (t *SecureTrie) NodeIterator() NodeIterator { - return t.trie.NodeIterator() +// NodeIterator returns an iterator that returns nodes of the underlying trie. Iteration +// starts at the key after the given start key. +func (t *SecureTrie) NodeIterator(start []byte) NodeIterator { + return t.trie.NodeIterator(start) } // CommitTo writes all nodes and the secure hash pre-images to the given database. diff --git a/trie/sync_test.go b/trie/sync_test.go index 6d345ad3f4..1e27cbb676 100644 --- a/trie/sync_test.go +++ b/trie/sync_test.go @@ -80,7 +80,7 @@ func checkTrieConsistency(db Database, root common.Hash) error { if err != nil { return nil // // Consider a non existent state consistent } - it := trie.NodeIterator() + it := trie.NodeIterator(nil) for it.Next(true) { } return it.Error() diff --git a/trie/trie.go b/trie/trie.go index dbffc0ac3f..5759f97e3a 100644 --- a/trie/trie.go +++ b/trie/trie.go @@ -125,9 +125,10 @@ func New(root common.Hash, db Database) (*Trie, error) { return trie, nil } -// Iterator returns an iterator over all mappings in the trie. -func (t *Trie) NodeIterator() NodeIterator { - return newNodeIterator(t) +// NodeIterator returns an iterator that returns nodes of the trie. Iteration starts at +// the key after the given start key. +func (t *Trie) NodeIterator(start []byte) NodeIterator { + return newNodeIterator(t, start) } // Get returns the value for key stored in the trie. diff --git a/trie/trie_test.go b/trie/trie_test.go index cacb088244..61adbba0ca 100644 --- a/trie/trie_test.go +++ b/trie/trie_test.go @@ -439,7 +439,7 @@ func runRandTest(rt randTest) bool { tr = newtr case opItercheckhash: checktr, _ := New(common.Hash{}, nil) - it := NewIterator(tr.NodeIterator()) + it := NewIterator(tr.NodeIterator(nil)) for it.Next() { checktr.Update(it.Key, it.Value) }