Roy Crihfield
7381b35dc6
* use logrus instead of geth log * remove benchmarks * impl NodeIterator.ParentPath * update go mods
605 lines
19 KiB
Go
605 lines
19 KiB
Go
// Package trie implements Merkle Patricia Tries.
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package trie
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import (
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"bytes"
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"errors"
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"fmt"
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"github.com/ethereum/go-ethereum/common"
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"github.com/ethereum/go-ethereum/core/types"
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log "github.com/sirupsen/logrus"
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"github.com/ethereum/go-ethereum/statediff/indexer/ipld"
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)
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var (
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StateTrieCodec uint64 = ipld.MEthStateTrie
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StorageTrieCodec uint64 = ipld.MEthStorageTrie
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)
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// Trie is a Merkle Patricia Trie. Use New to create a trie that sits on
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// top of a database. Whenever trie performs a commit operation, the generated
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// nodes will be gathered and returned in a set. Once the trie is committed,
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// it's not usable anymore. Callers have to re-create the trie with new root
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// based on the updated trie database.
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//
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// Trie is not safe for concurrent use.
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type Trie struct {
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root node
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owner common.Hash
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// Keep track of the number leaves which have been inserted since the last
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// hashing operation. This number will not directly map to the number of
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// actually unhashed nodes.
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unhashed int
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// reader is the handler trie can retrieve nodes from.
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reader *trieReader
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// tracer is the tool to track the trie changes.
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// It will be reset after each commit operation.
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tracer *tracer
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}
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// newFlag returns the cache flag value for a newly created node.
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func (t *Trie) newFlag() nodeFlag {
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return nodeFlag{dirty: true}
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}
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// Copy returns a copy of Trie.
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func (t *Trie) Copy() *Trie {
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return &Trie{
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root: t.root,
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owner: t.owner,
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unhashed: t.unhashed,
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reader: t.reader,
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tracer: t.tracer.copy(),
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}
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}
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// New creates a trie instance with the provided trie id and the read-only
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// database. The state specified by trie id must be available, otherwise
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// an error will be returned. The trie root specified by trie id can be
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// zero hash or the sha3 hash of an empty string, then trie is initially
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// empty, otherwise, the root node must be present in database or returns
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// a MissingNodeError if not.
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func New(id *ID, db NodeReader, codec uint64) (*Trie, error) {
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reader, err := newTrieReader(id.StateRoot, id.Owner, db, codec)
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if err != nil {
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return nil, err
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}
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trie := &Trie{
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owner: id.Owner,
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reader: reader,
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tracer: newTracer(),
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}
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if id.Root != (common.Hash{}) && id.Root != types.EmptyRootHash {
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rootnode, err := trie.resolveAndTrack(id.Root[:], nil)
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if err != nil {
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return nil, err
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}
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trie.root = rootnode
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}
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return trie, nil
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}
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// NewEmpty is a shortcut to create empty tree. It's mostly used in tests.
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func NewEmpty(db *Database) *Trie {
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tr, err := New(TrieID(common.Hash{}), db, StateTrieCodec)
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if err != nil {
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panic(err)
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}
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return tr
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}
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// NodeIterator returns an iterator that returns nodes of the trie. Iteration starts at
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// the key after the given start key.
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func (t *Trie) NodeIterator(start []byte) NodeIterator {
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return newNodeIterator(t, start)
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}
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// Get returns the value for key stored in the trie.
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// The value bytes must not be modified by the caller.
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func (t *Trie) Get(key []byte) []byte {
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res, err := t.TryGet(key)
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if err != nil {
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log.Error("Unhandled trie error in Trie.Get", "err", err)
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}
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return res
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}
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// TryGet returns the value for key stored in the trie.
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// The value bytes must not be modified by the caller.
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// If a node was not found in the database, a MissingNodeError is returned.
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func (t *Trie) TryGet(key []byte) ([]byte, error) {
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value, newroot, didResolve, err := t.tryGet(t.root, keybytesToHex(key), 0)
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if err == nil && didResolve {
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t.root = newroot
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}
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return value, err
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}
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func (t *Trie) tryGet(origNode node, key []byte, pos int) (value []byte, newnode node, didResolve bool, err error) {
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switch n := (origNode).(type) {
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case nil:
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return nil, nil, false, nil
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case valueNode:
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return n, n, false, nil
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case *shortNode:
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if len(key)-pos < len(n.Key) || !bytes.Equal(n.Key, key[pos:pos+len(n.Key)]) {
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// key not found in trie
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return nil, n, false, nil
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}
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value, newnode, didResolve, err = t.tryGet(n.Val, key, pos+len(n.Key))
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if err == nil && didResolve {
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n = n.copy()
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n.Val = newnode
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}
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return value, n, didResolve, err
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case *fullNode:
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value, newnode, didResolve, err = t.tryGet(n.Children[key[pos]], key, pos+1)
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if err == nil && didResolve {
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n = n.copy()
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n.Children[key[pos]] = newnode
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}
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return value, n, didResolve, err
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case hashNode:
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child, err := t.resolveAndTrack(n, key[:pos])
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if err != nil {
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return nil, n, true, err
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}
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value, newnode, _, err := t.tryGet(child, key, pos)
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return value, newnode, true, err
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default:
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panic(fmt.Sprintf("%T: invalid node: %v", origNode, origNode))
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}
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}
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// TryGetNode attempts to retrieve a trie node by compact-encoded path. It is not
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// possible to use keybyte-encoding as the path might contain odd nibbles.
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func (t *Trie) TryGetNode(path []byte) ([]byte, int, error) {
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item, newroot, resolved, err := t.tryGetNode(t.root, compactToHex(path), 0)
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if err != nil {
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return nil, resolved, err
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}
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if resolved > 0 {
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t.root = newroot
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}
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if item == nil {
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return nil, resolved, nil
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}
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return item, resolved, err
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}
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func (t *Trie) tryGetNode(origNode node, path []byte, pos int) (item []byte, newnode node, resolved int, err error) {
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// If non-existent path requested, abort
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if origNode == nil {
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return nil, nil, 0, nil
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}
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// If we reached the requested path, return the current node
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if pos >= len(path) {
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// Although we most probably have the original node expanded, encoding
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// that into consensus form can be nasty (needs to cascade down) and
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// time consuming. Instead, just pull the hash up from disk directly.
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var hash hashNode
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if node, ok := origNode.(hashNode); ok {
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hash = node
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} else {
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hash, _ = origNode.cache()
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}
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if hash == nil {
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return nil, origNode, 0, errors.New("non-consensus node")
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}
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blob, err := t.reader.nodeBlob(path, common.BytesToHash(hash))
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return blob, origNode, 1, err
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}
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// Path still needs to be traversed, descend into children
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switch n := (origNode).(type) {
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case valueNode:
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// Path prematurely ended, abort
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return nil, nil, 0, nil
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case *shortNode:
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if len(path)-pos < len(n.Key) || !bytes.Equal(n.Key, path[pos:pos+len(n.Key)]) {
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// Path branches off from short node
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return nil, n, 0, nil
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}
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item, newnode, resolved, err = t.tryGetNode(n.Val, path, pos+len(n.Key))
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if err == nil && resolved > 0 {
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n = n.copy()
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n.Val = newnode
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}
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return item, n, resolved, err
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case *fullNode:
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item, newnode, resolved, err = t.tryGetNode(n.Children[path[pos]], path, pos+1)
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if err == nil && resolved > 0 {
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n = n.copy()
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n.Children[path[pos]] = newnode
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}
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return item, n, resolved, err
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case hashNode:
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child, err := t.resolveAndTrack(n, path[:pos])
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if err != nil {
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return nil, n, 1, err
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}
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item, newnode, resolved, err := t.tryGetNode(child, path, pos)
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return item, newnode, resolved + 1, err
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default:
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panic(fmt.Sprintf("%T: invalid node: %v", origNode, origNode))
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}
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}
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// Update associates key with value in the trie. Subsequent calls to
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// Get will return value. If value has length zero, any existing value
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// is deleted from the trie and calls to Get will return nil.
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//
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// The value bytes must not be modified by the caller while they are
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// stored in the trie.
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func (t *Trie) Update(key, value []byte) {
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if err := t.TryUpdate(key, value); err != nil {
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log.Error("Unhandled trie error in Trie.Update", "err", err)
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}
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}
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// TryUpdate associates key with value in the trie. Subsequent calls to
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// Get will return value. If value has length zero, any existing value
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// is deleted from the trie and calls to Get will return nil.
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//
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// The value bytes must not be modified by the caller while they are
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// stored in the trie.
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//
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// If a node was not found in the database, a MissingNodeError is returned.
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func (t *Trie) TryUpdate(key, value []byte) error {
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return t.tryUpdate(key, value)
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}
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// tryUpdate expects an RLP-encoded value and performs the core function
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// for TryUpdate and TryUpdateAccount.
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func (t *Trie) tryUpdate(key, value []byte) error {
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t.unhashed++
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k := keybytesToHex(key)
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if len(value) != 0 {
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_, n, err := t.insert(t.root, nil, k, valueNode(value))
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if err != nil {
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return err
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}
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t.root = n
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} else {
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_, n, err := t.delete(t.root, nil, k)
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if err != nil {
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return err
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}
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t.root = n
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}
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return nil
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}
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func (t *Trie) insert(n node, prefix, key []byte, value node) (bool, node, error) {
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if len(key) == 0 {
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if v, ok := n.(valueNode); ok {
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return !bytes.Equal(v, value.(valueNode)), value, nil
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}
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return true, value, nil
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}
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switch n := n.(type) {
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case *shortNode:
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matchlen := prefixLen(key, n.Key)
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// If the whole key matches, keep this short node as is
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// and only update the value.
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if matchlen == len(n.Key) {
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dirty, nn, err := t.insert(n.Val, append(prefix, key[:matchlen]...), key[matchlen:], value)
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if !dirty || err != nil {
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return false, n, err
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}
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return true, &shortNode{n.Key, nn, t.newFlag()}, nil
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}
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// Otherwise branch out at the index where they differ.
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branch := &fullNode{flags: t.newFlag()}
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var err error
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_, branch.Children[n.Key[matchlen]], err = t.insert(nil, append(prefix, n.Key[:matchlen+1]...), n.Key[matchlen+1:], n.Val)
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if err != nil {
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return false, nil, err
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}
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_, branch.Children[key[matchlen]], err = t.insert(nil, append(prefix, key[:matchlen+1]...), key[matchlen+1:], value)
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if err != nil {
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return false, nil, err
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}
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// Replace this shortNode with the branch if it occurs at index 0.
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if matchlen == 0 {
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return true, branch, nil
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}
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// New branch node is created as a child of the original short node.
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// Track the newly inserted node in the tracer. The node identifier
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// passed is the path from the root node.
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t.tracer.onInsert(append(prefix, key[:matchlen]...))
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// Replace it with a short node leading up to the branch.
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return true, &shortNode{key[:matchlen], branch, t.newFlag()}, nil
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case *fullNode:
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dirty, nn, err := t.insert(n.Children[key[0]], append(prefix, key[0]), key[1:], value)
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if !dirty || err != nil {
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return false, n, err
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}
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n = n.copy()
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n.flags = t.newFlag()
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n.Children[key[0]] = nn
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return true, n, nil
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case nil:
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// New short node is created and track it in the tracer. The node identifier
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// passed is the path from the root node. Note the valueNode won't be tracked
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// since it's always embedded in its parent.
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t.tracer.onInsert(prefix)
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return true, &shortNode{key, value, t.newFlag()}, nil
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case hashNode:
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// We've hit a part of the trie that isn't loaded yet. Load
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// the node and insert into it. This leaves all child nodes on
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// the path to the value in the trie.
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rn, err := t.resolveAndTrack(n, prefix)
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if err != nil {
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return false, nil, err
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}
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dirty, nn, err := t.insert(rn, prefix, key, value)
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if !dirty || err != nil {
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return false, rn, err
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}
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return true, nn, nil
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default:
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panic(fmt.Sprintf("%T: invalid node: %v", n, n))
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}
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}
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// Delete removes any existing value for key from the trie.
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func (t *Trie) Delete(key []byte) {
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if err := t.TryDelete(key); err != nil {
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log.Error("Unhandled trie error in Trie.Delete", "err", err)
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}
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}
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// TryDelete removes any existing value for key from the trie.
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// If a node was not found in the database, a MissingNodeError is returned.
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func (t *Trie) TryDelete(key []byte) error {
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t.unhashed++
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k := keybytesToHex(key)
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_, n, err := t.delete(t.root, nil, k)
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if err != nil {
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return err
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}
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t.root = n
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return nil
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}
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// delete returns the new root of the trie with key deleted.
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// It reduces the trie to minimal form by simplifying
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// nodes on the way up after deleting recursively.
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func (t *Trie) delete(n node, prefix, key []byte) (bool, node, error) {
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switch n := n.(type) {
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case *shortNode:
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matchlen := prefixLen(key, n.Key)
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if matchlen < len(n.Key) {
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return false, n, nil // don't replace n on mismatch
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}
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if matchlen == len(key) {
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// The matched short node is deleted entirely and track
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// it in the deletion set. The same the valueNode doesn't
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// need to be tracked at all since it's always embedded.
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t.tracer.onDelete(prefix)
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return true, nil, nil // remove n entirely for whole matches
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}
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// The key is longer than n.Key. Remove the remaining suffix
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// from the subtrie. Child can never be nil here since the
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// subtrie must contain at least two other values with keys
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// longer than n.Key.
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dirty, child, err := t.delete(n.Val, append(prefix, key[:len(n.Key)]...), key[len(n.Key):])
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if !dirty || err != nil {
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return false, n, err
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}
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switch child := child.(type) {
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case *shortNode:
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// The child shortNode is merged into its parent, track
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// is deleted as well.
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t.tracer.onDelete(append(prefix, n.Key...))
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// Deleting from the subtrie reduced it to another
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// short node. Merge the nodes to avoid creating a
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// shortNode{..., shortNode{...}}. Use concat (which
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// always creates a new slice) instead of append to
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// avoid modifying n.Key since it might be shared with
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// other nodes.
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return true, &shortNode{concat(n.Key, child.Key...), child.Val, t.newFlag()}, nil
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default:
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return true, &shortNode{n.Key, child, t.newFlag()}, nil
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}
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case *fullNode:
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dirty, nn, err := t.delete(n.Children[key[0]], append(prefix, key[0]), key[1:])
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if !dirty || err != nil {
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return false, n, err
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}
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n = n.copy()
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n.flags = t.newFlag()
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n.Children[key[0]] = nn
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// Because n is a full node, it must've contained at least two children
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// before the delete operation. If the new child value is non-nil, n still
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// has at least two children after the deletion, and cannot be reduced to
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// a short node.
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if nn != nil {
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return true, n, nil
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}
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// Reduction:
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// Check how many non-nil entries are left after deleting and
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// reduce the full node to a short node if only one entry is
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// left. Since n must've contained at least two children
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// before deletion (otherwise it would not be a full node) n
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// can never be reduced to nil.
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//
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// When the loop is done, pos contains the index of the single
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// value that is left in n or -2 if n contains at least two
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// values.
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pos := -1
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for i, cld := range &n.Children {
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if cld != nil {
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if pos == -1 {
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pos = i
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} else {
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pos = -2
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break
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}
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}
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}
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if pos >= 0 {
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if pos != 16 {
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// If the remaining entry is a short node, it replaces
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// n and its key gets the missing nibble tacked to the
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// front. This avoids creating an invalid
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// shortNode{..., shortNode{...}}. Since the entry
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// might not be loaded yet, resolve it just for this
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// check.
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cnode, err := t.resolve(n.Children[pos], append(prefix, byte(pos)))
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if err != nil {
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return false, nil, err
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}
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if cnode, ok := cnode.(*shortNode); ok {
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// Replace the entire full node with the short node.
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// Mark the original short node as deleted since the
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// value is embedded into the parent now.
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t.tracer.onDelete(append(prefix, byte(pos)))
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k := append([]byte{byte(pos)}, cnode.Key...)
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return true, &shortNode{k, cnode.Val, t.newFlag()}, nil
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}
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}
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// Otherwise, n is replaced by a one-nibble short node
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// containing the child.
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return true, &shortNode{[]byte{byte(pos)}, n.Children[pos], t.newFlag()}, nil
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}
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// n still contains at least two values and cannot be reduced.
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return true, n, nil
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case valueNode:
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return true, nil, nil
|
|
|
|
case nil:
|
|
return false, nil, nil
|
|
|
|
case hashNode:
|
|
// We've hit a part of the trie that isn't loaded yet. Load
|
|
// the node and delete from it. This leaves all child nodes on
|
|
// the path to the value in the trie.
|
|
rn, err := t.resolveAndTrack(n, prefix)
|
|
if err != nil {
|
|
return false, nil, err
|
|
}
|
|
dirty, nn, err := t.delete(rn, prefix, key)
|
|
if !dirty || err != nil {
|
|
return false, rn, err
|
|
}
|
|
return true, nn, nil
|
|
|
|
default:
|
|
panic(fmt.Sprintf("%T: invalid node: %v (%v)", n, n, key))
|
|
}
|
|
}
|
|
|
|
func concat(s1 []byte, s2 ...byte) []byte {
|
|
r := make([]byte, len(s1)+len(s2))
|
|
copy(r, s1)
|
|
copy(r[len(s1):], s2)
|
|
return r
|
|
}
|
|
|
|
func (t *Trie) resolve(n node, prefix []byte) (node, error) {
|
|
if n, ok := n.(hashNode); ok {
|
|
return t.resolveAndTrack(n, prefix)
|
|
}
|
|
return n, nil
|
|
}
|
|
|
|
// resolveAndTrack loads node from the underlying store with the given node hash
|
|
// and path prefix and also tracks the loaded node blob in tracer treated as the
|
|
// node's original value. The rlp-encoded blob is preferred to be loaded from
|
|
// database because it's easy to decode node while complex to encode node to blob.
|
|
func (t *Trie) resolveAndTrack(n hashNode, prefix []byte) (node, error) {
|
|
blob, err := t.reader.nodeBlob(prefix, common.BytesToHash(n))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
t.tracer.onRead(prefix, blob)
|
|
return mustDecodeNode(n, blob), nil
|
|
}
|
|
|
|
// Hash returns the root hash of the trie. It does not write to the
|
|
// database and can be used even if the trie doesn't have one.
|
|
func (t *Trie) Hash() common.Hash {
|
|
hash, cached := t.hashRoot()
|
|
t.root = cached
|
|
return common.BytesToHash(hash.(hashNode))
|
|
}
|
|
|
|
// Commit collects all dirty nodes in the trie and replaces them with the
|
|
// corresponding node hash. All collected nodes (including dirty leaves if
|
|
// collectLeaf is true) will be encapsulated into a nodeset for return.
|
|
// The returned nodeset can be nil if the trie is clean (nothing to commit).
|
|
// Once the trie is committed, it's not usable anymore. A new trie must
|
|
// be created with new root and updated trie database for following usage
|
|
func (t *Trie) Commit(collectLeaf bool) (common.Hash, *NodeSet) {
|
|
defer t.tracer.reset()
|
|
|
|
nodes := NewNodeSet(t.owner, t.tracer.accessList)
|
|
t.tracer.markDeletions(nodes)
|
|
|
|
// Trie is empty and can be classified into two types of situations:
|
|
// - The trie was empty and no update happens
|
|
// - The trie was non-empty and all nodes are dropped
|
|
if t.root == nil {
|
|
return types.EmptyRootHash, nodes
|
|
}
|
|
// Derive the hash for all dirty nodes first. We hold the assumption
|
|
// in the following procedure that all nodes are hashed.
|
|
rootHash := t.Hash()
|
|
|
|
// Do a quick check if we really need to commit. This can happen e.g.
|
|
// if we load a trie for reading storage values, but don't write to it.
|
|
if hashedNode, dirty := t.root.cache(); !dirty {
|
|
// Replace the root node with the origin hash in order to
|
|
// ensure all resolved nodes are dropped after the commit.
|
|
t.root = hashedNode
|
|
return rootHash, nil
|
|
}
|
|
t.root = newCommitter(nodes, collectLeaf).Commit(t.root)
|
|
return rootHash, nodes
|
|
}
|
|
|
|
// hashRoot calculates the root hash of the given trie
|
|
func (t *Trie) hashRoot() (node, node) {
|
|
if t.root == nil {
|
|
return hashNode(types.EmptyRootHash.Bytes()), nil
|
|
}
|
|
// If the number of changes is below 100, we let one thread handle it
|
|
h := newHasher(t.unhashed >= 100)
|
|
defer func() {
|
|
returnHasherToPool(h)
|
|
t.unhashed = 0
|
|
}()
|
|
hashed, cached := h.hash(t.root, true)
|
|
return hashed, cached
|
|
}
|
|
|
|
// Reset drops the referenced root node and cleans all internal state.
|
|
func (t *Trie) Reset() {
|
|
t.root = nil
|
|
t.owner = common.Hash{}
|
|
t.unhashed = 0
|
|
t.tracer.reset()
|
|
}
|