plugeth/light/trie.go
Sheldon ca228569e4 light: odrTrie tryUpdate should use update (#18107)
TryUpdate does not call t.trie.TryUpdate(key, value) and calls t.trie.TryDelete
instead. The update operation simply deletes the corresponding entry, though
it could retrieve later by odr. However, it adds further network overhead.
2018-11-26 13:27:49 +01:00

244 lines
6.0 KiB
Go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library 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,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// 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/>.
package light
import (
"context"
"errors"
"fmt"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/trie"
)
func NewState(ctx context.Context, head *types.Header, odr OdrBackend) *state.StateDB {
state, _ := state.New(head.Root, NewStateDatabase(ctx, head, odr))
return state
}
func NewStateDatabase(ctx context.Context, head *types.Header, odr OdrBackend) state.Database {
return &odrDatabase{ctx, StateTrieID(head), odr}
}
type odrDatabase struct {
ctx context.Context
id *TrieID
backend OdrBackend
}
func (db *odrDatabase) OpenTrie(root common.Hash) (state.Trie, error) {
return &odrTrie{db: db, id: db.id}, nil
}
func (db *odrDatabase) OpenStorageTrie(addrHash, root common.Hash) (state.Trie, error) {
return &odrTrie{db: db, id: StorageTrieID(db.id, addrHash, root)}, nil
}
func (db *odrDatabase) CopyTrie(t state.Trie) state.Trie {
switch t := t.(type) {
case *odrTrie:
cpy := &odrTrie{db: t.db, id: t.id}
if t.trie != nil {
cpytrie := *t.trie
cpy.trie = &cpytrie
}
return cpy
default:
panic(fmt.Errorf("unknown trie type %T", t))
}
}
func (db *odrDatabase) ContractCode(addrHash, codeHash common.Hash) ([]byte, error) {
if codeHash == sha3_nil {
return nil, nil
}
if code, err := db.backend.Database().Get(codeHash[:]); err == nil {
return code, nil
}
id := *db.id
id.AccKey = addrHash[:]
req := &CodeRequest{Id: &id, Hash: codeHash}
err := db.backend.Retrieve(db.ctx, req)
return req.Data, err
}
func (db *odrDatabase) ContractCodeSize(addrHash, codeHash common.Hash) (int, error) {
code, err := db.ContractCode(addrHash, codeHash)
return len(code), err
}
func (db *odrDatabase) TrieDB() *trie.Database {
return nil
}
type odrTrie struct {
db *odrDatabase
id *TrieID
trie *trie.Trie
}
func (t *odrTrie) TryGet(key []byte) ([]byte, error) {
key = crypto.Keccak256(key)
var res []byte
err := t.do(key, func() (err error) {
res, err = t.trie.TryGet(key)
return err
})
return res, err
}
func (t *odrTrie) TryUpdate(key, value []byte) error {
key = crypto.Keccak256(key)
return t.do(key, func() error {
return t.trie.TryUpdate(key, value)
})
}
func (t *odrTrie) TryDelete(key []byte) error {
key = crypto.Keccak256(key)
return t.do(key, func() error {
return t.trie.TryDelete(key)
})
}
func (t *odrTrie) Commit(onleaf trie.LeafCallback) (common.Hash, error) {
if t.trie == nil {
return t.id.Root, nil
}
return t.trie.Commit(onleaf)
}
func (t *odrTrie) Hash() common.Hash {
if t.trie == nil {
return t.id.Root
}
return t.trie.Hash()
}
func (t *odrTrie) NodeIterator(startkey []byte) trie.NodeIterator {
return newNodeIterator(t, startkey)
}
func (t *odrTrie) GetKey(sha []byte) []byte {
return nil
}
func (t *odrTrie) Prove(key []byte, fromLevel uint, proofDb ethdb.Putter) error {
return errors.New("not implemented, needs client/server interface split")
}
// do tries and retries to execute a function until it returns with no error or
// an error type other than MissingNodeError
func (t *odrTrie) do(key []byte, fn func() error) error {
for {
var err error
if t.trie == nil {
t.trie, err = trie.New(t.id.Root, trie.NewDatabase(t.db.backend.Database()))
}
if err == nil {
err = fn()
}
if _, ok := err.(*trie.MissingNodeError); !ok {
return err
}
r := &TrieRequest{Id: t.id, Key: key}
if err := t.db.backend.Retrieve(t.db.ctx, r); err != nil {
return err
}
}
}
type nodeIterator struct {
trie.NodeIterator
t *odrTrie
err error
}
func newNodeIterator(t *odrTrie, startkey []byte) trie.NodeIterator {
it := &nodeIterator{t: t}
// Open the actual non-ODR trie if that hasn't happened yet.
if t.trie == nil {
it.do(func() error {
t, err := trie.New(t.id.Root, trie.NewDatabase(t.db.backend.Database()))
if err == nil {
it.t.trie = t
}
return err
})
}
it.do(func() error {
it.NodeIterator = it.t.trie.NodeIterator(startkey)
return it.NodeIterator.Error()
})
return it
}
func (it *nodeIterator) Next(descend bool) bool {
var ok bool
it.do(func() error {
ok = it.NodeIterator.Next(descend)
return it.NodeIterator.Error()
})
return ok
}
// do runs fn and attempts to fill in missing nodes by retrieving.
func (it *nodeIterator) do(fn func() error) {
var lasthash common.Hash
for {
it.err = fn()
missing, ok := it.err.(*trie.MissingNodeError)
if !ok {
return
}
if missing.NodeHash == lasthash {
it.err = fmt.Errorf("retrieve loop for trie node %x", missing.NodeHash)
return
}
lasthash = missing.NodeHash
r := &TrieRequest{Id: it.t.id, Key: nibblesToKey(missing.Path)}
if it.err = it.t.db.backend.Retrieve(it.t.db.ctx, r); it.err != nil {
return
}
}
}
func (it *nodeIterator) Error() error {
if it.err != nil {
return it.err
}
return it.NodeIterator.Error()
}
func nibblesToKey(nib []byte) []byte {
if len(nib) > 0 && nib[len(nib)-1] == 0x10 {
nib = nib[:len(nib)-1] // drop terminator
}
if len(nib)&1 == 1 {
nib = append(nib, 0) // make even
}
key := make([]byte, len(nib)/2)
for bi, ni := 0, 0; ni < len(nib); bi, ni = bi+1, ni+2 {
key[bi] = nib[ni]<<4 | nib[ni+1]
}
return key
}