go-ethereum/trie/notary.go
Péter Szilágyi 017831dd5b
core, eth: split eth package, implement snap protocol ()
This commit splits the eth package, separating the handling of eth and snap protocols. It also includes the capability to run snap sync (https://github.com/ethereum/devp2p/blob/master/caps/snap.md) , but does not enable it by default. 

Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Martin Holst Swende <martin@swende.se>
2020-12-14 10:27:15 +01:00

58 lines
2.0 KiB
Go

// Copyright 2020 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 trie
import (
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/ethdb/memorydb"
)
// KeyValueNotary tracks which keys have been accessed through a key-value reader
// with te scope of verifying if certain proof datasets are maliciously bloated.
type KeyValueNotary struct {
ethdb.KeyValueReader
reads map[string]struct{}
}
// NewKeyValueNotary wraps a key-value database with an access notary to track
// which items have bene accessed.
func NewKeyValueNotary(db ethdb.KeyValueReader) *KeyValueNotary {
return &KeyValueNotary{
KeyValueReader: db,
reads: make(map[string]struct{}),
}
}
// Get retrieves an item from the underlying database, but also tracks it as an
// accessed slot for bloat checks.
func (k *KeyValueNotary) Get(key []byte) ([]byte, error) {
k.reads[string(key)] = struct{}{}
return k.KeyValueReader.Get(key)
}
// Accessed returns s snapshot of the original key-value store containing only the
// data accessed through the notary.
func (k *KeyValueNotary) Accessed() ethdb.KeyValueStore {
db := memorydb.New()
for keystr := range k.reads {
key := []byte(keystr)
val, _ := k.KeyValueReader.Get(key)
db.Put(key, val)
}
return db
}