go-pulse/trie/notary.go
Péter Szilágyi 017831dd5b
core, eth: split eth package, implement snap protocol (#21482)
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
}