58 lines
2.0 KiB
Go
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
|
||
|
|
}
|