Merge pull request ethereum#26 from OffchainLabs/recordingdb

Recordingdb

arbitrum/recordingdb.go

@@ -0,0 +1,168 @@
+package arbitrum
+
+import (
+	"encoding/hex"
+	"errors"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/consensus"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/rawdb"
+	"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/log"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+type RecordingKV struct {
+	inner         *trie.Database
+	readDbEntries map[common.Hash][]byte
+	enableBypass  bool
+}
+
+func NewRecordingKV(inner *trie.Database) *RecordingKV {
+	return &RecordingKV{inner, make(map[common.Hash][]byte), false}
+}
+
+func (db *RecordingKV) Has(key []byte) (bool, error) {
+	if len(key) != 32 {
+		return false, nil
+	}
+	return false, errors.New("recording KV doesn't support Has")
+}
+
+func (db *RecordingKV) Get(key []byte) ([]byte, error) {
+	if len(key) != 32 {
+		return nil, fmt.Errorf("recording KV attempted to access non-hash key %v", hex.EncodeToString(key))
+	}
+	var hash common.Hash
+	copy(hash[:], key)
+	res, err := db.inner.Node(hash)
+	if err != nil {
+		return nil, err
+	}
+	if db.enableBypass {
+		return res, nil
+	}
+	if crypto.Keccak256Hash(res) != hash {
+		return nil, fmt.Errorf("recording KV attempted to access non-hash key %v", hash)
+	}
+	db.readDbEntries[hash] = res
+	return res, nil
+}
+
+func (db *RecordingKV) Put(key []byte, value []byte) error {
+	return errors.New("recording KV doesn't support Put")
+}
+
+func (db *RecordingKV) Delete(key []byte) error {
+	return errors.New("recording KV doesn't support Delete")
+}
+
+func (db *RecordingKV) NewBatch() ethdb.Batch {
+	if db.enableBypass {
+		return db.inner.DiskDB().NewBatch()
+	}
+	log.Error("recording KV: attempted to create batch when bypass not enabled")
+	return nil
+}
+
+func (db *RecordingKV) NewIterator(prefix []byte, start []byte) ethdb.Iterator {
+	if db.enableBypass {
+		return db.inner.DiskDB().NewIterator(prefix, start)
+	}
+	log.Error("recording KV: attempted to create iterator when bypass not enabled")
+	return nil
+}
+
+func (db *RecordingKV) Stat(property string) (string, error) {
+	return "", errors.New("recording KV doesn't support Stat")
+}
+
+func (db *RecordingKV) Compact(start []byte, limit []byte) error {
+	return nil
+}
+
+func (db *RecordingKV) Close() error {
+	return nil
+}
+
+func (db *RecordingKV) GetRecordedEntries() map[common.Hash][]byte {
+	return db.readDbEntries
+}
+func (db *RecordingKV) EnableBypass() {
+	db.enableBypass = true
+}
+
+type RecordingChainContext struct {
+	bc                     core.ChainContext
+	minBlockNumberAccessed uint64
+	initialBlockNumber     uint64
+}
+
+func NewRecordingChainContext(inner core.ChainContext, blocknumber uint64) *RecordingChainContext {
+	return &RecordingChainContext{
+		bc:                     inner,
+		minBlockNumberAccessed: blocknumber,
+		initialBlockNumber:     blocknumber,
+	}
+}
+
+func (r *RecordingChainContext) Engine() consensus.Engine {
+	return r.bc.Engine()
+}
+
+func (r *RecordingChainContext) GetHeader(hash common.Hash, num uint64) *types.Header {
+	if num == 0 {
+		return nil
+	}
+	if num < r.minBlockNumberAccessed {
+		r.minBlockNumberAccessed = num
+	}
+	return r.bc.GetHeader(hash, num)
+}
+
+func (r *RecordingChainContext) GetMinBlockNumberAccessed() uint64 {
+	return r.minBlockNumberAccessed
+}
+
+func PrepareRecording(blockchain *core.BlockChain, lastBlockHeader *types.Header) (*state.StateDB, core.ChainContext, *RecordingKV, error) {
+	rawTrie := blockchain.StateCache().TrieDB()
+	recordingKeyValue := NewRecordingKV(rawTrie)
+	recordingStateDatabase := state.NewDatabase(rawdb.NewDatabase(recordingKeyValue))
+	recordingStateDb, err := state.New(lastBlockHeader.Root, recordingStateDatabase, nil)
+	if err != nil {
+		return nil, nil, nil, fmt.Errorf("failed to create recordingStateDb: %w", err)
+	}
+	if !lastBlockHeader.Number.IsUint64() {
+		return nil, nil, nil, errors.New("block number not uint64")
+	}
+	recordingChainContext := NewRecordingChainContext(blockchain, lastBlockHeader.Number.Uint64())
+	return recordingStateDb, recordingChainContext, recordingKeyValue, nil
+}
+
+func PreimagesFromRecording(chainContextIf core.ChainContext, recordingDb *RecordingKV) (map[common.Hash][]byte, error) {
+	entries := recordingDb.GetRecordedEntries()
+	recordingChainContext, ok := chainContextIf.(*RecordingChainContext)
+	if (recordingChainContext == nil) || (!ok) {
+		return nil, errors.New("recordingChainContext invalid")
+	}
+	blockchain, ok := recordingChainContext.bc.(*core.BlockChain)
+	if (blockchain == nil) || (!ok) {
+		return nil, errors.New("blockchain invalid")
+	}
+	for i := recordingChainContext.GetMinBlockNumberAccessed(); i <= recordingChainContext.initialBlockNumber; i++ {
+		header := blockchain.GetHeaderByNumber(i)
+		hash := header.Hash()
+		bytes, err := rlp.EncodeToBytes(header)
+		if err != nil {
+			panic(fmt.Sprintf("Error RLP encoding header: %v\n", err))
+		}
+		entries[hash] = bytes
+	}
+	return entries, nil
+}