1package statedb
  2
  3import (
  4	"errors"
  5	"fmt"
  6	"math/big"
  7
  8	"github.com/hermeznetwork/hermez-node/common"
  9	"github.com/hermeznetwork/hermez-node/db/kvdb"
 10	"github.com/hermeznetwork/hermez-node/log"
 11	"github.com/hermeznetwork/tracerr"
 12	"github.com/iden3/go-merkletree"
 13	"github.com/iden3/go-merkletree/db"
 14)
 15
 16var (
 17	// ErrStateDBWithoutMT is used when a method that requires a MerkleTree
 18	// is called in a StateDB that does not have a MerkleTree defined
 19	ErrStateDBWithoutMT = errors.New("Can not call method to use MerkleTree in a StateDB without MerkleTree")
 20
 21	// ErrAccountAlreadyExists is used when CreateAccount is called and the
 22	// Account already exists
 23	ErrAccountAlreadyExists = errors.New("Can not CreateAccount because Account already exists")
 24
 25	// ErrIdxNotFound is used when trying to get the Idx from EthAddr or
 26	// EthAddr&ToBJJ
 27	ErrIdxNotFound = errors.New("Idx can not be found")
 28	// ErrGetIdxNoCase is used when trying to get the Idx from EthAddr &
 29	// BJJ with not compatible combination
 30	ErrGetIdxNoCase = errors.New("Can not get Idx due unexpected combination of ethereum Address & BabyJubJub PublicKey")
 31
 32	// PrefixKeyIdx is the key prefix for idx in the db
 33	PrefixKeyIdx = []byte("i:")
 34	// PrefixKeyAccHash is the key prefix for account hash in the db
 35	PrefixKeyAccHash = []byte("h:")
 36	// PrefixKeyMT is the key prefix for merkle tree in the db
 37	PrefixKeyMT = []byte("m:")
 38	// PrefixKeyAddr is the key prefix for address in the db
 39	PrefixKeyAddr = []byte("a:")
 40	// PrefixKeyAddrBJJ is the key prefix for address-babyjubjub in the db
 41	PrefixKeyAddrBJJ = []byte("ab:")
 42)
 43
 44const (
 45	// TypeSynchronizer defines a StateDB used by the Synchronizer, that
 46	// generates the ExitTree when processing the txs
 47	TypeSynchronizer = "synchronizer"
 48	// TypeTxSelector defines a StateDB used by the TxSelector, without
 49	// computing ExitTree neither the ZKInputs
 50	TypeTxSelector = "txselector"
 51	// TypeBatchBuilder defines a StateDB used by the BatchBuilder, that
 52	// generates the ExitTree and the ZKInput when processing the txs
 53	TypeBatchBuilder = "batchbuilder"
 54)
 55
 56// TypeStateDB determines the type of StateDB
 57type TypeStateDB string
 58
 59// StateDB represents the StateDB object
 60type StateDB struct {
 61	path string
 62	Typ  TypeStateDB
 63	db   *kvdb.KVDB
 64	MT   *merkletree.MerkleTree
 65	keep int
 66}
 67
 68// NewStateDB creates a new StateDB, allowing to use an in-memory or in-disk
 69// storage.  Checkpoints older than the value defined by `keep` will be
 70// deleted.
 71func NewStateDB(pathDB string, keep int, typ TypeStateDB, nLevels int) (*StateDB, error) {
 72	var kv *kvdb.KVDB
 73	var err error
 74
 75	kv, err = kvdb.NewKVDB(pathDB, keep)
 76	if err != nil {
 77		return nil, tracerr.Wrap(err)
 78	}
 79
 80	var mt *merkletree.MerkleTree = nil
 81	if typ == TypeSynchronizer || typ == TypeBatchBuilder {
 82		mt, err = merkletree.NewMerkleTree(kv.StorageWithPrefix(PrefixKeyMT), nLevels)
 83		if err != nil {
 84			return nil, tracerr.Wrap(err)
 85		}
 86	}
 87	if typ == TypeTxSelector && nLevels != 0 {
 88		return nil, tracerr.Wrap(fmt.Errorf("invalid StateDB parameters: StateDB type==TypeStateDB can not have nLevels!=0"))
 89	}
 90
 91	return &StateDB{
 92		path: pathDB,
 93		db:   kv,
 94		MT:   mt,
 95		Typ:  typ,
 96		keep: keep,
 97	}, nil
 98}
 99
100// MakeCheckpoint does a checkpoint at the given batchNum in the defined path.
101// Internally this advances & stores the current BatchNum, and then stores a
102// Checkpoint of the current state of the StateDB.
103func (s *StateDB) MakeCheckpoint() error {
104	log.Debugw("Making StateDB checkpoint", "batch", s.CurrentBatch()+1, "type", s.Typ)
105	return s.db.MakeCheckpoint()
106}
107
108// CurrentBatch returns the current in-memory CurrentBatch of the StateDB.db
109func (s *StateDB) CurrentBatch() common.BatchNum {
110	return s.db.CurrentBatch
111}
112
113// CurrentIdx returns the current in-memory CurrentIdx of the StateDB.db
114func (s *StateDB) CurrentIdx() common.Idx {
115	return s.db.CurrentIdx
116}
117
118// GetCurrentBatch returns the current BatchNum stored in the StateDB.db
119func (s *StateDB) GetCurrentBatch() (common.BatchNum, error) {
120	return s.db.GetCurrentBatch()
121}
122
123// GetCurrentIdx returns the stored Idx from the localStateDB, which is the
124// last Idx used for an Account in the localStateDB.
125func (s *StateDB) GetCurrentIdx() (common.Idx, error) {
126	return s.db.GetCurrentIdx()
127}
128
129// SetCurrentIdx stores Idx in the StateDB
130func (s *StateDB) SetCurrentIdx(idx common.Idx) error {
131	return s.db.SetCurrentIdx(idx)
132}
133
134// Reset resets the StateDB to the checkpoint at the given batchNum. Reset
135// does not delete the checkpoints between old current and the new current,
136// those checkpoints will remain in the storage, and eventually will be
137// deleted when MakeCheckpoint overwrites them.
138func (s *StateDB) Reset(batchNum common.BatchNum) error {
139	err := s.db.Reset(batchNum)
140	if err != nil {
141		return tracerr.Wrap(err)
142	}
143	if s.MT != nil {
144		// open the MT for the current s.db
145		mt, err := merkletree.NewMerkleTree(s.db.StorageWithPrefix(PrefixKeyMT), s.MT.MaxLevels())
146		if err != nil {
147			return tracerr.Wrap(err)
148		}
149		s.MT = mt
150	}
151	log.Debugw("Making StateDB Reset", "batch", batchNum)
152	return nil
153}
154
155// GetAccount returns the account for the given Idx
156func (s *StateDB) GetAccount(idx common.Idx) (*common.Account, error) {
157	return GetAccountInTreeDB(s.db.DB(), idx)
158}
159
160// GetAccounts returns all the accounts in the db.  Use for debugging pruposes
161// only.
162func (s *StateDB) GetAccounts() ([]common.Account, error) {
163	idxDB := s.db.StorageWithPrefix(PrefixKeyIdx)
164	idxs := []common.Idx{}
165	// NOTE: Current implementation of Iterate in the pebble interface is
166	// not efficient, as it iterates over all keys.  Improve it following
167	// this example: https://github.com/cockroachdb/pebble/pull/923/files
168	if err := idxDB.Iterate(func(k []byte, v []byte) (bool, error) {
169		idx, err := common.IdxFromBytes(k)
170		if err != nil {
171			return false, tracerr.Wrap(err)
172		}
173		idxs = append(idxs, idx)
174		return true, nil
175	}); err != nil {
176		return nil, tracerr.Wrap(err)
177	}
178	accs := []common.Account{}
179	for i := range idxs {
180		acc, err := s.GetAccount(idxs[i])
181		if err != nil {
182			return nil, tracerr.Wrap(err)
183		}
184		accs = append(accs, *acc)
185	}
186	return accs, nil
187}
188
189// GetAccountInTreeDB is abstracted from StateDB to be used from StateDB and
190// from ExitTree.  GetAccount returns the account for the given Idx
191func GetAccountInTreeDB(sto db.Storage, idx common.Idx) (*common.Account, error) {
192	idxBytes, err := idx.Bytes()
193	if err != nil {
194		return nil, tracerr.Wrap(err)
195	}
196	vBytes, err := sto.Get(append(PrefixKeyIdx, idxBytes[:]...))
197	if err != nil {
198		return nil, tracerr.Wrap(err)
199	}
200	accBytes, err := sto.Get(append(PrefixKeyAccHash, vBytes...))
201	if err != nil {
202		return nil, tracerr.Wrap(err)
203	}
204	var b [32 * common.NLeafElems]byte
205	copy(b[:], accBytes)
206	account, err := common.AccountFromBytes(b)
207	if err != nil {
208		return nil, tracerr.Wrap(err)
209	}
210	account.Idx = idx
211	return account, nil
212}
213
214// CreateAccount creates a new Account in the StateDB for the given Idx.  If
215// StateDB.MT==nil, MerkleTree is not affected, otherwise updates the
216// MerkleTree, returning a CircomProcessorProof.
217func (s *StateDB) CreateAccount(idx common.Idx, account *common.Account) (*merkletree.CircomProcessorProof, error) {
218	cpp, err := CreateAccountInTreeDB(s.db.DB(), s.MT, idx, account)
219	if err != nil {
220		return cpp, tracerr.Wrap(err)
221	}
222	// store idx by EthAddr & BJJ
223	err = s.setIdxByEthAddrBJJ(idx, account.EthAddr, account.BJJ, account.TokenID)
224	return cpp, tracerr.Wrap(err)
225}
226
227// CreateAccountInTreeDB is abstracted from StateDB to be used from StateDB and
228// from ExitTree.  Creates a new Account in the StateDB for the given Idx.  If
229// StateDB.MT==nil, MerkleTree is not affected, otherwise updates the
230// MerkleTree, returning a CircomProcessorProof.
231func CreateAccountInTreeDB(sto db.Storage, mt *merkletree.MerkleTree, idx common.Idx, account *common.Account) (*merkletree.CircomProcessorProof, error) {
232	// store at the DB the key: v, and value: leaf.Bytes()
233	v, err := account.HashValue()
234	if err != nil {
235		return nil, tracerr.Wrap(err)
236	}
237	accountBytes, err := account.Bytes()
238	if err != nil {
239		return nil, tracerr.Wrap(err)
240	}
241
242	// store the Leaf value
243	tx, err := sto.NewTx()
244	if err != nil {
245		return nil, tracerr.Wrap(err)
246	}
247
248	idxBytes, err := idx.Bytes()
249	if err != nil {
250		return nil, tracerr.Wrap(err)
251	}
252	_, err = tx.Get(append(PrefixKeyIdx, idxBytes[:]...))
253	if tracerr.Unwrap(err) != db.ErrNotFound {
254		return nil, tracerr.Wrap(ErrAccountAlreadyExists)
255	}
256
257	err = tx.Put(append(PrefixKeyAccHash, v.Bytes()...), accountBytes[:])
258	if err != nil {
259		return nil, tracerr.Wrap(err)
260	}
261	err = tx.Put(append(PrefixKeyIdx, idxBytes[:]...), v.Bytes())
262	if err != nil {
263		return nil, tracerr.Wrap(err)
264	}
265
266	if err := tx.Commit(); err != nil {
267		return nil, tracerr.Wrap(err)
268	}
269
270	if mt != nil {
271		return mt.AddAndGetCircomProof(idx.BigInt(), v)
272	}
273
274	return nil, nil
275}
276
277// UpdateAccount updates the Account in the StateDB for the given Idx.  If
278// StateDB.mt==nil, MerkleTree is not affected, otherwise updates the
279// MerkleTree, returning a CircomProcessorProof.
280func (s *StateDB) UpdateAccount(idx common.Idx, account *common.Account) (*merkletree.CircomProcessorProof, error) {
281	return UpdateAccountInTreeDB(s.db.DB(), s.MT, idx, account)
282}
283
284// UpdateAccountInTreeDB is abstracted from StateDB to be used from StateDB and
285// from ExitTree.  Updates the Account in the StateDB for the given Idx.  If
286// StateDB.mt==nil, MerkleTree is not affected, otherwise updates the
287// MerkleTree, returning a CircomProcessorProof.
288func UpdateAccountInTreeDB(sto db.Storage, mt *merkletree.MerkleTree, idx common.Idx, account *common.Account) (*merkletree.CircomProcessorProof, error) {
289	// store at the DB the key: v, and value: account.Bytes()
290	v, err := account.HashValue()
291	if err != nil {
292		return nil, tracerr.Wrap(err)
293	}
294	accountBytes, err := account.Bytes()
295	if err != nil {
296		return nil, tracerr.Wrap(err)
297	}
298
299	tx, err := sto.NewTx()
300	if err != nil {
301		return nil, tracerr.Wrap(err)
302	}
303	err = tx.Put(append(PrefixKeyAccHash, v.Bytes()...), accountBytes[:])
304	if err != nil {
305		return nil, tracerr.Wrap(err)
306	}
307	idxBytes, err := idx.Bytes()
308	if err != nil {
309		return nil, tracerr.Wrap(err)
310	}
311	err = tx.Put(append(PrefixKeyIdx, idxBytes[:]...), v.Bytes())
312	if err != nil {
313		return nil, tracerr.Wrap(err)
314	}
315
316	if err := tx.Commit(); err != nil {
317		return nil, tracerr.Wrap(err)
318	}
319
320	if mt != nil {
321		proof, err := mt.Update(idx.BigInt(), v)
322		return proof, tracerr.Wrap(err)
323	}
324	return nil, nil
325}
326
327// MTGetProof returns the CircomVerifierProof for a given Idx
328func (s *StateDB) MTGetProof(idx common.Idx) (*merkletree.CircomVerifierProof, error) {
329	if s.MT == nil {
330		return nil, tracerr.Wrap(ErrStateDBWithoutMT)
331	}
332	p, err := s.MT.GenerateSCVerifierProof(idx.BigInt(), s.MT.Root())
333	if err != nil {
334		return nil, tracerr.Wrap(err)
335	}
336	return p, nil
337}
338
339// MTGetRoot returns the current root of the underlying Merkle Tree
340func (s *StateDB) MTGetRoot() *big.Int {
341	return s.MT.Root().BigInt()
342}
343
344// LocalStateDB represents the local StateDB which allows to make copies from
345// the synchronizer StateDB, and is used by the tx-selector and the
346// batch-builder. LocalStateDB is an in-memory storage.
347type LocalStateDB struct {
348	*StateDB
349	synchronizerStateDB *StateDB
350}
351
352// NewLocalStateDB returns a new LocalStateDB connected to the given
353// synchronizerDB.  Checkpoints older than the value defined by `keep` will be
354// deleted.
355func NewLocalStateDB(path string, keep int, synchronizerDB *StateDB, typ TypeStateDB,
356	nLevels int) (*LocalStateDB, error) {
357	s, err := NewStateDB(path, keep, typ, nLevels)
358	if err != nil {
359		return nil, tracerr.Wrap(err)
360	}
361	return &LocalStateDB{
362		s,
363		synchronizerDB,
364	}, nil
365}
366
367// Reset performs a reset in the LocaStateDB. If fromSynchronizer is true, it
368// gets the state from LocalStateDB.synchronizerStateDB for the given batchNum.
369// If fromSynchronizer is false, get the state from LocalStateDB checkpoints.
370func (l *LocalStateDB) Reset(batchNum common.BatchNum, fromSynchronizer bool) error {
371	if fromSynchronizer {
372		err := l.db.ResetFromSynchronizer(batchNum, l.synchronizerStateDB.db)
373		if err != nil {
374			return tracerr.Wrap(err)
375		}
376		// open the MT for the current s.db
377		if l.MT != nil {
378			mt, err := merkletree.NewMerkleTree(l.db.StorageWithPrefix(PrefixKeyMT), l.MT.MaxLevels())
379			if err != nil {
380				return tracerr.Wrap(err)
381			}
382			l.MT = mt
383		}
384		return nil
385	}
386	// use checkpoint from LocalStateDB
387	return l.StateDB.Reset(batchNum)
388}