github.com/myafeier/go-ethereum@v1.6.8-0.20170719123245-3e0dbe0eaa72/light/txpool.go (about) 1 // Copyright 2016 The go-ethereum Authors 2 // This file is part of the go-ethereum library. 3 // 4 // The go-ethereum library is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU Lesser General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // The go-ethereum library is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU Lesser General Public License for more details. 13 // 14 // You should have received a copy of the GNU Lesser General Public License 15 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. 16 17 package light 18 19 import ( 20 "context" 21 "fmt" 22 "sync" 23 "time" 24 25 "github.com/ethereum/go-ethereum/common" 26 "github.com/ethereum/go-ethereum/core" 27 "github.com/ethereum/go-ethereum/core/state" 28 "github.com/ethereum/go-ethereum/core/types" 29 "github.com/ethereum/go-ethereum/ethdb" 30 "github.com/ethereum/go-ethereum/event" 31 "github.com/ethereum/go-ethereum/log" 32 "github.com/ethereum/go-ethereum/params" 33 "github.com/ethereum/go-ethereum/rlp" 34 ) 35 36 // txPermanent is the number of mined blocks after a mined transaction is 37 // considered permanent and no rollback is expected 38 var txPermanent = uint64(500) 39 40 // TxPool implements the transaction pool for light clients, which keeps track 41 // of the status of locally created transactions, detecting if they are included 42 // in a block (mined) or rolled back. There are no queued transactions since we 43 // always receive all locally signed transactions in the same order as they are 44 // created. 45 type TxPool struct { 46 config *params.ChainConfig 47 signer types.Signer 48 quit chan bool 49 eventMux *event.TypeMux 50 events *event.TypeMuxSubscription 51 mu sync.RWMutex 52 chain *LightChain 53 odr OdrBackend 54 chainDb ethdb.Database 55 relay TxRelayBackend 56 head common.Hash 57 nonce map[common.Address]uint64 // "pending" nonce 58 pending map[common.Hash]*types.Transaction // pending transactions by tx hash 59 mined map[common.Hash][]*types.Transaction // mined transactions by block hash 60 clearIdx uint64 // earliest block nr that can contain mined tx info 61 62 homestead bool 63 } 64 65 // TxRelayBackend provides an interface to the mechanism that forwards transacions 66 // to the ETH network. The implementations of the functions should be non-blocking. 67 // 68 // Send instructs backend to forward new transactions 69 // NewHead notifies backend about a new head after processed by the tx pool, 70 // including mined and rolled back transactions since the last event 71 // Discard notifies backend about transactions that should be discarded either 72 // because they have been replaced by a re-send or because they have been mined 73 // long ago and no rollback is expected 74 type TxRelayBackend interface { 75 Send(txs types.Transactions) 76 NewHead(head common.Hash, mined []common.Hash, rollback []common.Hash) 77 Discard(hashes []common.Hash) 78 } 79 80 // NewTxPool creates a new light transaction pool 81 func NewTxPool(config *params.ChainConfig, eventMux *event.TypeMux, chain *LightChain, relay TxRelayBackend) *TxPool { 82 pool := &TxPool{ 83 config: config, 84 signer: types.HomesteadSigner{}, 85 nonce: make(map[common.Address]uint64), 86 pending: make(map[common.Hash]*types.Transaction), 87 mined: make(map[common.Hash][]*types.Transaction), 88 quit: make(chan bool), 89 eventMux: eventMux, 90 events: eventMux.Subscribe(core.ChainHeadEvent{}), 91 chain: chain, 92 relay: relay, 93 odr: chain.Odr(), 94 chainDb: chain.Odr().Database(), 95 head: chain.CurrentHeader().Hash(), 96 clearIdx: chain.CurrentHeader().Number.Uint64(), 97 } 98 go pool.eventLoop() 99 100 return pool 101 } 102 103 // currentState returns the light state of the current head header 104 func (pool *TxPool) currentState(ctx context.Context) *state.StateDB { 105 return NewState(ctx, pool.chain.CurrentHeader(), pool.odr) 106 } 107 108 // GetNonce returns the "pending" nonce of a given address. It always queries 109 // the nonce belonging to the latest header too in order to detect if another 110 // client using the same key sent a transaction. 111 func (pool *TxPool) GetNonce(ctx context.Context, addr common.Address) (uint64, error) { 112 state := pool.currentState(ctx) 113 nonce := state.GetNonce(addr) 114 if state.Error() != nil { 115 return 0, state.Error() 116 } 117 sn, ok := pool.nonce[addr] 118 if ok && sn > nonce { 119 nonce = sn 120 } 121 if !ok || sn < nonce { 122 pool.nonce[addr] = nonce 123 } 124 return nonce, nil 125 } 126 127 type txBlockData struct { 128 BlockHash common.Hash 129 BlockIndex uint64 130 Index uint64 131 } 132 133 // txStateChanges stores the recent changes between pending/mined states of 134 // transactions. True means mined, false means rolled back, no entry means no change 135 type txStateChanges map[common.Hash]bool 136 137 // setState sets the status of a tx to either recently mined or recently rolled back 138 func (txc txStateChanges) setState(txHash common.Hash, mined bool) { 139 val, ent := txc[txHash] 140 if ent && (val != mined) { 141 delete(txc, txHash) 142 } else { 143 txc[txHash] = mined 144 } 145 } 146 147 // getLists creates lists of mined and rolled back tx hashes 148 func (txc txStateChanges) getLists() (mined []common.Hash, rollback []common.Hash) { 149 for hash, val := range txc { 150 if val { 151 mined = append(mined, hash) 152 } else { 153 rollback = append(rollback, hash) 154 } 155 } 156 return 157 } 158 159 // checkMinedTxs checks newly added blocks for the currently pending transactions 160 // and marks them as mined if necessary. It also stores block position in the db 161 // and adds them to the received txStateChanges map. 162 func (pool *TxPool) checkMinedTxs(ctx context.Context, hash common.Hash, number uint64, txc txStateChanges) error { 163 // If no transactions are pending, we don't care about anything 164 if len(pool.pending) == 0 { 165 return nil 166 } 167 block, err := GetBlock(ctx, pool.odr, hash, number) 168 if err != nil { 169 return err 170 } 171 // Gather all the local transaction mined in this block 172 list := pool.mined[hash] 173 for _, tx := range block.Transactions() { 174 if _, ok := pool.pending[tx.Hash()]; ok { 175 list = append(list, tx) 176 } 177 } 178 // If some transactions have been mined, write the needed data to disk and update 179 if list != nil { 180 // Retrieve all the receipts belonging to this block and write the loopup table 181 if _, err := GetBlockReceipts(ctx, pool.odr, hash, number); err != nil { // ODR caches, ignore results 182 return err 183 } 184 if err := core.WriteTxLookupEntries(pool.chainDb, block); err != nil { 185 return err 186 } 187 // Update the transaction pool's state 188 for _, tx := range list { 189 delete(pool.pending, tx.Hash()) 190 txc.setState(tx.Hash(), true) 191 } 192 pool.mined[hash] = list 193 } 194 return nil 195 } 196 197 // rollbackTxs marks the transactions contained in recently rolled back blocks 198 // as rolled back. It also removes any positional lookup entries. 199 func (pool *TxPool) rollbackTxs(hash common.Hash, txc txStateChanges) { 200 if list, ok := pool.mined[hash]; ok { 201 for _, tx := range list { 202 txHash := tx.Hash() 203 core.DeleteTxLookupEntry(pool.chainDb, txHash) 204 pool.pending[txHash] = tx 205 txc.setState(txHash, false) 206 } 207 delete(pool.mined, hash) 208 } 209 } 210 211 // reorgOnNewHead sets a new head header, processing (and rolling back if necessary) 212 // the blocks since the last known head and returns a txStateChanges map containing 213 // the recently mined and rolled back transaction hashes. If an error (context 214 // timeout) occurs during checking new blocks, it leaves the locally known head 215 // at the latest checked block and still returns a valid txStateChanges, making it 216 // possible to continue checking the missing blocks at the next chain head event 217 func (pool *TxPool) reorgOnNewHead(ctx context.Context, newHeader *types.Header) (txStateChanges, error) { 218 txc := make(txStateChanges) 219 oldh := pool.chain.GetHeaderByHash(pool.head) 220 newh := newHeader 221 // find common ancestor, create list of rolled back and new block hashes 222 var oldHashes, newHashes []common.Hash 223 for oldh.Hash() != newh.Hash() { 224 if oldh.Number.Uint64() >= newh.Number.Uint64() { 225 oldHashes = append(oldHashes, oldh.Hash()) 226 oldh = pool.chain.GetHeader(oldh.ParentHash, oldh.Number.Uint64()-1) 227 } 228 if oldh.Number.Uint64() < newh.Number.Uint64() { 229 newHashes = append(newHashes, newh.Hash()) 230 newh = pool.chain.GetHeader(newh.ParentHash, newh.Number.Uint64()-1) 231 if newh == nil { 232 // happens when CHT syncing, nothing to do 233 newh = oldh 234 } 235 } 236 } 237 if oldh.Number.Uint64() < pool.clearIdx { 238 pool.clearIdx = oldh.Number.Uint64() 239 } 240 // roll back old blocks 241 for _, hash := range oldHashes { 242 pool.rollbackTxs(hash, txc) 243 } 244 pool.head = oldh.Hash() 245 // check mined txs of new blocks (array is in reversed order) 246 for i := len(newHashes) - 1; i >= 0; i-- { 247 hash := newHashes[i] 248 if err := pool.checkMinedTxs(ctx, hash, newHeader.Number.Uint64()-uint64(i), txc); err != nil { 249 return txc, err 250 } 251 pool.head = hash 252 } 253 254 // clear old mined tx entries of old blocks 255 if idx := newHeader.Number.Uint64(); idx > pool.clearIdx+txPermanent { 256 idx2 := idx - txPermanent 257 if len(pool.mined) > 0 { 258 for i := pool.clearIdx; i < idx2; i++ { 259 hash := core.GetCanonicalHash(pool.chainDb, i) 260 if list, ok := pool.mined[hash]; ok { 261 hashes := make([]common.Hash, len(list)) 262 for i, tx := range list { 263 hashes[i] = tx.Hash() 264 } 265 pool.relay.Discard(hashes) 266 delete(pool.mined, hash) 267 } 268 } 269 } 270 pool.clearIdx = idx2 271 } 272 273 return txc, nil 274 } 275 276 // blockCheckTimeout is the time limit for checking new blocks for mined 277 // transactions. Checking resumes at the next chain head event if timed out. 278 const blockCheckTimeout = time.Second * 3 279 280 // eventLoop processes chain head events and also notifies the tx relay backend 281 // about the new head hash and tx state changes 282 func (pool *TxPool) eventLoop() { 283 for ev := range pool.events.Chan() { 284 switch ev.Data.(type) { 285 case core.ChainHeadEvent: 286 pool.setNewHead(ev.Data.(core.ChainHeadEvent).Block.Header()) 287 // hack in order to avoid hogging the lock; this part will 288 // be replaced by a subsequent PR. 289 time.Sleep(time.Millisecond) 290 } 291 } 292 } 293 294 func (pool *TxPool) setNewHead(head *types.Header) { 295 pool.mu.Lock() 296 defer pool.mu.Unlock() 297 298 ctx, cancel := context.WithTimeout(context.Background(), blockCheckTimeout) 299 defer cancel() 300 301 txc, _ := pool.reorgOnNewHead(ctx, head) 302 m, r := txc.getLists() 303 pool.relay.NewHead(pool.head, m, r) 304 pool.homestead = pool.config.IsHomestead(head.Number) 305 pool.signer = types.MakeSigner(pool.config, head.Number) 306 } 307 308 // Stop stops the light transaction pool 309 func (pool *TxPool) Stop() { 310 close(pool.quit) 311 pool.events.Unsubscribe() 312 log.Info("Transaction pool stopped") 313 } 314 315 // Stats returns the number of currently pending (locally created) transactions 316 func (pool *TxPool) Stats() (pending int) { 317 pool.mu.RLock() 318 defer pool.mu.RUnlock() 319 320 pending = len(pool.pending) 321 return 322 } 323 324 // validateTx checks whether a transaction is valid according to the consensus rules. 325 func (pool *TxPool) validateTx(ctx context.Context, tx *types.Transaction) error { 326 // Validate sender 327 var ( 328 from common.Address 329 err error 330 ) 331 332 // Validate the transaction sender and it's sig. Throw 333 // if the from fields is invalid. 334 if from, err = types.Sender(pool.signer, tx); err != nil { 335 return core.ErrInvalidSender 336 } 337 // Last but not least check for nonce errors 338 currentState := pool.currentState(ctx) 339 if n := currentState.GetNonce(from); n > tx.Nonce() { 340 return core.ErrNonceTooLow 341 } 342 343 // Check the transaction doesn't exceed the current 344 // block limit gas. 345 header := pool.chain.GetHeaderByHash(pool.head) 346 if header.GasLimit.Cmp(tx.Gas()) < 0 { 347 return core.ErrGasLimit 348 } 349 350 // Transactions can't be negative. This may never happen 351 // using RLP decoded transactions but may occur if you create 352 // a transaction using the RPC for example. 353 if tx.Value().Sign() < 0 { 354 return core.ErrNegativeValue 355 } 356 357 // Transactor should have enough funds to cover the costs 358 // cost == V + GP * GL 359 if b := currentState.GetBalance(from); b.Cmp(tx.Cost()) < 0 { 360 return core.ErrInsufficientFunds 361 } 362 363 // Should supply enough intrinsic gas 364 if tx.Gas().Cmp(core.IntrinsicGas(tx.Data(), tx.To() == nil, pool.homestead)) < 0 { 365 return core.ErrIntrinsicGas 366 } 367 368 return currentState.Error() 369 } 370 371 // add validates a new transaction and sets its state pending if processable. 372 // It also updates the locally stored nonce if necessary. 373 func (self *TxPool) add(ctx context.Context, tx *types.Transaction) error { 374 hash := tx.Hash() 375 376 if self.pending[hash] != nil { 377 return fmt.Errorf("Known transaction (%x)", hash[:4]) 378 } 379 err := self.validateTx(ctx, tx) 380 if err != nil { 381 return err 382 } 383 384 if _, ok := self.pending[hash]; !ok { 385 self.pending[hash] = tx 386 387 nonce := tx.Nonce() + 1 388 389 addr, _ := types.Sender(self.signer, tx) 390 if nonce > self.nonce[addr] { 391 self.nonce[addr] = nonce 392 } 393 394 // Notify the subscribers. This event is posted in a goroutine 395 // because it's possible that somewhere during the post "Remove transaction" 396 // gets called which will then wait for the global tx pool lock and deadlock. 397 go self.eventMux.Post(core.TxPreEvent{Tx: tx}) 398 } 399 400 // Print a log message if low enough level is set 401 log.Debug("Pooled new transaction", "hash", hash, "from", log.Lazy{Fn: func() common.Address { from, _ := types.Sender(self.signer, tx); return from }}, "to", tx.To()) 402 return nil 403 } 404 405 // Add adds a transaction to the pool if valid and passes it to the tx relay 406 // backend 407 func (self *TxPool) Add(ctx context.Context, tx *types.Transaction) error { 408 self.mu.Lock() 409 defer self.mu.Unlock() 410 411 data, err := rlp.EncodeToBytes(tx) 412 if err != nil { 413 return err 414 } 415 416 if err := self.add(ctx, tx); err != nil { 417 return err 418 } 419 //fmt.Println("Send", tx.Hash()) 420 self.relay.Send(types.Transactions{tx}) 421 422 self.chainDb.Put(tx.Hash().Bytes(), data) 423 return nil 424 } 425 426 // AddTransactions adds all valid transactions to the pool and passes them to 427 // the tx relay backend 428 func (self *TxPool) AddBatch(ctx context.Context, txs []*types.Transaction) { 429 self.mu.Lock() 430 defer self.mu.Unlock() 431 var sendTx types.Transactions 432 433 for _, tx := range txs { 434 if err := self.add(ctx, tx); err == nil { 435 sendTx = append(sendTx, tx) 436 } 437 } 438 if len(sendTx) > 0 { 439 self.relay.Send(sendTx) 440 } 441 } 442 443 // GetTransaction returns a transaction if it is contained in the pool 444 // and nil otherwise. 445 func (tp *TxPool) GetTransaction(hash common.Hash) *types.Transaction { 446 // check the txs first 447 if tx, ok := tp.pending[hash]; ok { 448 return tx 449 } 450 return nil 451 } 452 453 // GetTransactions returns all currently processable transactions. 454 // The returned slice may be modified by the caller. 455 func (self *TxPool) GetTransactions() (txs types.Transactions, err error) { 456 self.mu.RLock() 457 defer self.mu.RUnlock() 458 459 txs = make(types.Transactions, len(self.pending)) 460 i := 0 461 for _, tx := range self.pending { 462 txs[i] = tx 463 i++ 464 } 465 return txs, nil 466 } 467 468 // Content retrieves the data content of the transaction pool, returning all the 469 // pending as well as queued transactions, grouped by account and nonce. 470 func (self *TxPool) Content() (map[common.Address]types.Transactions, map[common.Address]types.Transactions) { 471 self.mu.RLock() 472 defer self.mu.RUnlock() 473 474 // Retrieve all the pending transactions and sort by account and by nonce 475 pending := make(map[common.Address]types.Transactions) 476 for _, tx := range self.pending { 477 account, _ := types.Sender(self.signer, tx) 478 pending[account] = append(pending[account], tx) 479 } 480 // There are no queued transactions in a light pool, just return an empty map 481 queued := make(map[common.Address]types.Transactions) 482 return pending, queued 483 } 484 485 // RemoveTransactions removes all given transactions from the pool. 486 func (self *TxPool) RemoveTransactions(txs types.Transactions) { 487 self.mu.Lock() 488 defer self.mu.Unlock() 489 var hashes []common.Hash 490 for _, tx := range txs { 491 //self.RemoveTx(tx.Hash()) 492 hash := tx.Hash() 493 delete(self.pending, hash) 494 self.chainDb.Delete(hash[:]) 495 hashes = append(hashes, hash) 496 } 497 self.relay.Discard(hashes) 498 } 499 500 // RemoveTx removes the transaction with the given hash from the pool. 501 func (pool *TxPool) RemoveTx(hash common.Hash) { 502 pool.mu.Lock() 503 defer pool.mu.Unlock() 504 // delete from pending pool 505 delete(pool.pending, hash) 506 pool.chainDb.Delete(hash[:]) 507 pool.relay.Discard([]common.Hash{hash}) 508 }