core, eth, les: fix messy code (#15367)

* core, eth, les: fix messy code

* les: fixed tx status test and rlp encoding

* core: add a workaround for light sync

5 files changed, 99 insertions, 148 deletions

diff --git a/core/bloombits/matcher.go b/core/bloombits/matcher.go
index 32a660337..a75f8c085 100644
--- a/core/bloombits/matcher.go
+++ b/core/bloombits/matcher.go
@@ -57,12 +57,16 @@ type partialMatches struct {
 // Retrieval represents a request for retrieval task assignments for a given
 // bit with the given number of fetch elements, or a response for such a request.
 // It can also have the actual results set to be used as a delivery data struct.
+//
+// The contest and error fields are used by the light client to terminate matching
+// early if an error is enountered on some path of the pipeline.
 type Retrieval struct {
 	Bit      uint
 	Sections []uint64
 	Bitsets  [][]byte
-	Error    error
-	Context  context.Context
+
+	Context context.Context
+	Error   error
 }
 
 // Matcher is a pipelined system of schedulers and logic matchers which perform
@@ -506,54 +510,31 @@ func (m *Matcher) distributor(dist chan *request, session *MatcherSession) {
 type MatcherSession struct {
 	matcher *Matcher
 
-	quit     chan struct{} // Quit channel to request pipeline termination
-	kill     chan struct{} // Term channel to signal non-graceful forced shutdown
-	ctx      context.Context
-	err      error
-	stopping bool
-	lock     sync.Mutex
-	pend     sync.WaitGroup
+	closer sync.Once     // Sync object to ensure we only ever close once
+	quit   chan struct{} // Quit channel to request pipeline termination
+	kill   chan struct{} // Term channel to signal non-graceful forced shutdown
+
+	ctx context.Context // Context used by the light client to abort filtering
+	err atomic.Value    // Global error to track retrieval failures deep in the chain
+
+	pend sync.WaitGroup
 }
 
 // Close stops the matching process and waits for all subprocesses to terminate
 // before returning. The timeout may be used for graceful shutdown, allowing the
 // currently running retrievals to complete before this time.
 func (s *MatcherSession) Close() {
-	s.lock.Lock()
-	stopping := s.stopping
-	s.stopping = true
-	s.lock.Unlock()
-	// ensure that we only close the session once
-	if stopping {
-		return
-	}
-
-	// Bail out if the matcher is not running
-	select {
-	case <-s.quit:
-		return
-	default:
-	}
-	// Signal termination and wait for all goroutines to tear down
-	close(s.quit)
-	time.AfterFunc(time.Second, func() { close(s.kill) })
-	s.pend.Wait()
+	s.closer.Do(func() {
+		// Signal termination and wait for all goroutines to tear down
+		close(s.quit)
+		time.AfterFunc(time.Second, func() { close(s.kill) })
+		s.pend.Wait()
+	})
 }
 
-// setError sets an error and stops the session
-func (s *MatcherSession) setError(err error) {
-	s.lock.Lock()
-	s.err = err
-	s.lock.Unlock()
-	s.Close()
-}
-
-// Error returns an error if one has happened during the session
+// Error returns any failure encountered during the matching session.
 func (s *MatcherSession) Error() error {
-	s.lock.Lock()
-	defer s.lock.Unlock()
-
-	return s.err
+	return s.err.Load().(error)
 }
 
 // AllocateRetrieval assigns a bloom bit index to a client process that can either
@@ -655,9 +636,9 @@ func (s *MatcherSession) Multiplex(batch int, wait time.Duration, mux chan chan
 
 			result := <-request
 			if result.Error != nil {
-				s.setError(result.Error)
+				s.err.Store(result.Error)
+				s.Close()
 			}
-
 			s.DeliverSections(result.Bit, result.Sections, result.Bitsets)
 		}
 	}
diff --git a/core/chain_indexer.go b/core/chain_indexer.go
index 837c908ab..7e7500dc8 100644
--- a/core/chain_indexer.go
+++ b/core/chain_indexer.go
@@ -36,17 +36,25 @@ import (
 type ChainIndexerBackend interface {
 	// Reset initiates the processing of a new chain segment, potentially terminating
 	// any partially completed operations (in case of a reorg).
-	Reset(section uint64, lastSectionHead common.Hash) error
+	Reset(section uint64, prevHead common.Hash) error
 
 	// Process crunches through the next header in the chain segment. The caller
 	// will ensure a sequential order of headers.
 	Process(header *types.Header)
 
-	// Commit finalizes the section metadata and stores it into the database. This
-	// interface will usually be a batch writer.
+	// Commit finalizes the section metadata and stores it into the database.
 	Commit() error
 }
 
+// ChainIndexerChain interface is used for connecting the indexer to a blockchain
+type ChainIndexerChain interface {
+	// CurrentHeader retrieves the latest locally known header.
+	CurrentHeader() *types.Header
+
+	// SubscribeChainEvent subscribes to new head header notifications.
+	SubscribeChainEvent(ch chan<- ChainEvent) event.Subscription
+}
+
 // ChainIndexer does a post-processing job for equally sized sections of the
 // canonical chain (like BlooomBits and CHT structures). A ChainIndexer is
 // connected to the blockchain through the event system by starting a
@@ -114,21 +122,14 @@ func (c *ChainIndexer) AddKnownSectionHead(section uint64, shead common.Hash) {
 	c.setValidSections(section + 1)
 }
 
-// IndexerChain interface is used for connecting the indexer to a blockchain
-type IndexerChain interface {
-	CurrentHeader() *types.Header
-	SubscribeChainEvent(ch chan<- ChainEvent) event.Subscription
-}
-
 // Start creates a goroutine to feed chain head events into the indexer for
 // cascading background processing. Children do not need to be started, they
 // are notified about new events by their parents.
-func (c *ChainIndexer) Start(chain IndexerChain) {
-	ch := make(chan ChainEvent, 10)
-	sub := chain.SubscribeChainEvent(ch)
-	currentHeader := chain.CurrentHeader()
+func (c *ChainIndexer) Start(chain ChainIndexerChain) {
+	events := make(chan ChainEvent, 10)
+	sub := chain.SubscribeChainEvent(events)
 
-	go c.eventLoop(currentHeader, ch, sub)
+	go c.eventLoop(chain.CurrentHeader(), events, sub)
 }
 
 // Close tears down all goroutines belonging to the indexer and returns any error
@@ -149,14 +150,12 @@ func (c *ChainIndexer) Close() error {
 			errs = append(errs, err)
 		}
 	}
-
 	// Close all children
 	for _, child := range c.children {
 		if err := child.Close(); err != nil {
 			errs = append(errs, err)
 		}
 	}
-
 	// Return any failures
 	switch {
 	case len(errs) == 0:
@@ -173,7 +172,7 @@ func (c *ChainIndexer) Close() error {
 // eventLoop is a secondary - optional - event loop of the indexer which is only
 // started for the outermost indexer to push chain head events into a processing
 // queue.
-func (c *ChainIndexer) eventLoop(currentHeader *types.Header, ch chan ChainEvent, sub event.Subscription) {
+func (c *ChainIndexer) eventLoop(currentHeader *types.Header, events chan ChainEvent, sub event.Subscription) {
 	// Mark the chain indexer as active, requiring an additional teardown
 	atomic.StoreUint32(&c.active, 1)
 
@@ -193,7 +192,7 @@ func (c *ChainIndexer) eventLoop(currentHeader *types.Header, ch chan ChainEvent
 			errc <- nil
 			return
 
-		case ev, ok := <-ch:
+		case ev, ok := <-events:
 			// Received a new event, ensure it's not nil (closing) and update
 			if !ok {
 				errc := <-c.quit
@@ -202,6 +201,8 @@ func (c *ChainIndexer) eventLoop(currentHeader *types.Header, ch chan ChainEvent
 			}
 			header := ev.Block.Header()
 			if header.ParentHash != prevHash {
+				// Reorg to the common ancestor (might not exist in light sync mode, skip reorg then)
+				// TODO(karalabe, zsfelfoldi): This seems a bit brittle, can we detect this case explicitly?
 				if h := FindCommonAncestor(c.chainDb, prevHeader, header); h != nil {
 					c.newHead(h.Number.Uint64(), true)
 				}
@@ -259,8 +260,8 @@ func (c *ChainIndexer) newHead(head uint64, reorg bool) {
 // down into the processing backend.
 func (c *ChainIndexer) updateLoop() {
 	var (
-		updated   time.Time
-		updateMsg bool
+		updating bool
+		updated  time.Time
 	)
 
 	for {
@@ -277,7 +278,7 @@ func (c *ChainIndexer) updateLoop() {
 				// Periodically print an upgrade log message to the user
 				if time.Since(updated) > 8*time.Second {
 					if c.knownSections > c.storedSections+1 {
-						updateMsg = true
+						updating = true
 						c.log.Info("Upgrading chain index", "percentage", c.storedSections*100/c.knownSections)
 					}
 					updated = time.Now()
@@ -300,8 +301,8 @@ func (c *ChainIndexer) updateLoop() {
 				if err == nil && oldHead == c.SectionHead(section-1) {
 					c.setSectionHead(section, newHead)
 					c.setValidSections(section + 1)
-					if c.storedSections == c.knownSections && updateMsg {
-						updateMsg = false
+					if c.storedSections == c.knownSections && updating {
+						updating = false
 						c.log.Info("Finished upgrading chain index")
 					}
 
@@ -412,7 +413,7 @@ func (c *ChainIndexer) setValidSections(sections uint64) {
 	c.storedSections = sections // needed if new > old
 }
 
-// sectionHead retrieves the last block hash of a processed section from the
+// SectionHead retrieves the last block hash of a processed section from the
 // index database.
 func (c *ChainIndexer) SectionHead(section uint64) common.Hash {
 	var data [8]byte
diff --git a/core/chain_indexer_test.go b/core/chain_indexer_test.go
index d685d3f8d..9fc09eda5 100644
--- a/core/chain_indexer_test.go
+++ b/core/chain_indexer_test.go
@@ -209,7 +209,7 @@ func (b *testChainIndexBackend) reorg(headNum uint64) uint64 {
 	return b.stored * b.indexer.sectionSize
 }
 
-func (b *testChainIndexBackend) Reset(section uint64, lastSectionHead common.Hash) error {
+func (b *testChainIndexBackend) Reset(section uint64, prevHead common.Hash) error {
 	b.section = section
 	b.headerCnt = 0
 	return nil
diff --git a/core/tx_list.go b/core/tx_list.go
index 94721aa5f..2935929d7 100644
--- a/core/tx_list.go
+++ b/core/tx_list.go
@@ -384,13 +384,13 @@ func (h *priceHeap) Pop() interface{} {
 // txPricedList is a price-sorted heap to allow operating on transactions pool
 // contents in a price-incrementing way.
 type txPricedList struct {
-	all    *map[common.Hash]txLookupRec // Pointer to the map of all transactions
-	items  *priceHeap                   // Heap of prices of all the stored transactions
-	stales int                          // Number of stale price points to (re-heap trigger)
+	all    *map[common.Hash]*types.Transaction // Pointer to the map of all transactions
+	items  *priceHeap                          // Heap of prices of all the stored transactions
+	stales int                                 // Number of stale price points to (re-heap trigger)
 }
 
 // newTxPricedList creates a new price-sorted transaction heap.
-func newTxPricedList(all *map[common.Hash]txLookupRec) *txPricedList {
+func newTxPricedList(all *map[common.Hash]*types.Transaction) *txPricedList {
 	return &txPricedList{
 		all:   all,
 		items: new(priceHeap),
@@ -416,7 +416,7 @@ func (l *txPricedList) Removed() {
 
 	l.stales, l.items = 0, &reheap
 	for _, tx := range *l.all {
-		*l.items = append(*l.items, tx.tx)
+		*l.items = append(*l.items, tx)
 	}
 	heap.Init(l.items)
 }
diff --git a/core/tx_pool.go b/core/tx_pool.go
index 5fdc91e65..0f008ddc0 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -103,6 +103,16 @@ var (
 	underpricedTxCounter = metrics.NewCounter("txpool/underpriced")
 )
 
+// TxStatus is the current status of a transaction as seen py the pool.
+type TxStatus uint
+
+const (
+	TxStatusUnknown TxStatus = iota
+	TxStatusQueued
+	TxStatusPending
+	TxStatusIncluded
+)
+
 // blockChain provides the state of blockchain and current gas limit to do
 // some pre checks in tx pool and event subscribers.
 type blockChain interface {
@@ -192,22 +202,17 @@ type TxPool struct {
 	locals  *accountSet // Set of local transaction to exepmt from evicion rules
 	journal *txJournal  // Journal of local transaction to back up to disk
 
-	pending map[common.Address]*txList   // All currently processable transactions
-	queue   map[common.Address]*txList   // Queued but non-processable transactions
-	beats   map[common.Address]time.Time // Last heartbeat from each known account
-	all     map[common.Hash]txLookupRec  // All transactions to allow lookups
-	priced  *txPricedList                // All transactions sorted by price
+	pending map[common.Address]*txList         // All currently processable transactions
+	queue   map[common.Address]*txList         // Queued but non-processable transactions
+	beats   map[common.Address]time.Time       // Last heartbeat from each known account
+	all     map[common.Hash]*types.Transaction // All transactions to allow lookups
+	priced  *txPricedList                      // All transactions sorted by price
 
 	wg sync.WaitGroup // for shutdown sync
 
 	homestead bool
 }
 
-type txLookupRec struct {
-	tx      *types.Transaction
-	pending bool
-}
-
 // NewTxPool creates a new transaction pool to gather, sort and filter inbound
 // trnsactions from the network.
 func NewTxPool(config TxPoolConfig, chainconfig *params.ChainConfig, chain blockChain) *TxPool {
@@ -223,7 +228,7 @@ func NewTxPool(config TxPoolConfig, chainconfig *params.ChainConfig, chain block
 		pending:     make(map[common.Address]*txList),
 		queue:       make(map[common.Address]*txList),
 		beats:       make(map[common.Address]time.Time),
-		all:         make(map[common.Hash]txLookupRec),
+		all:         make(map[common.Hash]*types.Transaction),
 		chainHeadCh: make(chan ChainHeadEvent, chainHeadChanSize),
 		gasPrice:    new(big.Int).SetUint64(config.PriceLimit),
 	}
@@ -599,7 +604,7 @@ func (pool *TxPool) validateTx(tx *types.Transaction, local bool) error {
 func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 	// If the transaction is already known, discard it
 	hash := tx.Hash()
-	if _, ok := pool.all[hash]; ok {
+	if pool.all[hash] != nil {
 		log.Trace("Discarding already known transaction", "hash", hash)
 		return false, fmt.Errorf("known transaction: %x", hash)
 	}
@@ -640,7 +645,7 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 			pool.priced.Removed()
 			pendingReplaceCounter.Inc(1)
 		}
-		pool.all[tx.Hash()] = txLookupRec{tx, false}
+		pool.all[tx.Hash()] = tx
 		pool.priced.Put(tx)
 		pool.journalTx(from, tx)
 
@@ -687,7 +692,7 @@ func (pool *TxPool) enqueueTx(hash common.Hash, tx *types.Transaction) (bool, er
 		pool.priced.Removed()
 		queuedReplaceCounter.Inc(1)
 	}
-	pool.all[hash] = txLookupRec{tx, false}
+	pool.all[hash] = tx
 	pool.priced.Put(tx)
 	return old != nil, nil
 }
@@ -730,13 +735,10 @@ func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx *types.T
 
 		pendingReplaceCounter.Inc(1)
 	}
-	if pool.all[hash].tx == nil {
-		// Failsafe to work around direct pending inserts (tests)
-		pool.all[hash] = txLookupRec{tx, true}
+	// Failsafe to work around direct pending inserts (tests)
+	if pool.all[hash] == nil {
+		pool.all[hash] = tx
 		pool.priced.Put(tx)
-	} else {
-		// set pending flag to true
-		pool.all[hash] = txLookupRec{tx, true}
 	}
 	// Set the potentially new pending nonce and notify any subsystems of the new tx
 	pool.beats[addr] = time.Now()
@@ -762,17 +764,15 @@ func (pool *TxPool) AddRemote(tx *types.Transaction) error {
 // AddLocals enqueues a batch of transactions into the pool if they are valid,
 // marking the senders as a local ones in the mean time, ensuring they go around
 // the local pricing constraints.
-func (pool *TxPool) AddLocals(txs []*types.Transaction) error {
-	pool.addTxs(txs, !pool.config.NoLocals)
-	return nil
+func (pool *TxPool) AddLocals(txs []*types.Transaction) []error {
+	return pool.addTxs(txs, !pool.config.NoLocals)
 }
 
 // AddRemotes enqueues a batch of transactions into the pool if they are valid.
 // If the senders are not among the locally tracked ones, full pricing constraints
 // will apply.
-func (pool *TxPool) AddRemotes(txs []*types.Transaction) error {
-	pool.addTxs(txs, false)
-	return nil
+func (pool *TxPool) AddRemotes(txs []*types.Transaction) []error {
+	return pool.addTxs(txs, false)
 }
 
 // addTx enqueues a single transaction into the pool if it is valid.
@@ -806,10 +806,11 @@ func (pool *TxPool) addTxs(txs []*types.Transaction, local bool) []error {
 func (pool *TxPool) addTxsLocked(txs []*types.Transaction, local bool) []error {
 	// Add the batch of transaction, tracking the accepted ones
 	dirty := make(map[common.Address]struct{})
-	txErr := make([]error, len(txs))
+	errs := make([]error, len(txs))
+
 	for i, tx := range txs {
 		var replace bool
-		if replace, txErr[i] = pool.add(tx, local); txErr[i] == nil {
+		if replace, errs[i] = pool.add(tx, local); errs[i] == nil {
 			if !replace {
 				from, _ := types.Sender(pool.signer, tx) // already validated
 				dirty[from] = struct{}{}
@@ -824,54 +825,23 @@ func (pool *TxPool) addTxsLocked(txs []*types.Transaction, local bool) []error {
 		}
 		pool.promoteExecutables(addrs)
 	}
-	return txErr
-}
-
-// TxStatusData is returned by AddOrGetTxStatus for each transaction
-type TxStatusData struct {
-	Status uint
-	Data   []byte
+	return errs
 }
 
-const (
-	TxStatusUnknown = iota
-	TxStatusQueued
-	TxStatusPending
-	TxStatusIncluded // Data contains a TxChainPos struct
-	TxStatusError    // Data contains the error string
-)
-
-// AddOrGetTxStatus returns the status (unknown/pending/queued) of a batch of transactions
-// identified by their hashes in txHashes. Optionally the transactions themselves can be
-// passed too in txs, in which case the function will try adding the previously unknown ones
-// to the pool. If a new transaction cannot be added, TxStatusError is returned. Adding already
-// known transactions will return their previous status.
-// If txs is specified, txHashes is still required and has to match the transactions in txs.
-
-// Note: TxStatusIncluded is never returned by this function since the pool does not track
-// mined transactions. Included status can be checked by the caller (as it happens in the
-// LES protocol manager)
-func (pool *TxPool) AddOrGetTxStatus(txs []*types.Transaction, txHashes []common.Hash) []TxStatusData {
-	status := make([]TxStatusData, len(txHashes))
-	if txs != nil {
-		if len(txs) != len(txHashes) {
-			panic(nil)
-		}
-		txErr := pool.addTxs(txs, false)
-		for i, err := range txErr {
-			if err != nil {
-				status[i] = TxStatusData{TxStatusError, ([]byte)(err.Error())}
-			}
-		}
-	}
+// Status returns the status (unknown/pending/queued) of a batch of transactions
+// identified by their hashes.
+func (pool *TxPool) Status(hashes []common.Hash) []TxStatus {
+	pool.mu.RLock()
+	defer pool.mu.RUnlock()
 
-	for i, hash := range txHashes {
-		r, ok := pool.all[hash]
-		if ok {
-			if r.pending {
-				status[i] = TxStatusData{TxStatusPending, nil}
+	status := make([]TxStatus, len(hashes))
+	for i, hash := range hashes {
+		if tx := pool.all[hash]; tx != nil {
+			from, _ := types.Sender(pool.signer, tx) // already validated
+			if pool.pending[from].txs.items[tx.Nonce()] != nil {
+				status[i] = TxStatusPending
 			} else {
-				status[i] = TxStatusData{TxStatusQueued, nil}
+				status[i] = TxStatusQueued
 			}
 		}
 	}
@@ -884,18 +854,17 @@ func (pool *TxPool) Get(hash common.Hash) *types.Transaction {
 	pool.mu.RLock()
 	defer pool.mu.RUnlock()
 
-	return pool.all[hash].tx
+	return pool.all[hash]
 }
 
 // removeTx removes a single transaction from the queue, moving all subsequent
 // transactions back to the future queue.
 func (pool *TxPool) removeTx(hash common.Hash) {
 	// Fetch the transaction we wish to delete
-	txl, ok := pool.all[hash]
+	tx, ok := pool.all[hash]
 	if !ok {
 		return
 	}
-	tx := txl.tx
 	addr, _ := types.Sender(pool.signer, tx) // already validated during insertion
 
 	// Remove it from the list of known transactions