mempool: handle orphan utreexo txs

Utreexo txs get put into the orphan pool but since the udata is no
longer included in the tx, we need to keep track of it separately. This
commit addresses that.

mempool/mempool.go

@@ -195,6 +195,7 @@ type TxPool struct {
 	pool          map[chainhash.Hash]*TxDesc
 	poolLeaves    map[chainhash.Hash][]wire.LeafData
 	orphans       map[chainhash.Hash]*orphanTx
+	orphanUData   map[chainhash.Hash]*wire.UData
 	orphansByPrev map[wire.OutPoint]map[chainhash.Hash]*btcutil.Tx
 	outpoints     map[wire.OutPoint]*btcutil.Tx
 	pennyTotal    float64 // exponentially decaying total for penny spends.
@@ -225,6 +226,21 @@ func (mp *TxPool) removeOrphan(tx *btcutil.Tx, removeRedeemers bool) {
 		return
 	}
 
+	if mp.cfg.IsUtreexoViewActive() {
+		ud, found := mp.orphanUData[*tx.Hash()]
+		if found {
+			// Remove related utreexo data.
+			//
+			// TODO uncache from the accumulator.
+			delete(mp.orphanUData, *tx.Hash())
+			err := mp.cfg.PruneFromAccumulator(ud.LeafDatas)
+			if err != nil {
+				log.Debugf("error while pruning proof for orphan tx %v"+
+					"from the accumulator.", tx.Hash())
+			}
+		}
+	}
+
 	// Remove the reference from the previous orphan index.
 	for _, txIn := range otx.tx.MsgTx().TxIn {
 		orphans, exists := mp.orphansByPrev[txIn.PreviousOutPoint]
@@ -337,7 +353,7 @@ func (mp *TxPool) limitNumOrphans() error {
 // addOrphan adds an orphan transaction to the orphan pool.
 //
 // This function MUST be called with the mempool lock held (for writes).
-func (mp *TxPool) addOrphan(tx *btcutil.Tx, tag Tag) {
+func (mp *TxPool) addOrphan(tx *btcutil.Tx, utreexoData *wire.UData, tag Tag) {
 	// Nothing to do if no orphans are allowed.
 	if mp.cfg.Policy.MaxOrphanTxs <= 0 {
 		return
@@ -360,6 +376,12 @@ func (mp *TxPool) addOrphan(tx *btcutil.Tx, tag Tag) {
 		}
 		mp.orphansByPrev[txIn.PreviousOutPoint][*tx.Hash()] = tx
 	}
+	if mp.cfg.IsUtreexoViewActive() {
+		// Ingest the proof. Shouldn't error out with the proof being invalid
+		// here since we've already verified it above.
+		mp.cfg.VerifyUData(utreexoData, tx.MsgTx().TxIn, true)
+		mp.orphanUData[*tx.Hash()] = utreexoData
+	}
 
 	log.Debugf("Stored orphan transaction %v (total: %d)", tx.Hash(),
 		len(mp.orphans))
@@ -368,7 +390,7 @@ func (mp *TxPool) addOrphan(tx *btcutil.Tx, tag Tag) {
 // maybeAddOrphan potentially adds an orphan to the orphan pool.
 //
 // This function MUST be called with the mempool lock held (for writes).
-func (mp *TxPool) maybeAddOrphan(tx *btcutil.Tx, tag Tag) error {
+func (mp *TxPool) maybeAddOrphan(tx *btcutil.Tx, utreexoData *wire.UData, tag Tag) error {
 	// Ignore orphan transactions that are too large.  This helps avoid
 	// a memory exhaustion attack based on sending a lot of really large
 	// orphans.  In the case there is a valid transaction larger than this,
@@ -388,7 +410,7 @@ func (mp *TxPool) maybeAddOrphan(tx *btcutil.Tx, tag Tag) error {
 	}
 
 	// Add the orphan if the none of the above disqualified it.
-	mp.addOrphan(tx, tag)
+	mp.addOrphan(tx, utreexoData, tag)
 
 	return nil
 }
@@ -1127,8 +1149,18 @@ func (mp *TxPool) processOrphans(acceptedTx *btcutil.Tx) []*TxDesc {
 
 			// Potentially accept an orphan into the tx pool.
 			for _, tx := range orphans {
+				var uData *wire.UData
+				if mp.cfg.IsUtreexoViewActive() {
+					var found bool
+					uData, found = mp.orphanUData[*tx.Hash()]
+					if !found {
+						log.Debugf("is a utreexo node but is missing udata for"+
+							"orphan tx %v", tx.Hash())
+						continue
+					}
+				}
 				missing, txD, err := mp.maybeAcceptTransaction(
-					tx, nil, true, true, false)
+					tx, uData, true, true, false)
 				if err != nil {
 					// The orphan is now invalid, so there
 					// is no way any other orphans which
@@ -1252,7 +1284,7 @@ func (mp *TxPool) ProcessTransaction(tx *btcutil.Tx, utreexoData *wire.UData, al
 	}
 
 	// Potentially add the orphan transaction to the orphan pool.
-	err = mp.maybeAddOrphan(tx, tag)
+	err = mp.maybeAddOrphan(tx, utreexoData, tag)
 	return nil, err
 }
 
@@ -1882,6 +1914,7 @@ func New(cfg *Config) *TxPool {
 		pool:           make(map[chainhash.Hash]*TxDesc),
 		poolLeaves:     make(map[chainhash.Hash][]wire.LeafData),
 		orphans:        make(map[chainhash.Hash]*orphanTx),
+		orphanUData:    make(map[chainhash.Hash]*wire.UData),
 		orphansByPrev:  make(map[wire.OutPoint]map[chainhash.Hash]*btcutil.Tx),
 		nextExpireScan: time.Now().Add(orphanExpireScanInterval),
 		outpoints:      make(map[wire.OutPoint]*btcutil.Tx),

mempool/mempool_test.go

@@ -325,13 +325,14 @@ func newPoolHarness(chainParams *chaincfg.Params) (*poolHarness, []spendableOutp
 				MinRelayTxFee:        1000, // 1 Satoshi per byte
 				MaxTxVersion:         1,
 			},
-			ChainParams:      chainParams,
-			FetchUtxoView:    chain.FetchUtxoView,
-			BestHeight:       chain.BestHeight,
-			MedianTimePast:   chain.MedianTimePast,
-			CalcSequenceLock: chain.CalcSequenceLock,
-			SigCache:         nil,
-			AddrIndex:        nil,
+			ChainParams:         chainParams,
+			FetchUtxoView:       chain.FetchUtxoView,
+			IsUtreexoViewActive: func() bool { return false },
+			BestHeight:          chain.BestHeight,
+			MedianTimePast:      chain.MedianTimePast,
+			CalcSequenceLock:    chain.CalcSequenceLock,
+			SigCache:            nil,
+			AddrIndex:           nil,
 		}),
 	}