Merge pull request #5248 from joostjager/concurrent-onion

htlcswitch: concurrent onion decoding

go.mod

@@ -39,7 +39,7 @@ require (
 	github.com/kkdai/bstream v0.0.0-20181106074824-b3251f7901ec
 	github.com/lightninglabs/neutrino v0.12.1
 	github.com/lightninglabs/protobuf-hex-display v1.4.3-hex-display
-	github.com/lightningnetwork/lightning-onion v1.0.2-0.20200501022730-3c8c8d0b89ea
+	github.com/lightningnetwork/lightning-onion v1.0.2-0.20210520211913-522b799e65b1
 	github.com/lightningnetwork/lnd/cert v1.0.3
 	github.com/lightningnetwork/lnd/clock v1.0.1
 	github.com/lightningnetwork/lnd/healthcheck v1.0.0

go.sum

@@ -213,8 +213,8 @@ github.com/lightninglabs/neutrino v0.12.1 h1:9umzk5kKNc/l3bAyak8ClSRP1qSulnjc6kp
 github.com/lightninglabs/neutrino v0.12.1/go.mod h1:GlKninWpRBbL7b8G0oQ36/8downfnFwKsr0hbRA6E/E=
 github.com/lightninglabs/protobuf-hex-display v1.4.3-hex-display h1:RZJ8H4ueU/aQ9pFtx5wqsuD3B/DezrewJeVwDKKYY8E=
 github.com/lightninglabs/protobuf-hex-display v1.4.3-hex-display/go.mod h1:2oKOBU042GKFHrdbgGiKax4xVrFiZu51lhacUZQ9MnE=
-github.com/lightningnetwork/lightning-onion v1.0.2-0.20200501022730-3c8c8d0b89ea h1:oCj48NQ8u7Vz+MmzHqt0db6mxcFZo3Ho7M5gCJauY/k=
-github.com/lightningnetwork/lightning-onion v1.0.2-0.20200501022730-3c8c8d0b89ea/go.mod h1:rigfi6Af/KqsF7Za0hOgcyq2PNH4AN70AaMRxcJkff4=
+github.com/lightningnetwork/lightning-onion v1.0.2-0.20210520211913-522b799e65b1 h1:h1BsjPzWea790mAXISoiT/qr0JRcixTCDNLmjsDThSw=
+github.com/lightningnetwork/lightning-onion v1.0.2-0.20210520211913-522b799e65b1/go.mod h1:rigfi6Af/KqsF7Za0hOgcyq2PNH4AN70AaMRxcJkff4=
 github.com/ltcsuite/ltcd v0.0.0-20190101042124-f37f8bf35796 h1:sjOGyegMIhvgfq5oaue6Td+hxZuf3tDC8lAPrFldqFw=
 github.com/ltcsuite/ltcd v0.0.0-20190101042124-f37f8bf35796/go.mod h1:3p7ZTf9V1sNPI5H8P3NkTFF4LuwMdPl2DodF60qAKqY=
 github.com/ltcsuite/ltcutil v0.0.0-20181217130922-17f3b04680b6/go.mod h1:8Vg/LTOO0KYa/vlHWJ6XZAevPQThGH5sufO0Hrou/lA=

htlcswitch/hop/iterator.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"sync"
 
 	"github.com/btcsuite/btcd/btcec"
 	sphinx "github.com/lightningnetwork/lightning-onion"
@@ -251,9 +252,8 @@ func (p *OnionProcessor) DecodeHopIterators(id []byte,
 
 	tx := p.router.BeginTxn(id, batchSize)
 
-	for i, req := range reqs {
-		onionPkt := &onionPkts[i]
-		resp := &resps[i]
+	decode := func(seqNum uint16, onionPkt *sphinx.OnionPacket,
+		req DecodeHopIteratorRequest) lnwire.FailCode {
 
 		err := onionPkt.Decode(req.OnionReader)
 		switch err {
@@ -261,45 +261,55 @@ func (p *OnionProcessor) DecodeHopIterators(id []byte,
 			// success
 
 		case sphinx.ErrInvalidOnionVersion:
-			resp.FailCode = lnwire.CodeInvalidOnionVersion
-			continue
+			return lnwire.CodeInvalidOnionVersion
 
 		case sphinx.ErrInvalidOnionKey:
-			resp.FailCode = lnwire.CodeInvalidOnionKey
-			continue
+			return lnwire.CodeInvalidOnionKey
 
 		default:
 			log.Errorf("unable to decode onion packet: %v", err)
-			resp.FailCode = lnwire.CodeInvalidOnionKey
-			continue
+			return lnwire.CodeInvalidOnionKey
 		}
 
 		err = tx.ProcessOnionPacket(
-			uint16(i), onionPkt, req.RHash, req.IncomingCltv,
+			seqNum, onionPkt, req.RHash, req.IncomingCltv,
 		)
 		switch err {
 		case nil:
 			// success
+			return lnwire.CodeNone
 
 		case sphinx.ErrInvalidOnionVersion:
-			resp.FailCode = lnwire.CodeInvalidOnionVersion
-			continue
+			return lnwire.CodeInvalidOnionVersion
 
 		case sphinx.ErrInvalidOnionHMAC:
-			resp.FailCode = lnwire.CodeInvalidOnionHmac
-			continue
+			return lnwire.CodeInvalidOnionHmac
 
 		case sphinx.ErrInvalidOnionKey:
-			resp.FailCode = lnwire.CodeInvalidOnionKey
-			continue
+			return lnwire.CodeInvalidOnionKey
 
 		default:
 			log.Errorf("unable to process onion packet: %v", err)
-			resp.FailCode = lnwire.CodeInvalidOnionKey
-			continue
+			return lnwire.CodeInvalidOnionKey
 		}
 	}
 
+	// Execute cpu-heavy onion decoding in parallel.
+	var wg sync.WaitGroup
+	for i := range reqs {
+		wg.Add(1)
+		go func(seqNum uint16) {
+			defer wg.Done()
+
+			onionPkt := &onionPkts[seqNum]
+
+			resps[seqNum].FailCode = decode(
+				seqNum, onionPkt, reqs[seqNum],
+			)
+		}(uint16(i))
+	}
+	wg.Wait()
+
 	// With that batch created, we will now attempt to write the shared
 	// secrets to disk. This operation will returns the set of indices that
 	// were detected as replays, and the computed sphinx packets for all