From aa76a367e045cb2b2ace57169b9929d74f015b7f Mon Sep 17 00:00:00 2001
From: Sam Kleinman <garen@tychoish.com>
Date: Fri, 7 Jan 2022 13:40:08 -0500
Subject: [PATCH] blocksync: standardize construction process (#7531)

---
 internal/blocksync/reactor.go      |  9 +++++++-
 internal/blocksync/reactor_test.go |  7 +++++-
 node/node.go                       | 18 +++++++++++-----
 node/setup.go                      | 34 ------------------------------
 4 files changed, 27 insertions(+), 41 deletions(-)

diff --git a/internal/blocksync/reactor.go b/internal/blocksync/reactor.go
index 361be537e..b3142d953 100644
--- a/internal/blocksync/reactor.go
+++ b/internal/blocksync/reactor.go
@@ -103,16 +103,18 @@ type Reactor struct {
 
 // NewReactor returns new reactor instance.
 func NewReactor(
+	ctx context.Context,
 	logger log.Logger,
 	state sm.State,
 	blockExec *sm.BlockExecutor,
 	store *store.BlockStore,
 	consReactor consensusReactor,
-	blockSyncCh *p2p.Channel,
+	channelCreator p2p.ChannelCreator,
 	peerUpdates *p2p.PeerUpdates,
 	blockSync bool,
 	metrics *consensus.Metrics,
 ) (*Reactor, error) {
+
 	if state.LastBlockHeight != store.Height() {
 		return nil, fmt.Errorf("state (%v) and store (%v) height mismatch", state.LastBlockHeight, store.Height())
 	}
@@ -125,6 +127,11 @@ func NewReactor(
 	requestsCh := make(chan BlockRequest, maxTotalRequesters)
 	errorsCh := make(chan peerError, maxPeerErrBuffer) // NOTE: The capacity should be larger than the peer count.
 
+	blockSyncCh, err := channelCreator(ctx, GetChannelDescriptor())
+	if err != nil {
+		return nil, err
+	}
+
 	r := &Reactor{
 		logger:               logger,
 		initialState:         state,
diff --git a/internal/blocksync/reactor_test.go b/internal/blocksync/reactor_test.go
index 786815e53..245f2753e 100644
--- a/internal/blocksync/reactor_test.go
+++ b/internal/blocksync/reactor_test.go
@@ -168,13 +168,18 @@ func (rts *reactorTestSuite) addNode(
 	rts.peerChans[nodeID] = make(chan p2p.PeerUpdate)
 	rts.peerUpdates[nodeID] = p2p.NewPeerUpdates(rts.peerChans[nodeID], 1)
 	rts.network.Nodes[nodeID].PeerManager.Register(ctx, rts.peerUpdates[nodeID])
+
+	chCreator := func(ctx context.Context, chdesc *p2p.ChannelDescriptor) (*p2p.Channel, error) {
+		return rts.blockSyncChannels[nodeID], nil
+	}
 	rts.reactors[nodeID], err = NewReactor(
+		ctx,
 		rts.logger.With("nodeID", nodeID),
 		state.Copy(),
 		blockExec,
 		blockStore,
 		nil,
-		rts.blockSyncChannels[nodeID],
+		chCreator,
 		rts.peerUpdates[nodeID],
 		rts.blockSync,
 		consensus.NopMetrics())
diff --git a/node/node.go b/node/node.go
index 704bf7faa..cbc95e0ec 100644
--- a/node/node.go
+++ b/node/node.go
@@ -16,6 +16,7 @@ import (
 	abci "github.com/tendermint/tendermint/abci/types"
 	"github.com/tendermint/tendermint/config"
 	"github.com/tendermint/tendermint/crypto"
+	"github.com/tendermint/tendermint/internal/blocksync"
 	"github.com/tendermint/tendermint/internal/consensus"
 	"github.com/tendermint/tendermint/internal/eventbus"
 	"github.com/tendermint/tendermint/internal/mempool"
@@ -327,13 +328,20 @@ func makeNode(
 
 	// Create the blockchain reactor. Note, we do not start block sync if we're
 	// doing a state sync first.
-	bcReactor, err := createBlockchainReactor(ctx,
-		logger, state, blockExec, blockStore, csReactor,
-		peerManager, router, blockSync && !stateSync, nodeMetrics.consensus,
+	bcReactor, err := blocksync.NewReactor(ctx,
+		logger.With("module", "blockchain"),
+		state.Copy(),
+		blockExec,
+		blockStore,
+		csReactor,
+		router.OpenChannel,
+		peerManager.Subscribe(ctx),
+		blockSync && !stateSync,
+		nodeMetrics.consensus,
 	)
 	if err != nil {
 		return nil, combineCloseError(
-			fmt.Errorf("could not create blockchain reactor: %w", err),
+			fmt.Errorf("could not create blocksync reactor: %w", err),
 			makeCloser(closers))
 	}
 
@@ -413,7 +421,7 @@ func makeNode(
 			ConsensusState: csState,
 
 			ConsensusReactor: csReactor,
-			BlockSyncReactor: bcReactor.(consensus.BlockSyncReactor),
+			BlockSyncReactor: bcReactor,
 
 			PeerManager: peerManager,
 
diff --git a/node/setup.go b/node/setup.go
index e83af95c9..5f1b078ab 100644
--- a/node/setup.go
+++ b/node/setup.go
@@ -243,40 +243,6 @@ func createEvidenceReactor(
 	return evidenceReactor, evidencePool, nil
 }
 
-func createBlockchainReactor(
-	ctx context.Context,
-	logger log.Logger,
-	state sm.State,
-	blockExec *sm.BlockExecutor,
-	blockStore *store.BlockStore,
-	csReactor *consensus.Reactor,
-	peerManager *p2p.PeerManager,
-	router *p2p.Router,
-	blockSync bool,
-	metrics *consensus.Metrics,
-) (service.Service, error) {
-
-	logger = logger.With("module", "blockchain")
-
-	ch, err := router.OpenChannel(ctx, blocksync.GetChannelDescriptor())
-	if err != nil {
-		return nil, err
-	}
-
-	peerUpdates := peerManager.Subscribe(ctx)
-
-	reactor, err := blocksync.NewReactor(
-		logger, state.Copy(), blockExec, blockStore, csReactor,
-		ch, peerUpdates, blockSync,
-		metrics,
-	)
-	if err != nil {
-		return nil, err
-	}
-
-	return reactor, nil
-}
-
 func createConsensusReactor(
 	ctx context.Context,
 	cfg *config.Config,