From df4f42db82136299fe6a6926def71393c68af2ee Mon Sep 17 00:00:00 2001
From: Alex Grintsvayg <grin@lbry.com>
Date: Wed, 1 Jul 2020 14:42:23 -0400
Subject: [PATCH] successfully shut down wallet server

---
 peer/http3/server.go   |  4 +--
 reflector/blocklist.go | 58 ++++++++++++++++++++++++++++++------------
 wallet/network.go      | 14 ++++++++++
 3 files changed, 58 insertions(+), 18 deletions(-)

diff --git a/peer/http3/server.go b/peer/http3/server.go
index c9bab5e..6f18db3 100644
--- a/peer/http3/server.go
+++ b/peer/http3/server.go
@@ -40,9 +40,9 @@ func NewServer(store store.BlobStore) *Server {
 
 // Shutdown gracefully shuts down the peer server.
 func (s *Server) Shutdown() {
-	log.Debug("shutting down peer server")
+	log.Debug("shutting down http3 peer server")
 	s.grp.StopAndWait()
-	log.Debug("peer server stopped")
+	log.Debug("http3 peer server stopped")
 }
 
 func (s *Server) logError(e error) {
diff --git a/reflector/blocklist.go b/reflector/blocklist.go
index ed2ba9c..9abfc4a 100644
--- a/reflector/blocklist.go
+++ b/reflector/blocklist.go
@@ -12,6 +12,7 @@ import (
 	"github.com/lbryio/reflector.go/wallet"
 
 	"github.com/lbryio/lbry.go/v2/extras/errors"
+	"github.com/lbryio/lbry.go/v2/extras/stop"
 
 	log "github.com/sirupsen/logrus"
 )
@@ -19,21 +20,28 @@ import (
 const blocklistURL = "https://api.lbry.com/file/list_blocked"
 
 func (s *Server) enableBlocklist(b store.Blocklister) {
-	// TODO: updateBlocklist should be killed when server is shutting down
-	updateBlocklist(b)
+	walletServers := []string{
+		"spv25.lbry.com:50001",
+		"spv26.lbry.com:50001",
+		"spv19.lbry.com:50001",
+		"spv14.lbry.com:50001",
+	}
+
+	updateBlocklist(b, walletServers, s.grp.Ch())
 	t := time.NewTicker(12 * time.Hour)
 	for {
 		select {
 		case <-s.grp.Ch():
 			return
 		case <-t.C:
-			updateBlocklist(b)
+			updateBlocklist(b, walletServers, s.grp.Ch())
 		}
 	}
 }
 
-func updateBlocklist(b store.Blocklister) {
-	values, err := blockedSdHashes()
+func updateBlocklist(b store.Blocklister, walletServers []string, stopper stop.Chan) {
+	log.Debugf("blocklist update starting")
+	values, err := blockedSdHashes(walletServers, stopper)
 	if err != nil {
 		log.Error(err)
 		return
@@ -50,10 +58,12 @@ func updateBlocklist(b store.Blocklister) {
 			log.Error(err)
 		}
 	}
+	log.Debugf("blocklist update done")
 }
 
-func blockedSdHashes() (map[string]valOrErr, error) {
-	resp, err := http.Get(blocklistURL)
+func blockedSdHashes(walletServers []string, stopper stop.Chan) (map[string]valOrErr, error) {
+	client := http.Client{Timeout: 1 * time.Second}
+	resp, err := client.Get(blocklistURL)
 	if err != nil {
 		return nil, errors.Err(err)
 	}
@@ -80,7 +90,7 @@ func blockedSdHashes() (map[string]valOrErr, error) {
 		return nil, errors.Prefix("list_blocked API call", r.Error)
 	}
 
-	return sdHashesForOutpoints(r.Data.Outpoints)
+	return sdHashesForOutpoints(walletServers, r.Data.Outpoints, stopper)
 }
 
 type valOrErr struct {
@@ -89,22 +99,33 @@ type valOrErr struct {
 }
 
 // sdHashesForOutpoints queries wallet server for the sd hashes in a given outpoints
-func sdHashesForOutpoints(outpoints []string) (map[string]valOrErr, error) {
+func sdHashesForOutpoints(walletServers, outpoints []string, stopper stop.Chan) (map[string]valOrErr, error) {
 	values := make(map[string]valOrErr)
 
 	node := wallet.NewNode()
-	defer node.Shutdown()
-	err := node.Connect([]string{
-		"spv25.lbry.com:50001",
-		"spv26.lbry.com:50001",
-		"spv19.lbry.com:50001",
-		"spv14.lbry.com:50001",
-	}, nil)
+	err := node.Connect(walletServers, nil)
 	if err != nil {
 		return nil, errors.Err(err)
 	}
 
+	done := make(chan bool)
+
+	go func() {
+		select {
+		case <-done:
+		case <-stopper:
+		}
+		node.Shutdown()
+	}()
+
+OutpointLoop:
 	for _, outpoint := range outpoints {
+		select {
+		case <-stopper:
+			break OutpointLoop
+		default:
+		}
+
 		parts := strings.Split(outpoint, ":")
 		if len(parts) != 2 {
 			values[outpoint] = valOrErr{Err: errors.Err("invalid outpoint format")}
@@ -127,5 +148,10 @@ func sdHashesForOutpoints(outpoints []string) (map[string]valOrErr, error) {
 		values[outpoint] = valOrErr{Value: hash, Err: nil}
 	}
 
+	select {
+	case done <- true:
+	default: // in case of race where stopper got stopped right after loop finished
+	}
+
 	return values, nil
 }
diff --git a/wallet/network.go b/wallet/network.go
index 20e86ba..10e4edf 100644
--- a/wallet/network.go
+++ b/wallet/network.go
@@ -115,7 +115,13 @@ func (n *Node) Connect(addrs []string, config *tls.Config) error {
 }
 
 func (n *Node) Shutdown() {
+	var addr net.Addr
+	if n.transport != nil {
+		addr = n.transport.conn.RemoteAddr()
+	}
+	log.Debugf("shutting down wallet %s", addr)
 	n.grp.StopAndWait()
+	log.Debugf("wallet stopped")
 }
 
 func (n *Node) handleErrors() {
@@ -138,6 +144,12 @@ func (n *Node) err(err error) {
 // listen processes messages from the server.
 func (n *Node) listen() {
 	for {
+		select {
+		case <-n.grp.Ch():
+			return
+		default:
+		}
+
 		select {
 		case <-n.grp.Ch():
 			return
@@ -248,6 +260,8 @@ func (n *Node) request(method string, params []string, v interface{}) error {
 
 	var r response
 	select {
+	case <-n.grp.Ch():
+		return nil
 	case r = <-c:
 	case <-time.After(n.timeout):
 		r = response{err: errors.Err(ErrTimeout)}