From 2735abe0608c7e7afe58888a8b46b6fd7982095f Mon Sep 17 00:00:00 2001
From: fiatjaf <fiatjaf@gmail.com>
Date: Fri, 3 Apr 2026 08:26:56 -0300
Subject: [PATCH] khatru: listener needed a xsync.Map instead of a map, because
 of concurrent access.

---
 khatru/listener.go | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/khatru/listener.go b/khatru/listener.go
index 4a4f5a6..48a6e3e 100644
--- a/khatru/listener.go
+++ b/khatru/listener.go
@@ -7,6 +7,7 @@ import (
 
 	"fiatjaf.com/lib/set"
 	"fiatjaf.com/nostr"
+	"github.com/puzpuzpuz/xsync/v3"
 )
 
 var ErrSubscriptionClosedByClient = errors.New("subscription closed by client")
@@ -31,7 +32,7 @@ type subscription struct {
 
 type dispatcher struct {
 	serial        int
-	subscriptions map[int]subscription
+	subscriptions *xsync.MapOf[int, subscription]
 	byAuthor      map[nostr.PubKey]set.Set[int]
 	byKind        map[nostr.Kind]set.Set[int]
 	fallback      set.Set[int]
@@ -39,7 +40,7 @@ type dispatcher struct {
 
 func newDispatcher() dispatcher {
 	return dispatcher{
-		subscriptions: make(map[int]subscription, 100),
+		subscriptions: xsync.NewMapOf[int, subscription](),
 		byAuthor:      make(map[nostr.PubKey]set.Set[int]),
 		byKind:        make(map[nostr.Kind]set.Set[int]),
 		fallback:      set.NewSliceSet[int](),
@@ -50,7 +51,7 @@ func (d *dispatcher) addSubscription(sub subscription) int {
 	d.serial++
 	ssid := d.serial
 
-	d.subscriptions[ssid] = sub
+	d.subscriptions.Store(ssid, sub)
 
 	indexed := false
 	if sub.filter.Authors != nil {
@@ -85,11 +86,10 @@ func (d *dispatcher) addSubscription(sub subscription) int {
 }
 
 func (d *dispatcher) removeSubscription(ssid int) {
-	sub, ok := d.subscriptions[ssid]
+	sub, ok := d.subscriptions.LoadAndDelete(ssid)
 	if !ok {
 		return
 	}
-	delete(d.subscriptions, ssid)
 
 	indexed := false
 	if sub.filter.Authors != nil {
@@ -132,7 +132,7 @@ func (d *dispatcher) candidates(event nostr.Event) iter.Seq[subscription] {
 
 		if hasAuthorSubs && hasKindSubs {
 			for _, ssid := range authorSubs.Slice() {
-				sub, _ := d.subscriptions[ssid]
+				sub, _ := d.subscriptions.Load(ssid)
 
 				if kindSubs.Has(ssid) {
 					if filterMatchesTimestampConstraintsAndTags(sub.filter, event) {
@@ -147,7 +147,8 @@ func (d *dispatcher) candidates(event nostr.Event) iter.Seq[subscription] {
 			}
 		} else if hasAuthorSubs {
 			for _, ssid := range authorSubs.Slice() {
-				sub, _ := d.subscriptions[ssid]
+				sub, _ := d.subscriptions.Load(ssid)
+
 				if sub.filter.Kinds != nil {
 					// if there are any kinds in the filter we already know this doesn't qualify
 					continue
@@ -161,7 +162,8 @@ func (d *dispatcher) candidates(event nostr.Event) iter.Seq[subscription] {
 			}
 		} else if hasKindSubs {
 			for _, ssid := range kindSubs.Slice() {
-				sub, _ := d.subscriptions[ssid]
+				sub, _ := d.subscriptions.Load(ssid)
+
 				if sub.filter.Authors != nil {
 					// if there are any authors in the filter we already know this doesn't qualify
 					continue
@@ -176,7 +178,8 @@ func (d *dispatcher) candidates(event nostr.Event) iter.Seq[subscription] {
 		}
 
 		for _, ssid := range d.fallback.Slice() {
-			sub, _ := d.subscriptions[ssid]
+			sub, _ := d.subscriptions.Load(ssid)
+
 			if filterMatchesTimestampConstraintsAndTags(sub.filter, event) {
 				if !yield(sub) {
 					return
@@ -211,8 +214,8 @@ func tagKeyValueKey(tagKey, tagValue string) string {
 }
 
 func (rl *Relay) GetListeningFilters() []nostr.Filter {
-	respfilters := make([]nostr.Filter, 0, len(rl.dispatcher.subscriptions))
-	for _, sub := range rl.dispatcher.subscriptions {
+	respfilters := make([]nostr.Filter, 0, rl.dispatcher.subscriptions.Size())
+	for _, sub := range rl.dispatcher.subscriptions.Range {
 		respfilters = append(respfilters, sub.filter)
 	}
 	return respfilters