From: Matthias Kruk <m@m10k.eu>
Date: Wed, 1 Dec 2021 09:40:28 +0000 (+0900)
Subject: include/ipc: Use the endpoint name as name for pubsub subscriptions
X-Git-Url: https://git.corax.cc/?a=commitdiff_plain;h=4c2d817f9568881b9f53acdab909c328646e6097;p=toolbox

include/ipc: Use the endpoint name as name for pubsub subscriptions

When subscribing to a pubsub channel, a name constructed from the
hostname and pid is used for the subscription name. When multiple
processes subscribe to the same topic using the same endpoint, this
causes the endpoint to be subscribed multiple times, and multiple
messages to be received by the endpoint, when it should only receive
one message (this usage is intended for load-balancing over pubsub
channels).
This commit modifies the ipc module so that the name of the endpoint
is used for the subscription name, preventing an endpoint from being
subscribed multiple times to the same topic.
---

diff --git a/include/ipc.sh b/include/ipc.sh
index c0b99bc..642f6bc 100644
--- a/include/ipc.sh
+++ b/include/ipc.sh
@@ -25,7 +25,6 @@ __init() {
 	declare -gxr  __ipc_public="$__ipc_root/pub"
 	declare -gxr  __ipc_private="$__ipc_root/priv/$USER"
 	declare -gxr  __ipc_group="toolbox_ipc"
-	declare -gxr  __ipc_self="$HOSTNAME.$$"
 	declare -gxr  __ipc_pubsub_root="$__ipc_root/pubsub"
 
 	declare -gxir __ipc_version=1
@@ -515,7 +514,7 @@ ipc_endpoint_close() {
 	fi
 
 	while read -r subscription; do
-		if ! rm "$subscription/$__ipc_self"; then
+		if ! rm "$subscription/${name//\//_}"; then
 			log_error "Could unsubscribe $name from $subscription"
 		fi
 	done < <(find "$endpoint/subscriptions")
@@ -647,15 +646,17 @@ _ipc_endpoint_topic_subscribe() {
 	local topic="$2"
 
 	local topicdir
+	local subscription
 
 	topicdir="$__ipc_pubsub_root/$topic"
+	subscription="$topicdir/${endpoint//\//_}"
 
-	if ! ln -sf "$endpoint" "$topicdir/$__ipc_self"; then
+	if ! ln -sf "$endpoint" "$subscription"; then
 		return 1
 	fi
 
 	if ! ln -sfn "$topicdir" "$__ipc_root/$endpoint/subscriptions/$topic"; then
-		rm -f "$topicdir/$__ipc_self"
+		rm -f "$subscription"
 		return 1
 	fi