From 7482d6950eb1fc554ff2c035dcf33c725a421003 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Toma=C5=BE=20Su=C5=A1nik?= <tomaz.susnik@cosylab.com>
Date: Tue, 28 Jul 2026 18:38:04 +0200
Subject: [PATCH] Client: match subscriptions by context, not path only

Add SubscriptionMatcher.pathAndContext() to select path-and-context matching
without naming Filter classes, and use it in OpenCmwDataSource. Notifications
are attributed to a subscription by the context keys whose Filter is registered
in FilterRegistry; keys without one are ignored.

Selecting context matching previously required passing Filter classes to the
constructor, which also registers them globally. A client that registers its
filters elsewhere had no way to enable it, so OpenCmwDataSource compared the
URI path only and could not tell apart concurrent subscriptions that differ
only by their query.
---
 .../io/opencmw/client/OpenCmwDataSource.java  |  5 ++++-
 .../opencmw/filter/SubscriptionMatcher.java   | 15 +++++++++++++++
 .../filter/SubscriptionMatcherTest.java       | 19 +++++++++++++++++++
 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/client/src/main/java/io/opencmw/client/OpenCmwDataSource.java b/client/src/main/java/io/opencmw/client/OpenCmwDataSource.java
index 592a4358..5558a811 100644
--- a/client/src/main/java/io/opencmw/client/OpenCmwDataSource.java
+++ b/client/src/main/java/io/opencmw/client/OpenCmwDataSource.java
@@ -96,7 +96,10 @@ public List<DnsResolver> getRegisteredDnsResolver() {
     private final ZMonitor socketMonitor;
     private final Map<String, URI> subscriptions = new HashMap<>(); // NOPMD: not accessed concurrently
     private final URI serverUri;
-    private final BiPredicate<URI, URI> subscriptionMatcher = new SubscriptionMatcher(); // <notify topic, subscribe topic>
+    // <notify topic, subscribe topic>
+    // Context matching differentiates subscriptions to the same path by the context keys whose Filter
+    // implementations are registered in FilterRegistry; keys without one are ignored.
+    private final BiPredicate<URI, URI> subscriptionMatcher = SubscriptionMatcher.pathAndContext();
     private final long heartbeatInterval;
     private Future<URI> dnsWorkerResult;
     private long nextReconnectAttemptTimeStamp;
diff --git a/core/src/main/java/io/opencmw/filter/SubscriptionMatcher.java b/core/src/main/java/io/opencmw/filter/SubscriptionMatcher.java
index 742d1123..7ecdb55d 100644
--- a/core/src/main/java/io/opencmw/filter/SubscriptionMatcher.java
+++ b/core/src/main/java/io/opencmw/filter/SubscriptionMatcher.java
@@ -28,6 +28,21 @@ public SubscriptionMatcher(final Class<? extends Filter>... filterConfig) {
         FilterRegistry.registerNewFilter(filterConfig);
     }
 
+    private SubscriptionMatcher(final boolean pathOnly) {
+        isPathOnly = pathOnly;
+    }
+
+    /**
+     * Matcher that compares path and context, discriminating on whichever filters are registered in
+     * the global {@link FilterRegistry} when a match is evaluated. Use this when the filters are
+     * registered elsewhere, rather than naming them here.
+     *
+     * @return context-aware matcher that registers no filters of its own
+     */
+    public static SubscriptionMatcher pathAndContext() {
+        return new SubscriptionMatcher(false);
+    }
+
     @Override
     public boolean test(final @NotNull URI notified, final @NotNull URI subscriber) {
         return isPathOnly ? testPathOnly(notified, subscriber) : testPathAndContext(notified, subscriber);
diff --git a/core/src/test/java/io/opencmw/filter/SubscriptionMatcherTest.java b/core/src/test/java/io/opencmw/filter/SubscriptionMatcherTest.java
index d574b43f..dce3d677 100644
--- a/core/src/test/java/io/opencmw/filter/SubscriptionMatcherTest.java
+++ b/core/src/test/java/io/opencmw/filter/SubscriptionMatcherTest.java
@@ -75,6 +75,25 @@ void testMatcherTimingContentContext() {
         test(matcher, false, "property?ctx=FAIR.SELECTOR.ALL", "property?ctx=FAIR.SELECTOR.C=2&contentType=text/html");
     }
 
+    @Test
+    void testMatcherPathAndContextFactory() {
+        // filters registered elsewhere, none named at construction
+        FilterRegistry.registerNewFilter(TestFilter1.class);
+
+        final BiPredicate<URI, URI> matcher = SubscriptionMatcher.pathAndContext();
+
+        // subscriptions to the same path differing only by a registered context key must not cross-match
+        test(matcher, false, "property/A?testKey1=41", "property/A?testKey1=42");
+        test(matcher, false, "property/A?testKey1=42", "property/A?testKey1=41");
+        test(matcher, true, "property/A?testKey1=42", "property/A?testKey1=42");
+
+        // unregistered context keys keep their existing 'ignore' semantics on either side
+        test(matcher, true, "property/A?testKey1=42&unknownKey=x", "property/A?testKey1=42");
+        test(matcher, true, "property/A?testKey1=42", "property/A?testKey1=42&unknownKey=x");
+        test(matcher, true, "property/A?testKey1=42", "property/A*");
+        test(matcher, false, "property/A?testKey1=42", "property/B?testKey1=42");
+    }
+
     private static void test(final BiPredicate<URI, URI> matcher, final boolean expected, final String notify, final String subscription) throws AssertionFailedError {
         final boolean actual = matcher.test(URI.create(notify), URI.create(subscription));
         if (actual != expected) {