feat: add generation-based cache, Stats, HasInterest, NumInterest, RemoveBatch, All, ReverseMatch to SubList

tests/NATS.Server.Tests/SubListTests.cs

@@ -156,4 +156,125 @@ public class SubListTests
         var r = sl.Match("foo.bar.baz");
         r.PlainSubs.Length.ShouldBe(3);
     }
+
+    [Fact]
+    public void Stats_returns_correct_values()
+    {
+        var sl = new SubList();
+        sl.Insert(MakeSub("foo.bar", sid: "1"));
+        sl.Insert(MakeSub("foo.baz", sid: "2"));
+        sl.Match("foo.bar");
+        sl.Match("foo.bar"); // cache hit
+
+        var stats = sl.Stats();
+        stats.NumSubs.ShouldBe(2u);
+        stats.NumInserts.ShouldBe(2ul);
+        stats.NumMatches.ShouldBe(2ul);
+        stats.CacheHitRate.ShouldBeGreaterThan(0.0);
+    }
+
+    [Fact]
+    public void HasInterest_returns_true_when_subscribers_exist()
+    {
+        var sl = new SubList();
+        sl.Insert(MakeSub("foo.bar"));
+        sl.HasInterest("foo.bar").ShouldBeTrue();
+        sl.HasInterest("foo.baz").ShouldBeFalse();
+    }
+
+    [Fact]
+    public void HasInterest_with_wildcards()
+    {
+        var sl = new SubList();
+        sl.Insert(MakeSub("foo.*"));
+        sl.HasInterest("foo.bar").ShouldBeTrue();
+        sl.HasInterest("bar.baz").ShouldBeFalse();
+    }
+
+    [Fact]
+    public void NumInterest_counts_subscribers()
+    {
+        var sl = new SubList();
+        sl.Insert(MakeSub("foo.bar", sid: "1"));
+        sl.Insert(MakeSub("foo.*", sid: "2"));
+        sl.Insert(MakeSub("foo.bar", queue: "q1", sid: "3"));
+
+        var (np, nq) = sl.NumInterest("foo.bar");
+        np.ShouldBe(2); // foo.bar + foo.*
+        nq.ShouldBe(1); // queue sub
+    }
+
+    [Fact]
+    public void RemoveBatch_removes_all()
+    {
+        var sl = new SubList();
+        var sub1 = MakeSub("foo.bar", sid: "1");
+        var sub2 = MakeSub("foo.baz", sid: "2");
+        var sub3 = MakeSub("bar.qux", sid: "3");
+        sl.Insert(sub1);
+        sl.Insert(sub2);
+        sl.Insert(sub3);
+        sl.Count.ShouldBe(3u);
+
+        sl.RemoveBatch([sub1, sub2]);
+        sl.Count.ShouldBe(1u);
+        sl.Match("foo.bar").PlainSubs.ShouldBeEmpty();
+        sl.Match("bar.qux").PlainSubs.ShouldHaveSingleItem();
+    }
+
+    [Fact]
+    public void All_returns_every_subscription()
+    {
+        var sl = new SubList();
+        var sub1 = MakeSub("foo.bar", sid: "1");
+        var sub2 = MakeSub("foo.*", sid: "2");
+        var sub3 = MakeSub("bar.>", queue: "q", sid: "3");
+        sl.Insert(sub1);
+        sl.Insert(sub2);
+        sl.Insert(sub3);
+
+        var all = sl.All();
+        all.Count.ShouldBe(3);
+        all.ShouldContain(sub1);
+        all.ShouldContain(sub2);
+        all.ShouldContain(sub3);
+    }
+
+    [Fact]
+    public void ReverseMatch_finds_patterns_matching_literal()
+    {
+        var sl = new SubList();
+        var sub1 = MakeSub("foo.bar", sid: "1");
+        var sub2 = MakeSub("foo.*", sid: "2");
+        var sub3 = MakeSub("foo.>", sid: "3");
+        var sub4 = MakeSub("bar.baz", sid: "4");
+        sl.Insert(sub1);
+        sl.Insert(sub2);
+        sl.Insert(sub3);
+        sl.Insert(sub4);
+
+        var result = sl.ReverseMatch("foo.bar");
+        result.PlainSubs.Length.ShouldBe(3); // foo.bar, foo.*, foo.>
+        result.PlainSubs.ShouldContain(sub1);
+        result.PlainSubs.ShouldContain(sub2);
+        result.PlainSubs.ShouldContain(sub3);
+    }
+
+    [Fact]
+    public void Generation_ID_invalidates_cache()
+    {
+        var sl = new SubList();
+        sl.Insert(MakeSub("foo.bar", sid: "1"));
+
+        // Prime cache
+        var r1 = sl.Match("foo.bar");
+        r1.PlainSubs.Length.ShouldBe(1);
+
+        // Insert another sub (bumps generation)
+        sl.Insert(MakeSub("foo.bar", sid: "2"));
+
+        // Cache should be invalidated by generation mismatch
+        var r2 = sl.Match("foo.bar");
+        r2.PlainSubs.Length.ShouldBe(2);
+    }
 }