Fix SearchKeysAsync database selection and RemoveByTagAsync tag cleanup

Directory.Build.props

@@ -3,7 +3,7 @@
     <!-- General information -->
     <PropertyGroup>
         <Authors>Ugo Lattanzi</Authors>
-        <VersionPrefix>12.1.0</VersionPrefix>
+        <VersionPrefix>12.2.0</VersionPrefix>
         <!--
         <VersionSuffix>pre</VersionSuffix>
         -->
@@ -46,6 +46,10 @@ Features:
 Serializer packages (pick one): System.Text.Json, Newtonsoft, MemoryPack, MsgPack, Protobuf, ServiceStack, Utf8Json.
         </Description>
         <PackageReleaseNotes>
+v12.2.0:
+- Fixed SearchKeysAsync ignoring database number — SCAN now correctly targets the specified database instead of always scanning DB0 (#651)
+- Fixed RemoveByTagAsync not deleting the tag Set key itself, causing a slow memory leak of empty tag Sets in Redis (#650)
+
 v12.1.0:
 - Added VectorSet API for AI/ML similarity search (Redis 8.0+): VADD, VSIM, VREM, VCONTAINS, VCARD, VDIM, VGETATTR, VSETATTR, VINFO, VRANDMEMBER, VLINKS
 - Added llms.txt for AI coding assistant documentation indexing

src/core/StackExchange.Redis.Extensions.Core/Implementations/RedisDatabase.Tags.cs

@@ -38,7 +38,11 @@ public async Task<long> RemoveByTagAsync(string tag, CommandFlags flag = Command
 
         var keys = await SetMembersAsync<string>(tagKey, flag).ConfigureAwait(false);
 
-        return await RemoveAllAsync(keys, flag).ConfigureAwait(false);
+        var deletedCount = await RemoveAllAsync(keys, flag).ConfigureAwait(false);
+
+        await Database.KeyDeleteAsync(tagKey, flag).ConfigureAwait(false);
+
+        return deletedCount;
     }
 
     private Task<bool> ExecuteAddWithTagsAsync(

src/core/StackExchange.Redis.Extensions.Core/Implementations/RedisDatabase.cs

@@ -2,7 +2,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Globalization;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
@@ -482,25 +481,15 @@ public async Task<IEnumerable<string>> SearchKeysAsync(string pattern)
         pattern = $"{keyPrefix}{pattern}";
         var keys = new HashSet<string>();
 
-        foreach (var unused in ServerIteratorFactory.GetServers(connectionPoolManager.GetConnection(), serverEnumerationStrategy))
+        foreach (var server in ServerIteratorFactory.GetServers(connectionPoolManager.GetConnection(), serverEnumerationStrategy))
         {
-            ulong nextCursor = 0;
-            do
-            {
-                var redisResult = await unused.ExecuteAsync("SCAN", nextCursor.ToString(CultureInfo.InvariantCulture), "MATCH", pattern, "COUNT", "1000").ConfigureAwait(false);
-                var innerResult = (RedisResult[])redisResult!;
-
-                nextCursor = ulong.Parse((string)innerResult[0]!, CultureInfo.InvariantCulture);
-
-                var resultLines = ((string[])innerResult[1]!).ToArray();
-                keys.UnionWith(resultLines);
-            }
-            while (nextCursor != 0);
+            await foreach (var key in server.KeysAsync(dbNumber, pattern, 1000).ConfigureAwait(false))
+                keys.Add(key!);
         }
 
         return !string.IsNullOrEmpty(keyPrefix)
-            ? keys.Select(k => k[keyPrefix.Length..])
-            : keys;
+            ? keys.Select(k => k.ToString()[keyPrefix.Length..])
+            : keys.Select(k => k.ToString());
     }
 
     /// <inheritdoc/>

tests/StackExchange.Redis.Extensions.Core.Tests/CacheClientTestBase.Tags.cs

@@ -212,4 +212,25 @@ public async Task RemoveByTagAsync_ShouldReturnOneDeletedValue_Async()
 
         Assert.Equal(1, result);
     }
+
+    [Fact]
+    [Trait("Category", "Tags")]
+    public async Task RemoveByTagAsync_ShouldDeleteTagKey_Async()
+    {
+        const string testKey = "test_key";
+        const string testValue = "test_value";
+        var testClass = new Helpers.TestClass<string>(testKey, testValue);
+        const string testTag = "test_tag";
+
+        await Sut.GetDefaultDatabase().AddAsync(testKey, testClass, tags: [testTag]);
+
+        var tagKeyName = TagHelper.GenerateTagKey(testTag);
+        var tagExistsBefore = await db.KeyExistsAsync(tagKeyName);
+        Assert.True(tagExistsBefore);
+
+        await Sut.GetDefaultDatabase().RemoveByTagAsync(testTag);
+
+        var tagExistsAfter = await db.KeyExistsAsync(tagKeyName);
+        Assert.False(tagExistsAfter);
+    }
 }

tests/StackExchange.Redis.Extensions.Core.Tests/CacheClientTestBase.cs

@@ -338,6 +338,31 @@ public async Task SearchKeys_With_Key_Prefix_Should_Return_Keys_Without_Prefix_A
             Assert.Equal(keys[i], values[i].Key);
     }
 
+    [Fact]
+    public async Task SearchKeysAsync_Should_Respect_Database_Number_Async()
+    {
+        var db1 = Sut.Db1;
+        var db1Raw = db1.Database;
+
+        try
+        {
+            await db1Raw.StringSetAsync("db1_key1", "value1");
+            await db1Raw.StringSetAsync("db1_key2", "value2");
+
+            await db.StringSetAsync("db0_key1", serializer.Serialize("value_db0"));
+
+            var keysFromDb1 = (await db1.SearchKeysAsync("db1_*")).ToList();
+
+            Assert.Equal(2, keysFromDb1.Count);
+            Assert.Contains("db1_key1", keysFromDb1);
+            Assert.Contains("db1_key2", keysFromDb1);
+        }
+        finally
+        {
+            await db1Raw.ExecuteAsync("FLUSHDB");
+        }
+    }
+
     [Fact]
     public async Task Exist_With_Valid_Object_Should_Return_The_Correct_Instance_Async()
     {