From 14f60a108ab5834c67a968c8c422648f1561075c Mon Sep 17 00:00:00 2001
From: Andy Butland <abutland73@gmail.com>
Date: Tue, 29 Apr 2025 18:10:44 +0200
Subject: [PATCH] V13: Clear Member Username Cache in Load Balanced
 Environments (#19191)

* Clear usernamekey

* Odd explaining comment

* Update src/Umbraco.Core/Cache/Refreshers/Implement/MemberCacheRefresher.cs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Make UserNameCachePrefix readonly for better immutabilityly

* Move prefix to CacheKeys constants

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
# Conflicts:
#	src/Umbraco.Core/Cache/CacheKeys.cs
---
 src/Umbraco.Core/Cache/CacheKeys.cs             |  2 ++
 .../Implement/MemberCacheRefresher.cs           | 17 ++++++++++++++---
 .../Repositories/Implement/MemberRepository.cs  |  7 +++----
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/Umbraco.Core/Cache/CacheKeys.cs b/src/Umbraco.Core/Cache/CacheKeys.cs
index 7f8484fca4..0e75b6820d 100644
--- a/src/Umbraco.Core/Cache/CacheKeys.cs
+++ b/src/Umbraco.Core/Cache/CacheKeys.cs
@@ -22,4 +22,6 @@ public static class CacheKeys
 
     public const string PreviewPropertyCacheKeyPrefix = "Cache.Property.CacheValues[D:";
     public const string PropertyCacheKeyPrefix = "Cache.Property.CacheValues[P:";
+
+    public const string MemberUserNameCachePrefix = "uRepo_userNameKey+";
 }
diff --git a/src/Umbraco.Core/Cache/Refreshers/Implement/MemberCacheRefresher.cs b/src/Umbraco.Core/Cache/Refreshers/Implement/MemberCacheRefresher.cs
index 18809a6bbe..1c19f62576 100644
--- a/src/Umbraco.Core/Cache/Refreshers/Implement/MemberCacheRefresher.cs
+++ b/src/Umbraco.Core/Cache/Refreshers/Implement/MemberCacheRefresher.cs
@@ -71,11 +71,22 @@ public sealed class MemberCacheRefresher : PayloadCacheRefresherBase<MemberCache
         foreach (JsonPayload p in payloads)
         {
             _idKeyMap.ClearCache(p.Id);
-            if (memberCache.Success)
+            if (memberCache.Success is false)
             {
-                memberCache.Result?.Clear(RepositoryCacheKeys.GetKey<IMember, int>(p.Id));
-                memberCache.Result?.Clear(RepositoryCacheKeys.GetKey<IMember, string>(p.Username));
+                continue;
             }
+
+            memberCache.Result?.Clear(RepositoryCacheKeys.GetKey<IMember, int>(p.Id));
+            memberCache.Result?.Clear(RepositoryCacheKeys.GetKey<IMember, string>(p.Username));
+
+            // This specific cache key was introduced to fix an issue where the member username could not be the same as the member id, because the cache keys collided.
+            // This is done in a bit of a hacky way, because the cache key is created internally in the repository, but we need to clear it here.
+            // Ideally, we want to use a shared way of generating the key between this and the repository.
+            // Additionally, the RepositoryCacheKeys actually caches the string to avoid re-allocating memory; we would like to also use this in the repository
+            // See:
+            // https://github.com/umbraco/Umbraco-CMS/pull/17350
+            // https://github.com/umbraco/Umbraco-CMS/pull/17815
+            memberCache.Result?.Clear(RepositoryCacheKeys.GetKey<IMember, string>(CacheKeys.MemberUserNameCachePrefix + p.Username));
         }
     }
 }
diff --git a/src/Umbraco.Infrastructure/Persistence/Repositories/Implement/MemberRepository.cs b/src/Umbraco.Infrastructure/Persistence/Repositories/Implement/MemberRepository.cs
index 75ea4f365d..9adc60426f 100644
--- a/src/Umbraco.Infrastructure/Persistence/Repositories/Implement/MemberRepository.cs
+++ b/src/Umbraco.Infrastructure/Persistence/Repositories/Implement/MemberRepository.cs
@@ -39,7 +39,6 @@ public class MemberRepository : ContentRepositoryBase<int, IMember, MemberReposi
     private readonly ITagRepository _tagRepository;
     private bool _passwordConfigInitialized;
     private string? _passwordConfigJson;
-    private const string UsernameCacheKey = "uRepo_userNameKey+";
 
     public MemberRepository(
         IScopeAccessor scopeAccessor,
@@ -327,7 +326,7 @@ public class MemberRepository : ContentRepositoryBase<int, IMember, MemberReposi
     }
 
     public IMember? GetByUsername(string? username) =>
-        _memberByUsernameCachePolicy.GetByUserName(UsernameCacheKey, username, PerformGetByUsername, PerformGetAllByUsername);
+        _memberByUsernameCachePolicy.GetByUserName(CacheKeys.MemberUserNameCachePrefix, username, PerformGetByUsername, PerformGetAllByUsername);
 
     public int[] GetMemberIds(string[] usernames)
     {
@@ -609,7 +608,7 @@ public class MemberRepository : ContentRepositoryBase<int, IMember, MemberReposi
 
     protected override void PersistDeletedItem(IMember entity)
     {
-        _memberByUsernameCachePolicy.DeleteByUserName(UsernameCacheKey, entity.Username);
+        _memberByUsernameCachePolicy.DeleteByUserName(CacheKeys.MemberUserNameCachePrefix, entity.Username);
         base.PersistDeletedItem(entity);
     }
 
@@ -943,7 +942,7 @@ public class MemberRepository : ContentRepositoryBase<int, IMember, MemberReposi
 
         OnUowRefreshedEntity(new MemberRefreshNotification(entity, new EventMessages()));
 
-        _memberByUsernameCachePolicy.DeleteByUserName(UsernameCacheKey, entity.Username);
+        _memberByUsernameCachePolicy.DeleteByUserName(CacheKeys.MemberUserNameCachePrefix, entity.Username);
 
         entity.ResetDirtyProperties();
     }