## Summary
- **Add a self-referencing `InterpolationHandler` to `ValueStringBuilder`** that writes directly into the builder's buffer — zero intermediate allocation, works with `stackalloc`-backed builders
- **Replace all `System.Text.StringBuilder` usage** across the codebase with `ValueStringBuilder`
- **Convert `ValueStringBuilder.Create()` to `stackalloc`** at 10 sites where output length is provably bounded
- **Convert manual `Dispose()` to `using var`** where possible, and hoist loop-scoped builders outside loops with `Reset()`
- **Convert verbose `Append()` chains to `Append($"...")`** interpolation for readability
- **Add comprehensive documentation** for string handling patterns
## InterpolationHandler Design
`ValueStringBuilder` is a `ref struct`, which creates challenges for C#'s interpolated string handler pattern:
- **`ref` fields to ref structs are not allowed** (CS9050)
- **`[InterpolatedStringHandlerArgument("")]` passes struct receivers by value**, not by ref
- **`ISelfInterpolatedStringHandler` requires boxing** ref structs into interface fields
**Solution: Copy-and-reconcile pattern.** The handler receives a value copy of the builder. The copy shares the same underlying `char` buffer (`Span` points to the same `stackalloc`/pooled memory), so writes go to the original buffer. `Append()` reconciles by `this = handler._builder`, updating `_length` and any buffer references changed by `Grow()`.
This is safe because:
- The game loop is single-threaded — no concurrent access between handler construction and reconciliation
- If `Grow()` occurs in the copy, the original's stale buffer isn't accessed until `Append()` replaces it
- `Dispose()` correctly returns the reconciled buffer to the pool
## Changes by Category
### ValueStringBuilder (`Projects/Server/Buffers/ValueStringBuilder.cs`)
- Added nested `InterpolationHandler` ref struct with copy-and-reconcile pattern
- Added `Append([InterpolatedStringHandlerArgument("")] scoped ref InterpolationHandler)` method
- Removed `RawInterpolatedStringHandler` overloads (new handler replaces them)
- All `AppendFormatted` overloads delegate to existing `Append` methods (no code duplication)
- Alignment support via direct private field access (nested type privilege)
### StringBuilder → ValueStringBuilder (15 files)
Replaced all `new StringBuilder()` with `ValueStringBuilder.Create()` or `stackalloc`:
- ConPVP games: KingOfTheHill, DoubleDom, CTF, BombingRun, TourneyMatch
- ConPVP infrastructure: Tournament, Participant, TourneyParticipant
- ConPVP gumps: ArenaGump, TournamentBracketGump, AcceptTeamGump, ConfirmSignupGump
- Commands: Handlers, Logging, Add
- Other: TownCrier, SpeechLogGump, TestCenter
Key patterns:
- `sb = new StringBuilder()` reassignment → `sb.Reset()`
- `sb.AppendFormat("{0:N0}", value)` → `sb.Append($"{value:N0}")`
- `sb.Append(x).Append(y)` chains → separate statements (VSB returns void)
### Create() → stackalloc (10 files)
Converted heap-allocated builders to stackalloc where output is bounded:
- ClientVersion (32), MapSelection (160), HouseRaffleStone (48)
- HolySense (96), UnholySense (96), ClientVerification (192)
- AcceptTeamGump (64), ConfirmSignupGump (64)
- BaseWeapon (160), BaseArmor (128)
### Loop optimizations (2 files)
Hoisted `ValueStringBuilder` creation outside loops with `Reset()` per iteration:
- TourneyMatch.cs: `using var` inside for loop → stackalloc before loop
- ArenaGump.cs: `Create()` + `Dispose()` per iteration → stackalloc before loop
### Append chain → interpolation (5 files)
Converted multi-line `Append()` chains to `Append($"...")`:
- BountyMessage.cs: title switch (6 cases), paragraph (15→1 Append), description lines, closing
- AcceptTeamGump, ConfirmSignupGump, TournamentBracketGump: tournament type strings
- AdminGump: comment/tag formatting in loops
### Documentation
- `dev-docs/string-handling.md`: Full reference — construction, interpolation, disposal, decision guide
- `dev-docs/claude-skills/modernuo-string-handling.md`: Claude skill with quick reference
- `CLAUDE.md`: Added rule 17 (no StringBuilder), dev-docs table entry, skills table entry
- `dev-docs/code-standards.md`: Updated memory management section
## Test Plan
- [x] `dotnet build` — 0 errors, 0 warnings
- [x] `dotnet test` — 940/940 tests pass
- [x] 28 ValueStringBuilder tests covering all reconciliation scenarios:
- Stackalloc no-grow, stackalloc with grow (→pool transition)
- Heap no-grow, heap with grow, heap double grow
- Pre-existing content with and without grow
- Sequential multiple `Append($"...")` calls
- Mixed plain + interpolated Append
- Empty interpolation, literal-only, format specifiers
- Null string holes, ISpanFormattable types
- Dispose after stackalloc→pool grow
## Summary
- Adds `public virtual bool Murderer => Kills >= 5` property to `Mobile`, replacing ~30 scattered `Kills >= 5` / `Kills < 5` magic-number checks across the codebase
- `BaseCreature` overrides `Murderer` to also return `true` when `AlwaysMurderer` is set
- Updates `Corpse` serialization to v15, storing `_murderer` as a `bool` field (migrated from `int Kills >= 5` in earlier versions)
### Summary
- Fix AccountGold gold duplication exploit: When AccountGold.Enabled was true, double-clicking a BankCheck deposited
the full value to the account but then continued creating physical gold piles for the same amount, duplicating the
value
- Fix Deposit/DepositUpTo partial deposit exploit: Both methods created new max-size gold piles and checks without
first filling existing partial stacks, wasting container slots and causing premature "bank full" failures that could
be leveraged to manipulate gold distribution
- Fix BagOfSending bank stacking: Gold and BankCheck items sent via BagOfSending now use Banker.Deposit for efficient
stacking instead of naive TryDropItem, which could fail on a full bank even when existing piles had room
- Improve gold/check deposit efficiency: Banker.Deposit and Banker.DepositUpTo now top off existing gold piles (up to
60k) and bank checks (up to 1M) before creating new items, maximizing use of available container slots
> [!IMPORTANT]
> **Developer Note**
> THIS IS A BREAKING CHANGE TO THE NEW API GUMP.
> Please give us feedback in [discord ](https://muo.gg/discord) if you have issues, need help, or have ideas for a better API change!
### Summary
* Adds support for size/style to dynamic/static builder.
* Drastically simplifies the dynamic/static builder api for AddHtml.
* Cleans up some legacy gump files.
### Summary
- Adds [Code Generated Events](https://github.com/modernuo/CodeGeneratedEvents)
- Removes EventSink.PlayerDeath
- Adds `PlayerDeathEvent` and `CreatureDeathEvent` using code generated events
> [!Important]
> **Developer Note**
> Use `[OnEvent(nameof(PlayerMobile.PlayerDeathEvent))]` instead of `EventSink.PlayerDeath` delegate
> Check this commit for examples of how to use this.
> [!Important]
> **Developer Note**
> This code change will **completely move gumps out of the core**
### Summary
- Adds `GetGumps()` convenience which exposes methods to Find/Close/Send multiple gumps. This helper is a performance improvement by eliminating the Dictionary<Player, List> lookup for gumps.
## Summary
- Removes allocation of a `List<ContextMenuEntry>` every time a context menu is created.
- Moves packet/context menu creation logic out of the core
- Fixes tame entry
## BREAKING CHANGE
> [!Important]
> **Developer Note**
> ```cs
> public virtual void GetContextMenuEntries(Mobile from, List<ContextMenuEntry> list)
> ```
> and similar functions changed to
> ```cs
> public virtual void GetContextMenuEntries(Mobile from, ref PooledRefList<ContextMenuEntry> list)
> ```
### Summary
- Generalizes the On/Off toggle items concept
- Updates the OnOffGump so it is static
- Standardizes OnOff items so they can be used by staff
### Notes
Decided to not fix#1417 because it is not clear that the clilocs or errors are for that purpose. Can't test this on OSI anyways.
## Summary
### Changes
- Adds `[IgnoreDupe]` and `[SerializedIgnoreDupe]`
- Updates all _known_ classes that need the attribute. Some might be missing, please helps us find them!
- Adds `Item.Dupe()` command and encapsulates `CopyProperties` and `OnAfterDuped`. This is also overridable.
- Updates Dupe command to use the new logic.
- Fixes duping multiple kinds of objects that used to be outright broken.
### Bug Fixes
- Fixes issue with durability after duping
- Fixes issue with hue after duping
> [!Note]
> **Developer Note**
> Customizing how duping an item works now requires two steps:
> 1. Add `[IgnoreDupe]` or `[SerializedIgnoreDupe]` to the property/field
> 2. Add custom logic in an `OnAfterDuped` override
>
> When do you need to do this?
> *When the property being copied is not a primitive, and you need to manually deep-clone the contents of the property such as with Lists, Dictionaries, or sub classes.*
### Summary
- Fixes an issue that causes CUO to crash due to bad string caching in static gumps
- Fixes wrong/bad 16bit html gump hues.
- Moves `C16232` (16-bit to 32-bit) and `C32216` (32-bit to 16-bit) to Utility class for broader use.
TODO:
- Some gumps have different 32bit (for string content) vs 16bit (for localized content) strings. Does this matter?
### Summary
* Adds `StaticNoticeGump<T>` and `StaticWarningGump<T>`
* Converts NoticeGump/WarningGump to use `DynamicGump`
* Changes various uses of notice gump and warning gump to their static counterpart.
### Summary
- Fixes edge case calculations with values that aren't exact.
- Fixes skill text casing.
- Fixes cliloc error for stat cap scroll gump.
- Adds `AosSkillBonuses.GetLowercaseLabel()` for lower case localized skill names.
- Fixes initial value for constructing a stat scroll so it isn't negative.
- Fixes message for Scroll of Alacrity gump.
- Fixes missing property invalidation for Skill/Value.
## Breaking Changes
* The Firewall and IP Limiter have been rewritten. Please read the notes carefully!
* `TcpServer.Instances` moved back to `NetState.Instances` - sorry - it was stupid to move it to begin with.
> [!Note]
> Sockets that fail the IP Limiter or Firewall will be immediately and forcibly disconnected.
> This means they will be stuck at "Verifying account..." if it was a real client.
### Summary
- Removes firewall wildcard support.
- Removes `AccessRestrictions`.
- Moves Firewall/IPLimiter to the core.
- Moves `TcpServer` to its own thread.
- Removes the `SocketConnect` and `SocketDisconnect` event sinks.
- Moves `Instances` back to `NetState.Instances`.
- Fixes a long standing bug with bad handling of duplicate listener addresses.
#### Firewall
The firewall has been completely rewritten. There is now an "Admin Firewall" which saves to the config file. Secondarily, there is an internal firewall used exclusively by the TcpServer while processing sockets. The Admin firewall mirrors it's additions/deletions to the internal firewall by adding requests to a queue.
> [!IMPORTANT]
> **Wildcard firewall entries, such as `X`, `*`, `?` are not allowed.**
> **Ranges in between IP classes or sextets are not allowed.**
> **Please make sure to use one of the following:**
> * IP Address - `192.168.1.1`
> * CIDR - `192.168.1.0/24`
> * Range - `192.168.1.1-192.168.1.100`
#### IP Limiter
The IP Limiter has been completely rewritten. The available configurations are:
```json
"ipLimiter.enable": "True",
"ipLimiter.maxConnectionsPerIP": 10,
"ipLimiter.clearConnectionAttemptsDuration": "00:00:00:10",
"ipLimiter.clearThrottledDuration": "00:00:02:00",
```
The IP Limiter is set up to prevent spamming connections from the same IP. Every time an IP connects, it is added to a connection list. After 10 attempts, the IP is added to the throttle list. To keep the system fast, the connection list is entirely wiped every 10 seconds, and the throttle list is entirely wiped every 2 minutes.
### Summary
- Fixes issues with non-_ISerializable_ objects having bad serialization (Skill/Stat. Mods)
- Fixes issues with MarkDirty and namespaces: https://github.com/modernuo/SerializationGenerator/issues/29
- Fixes missing dirty tracking for some data structures.
- Fixes cascading MarkDirty for non-serializable types that have owners that are also non-serializable types.
### New Codegenned API
When a data structure (Array, List, Dictionary, HashSet, etc) is source generated for serialization, new methods are added which will handle dirty tracking. Use these instead of the built in methods for that data structure.
_All Data Structures_
```cs
public void Clear<PropertyName>();
```
_Lists and Sets_
```cs
public void AddTo<PropertyName>(V value);
public void RemoveFrom<PropertyName>(V value);
```
_Lists_
```cs
public void InsertInto<PropertyName>(int index, V value);
public void RemoveFrom<PropertyName>At(int index);
```
_Dictionaries_
```cs
public void AddTo<PropertyName>(T key, V value);
public void RemoveFrom<PropertyName>(T key);
public void ReplaceIn<PropertyName>(T key, V value);
```
Over time, they will be cleaned up and more variants added such as `bool RemoveFrom<PropertyName>(T key, out V value)`
## MAJOR CHANGE (API BREAKING)
Moved the virtues to it's own system _VirtueSystem_. This should make it easier to extend or remove the virtue system. Virtues will be saved to a new folder called _Virtues_.
### Motivation
The motivation was also two-fold, performance/stability, and to fix bugs.
First, virtues is the second system (first is murders), that has a pre-world-save check on _every mobile in the game_ to atrophy virtue stats. This is taxing since it freexes the world and makes world saves take longer. Every mobile had Gain/Loss dates for each virtue, whether they needed them or not. Most players don't even use the virtue system, so this will increase performance considerably.
Second, when I tried to optimize/refactor the code, I found several bugs that needed to be fixed.
### Major API Changes
- [X] The properties on players related to virtues are gone. Use `pm.GetVirtues()?.<PropertyName>` instead.
- [X] Virtues were removed from non-player Mobiles.
- [X] `pm.JusticeProtectors` was removed. Use `JusticeVirtue.GetProtector()` or `JusticeVirtue.GetProtected()` instead.
### Screenshots
<img width="221" alt="Props-1" src="https://github.com/modernuo/ModernUO/assets/3953314/5c09cb83-b8d5-44a2-b899-a7ed7cd736ac">
<img width="220" alt="props-2" src="https://github.com/modernuo/ModernUO/assets/3953314/aeade4d3-8df0-47bd-955a-a864d0946cf7">
## **MAJOR CHANGE**
* `Stabled` has been moved to `PlayerMobile`.
* New methods added, `PlayerMobile.AddStabled` and `PlayerMobile.RemoveStabled`.
* Added `PlayerMobile.AddFollower` and `PlayerMobile.RemoveFollower`.
* `Stabled`, `AutoStabled`, and `AllFollowers` are now `HashSet` and **_CAN BE NULL_**.
### Summary
* Fixes monster abilities causing harm to the monster through reflect
* Adds `CanTriggerAgainstSelf` to override this for healing or some other self-affecting ability
* Fixes a major memory leak where `UnsummonTimer` from animated dead spell lasts up-to 24hrs and therefore holds onto references of dead/deleted mobs.
* Fixes another minor leak where a mob is not unregistered from the animated dead spell list until the next spell cast.
### Summary
- [X] Fixes 4 TormentedMinotaur created at `(0, 0, 0) [null]` when `[add` is used.
- [X] Fixes client crash from a bug in HouseRaffleStone when `[add` is used.
Recommend viewing with [_whitespace disabled_](https://github.com/modernuo/ModernUO/pull/1404/files?diff=split&w=1)
### Summary
- [X] Fixes a bug in wall banner East setter: [[ServerUO#5046]](https://github.com/ServUO/ServUO/pull/5046)
- [X] Eliminates the timer in tree stump.
- [X] Codegens the rewards
