# New Gump API
We are pleased to release a new API that is faster, allocates nearly zero memory, and still feels very similar to the original API. The API is broken into 3 types of gumps, dynamic, static with placeholders, and static without placeholders.
### Dynamic Gumps
These gumps will inherit `DynamicGump` and are meant for gumps that have a dynamic layout. This includes specifying dynamic arguments to HtmlLocalized entries.
## Static Gumps
Static gumps are those where the function to the build the layout is called only once and cached forever. They can optionally have placeholders. These placeholders allow the developer to specify the string values later, dynamically in a `BuildStrings` method on the gump. If a gump does not have any placeholders, the string entries will also be cached forever.
## Benchmarks
To make sure we were going in the right direction and not wasting time, we took copious benchmarks. Here are the final benchmarks for a really simple gump.
Note:
* The majority of creating a gump is compressing the layout and the strings. Compressing each section takes ~6,000ns (12us total).
```cs
| Method | Mean | Error | StdDev | Median | Ratio | RatioSD | Gen0 | Allocated | Alloc Ratio |
|------------------------------- |-------------:|-------------:|-------------:|-------------:|------:|--------:|-------:|----------:|------------:|
| OldGump | 13,308.29 ns | 1,059.695 ns | 1,883.608 ns | 14,330.72 ns | 1.000 | 0.00 | 0.1526 | 2400 B | 1.00 |
| DynamicLayoutGump | 13,357.86 ns | 129.144 ns | 226.185 ns | 13,323.60 ns | 1.029 | 0.17 | - | 48 B | 0.02 |
| StaticLayoutDynamicStringsGump | 6,653.10 ns | 81.815 ns | 143.292 ns | 6,617.45 ns | 0.514 | 0.09 | - | 40 B | 0.02 |
| StaticLayoutGump | 86.33 ns | 0.760 ns | 1.350 ns | 86.07 ns | 0.007 | 0.00 | 0.0020 | 32 B | 0.01 |
```
# Non-Breaking Changes
* All gump components in the core have been moved to `Gumps/Legacy`.
* All legacy gumps will still inherit `Gump`, which now inherits `BaseGump`
# Special Thanks
Thank you to @stefanomerotta for considerable contributions/benchmarking/testing to make this effort a reality! We collectively went through over 10 iterations, but it is finally ready.
## Breaking Changes
Incoming packet registration signature has changed to:
```cs
delegate* void OnReceiveCallback(NetState state, SpanReader reader, int packetLength);
IncomingPackets.Register(int packetID, int length, bool ingame, OnReceiveCallback onReceive);
```
For example, an incoming packet handler signature would now look like this:
```cs
public static void SomeIncomingPacket(NetState state, SpanReader reader, int packetLength)
{
// Parse the data
}
```
## Summary
Updates the network Pipe class to use a mirrored memory technique. This technique involves mapping the same physical memory to two contiguous virtual memory spaces so the byte buffer appears duplicated. This allows writing to a double-sized array to wrap around without the need for the `CircularBuffer` classes.
In practice this allows us to use `Span<byte>` as if the buffer was a regular array.
### Bug Fixes
- [X] Fixes bad fixed length string parsing
**Only one functional change**
* Fixes a bug in LogFactory where `Warning` is being logged as `Information`
Non-functional changes:
* Updates/Fixes copyright headers
* Removes namespace scopes for core files.
View with [whitespace off](https://github.com/modernuo/ModernUO/pull/1187/files?w=1).
- [X] Fixes NPE from account tags.
- [X] Fixes bad skill check due to missing cast to double.
- [X] Fixes water elemental duration.
- [X] Standardizes spell summon duration by expansion.
## Breaking Changes (New API)
ObjectPropertyList supports the following API:
```cs
list.Add(500000);
list.Add(500001, stringArgument);
list.Add("Some text");
list.Add($"Some text with {argument}");
list.Add(500002, $"{arg1}\t{arg2}");
```
## Notes
1. All API uses that require a formatter like this:
```cs
list.Add(500002, "{0}\t{1}", arg1, arg2);
```
Should be changed to use string interpolation, for example:
```cs
list.Add(500002, $"{arg1}\t{arg2}");
```
2. The following paradigm should no longer be used:
```cs
list.Add(1061170, prop.ToString()); // strength requirement ~1_val~
```
The new string interpolation API will avoid having to convert the argument to a string before writing it to the packet. Instead use the following:
```cs
list.Add(1061170, $"{prop}"); // strength requirement ~1_val~
```
### Benchmarks
```cs
| Method | Mean | Error | StdDev | Gen 0 | Allocated |
|------------------------------- |---------:|--------:|--------:|-------:|----------:|
| BenchmarkOldOPL | 241.0 ns | 0.56 ns | 0.47 ns | 0.0105 | 88 B |
| BenchmarkStringInterpolatedOPL | 199.9 ns | 2.44 ns | 2.39 ns | - | - |
```
### Changes
- [X] Removes crash in STArray.Return when array is null.
- [X] Fixes NPE in OPL when entity is null. Serial in packet will be 0 when entity is null.
- [X] Fixes NPE in AosAttributes when Parent is null.
- [X] Changes OPL to use string interpolation.
- [X] Introduces `IPropertyList` to allow extending PropertyList for other uses.
* Introduces `RawInterpolatedStringHandler` which is exactly the same as `DefaultInterpolatedStringHandler` except it _unsafely exposes_ it's `ReadOnlySpan<char>` buffer. This is useful for writing the string's data without actually building the string.
* Uses this new string interpolation handler in `SpanWriter` to eliminate intermediate strings built. This is immensely useful in eliminating string allocations in writing Gump packets.
Adds. Gen2Callback for STArrayPool so it can purge the internal array stacks properly. This only happens if significant timed has passed, 2 Gen 2's have been run, and memory pressure exceeds a threshold.
### Enabling Packet Logging
`[packetlogging on` and target the user.
Supports command modifiers such as:
`[online packetlogging on where accesslevel = player`
Logs are saved in `path/<ip address>/packets.log`. It is a simple append-format log with no date splitting.
- [X] Adds `AdhocPersistence` which replaces RunUO `Persistence`
- [X] Fixes a few minor bugs with EntityPersistence deserialization
- [X] Reverts/updates some serialization changes
- [X] Fixes map issues at New Haven by turning off static diffs
- [X] Some code cleanup and reformatting of tile matrix, tile matrix patch, and tile data
- [X] Adds NetState.Flush for generating spawners so it doesn't feel like the server is frozen
- [X] Reverts NativeReader changes from a while back.
- [X] Adds more string reading for BufferReader.
Notes:
BufferReader is still `little endian` compared to `SpanReader` which is `big endian` (for packets). To that end, the RunUO deserialization `ReadString()` was made obsolete since it is ambiguous, and contains extra fields other than simply reading a string. Furthermore, we shouldn't be using UTF8 (for now) since it is slow.
- [X] Adds `ToSpan()` for SpanWriter.
- [X] Moves house files to UOContent/Multis/Houses
- [X] Adds house packets
### SpanWriter.ToSpan()
`ToSpan()` returns an `SpanOwner` struct which allows access to the buffer as a Span by calling `Span`.
Example:
```cs
public SpanOwner CreatePacket()
{
var writer = new SpanWriter(0x400);
// write some stuff
return writer.ToSpan();
}
```
In this example, we are creating a packet and returning the `SpanOwner` for caching. This means in the future we can do something like this:
```cs
ns.Send(_cachedPacket.Span);
```
Where `_cachedPacket` is the `SpanOwner`
Notes:
Do not use a SpanWriter, or attempt to dispose of it after calling `ToSpan()`. Doing so will probably cause an NPE.
- [X] Cleans up gump packets
- [X] Adds event loop task synchronization
- [X] Moves timer pause and cleans up the delay task timer class
- [X] Cleans up the conserve cpu
- [X] Renames variables to make them consistent with the new style
- [X] Removes process delta recursion checking.
- [X] Properly diposes net states. This fixes edge cases that may cause hanging connections to stay open longer than they should.
- [X] Fixes an issue with gump items not compiling properly
Users can now utilize `Timer.Pause()` since the code will be executed on the proper thread.
```cs
public void async void Talk()
{
_canTalk = false;
await Timer.Pause(Utility.RandomMinMax(5000, 8000)); // Talk after 5-8 seconds
DoTalk();
await Timer.Pause(Utility.RandomMinMax(12000, 25000)); // Reset ability to talk after 12-25 seconds
_canTalk = true;
}
```
- [X] Fixes an issue with OPL packets using the wrong endianness and not updating the position properly.
- [X] Fixes an issue with SpanWriter not updating bytes written when it is used adhoc.
- [X] Moves packet creation for OPL inside the SendInfoTo function.
Bumps release version
SpanWriter now has an argument that allows it to be resizable.
```cs
public SpanWriter(Span<byte> initialBuffer, bool resize = false)
public SpanWriter(int initialCapacity, bool resize = false)
```
If a SpanWriter is set to be resizable, or given an initial capacity instead of a buffer, it must be disposed:
```cs
public static void SomeMethod()
{
using var writer = new SpanWriter(stackalloc byte[512], true);
// stuff
// Automatic Dispose of writer
}
```
This is because the SpanWriter uses `ArrayPool<byte>.Shared` _rented buffers_ to resize. If the writer is not disposed, those buffers will never be reused resulting in a _memory leak_.
It is possible that the SpanWriter will outright ditch the initial buffer if resize is set to true and growing is needed. To check/account for that we can do the following:
```cs
public static void SomeMethod()
{
Span<byte> span = stackalloc byte[512];
using var writer = new SpanWriter(span, true);
// write some stuff that causes the span to grow
span = writer.RawBuffer;
// Do stuff with the span
}
```
Make sure you don't accidentally `Dispose()` the writer or use the `RawBuffer` outside of the `using` block. If you do, bad things will happen! (NullPointerException, or a fresh SpanWriter with no buffer, depending on the situation).
SpanWriter can also now be used with a fixed statement since it has a `PinnableReference()` function.
- [X] Removes some string allocations (e.g. split)
- [X] Optimizes some collections
- [X] Converts insensitive to extension methods of built-ins.
- [X] Adds ordinal (case sensitive) string helpers
- [X] Fixes conditionals for in-game commands so they use Ordinal comparisons.
- [X] Replaces ToLower.Contains with InsensitiveContains
- [X] Adds ValueStringBuilder
- [X] Implements ValueStringBuilder in a few places where it makes sense
- [X] Removes the redundant Wrap function and replaces it with an optimized version
- [X] Fixes list conversions in Utility
Closes#351
Bumps release version
