chore: initialize standalone UPM package

2026-08-26 02:50:18 +08:00
commit 1c921f5aec
86 changed files with 6934 additions and 0 deletions
@@ -0,0 +1,205 @@
+#nullable enable
+
+using System;
+using System.Collections.Concurrent;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace ShrinkEventBus
+{
+    internal interface IDotNetScheduler : IDisposable
+    {
+        bool IsOnSchedulerThread { get; }
+        bool TryPost(Action action);
+        ValueTask PostAsync(Func<ValueTask> action, CancellationToken cancellationToken);
+    }
+
+    internal sealed class QueueFullException : InvalidOperationException { }
+
+    internal static class DotNetSchedulerFactory
+    {
+        public static IDotNetScheduler Create(string name, ShrinkBusOptions options)
+        {
+            return options.Scheduler switch
+            {
+                ShrinkBusSchedulerKind.MainThread => new SynchronizationContextScheduler(options),
+                ShrinkBusSchedulerKind.DedicatedThread => new DedicatedScheduler(name, options),
+                ShrinkBusSchedulerKind.TaskPool => new TaskPoolScheduler(options),
+                _ => new InlineScheduler()
+            };
+        }
+    }
+
+    internal sealed class InlineScheduler : IDotNetScheduler
+    {
+        public bool IsOnSchedulerThread => true;
+        public bool TryPost(Action action) { action(); return true; }
+        public ValueTask PostAsync(Func<ValueTask> action, CancellationToken cancellationToken)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            return action();
+        }
+        public void Dispose() { }
+    }
+
+    internal sealed class SynchronizationContextScheduler : IDotNetScheduler
+    {
+        private readonly SynchronizationContext _context;
+        private readonly int _threadId;
+        private int _disposed;
+
+        public SynchronizationContextScheduler(ShrinkBusOptions options)
+        {
+            _context = SynchronizationContext.Current ?? throw new InvalidOperationException(
+                "MainThread scheduler requires a current SynchronizationContext in a pure .NET host.");
+            _threadId = Thread.CurrentThread.ManagedThreadId;
+        }
+
+        public bool IsOnSchedulerThread => Thread.CurrentThread.ManagedThreadId == _threadId;
+
+        public bool TryPost(Action action)
+        {
+            if (Volatile.Read(ref _disposed) != 0)
+                return false;
+            if (IsOnSchedulerThread)
+                action();
+            else
+                _context.Post(_ => action(), null);
+            return true;
+        }
+
+        public ValueTask PostAsync(Func<ValueTask> action, CancellationToken cancellationToken)
+        {
+            if (IsOnSchedulerThread)
+                return action();
+            return new ValueTask(PostCoreAsync(action, cancellationToken));
+        }
+
+        private Task PostCoreAsync(Func<ValueTask> action, CancellationToken cancellationToken)
+        {
+            var completion = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);
+            _context.Post(async _ =>
+            {
+                try { cancellationToken.ThrowIfCancellationRequested(); await action(); completion.SetResult(true); }
+                catch (OperationCanceledException) { completion.SetCanceled(); }
+                catch (Exception ex) { completion.SetException(ex); }
+            }, null);
+            return completion.Task;
+        }
+
+        public void Dispose() => Interlocked.Exchange(ref _disposed, 1);
+    }
+
+    internal sealed class TaskPoolScheduler : IDotNetScheduler
+    {
+        private readonly SemaphoreSlim _concurrency;
+        private readonly int _capacity;
+        private int _pending;
+        private int _disposed;
+
+        public TaskPoolScheduler(ShrinkBusOptions options)
+        {
+            var concurrency = options.DispatchMode == ShrinkDispatchMode.Ordered ? 1 : options.MaxConcurrency;
+            _concurrency = new SemaphoreSlim(concurrency, concurrency);
+            _capacity = options.QueueCapacity;
+        }
+
+        public bool IsOnSchedulerThread => false;
+
+        public bool TryPost(Action action)
+        {
+            if (Volatile.Read(ref _disposed) != 0 || Interlocked.Increment(ref _pending) > _capacity)
+            {
+                Interlocked.Decrement(ref _pending);
+                return false;
+            }
+            _ = Task.Run(async () =>
+            {
+                await _concurrency.WaitAsync().ConfigureAwait(false);
+                try { action(); }
+                finally { _concurrency.Release(); Interlocked.Decrement(ref _pending); }
+            });
+            return true;
+        }
+
+        public async ValueTask PostAsync(Func<ValueTask> action, CancellationToken cancellationToken)
+        {
+            if (Volatile.Read(ref _disposed) != 0 || Interlocked.Increment(ref _pending) > _capacity)
+            {
+                Interlocked.Decrement(ref _pending);
+                throw new QueueFullException();
+            }
+            await _concurrency.WaitAsync(cancellationToken).ConfigureAwait(false);
+            try { await action().ConfigureAwait(false); }
+            finally { _concurrency.Release(); Interlocked.Decrement(ref _pending); }
+        }
+
+        public void Dispose()
+        {
+            Interlocked.Exchange(ref _disposed, 1);
+            _concurrency.Dispose();
+        }
+    }
+
+    internal sealed class DedicatedScheduler : IDotNetScheduler
+    {
+        private sealed class Work
+        {
+            public Func<ValueTask> Action = null!;
+            public TaskCompletionSource<bool>? Completion;
+        }
+
+        private readonly BlockingCollection<Work> _queue;
+        private readonly Thread _thread;
+        private int _threadId;
+        private int _disposed;
+
+        public DedicatedScheduler(string name, ShrinkBusOptions options)
+        {
+            _queue = new BlockingCollection<Work>(options.QueueCapacity);
+            _thread = new Thread(Run) { IsBackground = true, Name = $"ShrinkBus:{name}" };
+            _thread.Start();
+        }
+
+        public bool IsOnSchedulerThread => Thread.CurrentThread.ManagedThreadId == Volatile.Read(ref _threadId);
+
+        public bool TryPost(Action action)
+        {
+            if (IsOnSchedulerThread) { action(); return true; }
+            return Volatile.Read(ref _disposed) == 0 && _queue.TryAdd(new Work
+            {
+                Action = () => { action(); return default; }
+            });
+        }
+
+        public ValueTask PostAsync(Func<ValueTask> action, CancellationToken cancellationToken)
+        {
+            if (IsOnSchedulerThread)
+                return action();
+            var completion = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);
+            if (Volatile.Read(ref _disposed) != 0 || !_queue.TryAdd(new Work
+                { Action = action, Completion = completion }))
+                throw new QueueFullException();
+            return new ValueTask(completion.Task);
+        }
+
+        public void Dispose()
+        {
+            if (Interlocked.Exchange(ref _disposed, 1) != 0)
+                return;
+            _queue.CompleteAdding();
+        }
+
+        private void Run()
+        {
+            Volatile.Write(ref _threadId, Thread.CurrentThread.ManagedThreadId);
+            foreach (var work in _queue.GetConsumingEnumerable())
+            {
+                try { work.Action().AsTask().GetAwaiter().GetResult(); work.Completion?.SetResult(true); }
+                catch (OperationCanceledException) { work.Completion?.SetCanceled(); }
+                catch (Exception ex) { work.Completion?.SetException(ex); }
+            }
+            _queue.Dispose();
+        }
+    }
+}