feat(ThrottleDispatcher): refine code improve readability

src/BootstrapBlazor/Services/ThrottleDispatcher.cs

@@ -10,16 +10,13 @@ namespace BootstrapBlazor.Components;
 /// </summary>
 public class ThrottleDispatcher(ThrottleOptions options)
 {
-    private readonly object _locker = new();
-    private Task? _lastTask;
     private DateTime? _invokeTime;
-    private bool _busy;
 
     /// <summary>
     /// 判断是否等待方法
     /// </summary>
     /// <returns></returns>
-    protected virtual bool ShouldWait() => _busy || _invokeTime.HasValue && (DateTime.UtcNow - _invokeTime.Value) < options.Interval;
+    protected virtual bool ShouldWait() => _invokeTime.HasValue && (DateTime.UtcNow - _invokeTime.Value) < options.Interval;
 
     /// <summary>
     /// 异步限流方法
@@ -32,83 +29,53 @@ public class ThrottleDispatcher(ThrottleOptions options)
     /// 同步限流方法
     /// </summary>
     /// <param name="action">同步回调方法</param>
-    /// <param name="cancellationToken">取消令牌</param>
-    public void Throttle(Action action, CancellationToken cancellationToken = default)
+    /// <param name="token">取消令牌</param>
+    public void Throttle(Action action, CancellationToken token = default)
     {
         var task = InternalThrottleAsync(() => Task.Run(() =>
         {
             action();
             return Task.CompletedTask;
-        }, cancellationToken), cancellationToken);
-        Wait();
-        return;
-
-        [ExcludeFromCodeCoverage]
-        void Wait()
+        }, CancellationToken.None), token);
+        try
         {
-            try
-            {
-                task.Wait(cancellationToken);
-            }
-            catch (AggregateException ex)
-            {
-                if (ex.InnerException is not null)
-                {
-                    throw ex.InnerException;
-                }
-            }
-            catch (Exception)
-            {
-                throw;
-            }
+            task.Wait(token);
+        }
+        catch (Exception)
+        {
+            throw;
         }
+        return;
     }
 
-    /// <summary>
-    /// 任务实例
-    /// </summary>
-    protected Task LastTask => _lastTask ?? Task.CompletedTask;
-
     /// <summary>
     /// 限流异步方法
     /// </summary>
     /// <param name="function">异步回调方法</param>
     /// <param name="cancellationToken">取消令牌</param>
-    private Task InternalThrottleAsync(Func<Task> function, CancellationToken cancellationToken = default)
+    private async Task InternalThrottleAsync(Func<Task> function, CancellationToken cancellationToken = default)
     {
         if (ShouldWait())
         {
-            return LastTask;
+            return;
         }
 
-        lock (_locker)
+        _invokeTime = DateTime.UtcNow;
+
+        try
         {
-            if (ShouldWait())
+            await function();
+            if (options.DelayAfterExecution)
             {
-                return LastTask;
+                _invokeTime = DateTime.UtcNow;
             }
-
-            _busy = true;
-            _invokeTime = DateTime.UtcNow;
-            _lastTask = function();
-            _lastTask.ContinueWith(_ =>
-            {
-                if (options.DelayAfterExecution)
-                {
-                    _invokeTime = DateTime.UtcNow;
-                }
-                _busy = false;
-            }, cancellationToken);
-
+        }
+        catch
+        {
             if (options.ResetIntervalOnException)
             {
-                _lastTask.ContinueWith((_, _) =>
-                {
-                    _lastTask = null;
-                    _invokeTime = null;
-                }, cancellationToken, TaskContinuationOptions.OnlyOnFaulted);
+                _invokeTime = null;
             }
-            return LastTask;
         }
     }
 }

test/UnitTest/Services/ThrottleTest.cs

@@ -81,19 +81,21 @@ public async Task ResetIntervalOnException_Ok()
         var dispatcher = factory.GetOrCreate("Error", new ThrottleOptions() { ResetIntervalOnException = true });
 
         var count = 0;
-        await Assert.ThrowsAnyAsync<InvalidOperationException>(() => dispatcher.ThrottleAsync(() =>
+        await dispatcher.ThrottleAsync(() =>
         {
             count++;
-            throw new InvalidOperationException();
-        }));
+            throw new Exception();
+        });
+        Assert.Equal(1, count);
 
-        Assert.ThrowsAny<InvalidOperationException>(() => dispatcher.Throttle(() => throw new InvalidOperationException()));
+        dispatcher.Throttle(() => throw new InvalidOperationException());
 
         // 发生错误后可以立即执行下一次任务，不限流
         dispatcher.Throttle(() =>
         {
             count++;
         });
+        Assert.Equal(2, count);
     }
 
     [Fact]
@@ -104,16 +106,21 @@ public async Task Cancel_Ok()
 
         var cts = new CancellationTokenSource();
         cts.Cancel();
-        Assert.ThrowsAny<OperationCanceledException>(() => dispatcher.Throttle(async () =>
+        var ex = await Assert.ThrowsAsync<OperationCanceledException>(() =>
         {
-            await Task.Delay(300);
-        }, cts.Token));
+            dispatcher.Throttle(() =>
+            {
+
+            }, cts.Token);
+            return Task.CompletedTask;
+        });
+        Assert.NotNull(ex);
 
         cts = new CancellationTokenSource(100);
-        await Assert.ThrowsAnyAsync<OperationCanceledException>(() => dispatcher.ThrottleAsync(async () =>
+        await dispatcher.ThrottleAsync(async () =>
         {
             await Task.Delay(300);
-        }, cts.Token));
+        }, cts.Token);
     }
 
     [Fact]
@@ -125,38 +132,37 @@ public void Clear()
         factory.Clear("Clear");
     }
 
-    [Fact]
-    public void LatTask_Ok()
-    {
-        var dispatch = new MockDispatcher(new ThrottleOptions());
-        Assert.NotNull(dispatch.TestLastTask());
-    }
-
     [Fact]
     public void ShouldWait_Ok()
     {
-        var dispatch = new MockDispatcher(new ThrottleOptions());
+        var dispatch = new ThrottleDispatcher(new ThrottleOptions());
         var count = 0;
         dispatch.Throttle(() => count++);
-        Assert.Equal(0, count);
+        Assert.Equal(1, count);
+        dispatch.Throttle(() => count++);
+        Assert.Equal(1, count);
     }
 
-    class MockDispatcher(ThrottleOptions options) : ThrottleDispatcher(options)
+    [Fact]
+    public async Task MultipleThread_ThrottleAsync_Ok()
     {
-        public Task TestLastTask()
+        var count = 0;
+        var dispatch = new ThrottleDispatcher(new ThrottleOptions()
         {
-            return LastTask;
-        }
-
-        private int count = 0;
-
-        /// <summary>
-        /// <inheritdoc/>
-        /// </summary>
-        /// <returns></returns>
-        protected override bool ShouldWait()
+            Interval = TimeSpan.FromMilliseconds(100),
+            DelayAfterExecution = true
+        });
+        var tasks = Enumerable.Range(1, 2).Select(i => dispatch.ThrottleAsync(() =>
         {
-            return count++ == 1;
-        }
+            count++;
+            return Task.CompletedTask;
+        })).ToList();
+        tasks.Add(dispatch.ThrottleAsync(async () =>
+        {
+            await Task.Delay(120);
+            count++;
+        }));
+        await Task.WhenAll(tasks);
+        Assert.Equal(1, count);
     }
 }