声明 调度任务器的接口

[LostAsk]

你好. 看了你的节点编辑器 做的很不错. 其中推送任务的时候.能否抽象成一个接口.明确接口的职责. 方便开发者根据自定义业务进行重写调度.

[Axvser]

感谢您的反馈！以下是答复，希望能帮到您。若仍有疑问，可 QQ 联系（2789083329），也可微信联系（Axvser），头像均与 GitHub 保持一致，通常在周末有时间。

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关于任务推送

任务推送存在两套模式，我会先说明什么是无状态模式，它更契合您所希望的自定义。需要注意，此处所述均为 V7 版本下的模式，先前版本的模式已过时。

• 无状态：传播由节点自驱动
• 有状态：传播由简单状态机驱动，特点是预编译、扇入参数自动汇合

入口

源生成器补全节点的视图模型代码，其内部持有一个 Helper 属性用于动态替换节点服务。Helper 实现 IWorkflowNodeViewModelHelper 接口，节点的一切服务都将通过视图模型的 ReceiveCommand 转发给 Helper 的如下函数。您可以将其作为任务入口，通过重写此函数实现自定义，该重写逻辑对四大组件的 Helper 均适用：

VeloxDev/Src/Core/VeloxDev.Core/Interfaces/WorkflowSystem/IWorkflowNodeViewModel.cs

Lines 84 to 92 in ebc572d

	/// <summary>
	/// Called when this node receives a dataflow task — the single execution entry.
	/// The source generator's Receive handler forwards the incoming
	/// <see cref="ITaskContext"/> here. Returning a non-null value allows the
	/// Compiler to chain results.
	/// </summary>
	/// <param name="context">The task context (data/sender/receiver, all nullable).</param>
	/// <param name="ct">Cancellation token.</param>
	public Task<object?> ReceiveAsync(ITaskContext context, CancellationToken ct);

传播 & 参数

传播

Helper 也提供可重写的双向传播方法，有默认实现，可以重写以定制：

VeloxDev/Src/Core/VeloxDev.Core/Interfaces/WorkflowSystem/IWorkflowNodeViewModel.cs

Lines 94 to 95 in ebc572d

	public Task BroadcastAsync(object? parameter, CancellationToken ct);
	public Task ReverseBroadcastAsync(object? parameter, CancellationToken ct);

为了便于您在定制过程中过滤节点，框架提供了标准扩展方法，支持从当前节点进行如下查询：

正向搜索

VeloxDev/Src/Core/VeloxDev.Core/WorkflowSystem/StandardEx/WorkflowNodeEx.cs

Lines 152 to 163 in ebc572d

	/// <summary>
	/// Search downstream (forward) nodes along the propagation chain starting from the given node.
	/// Uses BFS with depth limiting and an optional predicate filter.
	/// </summary>
	/// <param name="component">The starting node.</param>
	/// <param name="predicate">Optional filter predicate. If null, all reachable nodes are returned.</param>
	/// <param name="maxDepth">Maximum search depth. 0 means unlimited.</param>
	/// <returns>An enumerable of matching downstream nodes (excluding the starting node).</returns>
	public static IEnumerable<IWorkflowNodeViewModel> SearchForwardNodes(
	this IWorkflowNodeViewModel component,
	Func<IWorkflowNodeViewModel, bool>? predicate = null,
	int maxDepth = 0)

逆向搜索

VeloxDev/Src/Core/VeloxDev.Core/WorkflowSystem/StandardEx/WorkflowNodeEx.cs

Lines 168 to 179 in ebc572d

	/// <summary>
	/// Search upstream (reverse) nodes along the propagation chain starting from the given node.
	/// Uses BFS with depth limiting and an optional predicate filter.
	/// </summary>
	/// <param name="component">The starting node.</param>
	/// <param name="predicate">Optional filter predicate. If null, all reachable nodes are returned.</param>
	/// <param name="maxDepth">Maximum search depth. 0 means unlimited.</param>
	/// <returns>An enumerable of matching upstream nodes (excluding the starting node).</returns>
	public static IEnumerable<IWorkflowNodeViewModel> SearchReverseNodes(
	this IWorkflowNodeViewModel component,
	Func<IWorkflowNodeViewModel, bool>? predicate = null,
	int maxDepth = 0)

全向搜索

VeloxDev/Src/Core/VeloxDev.Core/WorkflowSystem/StandardEx/WorkflowNodeEx.cs

Lines 184 to 194 in ebc572d

	/// <summary>
	/// Search both forward and reverse nodes simultaneously along the propagation chain.
	/// </summary>
	/// <param name="component">The starting node.</param>
	/// <param name="predicate">Optional filter predicate. If null, all reachable nodes are returned.</param>
	/// <param name="maxDepth">Maximum search depth. 0 means unlimited.</param>
	/// <returns>An enumerable of matching nodes from both directions (excluding the starting node).</returns>
	public static IEnumerable<IWorkflowNodeViewModel> SearchAllRelativeNodes(
	this IWorkflowNodeViewModel component,
	Func<IWorkflowNodeViewModel, bool>? predicate = null,
	int maxDepth = 0)

参数

ITaskContext 包含三个常用属性，在无状态模式下仅需这三个即可：

• Data 数据
• Sender 传播发起者
• Receiver 传播接收者

VeloxDev/Src/Core/VeloxDev.Core/Interfaces/WorkflowSystem/ITaskContext.cs

Lines 3 to 17 in ebc572d

	namespace VeloxDev.WorkflowSystem;
	/// <summary>
	/// The dataflow task context: the only payload shape a node receives via
	/// <see cref="IWorkflowNodeViewModel.ReceiveCommand"/>. Access members (Data/Sender/Receiver/IsCompilePhase) all
	/// inherit from <see cref="IAccessContext"/> — broadcast along a concrete link carries
	/// <see cref="IAccessContext.Sender"/>/<see cref="IAccessContext.Receiver"/>; the compiler driving in order or a
	/// manual Run carries only <see cref="IContext.Data"/>.
	/// </summary>
	[AgentContext(AgentLanguages.Chinese, "数据流任务上下文，节点 ReceiveCommand → Helper.ReceiveAsync 的入参契约，含可空的 data/sender/receiver")]
	[AgentContext(AgentLanguages.English, "Dataflow task context; the input contract of ReceiveCommand → Helper.ReceiveAsync, carrying nullable data/sender/receiver")]
	public interface ITaskContext : IAccessContext
	{
	// Data / Sender / Receiver / IsCompilePhase are all inherited from IAccessContext.
	}

当您过滤出需要传播参数的节点时，可以手动构造从 ITaskContext 派生的数据实体（Entry），然后调用节点的 ReceiveCommand.Execute(Entry) 即可触发节点任务。

IVeloxCommand 是一种特殊的 Command，该框架中的一切 Command 均属此类。它天然带有并发量限制，可在任务并发量达到上限时自动排队；声明 Command 时配置 semaphore 即可，且该限制支持动态更新：

VeloxDev/Src/Core/VeloxDev.Core/MVVM/VeloxCommandAttribute.cs

Lines 34 to 38 in ebc572d

	[AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = false)]
	public sealed class VeloxCommandAttribute(
	string name = "Auto",
	bool canValidate = false,
	int semaphore = 1) : Attribute

小结

框架逻辑与业务逻辑均被转发给 Helper：源生成器在构造节点 ViewModel 时注入默认的 Helper（可替换），于是逻辑被挂载到节点，节点便具备了工作能力。重写 Helper 的各种函数是推荐的定制路径，理论上它可以覆盖该框架的全部运行逻辑（包括撤销/重做实现）。