Tapeti/Tapeti.Flow/IFlowStore.cs

102 lines
3.2 KiB
C#

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Tapeti.Flow.Default;
// ReSharper disable UnusedMember.Global
namespace Tapeti.Flow
{
/// <summary>
/// Provides a way to store and load flow state.
/// </summary>
public interface IFlowStore
{
/// <summary>
/// Must be called during application startup before subscribing or starting a flow.
/// If using an IFlowRepository that requires an update (such as creating tables) make
/// sure it is called before calling Load.
/// </summary>
ValueTask Load();
/// <summary>
/// Looks up the FlowID corresponding to a ContinuationID. For internal use.
/// </summary>
/// <param name="continuationID"></param>
ValueTask<Guid?> FindFlowID(Guid continuationID);
/// <summary>
/// Acquires a lock on the flow with the specified FlowID.
/// </summary>
/// <param name="flowID"></param>
ValueTask<IFlowStateLock> LockFlowState(Guid flowID);
/// <summary>
/// Returns information about the currently active flows.
/// </summary>
/// <remarks>
/// This is intended for monitoring purposes and should be treated as a snapshot.
/// </remarks>
/// <param name="minimumAge">The minimum age of the flow before it is included in the result. Set to TimeSpan.Zero to return all active flows.</param>
ValueTask<IEnumerable<ActiveFlow>> GetActiveFlows(TimeSpan minimumAge);
}
/// <summary>
/// Represents a lock on the flow state, to provide thread safety.
/// </summary>
public interface IFlowStateLock : IDisposable
{
/// <summary>
/// The unique ID of the flow state.
/// </summary>
Guid FlowID { get; }
/// <summary>
/// Acquires a copy of the flow state.
/// </summary>
ValueTask<FlowState?> GetFlowState();
/// <summary>
/// Stores the new flow state.
/// </summary>
/// <param name="flowState"></param>
/// <param name="persistent"></param>
ValueTask StoreFlowState(FlowState flowState, bool persistent);
/// <summary>
/// Disposes of the flow state corresponding to this Flow ID.
/// </summary>
ValueTask DeleteFlowState();
}
/// <summary>
/// Contains information about an active flow, as returned by <see cref="IFlowStore.GetActiveFlows"/>.
/// </summary>
public class ActiveFlow
{
/// <summary>
/// The ID of the active flow.
/// </summary>
public Guid FlowID { get; }
/// <summary>
/// The time when the flow was initially created.
/// </summary>
public DateTime CreationTime { get; }
/// <summary>
/// Create a new instance of an ActiveFlow.
/// </summary>
/// <param name="flowID">The ID of the active flow.</param>
/// <param name="creationTime">The time when the flow was initially created.</param>
public ActiveFlow(Guid flowID, DateTime creationTime)
{
FlowID = flowID;
CreationTime = creationTime;
}
}
}