FuncChainTaskBase.cs
60 lines
| 1.8 KiB
| text/x-csharp
|
CSharpLexer
/ Implab / FuncChainTaskBase.cs
cin
|
r145 | using System; | ||
| using System.Threading; | ||||
| namespace Implab { | ||||
| public class FuncChainTaskBase<TResult> : AbstractPromise<TResult> { | ||||
| readonly Func<Exception, IPromise<TResult>> m_error; | ||||
| readonly Func<Exception, IPromise<TResult>> m_cancel; | ||||
| int m_cancelationLock; | ||||
| protected FuncChainTaskBase( Func<Exception, IPromise<TResult>> error, Func<Exception, IPromise<TResult>> cancel) { | ||||
| m_error = error; | ||||
| m_cancel = cancel; | ||||
| } | ||||
| public void Reject(Exception error) { | ||||
| if (LockCancelation()) | ||||
| HandleErrorInternal(error); | ||||
| } | ||||
| public override void CancelOperation(Exception reason) { | ||||
| if (m_cancel != null && LockCancelation()) { | ||||
| try { | ||||
| Observe(m_cancel(reason)); | ||||
| } catch(Exception err) { | ||||
| HandleErrorInternal(err); | ||||
| } | ||||
| } | ||||
| } | ||||
| protected void HandleErrorInternal(Exception error) { | ||||
| if (m_error != null) { | ||||
| try { | ||||
| Observe(m_error(error)); | ||||
| } catch(Exception err) { | ||||
| SetError(err); | ||||
| } | ||||
| } else { | ||||
| SetError(error); | ||||
| } | ||||
| } | ||||
| protected void Observe(IPromise<TResult> operation) { | ||||
| if (operation == null) | ||||
| throw new NullReferenceException("The task returned null promise"); | ||||
| // pass operation results to the current promise | ||||
| operation.On(SetResult, SetError, SetCancelled); | ||||
| // pass the cancelation request | ||||
| CancellationRequested(operation.Cancel); | ||||
| } | ||||
| protected bool LockCancelation() { | ||||
| return 0 == Interlocked.CompareExchange(ref m_cancelationLock, 1, 0); | ||||
| } | ||||
| } | ||||
| } | ||||