Promise.cs
209 lines
| 5.5 KiB
| text/x-csharp
|
CSharpLexer
/ Implab / Promise.cs
cin
|
r248 | using System; | ||
| using System.Collections.Generic; | ||||
| using System.Diagnostics; | ||||
| using System.Reflection; | ||||
| using System.Threading.Tasks; | ||||
| using Implab.Parallels; | ||||
| namespace Implab { | ||||
| public class Promise : AbstractEvent<IResolvable>, IPromise { | ||||
| public static IDispatcher DefaultDispatcher { | ||||
| get { | ||||
| return ThreadPoolDispatcher.Instance; | ||||
| } | ||||
| } | ||||
| class ResolvableSignal : IResolvable { | ||||
| public Signal Signal { get; private set; } | ||||
| public ResolvableSignal() { | ||||
| Signal = new Signal(); | ||||
| } | ||||
| public void Reject(Exception error) { | ||||
| Signal.Set(); | ||||
| } | ||||
| public void Resolve() { | ||||
| Signal.Set(); | ||||
| } | ||||
| } | ||||
| PromiseState m_state; | ||||
| Exception m_error; | ||||
| public bool IsRejected { | ||||
| get { | ||||
| return m_state == PromiseState.Rejected; | ||||
| } | ||||
| } | ||||
| public bool IsFulfilled { | ||||
| get { | ||||
| return m_state == PromiseState.Fulfilled; | ||||
| } | ||||
| } | ||||
| public Exception RejectReason { | ||||
| get { | ||||
| return m_error; | ||||
| } | ||||
| } | ||||
| internal Promise() { | ||||
| } | ||||
| internal void ResolvePromise() { | ||||
| if (BeginTransit()) { | ||||
| m_state = PromiseState.Fulfilled; | ||||
| CompleteTransit(); | ||||
| } | ||||
| } | ||||
| internal void RejectPromise(Exception reason) { | ||||
| if (BeginTransit()) { | ||||
| m_error = reason; | ||||
| m_state = PromiseState.Rejected; | ||||
| CompleteTransit(); | ||||
| } | ||||
| } | ||||
| #region implemented abstract members of AbstractPromise | ||||
| protected override void SignalHandler(IResolvable handler) { | ||||
| switch (m_state) { | ||||
| case PromiseState.Fulfilled: | ||||
| handler.Resolve(); | ||||
| break; | ||||
| case PromiseState.Rejected: | ||||
| handler.Reject(RejectReason); | ||||
| break; | ||||
| default: | ||||
| throw new InvalidOperationException(String.Format("Invalid promise signal: {0}", m_state)); | ||||
| } | ||||
| } | ||||
| protected void WaitResult(int timeout) { | ||||
| if (!(IsResolved || GetFulfillSignal().Wait(timeout))) | ||||
| throw new TimeoutException(); | ||||
| } | ||||
| protected Signal GetFulfillSignal() { | ||||
| var next = new ResolvableSignal(); | ||||
| Then(next); | ||||
| return next.Signal; | ||||
| } | ||||
| #endregion | ||||
| public Type ResultType { | ||||
| get { | ||||
| return typeof(void); | ||||
| } | ||||
| } | ||||
| protected void Rethrow() { | ||||
| Debug.Assert(m_error != null); | ||||
| if (m_error is OperationCanceledException) | ||||
| throw new OperationCanceledException("Operation cancelled", m_error); | ||||
| else | ||||
| throw new TargetInvocationException(m_error); | ||||
| } | ||||
| public void Then(IResolvable next) { | ||||
| AddHandler(next); | ||||
| } | ||||
| public IPromise<T> Cast<T>() { | ||||
| throw new InvalidCastException(); | ||||
| } | ||||
| public void Join() { | ||||
| WaitResult(-1); | ||||
| if (IsRejected) | ||||
| Rethrow(); | ||||
| } | ||||
| public void Join(int timeout) { | ||||
| WaitResult(timeout); | ||||
| if (IsRejected) | ||||
| Rethrow(); | ||||
| } | ||||
| public static ResolvedPromise Resolve() { | ||||
| return new ResolvedPromise(); | ||||
| } | ||||
| public static ResolvedPromise<T> Resolve<T>(T result) { | ||||
| return new ResolvedPromise<T>(result); | ||||
| } | ||||
| public static RejectedPromise Reject(Exception reason) { | ||||
| return new RejectedPromise(reason); | ||||
| } | ||||
| public static RejectedPromise<T> Reject<T>(Exception reason) { | ||||
| return new RejectedPromise<T>(reason); | ||||
| } | ||||
| public static IPromise Create(PromiseExecutor executor) { | ||||
| Safe.ArgumentNotNull(executor, nameof(executor)); | ||||
| var p = new Promise(); | ||||
| var d = new Deferred(p, DefaultDispatcher); | ||||
| try { | ||||
| executor(d); | ||||
| } catch (Exception e) { | ||||
| d.Reject(e); | ||||
| } | ||||
| return d.Promise; | ||||
| } | ||||
| public static IPromise<T> Create<T>(PromiseExecutor<T> executor) { | ||||
| Safe.ArgumentNotNull(executor, nameof(executor)); | ||||
| var p = new Promise<T>(); | ||||
| var d = new Deferred<T>(p, DefaultDispatcher); | ||||
| try { | ||||
| executor(d); | ||||
| } catch (Exception e) { | ||||
| d.Reject(e); | ||||
| } | ||||
| return d.Promise; | ||||
| } | ||||
| public static IPromise All(IEnumerable<IPromise> promises) { | ||||
| var d = new Deferred(DefaultDispatcher); | ||||
| var all = new PromiseAll(d); | ||||
| foreach (var promise in promises) { | ||||
| all.AddPromise(promise); | ||||
| if (all.Done) | ||||
| break; | ||||
| } | ||||
| all.Complete(); | ||||
| return all.ResultPromise; | ||||
| } | ||||
| public static IPromise<T[]> All<T>(IEnumerable<IPromise<T>> promises, Func<T, IPromise> cleanup, Action cancel) { | ||||
| var d = new Deferred<T[]>(DefaultDispatcher); | ||||
| var all = new PromiseAll<T>(d, cleanup, cancel); | ||||
| foreach (var promise in promises) { | ||||
| all.AddPromise(promise); | ||||
| if (all.Done) | ||||
| break; | ||||
| } | ||||
| all.Complete(); | ||||
| return all.ResultPromise; | ||||
| } | ||||
| } | ||||
| } | ||||