view Implab/FuncChainTaskBase.cs @ 209:a867536c68fc v2

Bound promise to CancellationToken Added new states to ExecutionSate enum. Added Safe.Guard() method to handle cleanup of the result of the promise
author cin
date Wed, 16 Nov 2016 03:06:08 +0300
parents 40d7fed4a09e
children
line wrap: on
line source

using System;

namespace Implab {
    public class FuncChainTaskBase<TResult> : AbstractTask<TResult> {
        readonly Func<Exception, IPromise<TResult>> m_error;
        readonly Func<Exception, IPromise<TResult>> m_cancel;

        protected FuncChainTaskBase( Func<Exception, IPromise<TResult>> error, Func<Exception, IPromise<TResult>> cancel, bool autoCancellable) {
            m_error = error;
            m_cancel = cancel;
            if (autoCancellable)
                CancellationRequested(CancelOperation);
        }

        public void Reject(Exception error) {
            if (LockCancelation())
                HandleErrorInternal(error);
        }

        public override void CancelOperation(Exception reason) {
            if (LockCancelation())
                HandleCancelInternal(reason);
        }

        protected void HandleErrorInternal(Exception error) {
            if (m_error != null) {
                try {
                    var p = m_error(error);
                    p.On(SetResult, SetErrorInternal, SetCancelledInternal);
                    CancellationRequested(p.Cancel);
                } catch(Exception err) {
                    SetErrorInternal(err);
                }
            } else {
                SetErrorInternal(error);
            }
        }

        protected void HandleCancelInternal(Exception reason) {
            if (m_cancel != null) {
                try {
                    var p = m_cancel(reason);
                    p.On(SetResult, HandleErrorInternal, SetCancelledInternal);
                    CancellationRequested(p.Cancel);
                } catch (Exception err) {
                    SetErrorInternal(err);
                }
            } else {
                SetCancelledInternal(reason);
            }
        }
    }
}