/// <summary>
/// Creates a new instance of the <see cref="DisposableAsyncLazy{T}"/> type
/// with the specified factory and disposal operations.
/// </summary>
/// <param name="factory">The factory that is used to instantiate the value.</param>
/// <param name="disposal">The disposal the is used to destroy the value.</param>
/// <param name="options">
/// A combination of <see cref="DisposableAsyncLazyOptions"/> flags that control the
/// behavior of the created <see cref="DisposableAsyncLazy{T}"/>
/// or <see cref="DisposableAsyncLazyOptions.None"/>.
/// </param>
/// <exception cref="ArgumentNullException">
/// Thrown if either <paramref name="factory"/> or <paramref name="disposal"/> is <c>null</c>.
/// </exception>
public DisposableAsyncLazy(
Func <CancellationToken, Task <T> > factory,
Func <T, Task> disposal,
DisposableAsyncLazyOptions options = default)
{
if (factory == null)
{
throw new ArgumentNullException(nameof(factory));
}
if (disposal == null)
{
throw new ArgumentNullException(nameof(disposal));
}
_cancellationSource = new CancellationTokenSource();
async Task <T> WithCancellation()
{
try
{
return(await factory(_cancellationSource.Token).ConfigureAwait(false));
}
catch (OperationCanceledException) when(_cancellationSource.IsCancellationRequested)
{
throw new ObjectDisposedException(GetType().FullName);
}
}
_disposal = disposal;
_factory = WithCancellation;
if ((options & DisposableAsyncLazyOptions.RetryOnFailure) == DisposableAsyncLazyOptions.RetryOnFailure)
{
_factory = RetryOnFailure(_factory);
}
if ((options & DisposableAsyncLazyOptions.ExecuteOnCallingThread)
!= DisposableAsyncLazyOptions.ExecuteOnCallingThread)
{
_factory = RunOnThreadPool(_factory);
}
_instance = new Lazy <Task <T> >(_factory);
if ((options & DisposableAsyncLazyOptions.Autostart) == DisposableAsyncLazyOptions.Autostart)
{
Start();
}
}
/// <summary>
/// Creates a new instance of the <see cref="DisposableAsyncLazy{T}"/> type
/// with the specified factory and disposal operations.
/// </summary>
/// <param name="factory">The factory that is used to instantiate the value.</param>
/// <param name="disposal">The disposal the is used to destroy the value.</param>
/// <param name="options">
/// A combination of <see cref="DisposableAsyncLazyOptions"/> flags that control the
/// behavior of the created <see cref="DisposableAsyncLazy{T}"/>
/// or <see cref="DisposableAsyncLazyOptions.None"/>.
/// </param>
/// <exception cref="ArgumentNullException">
/// Thrown if either <paramref name="factory"/> or <paramref name="disposal"/> is <c>null</c>.
/// </exception>
public DisposableAsyncLazy(
Func <Task <T> > factory, Func <T, Task> disposal, DisposableAsyncLazyOptions options = default)
{
if (factory == null)
{
throw new ArgumentNullException(nameof(factory));
}
if (disposal == null)
{
throw new ArgumentNullException(nameof(disposal));
}
// TODO: Validate the options.
_cancellationSource = new CancellationTokenSource();
_disposal = disposal;
_factory = factory;
if ((options & DisposableAsyncLazyOptions.RetryOnFailure) == DisposableAsyncLazyOptions.RetryOnFailure)
{
_factory = RetryOnFailure(_factory);
}
if ((options & DisposableAsyncLazyOptions.ExecuteOnCallingThread)
!= DisposableAsyncLazyOptions.ExecuteOnCallingThread)
{
_factory = RunOnThreadPool(_factory);
}
_instance = new Lazy <Task <T> >(_factory);
if ((options & DisposableAsyncLazyOptions.Autostart) != DisposableAsyncLazyOptions.Autostart)
{
Start();
}
}
/// <summary>
/// Creates a new instance of the <see cref="DisposableAsyncLazy{T}"/> type
/// with the specified factory and disposal operations.
/// </summary>
/// <param name="factory">The factory that is used to instantiate the value.</param>
/// <param name="options">
/// A combination of <see cref="DisposableAsyncLazyOptions"/> flags that control the
/// behavior of the created <see cref="DisposableAsyncLazy{T}"/>
/// or <see cref="DisposableAsyncLazyOptions.None"/>.
/// </param>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="factory"/> is <c>null</c>.</exception>
public DisposableAsyncLazy(
Func <CancellationToken, Task <T> > factory,
DisposableAsyncLazyOptions options = default)
: this(factory, _noDisposal, options)
{
}
