/// <summary>
/// Standardized implementation to recover single item from buffer.
/// Calls <see cref="Adapt"/> to perform the desired transformed.
/// <para>Returns true when a consumable instance can be created from
/// <paramref name="producerDataFeed"/> else returns false.</para>
/// </summary>
/// <param name="producerDataFeed">Feed that is getting populated by producers.</param>
/// <param name="token">Cancellation token</param>
/// <param name="consumable">transfomed item that can be passed to consumer</param>
public bool TryGet(IConsumerBuffer <TP> producerDataFeed, CancellationToken token, out TC consumable)
{
if (producerDataFeed.TryGet(Timeout.Infinite, token, out var produced))
{
consumable = Adapt(produced, token);
return(true);
}
consumable = default;
return(false);
}
/// <summary>
/// Return true when a consumable instance can be created from
/// <paramref name="producerDataFeed"/> else returns false.
/// <para>NOTE:</para>
/// <para>1. It does NOT observes <seealso cref="IConsumerBuffer{T}.Finished"/> status</para>
/// <para>2. The first element is ALWAYS (irrespective of provided timeout value) waited for
/// <seealso cref="Timeout.Infinite"/>. Then items are added to list as long as they can be recovered
/// before provided millisecond timeout is reached.</para>
/// <para>3. Further, items are recovered and populated as long as they are available without
/// any wait. Then the list if finalized and returned. Step 2 and 3 are same when inifinite timeout
/// is suplied.</para>
/// <para>4. If method returns true, then the list would contains at least 1 item.</para>
/// <para>5. List max size would be respected as provided in Ctor.</para>
/// </summary>
/// <param name="producerDataFeed">Data feed</param>
/// <param name="token">token to observe</param>
/// <param name="consumable">consumable data instance</param>
public bool TryGet(IConsumerBuffer <TP> producerDataFeed, CancellationToken token, out List <TC> consumable)
{
consumable = default(List <TC>);
if (!producerDataFeed.TryGet(Timeout.Infinite, token, out var value))
{
return(false);
}
consumable = new List <TC>(_maxListSize)
{
Adapt(value, token)
};
return(_millisecTimeout == Timeout.Infinite
? TryGetWithInfiniteTo(producerDataFeed, token, consumable)
: TryGetWithFiniteTo(producerDataFeed, token, consumable));
}
private bool TryGetWithInfiniteTo(IConsumerBuffer <TP> producerDataFeed, CancellationToken token,
ICollection <TC> consumable)
{
while (consumable.Count < _maxListSize)
{
if (producerDataFeed.TryGet(Timeout.Infinite, token, out var value))
{
consumable.Add(Adapt(value, token));
}
else
{
return(true);
}
}
return(true);
}
private bool TryGetWithFiniteTo(IConsumerBuffer <TP> producerDataFeed, CancellationToken token,
ICollection <TC> consumable)
{
var timeRemains = _millisecTimeout;
var sw = Stopwatch.StartNew();
while (consumable.Count < _maxListSize)
{
if (producerDataFeed.TryGet(timeRemains, token, out var value))
{
consumable.Add(Adapt(value, token));
if (timeRemains != 0)
{
timeRemains = (int)Math.Max(0, _millisecTimeout - sw.ElapsedMilliseconds);
}
}
else
{
return(true);
}
}
return(true);
}
