private static AsyncStream <TResult> ParallelizeStreamInternalAsync <T, TResult>(this AsyncStream <T> source,
Func <T, CancellationToken, Task <TResult> > actionAsync, ParallelizeOption option)
{
var core = new ParallelizeCore(source.CancellationToken, option);
var monitor = new ParallelMonitor <T>(option.MaxDegreeOfParallelism);
var channel = Channel.CreateUnbounded <StreamedValue <TResult> >();
return(new AsyncStream <TResult>(channel, source.CancellationToken, async() =>
{
try
{
using (core)
{
await Task.WhenAll(Enumerable.Range(0, option.MaxDegreeOfParallelism)
.Select(i => ParallelizeCoreStreamAsync(core, actionAsync, source, channel, i, monitor)));
}
}
catch (Exception e)
{
channel.Writer.Complete(e);
throw;
}
finally
{
channel.Writer.Complete();
}
ThrowOnErrors(option, core);
}));
}
private static Task ParallelizeCoreStreamAsync <T, TResult>(ParallelizeCore core,
Func <T, CancellationToken, Task <TResult> > actionAsync,
AsyncStream <T> source,
ChannelWriter <StreamedValue <TResult> > resultsChannel,
int index,
ParallelMonitor <T> monitor)
{
return(Task.Run(async() =>
{
while (await source.ChannelReader.WaitToReadAsync()) //returns false when the channel is completed
{
while (source.ChannelReader.TryRead(out StreamedValue <T> streamedValue))
{
if (streamedValue.Status != ExecutionStatus.Succeeded)
{
continue;
}
var item = streamedValue.Item;
monitor.SetActive(index, item);
if (core.IsLoopBreakRequested)
{
await YieldNotExecutedAsync(resultsChannel, default, item);