/// <summary>
/// Context-preserving variant of <see cref="FlowOperations.Select{T,TIn,TOut,TMat}"/>
/// </summary>
public static FlowWithContext <TCtx, TIn, TCtx, TOut2, TMat> Select <TCtx, TIn, TOut, TOut2, TMat>(
this FlowWithContext <TCtx, TIn, TCtx, TOut, TMat> flow, Func <TOut, TOut2> fn)
{
var stage = new Select <(TOut, TCtx), (TOut2, TCtx)>(x => (fn(x.Item1), x.Item2));
return(flow.Via(Flow.FromGraph(stage)));
}
/// <summary>
/// Context-preserving variant of <see cref="FlowOperations.Grouped{TIn,TOut,TMat}"/>
/// </summary>
public static FlowWithContext <TCtx, TIn, TCtx, TOut, TMat> WhereNot <TCtx, TIn, TOut, TMat>(
this FlowWithContext <TCtx, TIn, TCtx, TOut, TMat> flow, Func <TOut, bool> predicate)
{
var stage = new Where <(TOut, TCtx)>(x => !predicate(x.Item1));
return(flow.Via(Flow.FromGraph(stage)));
}
/// <summary>
/// Context-preserving variant of <see cref="FlowOperations.SelectAsync{T,TIn,TOut,TMat}"/>
/// </summary>
public static FlowWithContext <TCtx, TIn, TCtx, TOut2, TMat> SelectAsync <TCtx, TIn, TOut, TOut2, TMat>(
this FlowWithContext <TCtx, TIn, TCtx, TOut, TMat> flow, int parallelism, Func <TOut, Task <TOut2> > fn)
{
var stage = new SelectAsync <(TOut, TCtx), (TOut2, TCtx)>(parallelism,
async x => (await fn(x.Item1), x.Item2));
return(flow.Via(Flow.FromGraph(stage)));
}
/// <summary>
/// Apply the given function to each context element (leaving the data elements unchanged).
/// </summary>
public static FlowWithContext <TCtx, TIn, TCtx2, TOut, TMat> SelectContext <TCtx, TIn, TCtx2, TOut, TMat>(
this FlowWithContext <TCtx, TIn, TCtx, TOut, TMat> flow, Func <TCtx, TCtx2> mapContext)
{
var stage = new Select <(TOut, TCtx), (TOut, TCtx2)>(x =>
(x.Item1, mapContext(x.Item2)));
return(flow.Via(Flow.FromGraph(stage)));
}
public static FlowWithContext <ICommittableOffset, E, ICommittableOffsetBatch, NotUsed, NotUsed> FlowWithOffsetContext <E>(CommitterSettings settings)
{
var value = Akka.Streams.Dsl.Flow.Create <(E, ICommittableOffset)>()
.Select(m => m.Item2 as ICommittable)
.Via(BatchFlow(settings))
.Select(b => (NotUsed.Instance, b));
return(FlowWithContext.From(value));
}
/// <summary>
/// Context-preserving variant of <see cref="FlowOperations.Collect{T,TIn,TOut,TMat}"/>
/// </summary>
public static FlowWithContext <TCtx, TIn, TCtx, TOut2, TMat> Collect <TCtx, TIn, TOut, TOut2, TMat>(
this FlowWithContext <TCtx, TIn, TCtx, TOut, TMat> flow, Func <TOut, TOut2> fn) where TOut2 : class
{
var stage = new Collect <(TOut, TCtx), (TOut2, TCtx)>(func: x =>
{
var result = fn(x.Item1);
return(ReferenceEquals(result, null) ? default((TOut2, TCtx)) : (result, x.Item2));
});
return(flow.Via(Flow.FromGraph(stage)));
}
/// <summary>
/// Context-preserving variant of <see cref="FlowOperations.StatefulSelectMany{T,TIn,TOut,TMat}"/>.
/// </summary>
public static FlowWithContext <TCtx, TIn, TCtx, TOut2, TMat> StatefulSelectConcat <TCtx, TIn, TOut, TOut2, TMat>(
this FlowWithContext <TCtx, TIn, TCtx, TOut, TMat> flow, Func <Func <TOut, IEnumerable <TOut2> > > fn)
{
var stage = new StatefulSelectMany <(TOut, TCtx), (TOut2, TCtx)>(() =>
{
var fun = fn();
return(itemWithContext =>
{
var items = fun(itemWithContext.Item1);
return items.Select(i => (i, itemWithContext.Item2));
});
});
return(flow.Via(Flow.FromGraph(stage)));
}
/// <summary>
/// Context-preserving variant of <see cref="FlowOperations.Grouped{TIn,TOut,TMat}"/>
/// Each output group will be associated with a `Seq` of corresponding context elements.
/// </summary>
public static FlowWithContext <TCtx, TIn, IReadOnlyList <TCtx>, IReadOnlyList <TOut>, TMat> Grouped <TCtx, TIn,
TOut, TMat>(
this FlowWithContext <TCtx, TIn, TCtx, TOut, TMat> flow, int n)
{
var stage = new Grouped <(TOut, TCtx)>(n);
return(flow.Via(Flow.FromGraph(stage).Select(itemsWithContexts =>
{
var items = new List <TOut>(n);
var ctxs = new List <TCtx>(n);
foreach (var tuple in itemsWithContexts)
{
items.Add(tuple.Item1);
ctxs.Add(tuple.Item2);
}
return ((IReadOnlyList <TOut>)items, (IReadOnlyList <TCtx>)ctxs);
})));
}
public void SourceWithContext_must_pass_through_context_using_FlowWithContext()
{
var flowWithContext = FlowWithContext.Create <long, string>();
var msg = new Message("a", 1);
var sink = this.CreateSubscriberProbe <(string, long)>();
Source.From(new[] { msg })
.AsSourceWithContext(x => x.Offset)
.Select(x => x.Data)
.Via(flowWithContext.Select(s => s + "b"))
.AsSource()
.RunWith(Sink.FromSubscriber(sink), Materializer);
var sub = sink.ExpectSubscription();
sub.Request(1);
sink.ExpectNext(("ab", 1L));
sink.ExpectComplete();
}
/// <summary>
/// Context-preserving variant of <see cref="FlowOperations.SelectMany{T,TIn,TOut,TMat}"/>.
/// The context of the input element will be associated with each of the output elements calculated from
/// this input element.
/// </summary>
public static FlowWithContext <TCtx, TIn, TCtx, TOut2, TMat> SelectConcat <TCtx, TIn, TOut, TOut2, TMat>(
this FlowWithContext <TCtx, TIn, TCtx, TOut, TMat> flow, Func <TOut, IEnumerable <TOut2> > fn) =>
StatefulSelectConcat(flow, () => fn);
