Hi Rob, What is the buffered channel’s buffer used for? If that’s set to 1 and the channel’s transducer is `(mapcat identity)` then the producer should be able to continuously put chunks of work onto the channel with the puts only completing when the previous chunk is completely consumed.
That would make the producer block/park until the previous chunk is consumed. For your use case I think an interesting result of this approach (maybe a downside?) is initially 2 db queries would be performed, 1 whose result makes it onto the channel while 2’s result will be parked until the previous query’s result is consumed. Brian > On Jan 5, 2018, at 1:44 PM, Rob Nikander <rob.nikan...@gmail.com> wrote: > > Hi, > > I’m wondering if there is a core.async design idiom for this situation... > > - A buffered channel > - One producer feeding it > - A bunch of consumers pulling from it. > - Producer should wake up and fill the channel only when it’s empty. In other > words, the producer should work in chunks. > > My first idea is to have two channels. The second will be used by consumers > to signal the producer that the primary channel is empty. But I'm wondering > if there is a better way. > > The motive for this is that the producer is doing a DB query that is more > efficient in bulk. `select ... limit 50` rather than `select ... limit 1` 50 > times. > > Rob > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with your > first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > <http://groups.google.com/group/clojure?hl=en> > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com > <mailto:clojure+unsubscr...@googlegroups.com>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
