I found a somewhat simple pattern that seems to work for me: function processSequential(r, processFn) { function getNext() { var res = r.read(); if (res) processFn(res, getNext); else r.once('readable', getNext); } getNext(); }
And calling it: processSequential(r, function(buf, cb) { // do stuff cb(); }); I'm thinking about putting this into an npm module. On 02/07/2013, at 11.38, Gil Pedersen <gp...@gpost.dk> wrote: > Thanks, this looks like a somewhat interesting pattern. Looking at it, things > quickly get complicated: > > I need to loop, so I'll wrap it in a method, calling it recursively. > I don't want to call doAsync when bytes === null. > I can't "kick" when bytes === null, since I get an infinite recursive loop. > Depending on internal stream state, kicking will not always trigger a > 'readable' emit, leading to a stall. > > I really wish this was simpler :-/ > > On 02/07/2013, at 09.28, Floby <florent.j...@gmail.com> wrote: > >> I'd use some kind of withReadable(stream, fn) helper >> >> var bytes = stream.read(2); >> doAsync(bytes, function(err, res) { >> withReadable(stream, function () { >> // stream is readable for sure >> }); >> }); >> >> function withReadable(stream, callback) { >> stream.once(callback); >> stream.read(0); >> } >> >> >> On Monday, 1 July 2013 15:23:44 UTC+2, Gil Pedersen wrote: >> Hi, >> >> I have a case where I want to consume a Readable, by: >> >> 1. Read n bytes. >> 2. Process buffer using a function with an async callback. >> 3. When callback completes, goto 1. >> >> I fail to see any simple solution to what I feel must be a somewhat common >> use case. The standard "on('readable', function() { this.read(); ... })" >> doesn't apply, as I have no way of deferring future 'readable' emits once I >> have returned from the handler. >> >> Can it really be that the most sensible solution is to fall back to the old >> API, using pause() and resume()? or have I missed something? >> >> Regards, >> Gil > -- -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en --- You received this message because you are subscribed to the Google Groups "nodejs" group. To unsubscribe from this group and stop receiving emails from it, send an email to nodejs+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.