You don't need the io.Pipe: it's fairly trivial to implement io.Reader in terms of a channel of strings and a strings.Reader.
You can even implement io.WriterTo efficiently that way: https://play.golang.org/p/PxIEQYUoC50 (In theory that can make the whole pipeline zero-copy, but in practice I doubt that csv.Reader is that specialized.) On Sunday, September 16, 2018 at 4:07:35 AM UTC-4, Sherif Eldeeb wrote: > > Even though Yannic's answer was really useful and appreciated, I ended up > using io.Pipe() which looks simpler and more efficient (explained below): > > <snip> > rp, wp := io.Pipe() > go func() { > defer wp.Close() > for i := range feederChan { > fmt.Fprintln(wp, i) > } > }() > r := csv.NewReader(rp) > for { // keep reading > a, err := r.Read() > if err == io.EOF { > break > } > // do stuff with 'a' > // ... > } > </snip> > > The io.Pipe() is synchronous, and should be fairly efficient: it pipes > data from writer to a reader; I fed the csv.NewReader() the reader part, > and created a goroutine that drains the chan writing to the writer part. > > Thanks a lot. > > On Sun, Sep 16, 2018 at 1:25 AM Yannic Bonenberger < > yan...@yannic-bonenberger.com <javascript:>> wrote: > >> You can use a bytes.Buffer to create a single csv.Reader and write the >> log lines into that buffer. >> The code will look roughly like this >> https://play.golang.org/p/gbCPwSsx5gy . >> However, depending on the implementation of strings.Reader and the level >> of optimization the Go compiler does, your approach of creating a new >> csv.Reader for every iteration might actually be faster and consume less >> memory than my code. >> >> >> Greetings all, >> I have a channel of 'string', where each item is a single CSV log line >> that I want to convert to columns using "encoding/csv" >> Currently, I am creating a new csv.Reader at each iteration for each >> item, which is much more work than it needs to be. >> >> <snip> >> for i := range feederChan { >> r := csv.NewReader(strings.NewReader(i)) >> a := r.Read() >> // Do stuff with a >> // ... >> } >> </snip> >> >> I would really appreciate sharing with me if there's a way to iterate >> through a 'chan string' using 'csv.Reader()' without the need to create a >> new Reader for each item. >> Thanks. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "golang-nuts" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to golang-nuts...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> >> >> -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
