Thanks, i know that optimization can lead obscurity, but for critical paths i think that it useful =)
2017-11-10 8:41 GMT+03:00 peterGo <go.peter...@gmail.com>: > Vasiliy, > > For portability, when you initialize cfg.WorkDir, clean it: cfg.WorkDir = > filepath.Clean(cfg.WorkDir) > > You can reduce the allocations from 5 to 1. However, optimization can lead > to obscurity. For example, > > $ go test oid_test.go -bench=. > BenchmarkVasiliy-4 2000000 700 ns/op 88 B/op 5 allocs/op > BenchmarkKrolaw-4 3000000 550 ns/op 80 B/op 4 allocs/op > BenchmarkPeter-4 10000000 201 ns/op 48 B/op 1 allocs/op > > Playground: https://play.golang.org/p/DnGoM8PYd6 > > Peter > > > On Thursday, November 9, 2017 at 3:58:03 PM UTC-5, Vasiliy Tolstov wrote: >> >> Hi. I have server that read/write data to many files (each is about >> 4-32Mb). To determine on which file i need to read/write i'm use this >> function to os.OpenFile >> >> func oid2filepath(cfg *Config, oID uint64) string { >> file_path := filepath.Join(cfg.WorkDir, fmt.Sprintf("%x", >> oid2vid(oID)), fmt.Sprintf("%016x", oID)) >> return file_path >> } >> >> oid2vid function get uint32 and return uint32 with shift some bits >> path looks like (for one of 4Mb chunk) store/obj/7c2b25/007c2b2500000180 >> >> When i'm write 4Gb data i need to call this function 1024 times for >> single big chunk of data. >> Does it possible to write function that does not have additional >> allocations? >> And does it possible to write it in portable way (i mean path separator). >> >> >> -- >> Vasiliy Tolstov, >> e-mail: v.to...@selfip.ru > > -- > 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. -- Vasiliy Tolstov, e-mail: v.tols...@selfip.ru -- 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.
