# IO#write\_nonblock(string, offset) useful? **URL:** \ **Category:** Ruby\ **Created:** [September 2, 2008, 8:51pm UTC](https://www.ruby-forum.com/t/io-write-nonblock-string-offset-useful/147526 "2008-09-02T20:51:34Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\ **Post date:** [September 2, 2008, 8:51pm UTC](https://www.ruby-forum.com/t/io-write-nonblock-string-offset-useful/147526/1 "2008-09-02T20:51:34Z")
Was asked to repost this under a separate thread, so here it is! Currently we have IO#write\_nonblock(string) [writes as much of the string as currently possible] What I was thinking would be useful would be IO#write\_nonblock(string, offset) [starts the write at offset bytes into the string]. Would anybody else find this useful? Thanks! -=R ---
**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\ **Post date:** [September 2, 2008, 9:12pm UTC](https://www.ruby-forum.com/t/io-write-nonblock-string-offset-useful/147526/2 "2008-09-02T21:12:52Z")
Roger P. wrote: > Would anybody else find this useful? > Thanks! With COW strings, is this really needed? s = (0…9).to\_a.to\_s \* 1000000 sa = (1…10000).map {|i| s[i…-1]} puts `cat /proc/#{$$}/status`[/VmRSS:\s\*(.\*)/,1] # 13292 kB Is there a reason other than saving memory and avoiding a #slice call? ---
**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\ **Post date:** [September 2, 2008, 10:12pm UTC](https://www.ruby-forum.com/t/io-write-nonblock-string-offset-useful/147526/3 "2008-09-02T22:12:54Z")
Roger P. wrote: > > puts `cat /proc/#{$$}/status`[/VmRSS:\s\*(.\*)/,1] # 13292 kB > > Is there a reason other than saving memory and avoiding a #slice call? > > Those would be the reasons I’d consider it useful–to save on CPU and > RAM [since it would avoid having to create all those extra objects]. I > think that’s what you were pointing out? It’s just that those extra objects are fairly small, due to copy-on-write… just the 20 byte ruby RString object for each slice rather than a copy of the whole 1Mb string you are trying to send. They share the 1Mb string data. ---
**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\ **Post date:** [September 2, 2008, 10:05pm UTC](https://www.ruby-forum.com/t/io-write-nonblock-string-offset-useful/147526/4 "2008-09-02T22:05:54Z")
> puts `cat /proc/#{$$}/status`[/VmRSS:\s\*(.\*)/,1] # 13292 kB > Is there a reason other than saving memory and avoiding a #slice call? Those would be the reasons I’d consider it useful–to save on CPU and RAM [since it would avoid having to create all those extra objects]. I think that’s what you were pointing out? Thanks! -=R ---
**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\ **Post date:** [September 3, 2008, 2:37pm UTC](https://www.ruby-forum.com/t/io-write-nonblock-string-offset-useful/147526/5 "2008-09-03T14:37:35Z")
Rob B. wrote: Rob, are you aware that your message body is empty, at least on ruby-talk. Are you posting from the forum or newsgroup? ---
**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\ **Post date:** [September 3, 2008, 3:05pm UTC](https://www.ruby-forum.com/t/io-write-nonblock-string-offset-useful/147526/6 "2008-09-03T15:05:09Z")
On Tue, Sep 2, 2008 at 2:29 PM, Joel VanderWerf [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Rob B. wrote: > > Rob, are you aware that your message body is empty, at least on ruby-talk. > Are you posting from the forum or newsgroup? Hi Rob, i’ve noticed loss of the message with some of you other posts, too, the most recent group starting from the Chris P. tutorial thread. Todd ---
**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\ **Post date:** [September 3, 2008, 12:35am UTC](https://www.ruby-forum.com/t/io-write-nonblock-string-offset-useful/147526/7 "2008-09-03T00:35:30Z")
> It’s just that those extra objects are fairly small, due to > copy-on-write… just the 20 byte ruby RString object for each slice > rather than a copy of the whole 1Mb string you are trying to send. They > share the 1Mb string data. Fascinating. Thanks for pointing that out. I guess that being the case then it’d be only a small improvement–10,000 slices on my machine takes 0.02s and calls the GC twice, so…there’s some room for improvement, but it’s probably not a bottleneck.] Thanks! -=R ---
**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\ **Post date:** [September 3, 2008, 3:05pm UTC](https://www.ruby-forum.com/t/io-write-nonblock-string-offset-useful/147526/8 "2008-09-03T15:05:45Z")
On Sep 2, 2008, at 3:29 PM, Joel VanderWerf wrote: > Rob B. wrote: > > Rob, are you aware that your message body is empty, at least on ruby- > talk. Are you posting from the forum or newsgroup? > > – > vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407 From email (therefore the newsgroup). This happens when I forget to uncheck the “digitally signed” option. What I meant to say was: I presume that the IO#write\_nonblock returns the number of bytes written (which the write(2) man page says, but is only implied by the rdoc). Assuming this is the case (and the method will become IO#write\_nonblock(string, offset=0)), I’d think that this was a good idea. (Even though I’ve never had to use it.) -Rob Rob B. [http://agileconsultingllc.com](http://agileconsultingllc.com) removed\_email\_address@domain.invalid