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Re: Best way to write the vector content to a file.

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On 09/20/11 03:28 PM, sravanreddy001 wrote:

Context is nice!

> I'm actually writing this to a file.
> But, file operation is just one simple write.
> (the string that is constructed in the loop is written.. and the file size is around 5 MB.)
>
> but.. string+ = string + some_thing;
>
> if this is going to allocate a new memory location, then.. writing it multiple times to file.. will any of this approach help?
>
> One my i3 2nd gen computer.. it took around 10 mins. (using one single core)
> not multithreaded.

You would probably be better off just using an ofstream and writing a 
line at a time.  I have one application that reads and writes in excess 
of 1GB with fstreams.  Reading takes a couple of minutes, writing about 5.

Your huge string will do a lot of progressively bigger memory moves, 
which are a bigger issue than the allocations.  Kind of a 
macro-deoptimisation!

-- 
Ian Collins

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Thread

Best way to write the vector content to a file. sravanreddy001 <sravanreddy001@gmail.com> - 2011-09-19 20:05 -0700
  Re: Best way to write the vector content to a file. Ian Collins <ian-news@hotmail.com> - 2011-09-20 15:12 +1200
  Re: Best way to write the vector content to a file. sravanreddy001 <sravanreddy001@gmail.com> - 2011-09-19 20:28 -0700
    Re: Best way to write the vector content to a file. Ian Collins <ian-news@hotmail.com> - 2011-09-20 15:37 +1200
      Re: Best way to write the vector content to a file. sravanreddy001 <sravanreddy001@gmail.com> - 2011-09-19 20:50 -0700
        Re: Best way to write the vector content to a file. Ian Collins <ian-news@hotmail.com> - 2011-09-20 16:03 +1200
      Re: Best way to write the vector content to a file. sravanreddy001 <sravanreddy001@gmail.com> - 2011-09-19 20:47 -0700
        Re: Best way to write the vector content to a file. Ian Collins <ian-news@hotmail.com> - 2011-09-20 16:09 +1200
    Re: Best way to write the vector content to a file. sravanreddy001 <sravanreddy001@gmail.com> - 2011-09-19 20:29 -0700
  Re: Best way to write the vector content to a file. Juha Nieminen <nospam@thanks.invalid> - 2011-09-20 06:44 +0000
  Re: Best way to write the vector content to a file. Goran <goran.pusic@gmail.com> - 2011-09-20 00:37 -0700
    Re: Best way to write the vector content to a file. Ian Collins <ian-news@hotmail.com> - 2011-09-20 19:45 +1200
      Re: Best way to write the vector content to a file. Goran <goran.pusic@gmail.com> - 2011-09-20 02:01 -0700
  Re: Best way to write the vector content to a file. Rui Maciel <rui.maciel@gmail.com> - 2011-09-20 10:56 +0100
  Re: Best way to write the vector content to a file. Fulvio Esposito <esposito.fulvio@gmail.com> - 2011-09-20 04:03 -0700
  Re: Best way to write the vector content to a file. sravanreddy001 <sravanreddy001@gmail.com> - 2011-09-20 05:00 -0700
    Re: Best way to write the vector content to a file. Goran <goran.pusic@gmail.com> - 2011-09-20 06:55 -0700
    Re: Best way to write the vector content to a file. Paavo Helde <myfirstname@osa.pri.ee> - 2011-09-20 13:39 -0500
  Re: Best way to write the vector content to a file. sravanreddy001 <sravanreddy001@gmail.com> - 2011-09-20 17:50 -0700

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