On Mit 21.07.2010 13:54, Daniel Stenberg wrote:
On Wed, 21 Jul 2010, Aleksandar Lazic wrote:
Yes, since the application knows how you want the data so it is way
better if you allocate or by any other means provide the buffer. If
libcurl would do that, you can bet that it won't be enough. An
application could use mmap(), malloc(), alloca() or other
ways. libcurl could not offer such fancy ways.
Isn't possible to use the
http://curl.haxx.se/libcurl/c/curl_global_init_mem.html
as a possible start for a solution.
I could perhaps, but in my mind I can imagine a program that uses a
certain set of malloc()-functions for the ordinary memory handling and
it passes those functions in the curl_bloal_init_mem() funciton but it
wants _another_ way for the downloaded stream. I think assuming the
same malloc for both downloaded data as well as for all the normal
mallocs is a bit too limiting.
Like for example, a program may want to use its own mallocs but wants
to download directly into a mmap file.
All this said, I would really like to see some actual numbers on how
much time anyone actually wastes with this single copy we avoid with
this zero copy approach (as it really isn't zero copy, it just avoids
one of the many copies that a typical libcurl-based transfer
involves).
Thank you for explanation.
BR
Aleks
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