On Thu, 18 Sep 2014, Pashupati Kumar wrote:
I am new to libcurI and still learning my ways around it. I have few questions on it. I discovered that user needs to copy the data in write call-back function and also the way our application behave, it will end up doing copy during read call back function as well. This will be a big draw-back as the application is data intensive.
Will it really? Some people have claimed this over the years but I've never seen any real numbers proving this. On the contrary I think this is a common belief and suspicion that rarely actually turns out to be an actual problem.
Have you measured how much CPU - in your case - that would be "wasted" on this extra copy? Or perhaps if that waste even makes a difference to the total performance of your application.
I came across an old mail thread on avoiding copy for CURLOPT_WRITEFUNCTION. I don't know what was the final outcome of it.
We discuss this topic every once in a while and it always ends up getting burried again when the work to implement something like this ends up being more than the gains in having the feature. But maybe it is different this time?
For read callback function, application data is available in scatter list of buffers. This brings me to my next question. Can libcurl use scatter-gather buffers?
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