Hey
Responding to a forwarded message and I'm not subscribed. Excuse the formatting. I'm the lead developer of libcurl and was asked to comment on this.
From: Alex Balashov abalashov@evaristesys.com
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_function);
As far as I can tell from how write_function() is constructed, it expects to be called once:
- Does this function need to be rewritten to realloc() and concatenate?
Yes. libcurl will deliver data to the callback as soon as it has read some off the network, it can thus deliver one byte at a time during slow conditions or a whole bunch. It will keep calling the callback as long as data is coming.
This is also documented in the man page: http://curl.haxx.se/libcurl/c/CURLOPT_WRITEFUNCTION.html
- Is there an option in CURL that can use internal buffering and only
invoke the callback once all the response chunks are received?
Nope.
- Would increasing the curl.h constant CURL_MAX_WRITE_SIZE help?
No. That would just make libcurl able to read a larger chunk from the socket into its own buffer, but it wouldn't prevent it from calling the callback one or many times.
Hi Daniel,
Thank you very much for your feedback, I really appreciate it. I'll reimplement the callback to dynamically resize the buffer and submit as a patch to the Kamailio project.
Cheers,
-- Alex
On 12/10/2014 05:20 PM, Daniel Stenberg wrote:
Hey
Responding to a forwarded message and I'm not subscribed. Excuse the formatting. I'm the lead developer of libcurl and was asked to comment on this.
From: Alex Balashov abalashov@evaristesys.com
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_function);
As far as I can tell from how write_function() is constructed, it expects to be called once:
- Does this function need to be rewritten to realloc() and concatenate?
Yes. libcurl will deliver data to the callback as soon as it has read some off the network, it can thus deliver one byte at a time during slow conditions or a whole bunch. It will keep calling the callback as long as data is coming.
This is also documented in the man page: http://curl.haxx.se/libcurl/c/CURLOPT_WRITEFUNCTION.html
- Is there an option in CURL that can use internal buffering and
only invoke the callback once all the response chunks are received?
Nope.
- Would increasing the curl.h constant CURL_MAX_WRITE_SIZE help?
No. That would just make libcurl able to read a larger chunk from the socket into its own buffer, but it wouldn't prevent it from calling the callback one or many times.
-
Alex Balashov -
Daniel Stenberg