The _c structure used to store the Curl function pointers needs
referencing to be sure it is not freed although still needed.
The non-referencing was leading to a crash during the destruction
of the dialers. The _c was still used although it has been freed
by ecore_con_url_shutdown.
CURL needs some special curl_easy_setopt() calls to enable automatic
gzip deflate (CURLOPT_ENCODING) and
If-Modified-Since/If-Unmodified-Since logic.
As If-Modified-Since/If-Unmodified-Since requires a timestamp string,
let's expose class methods to handle those.
When CURLOPT_WRITEFUNCTION returns less then the requested amount,
CURL will fail, not call us back with the remaining data.
Then in such cases we must pause CURL and read nothing.
When unpausing we need to kick curl with timeout action so FD handlers
will be re-arranged.
Last but not least, sync our buffer limit with CURL, otherwise it may
always fail if we're smaller than CURL.
provide curl with CURLOPT_OPENSOCKETFUNCTION and keep the fd in our
private data.
This is required because on _efl_net_dialer_http_efl_io_writer_write()
we may have no fdhandler.
It happened to me while implementing the WebSocket that uses a
bi-directional communication on top of HTTP and the server sent the
whole message, CURL reads:
recvfrom(7, "...", 16384, 0, NULL, NULL) = 86
recvfrom(7, "", 16384, 0, NULL, NULL) = 0
After the empty (second) recvfrom(), CURL will remove the fdhandler:
DBG:ecore_con lib/ecore_con/efl_net_dialer_http.c:482 _efl_net_dialer_http_curlm_socket_manage() dialer=0x4000000040000005 fdhandler=(nil), fd=7, curl_easy=0x5561846ca8d0, flags=0x4
However I should be able to write to this socket, in my case I need to
reply to a PING request with a PONG.
This class implements the Efl.Net.Dialer interface using libcurl to
perform HTTP requests. That means it's an Efl.Net.Dialer,
Efl.Net.Socket, Efl.Io.Reader, Efl.Io.Writer and Efl.Io.Closer, thus
being usable with Efl.Io.Copier as demonstrated in the
efl_io_copier_example.c
this splits out out "manual" dlopen (eina_module_load) of curl into
its own .c file and special header out of ecore_con_url.c to tidy up
that code a bit and isolate our curl magic loading/handling
Arnaud Ferraris
Daniel Zaoui
Gustavo Sverzut Barbieri
Andrii Kroitor
Jean-Philippe Andre
Carsten Haitzler