Using libcurl with libevent

Question

Can anyone show (through code) or explain to me how I might use libevent and curl together in a c program? I'm trying to write a high-performance non-blocking data monitor which needs to upload data to a CouchDB instance. I'm familiar with both libevent and curl, but merging curl_multi with libevent has me stumped for some reason. I do not understand the program flow of the offical libcurl example - can anyone point me to, or supply, a simpler example?

Cancellate

Answer 1

The key is really the curl_multi_socket_action() function that should be used as soon as your event library says there's something on a socket to deal with. Event-based libcurl is more complex than "plain" libcurl so doing a very easy example is not that straight forward.

Pentylenetetrazol

when I call curl_multi_socket_action() telling it either to read or write, does it use the read/write callback functions that were set up using curl_easy_setopt()? If not, how does it perform the read/write? – Cancellate

Yes, it will use the callbacks for reading/writing as you have setup. – Pentylenetetrazol

Ah, alright, that make this a little clearer. Thanks for your help. – Cancellate

Answer 2

One exotic way to use curl with libevent is in a coroutine.

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