I guess the "offset" and "bytesleft" in the curl_ws_meta structure (https://curl.se/libcurl/c/curl_ws_meta.html) provide information about WS message fragments.
"offset" When this frame is a continuation of fragment data already delivered, this is the offset into the final fragment where this piece belongs. "bytesleft" If this is not a complete fragment, the bytesleft field informs about how many additional bytes are expected to arrive before this fragment is complete. I suppose that for the final frame in the WS message the "bytesleft" field should be set to zero thus indicating the end of the message. Thanks, Dmitry Karpov -----Original Message----- From: curl-library <curl-library-boun...@lists.haxx.se> On Behalf Of Paul Fotheringham via curl-library Sent: Tuesday, July 11, 2023 9:35 AM To: curl-library@lists.haxx.se Cc: Paul Fotheringham <fotheringham.p...@gmail.com> Subject: [EXTERNAL] Detecting final WebSocket frame of a fragmented message Hi, I've been using libcurl for some months now and recently tried to get WebSocket going in CURLOPT_CONNECT_ONLY=2L mode. The problem I'm having is if the server sends a message fragmented over multiple frames then I cannot work out how I am meant to know when the final frame of the message is received via curl_ws_recv. Even if it is not fragmented then I get the whole message but again I guess I don't know that the message is finished. My understanding of WebSocket is that only the final frame (might be the only frame) has the FIN bit set in the header but I see no corresponding exposure of that in the API and a quick scan of the code seems to suggest it is not being passed out in any way. The server is mine too so I may have a bug but at the same time I just don't see how I'm meant to detect the final frame. I understand WebSocket support is still experimental so I'm wondering if I am missing something or if this is just not available yet? Paul -- Unsubscribe: https://lists.haxx.se/mailman/listinfo/curl-library Etiquette: https://curl.se/mail/etiquette.html -- Unsubscribe: https://lists.haxx.se/mailman/listinfo/curl-library Etiquette: https://curl.se/mail/etiquette.html
