curl/lib/ws.h
Daniel Stenberg e3f335148a
websockets: remodeled API to support 63 bit frame sizes
curl_ws_recv() now receives data to fill up the provided buffer, but can
return a partial fragment. The function now also get a pointer to a
curl_ws_frame struct with metadata that also mentions the offset and
total size of the fragment (of which you might be receiving a smaller
piece). This way, large incoming fragments will be "streamed" to the
application. When the curl_ws_frame struct field 'bytesleft' is 0, the
final fragment piece has been delivered.

curl_ws_recv() was also adjusted to work with a buffer size smaller than
the fragment size. (Possibly needless to say as the fragment size can
now be 63 bit large).

curl_ws_send() now supports sending a piece of a fragment, in a
streaming manner, in addition to sending the entire fragment in a single
call if it is small enough. To send a huge fragment, curl_ws_send() can
be used to send it in many small calls by first telling libcurl about
the total expected fragment size, and then send the payload in N number
of separate invokes and libcurl will stream those over the wire.

The struct curl_ws_meta() returns is now called 'curl_ws_frame' and it
has been extended with two new fields: *offset* and *bytesleft*. To help
describe the passed on data chunk when a fragment is delivered in many
smaller pieces.

The documentation has been updated accordingly.

Closes #9636
2022-10-07 12:50:58 +02:00

70 lines
2.6 KiB
C

#ifndef HEADER_CURL_WS_H
#define HEADER_CURL_WS_H
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#ifdef USE_WEBSOCKETS
#ifdef USE_HYPER
#define REQTYPE void
#else
#define REQTYPE struct dynbuf
#endif
/* this is the largest single fragment size we support */
#define MAX_WS_SIZE 65535
/* part of 'struct HTTP', when used in the 'struct SingleRequest' in the
Curl_easy struct */
struct websocket {
bool contfragment; /* set TRUE if the previous fragment sent was not final */
unsigned char mask[4]; /* 32 bit mask for this connection */
struct Curl_easy *data; /* used for write callback handling */
struct dynbuf buf;
size_t usedbuf; /* number of leading bytes in 'buf' the most recent complete
websocket frame uses */
struct curl_ws_frame frame; /* the struct used for frame state */
curl_off_t oleft; /* outstanding number of payload bytes left from the
server */
curl_off_t stillbuffer; /* number of bytes left in the buffer to deliver in
the next curl_ws_recv() call */
char *stillb; /* the stillbuffer pending bytes are here */
curl_off_t sleft; /* outstanding number of payload bytes left to send */
unsigned int xori; /* xor index */
};
CURLcode Curl_ws_request(struct Curl_easy *data, REQTYPE *req);
CURLcode Curl_ws_accept(struct Curl_easy *data);
size_t Curl_ws_writecb(char *buffer, size_t size, size_t nitems, void *userp);
void Curl_ws_done(struct Curl_easy *data);
#else
#define Curl_ws_request(x,y) CURLE_OK
#define Curl_ws_done(x) Curl_nop_stmt
#endif
#endif /* HEADER_CURL_WS_H */